{
  "openapi": "3.1.0",
  "info": {
    "title": "x402 Marketplace API",
    "version": "1.0.0",
    "description": "Catalog-derived OpenAPI description of the x402 Marketplace endpoints on the Radius eip155:72344 testnet (chain 72344). 21 fully-compliant endpoints and 76 intentional protocol quirks. Every operation responds 402 Payment Required with an x402 challenge; complete the payment with radius-cli (documented per operation) to receive the 200 resource. Generated live from /api/x402/catalog so it never drifts from the real endpoints. Built by people at Radius (https://radiustech.xyz) — Built for Radius workshop. Stablecoin-native settlement infrastructure for the agentic internet.",
    "contact": {
      "name": "Radius",
      "url": "https://radiustech.xyz"
    }
  },
  "servers": [
    {
      "url": "http://127.0.0.1:8080",
      "description": "x402 API server"
    }
  ],
  "tags": [
    {
      "name": "Happy Path"
    },
    {
      "name": "402 / Challenge Construction"
    },
    {
      "name": "Verification Gaps"
    },
    {
      "name": "Replay / Idempotency / Race"
    },
    {
      "name": "Web / HTTP Layer"
    },
    {
      "name": "Schemes (exact / upto / batch)"
    },
    {
      "name": "Multi-Network Selection (MCP)"
    },
    {
      "name": "Client Policy Gate (MCP)"
    },
    {
      "name": "Facilitator Dependency"
    },
    {
      "name": "Paid-but-Denied / Unpaid-Service"
    },
    {
      "name": "Edge / CDN Controls"
    }
  ],
  "paths": {
    "/api/x402/compliant-get": {
      "get": {
        "operationId": "compliant-get",
        "summary": "Canonical GET (real verify and settle)",
        "description": "**Expected behavior:** The textbook x402 flow: an unpaid GET gets a 402 with a PAYMENT-REQUIRED challenge, then the server runs a real /verify and /settle against the Radius testnet facilitator.\n\n**What to watch:** Returns 200 with a PAYMENT-RESPONSE header carrying a real testnet txHash.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/compliant-get\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/compliant-post": {
      "post": {
        "operationId": "compliant-post",
        "summary": "Canonical POST with body",
        "description": "**Expected behavior:** The same compliant flow as the canonical GET, for a POST that carries a JSON body.\n\n**What to watch:** The body is echoed back, and the payment really settles.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/compliant-post -H 'Content-Type: application/json' -d '{\"query\":\"radius\"}'\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "query": "radius"
              }
            }
          }
        }
      }
    },
    "/api/x402/compliant-body-get": {
      "get": {
        "operationId": "compliant-body-get",
        "summary": "Body-primary GET challenge",
        "description": "**Expected behavior:** Returns a valid x402 challenge in the response body only (no PAYMENT-REQUIRED header). Clients that read the challenge from the JSON body rather than decoding the base64 header must handle this path.\n\n**What to watch:** Returns 402 with the full PaymentRequired object as JSON body. No PAYMENT-REQUIRED header is set. Pay with radius-cli to confirm the body-reading path works end-to-end.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/compliant-body-get\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/compliant-body-post": {
      "post": {
        "operationId": "compliant-body-post",
        "summary": "Body-primary POST challenge",
        "description": "**Expected behavior:** The body-primary happy path for a POST endpoint. Challenge is delivered in the JSON response body only, no PAYMENT-REQUIRED header.\n\n**What to watch:** Returns 402 with the full PaymentRequired object as JSON body. No PAYMENT-REQUIRED header is set.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/compliant-body-post -H 'Content-Type: application/json' -d '{\"query\":\"radius\"}'\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "query": "radius"
              }
            }
          }
        }
      }
    },
    "/api/x402/cheapest": {
      "get": {
        "operationId": "cheapest",
        "summary": "Minimal price (1 atomic unit)",
        "description": "**Expected behavior:** A compliant endpoint priced at the smallest atomic unit, 0.000001 SBC.\n\n**What to watch:** Settles a micro-payment without rounding the amount down to zero.\n\n**Status:** Compliant\n**Price:** 0.000001 SBC (1 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/cheapest\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/multi-accepts": {
      "get": {
        "operationId": "multi-accepts",
        "summary": "Single testnet accepts entry",
        "description": "**Expected behavior:** Advertises one testnet requirement that a correct client selects by matching its network.\n\n**What to watch:** The client picks the eip155:72344 entry rather than blindly taking accepts[0].\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/multi-accepts\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/idempotent-retry": {
      "get": {
        "operationId": "idempotent-retry",
        "summary": "Correct idempotency (cached retry)",
        "description": "**Expected behavior:** Caches the result by payment id, so retrying the same payment returns the cached 200 without charging twice.\n\n**What to watch:** A second call with the same payment returns Idempotent-Replay: true and does not re-settle.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/idempotent-retry\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/weather-now": {
      "get": {
        "operationId": "weather-now",
        "summary": "Weather API (pay-per-call)",
        "description": "**Expected behavior:** A themed but fully compliant data endpoint, gated by a real settlement.\n\n**What to watch:** Behaves like a genuine paid API: real verify and settle, then 200.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/weather-now\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/fx-rate": {
      "get": {
        "operationId": "fx-rate",
        "summary": "FX rate API (pay-per-call)",
        "description": "**Expected behavior:** A themed compliant endpoint that returns an exchange rate after settlement.\n\n**What to watch:** Real verify and settle before the rate is returned.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/fx-rate\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/haiku-generator": {
      "post": {
        "operationId": "haiku-generator",
        "summary": "Haiku generator (POST, paid)",
        "description": "**Expected behavior:** A compliant POST endpoint that returns generated content after settlement.\n\n**What to watch:** The body is accepted and the payment settles before content is returned.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/haiku-generator -H 'Content-Type: application/json' -d '{\"topic\":\"x402\"}'\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "topic": "x402"
              }
            }
          }
        }
      }
    },
    "/api/x402/status-401": {
      "get": {
        "operationId": "status-401",
        "summary": "Returns 401 instead of 402",
        "description": "**Expected behavior:** Gates the resource with 401 Unauthorized instead of 402 Payment Required.\n\n**What to watch:** Clients that key on a 402 never start the payment flow.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/status-401\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/status-403": {
      "get": {
        "operationId": "status-403",
        "summary": "Returns 403 instead of 402",
        "description": "**Expected behavior:** Gates the resource with 403 Forbidden instead of 402.\n\n**What to watch:** Looks like a hard authorization failure, so the client never sees a payment challenge.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/status-403\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/status-400": {
      "get": {
        "operationId": "status-400",
        "summary": "Returns 400 instead of 402",
        "description": "**Expected behavior:** Gates the resource with 400 Bad Request instead of 402.\n\n**What to watch:** A valid call looks malformed, so the client never starts paying.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/status-400\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/status-200-leak": {
      "get": {
        "operationId": "status-200-leak",
        "summary": "Returns 200 with content (no gate)",
        "description": "**Expected behavior:** Serves the protected content for free with a 200 and no payment gate.\n\n**What to watch:** A total bypass — paid content is leaked to non-payers.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/status-200-leak\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/missing-payment-required": {
      "get": {
        "operationId": "missing-payment-required",
        "summary": "402 without PAYMENT-REQUIRED header",
        "description": "**Expected behavior:** Returns a 402 but omits the PAYMENT-REQUIRED header entirely.\n\n**What to watch:** The client is told to pay but has no requirements to sign against.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/missing-payment-required\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/header-raw-json": {
      "get": {
        "operationId": "header-raw-json",
        "summary": "PAYMENT-REQUIRED is raw JSON (not base64)",
        "description": "**Expected behavior:** Sends the PAYMENT-REQUIRED requirements as raw JSON instead of base64.\n\n**What to watch:** Strict base64 decoders fail to parse the header.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/header-raw-json\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/header-bad-base64": {
      "get": {
        "operationId": "header-bad-base64",
        "summary": "PAYMENT-REQUIRED is invalid base64",
        "description": "**Expected behavior:** The PAYMENT-REQUIRED header value is not valid base64.\n\n**What to watch:** The client throws at the decode step, before it can read the requirements.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/header-bad-base64\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/header-base64-not-json": {
      "get": {
        "operationId": "header-base64-not-json",
        "summary": "Base64 decodes to non-JSON",
        "description": "**Expected behavior:** The PAYMENT-REQUIRED header is valid base64 but decodes to bytes that are not JSON.\n\n**What to watch:** JSON parsing fails after a successful base64 decode.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/header-base64-not-json\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/amount-as-number": {
      "get": {
        "operationId": "amount-as-number",
        "summary": "Atomic amount as a JSON number",
        "description": "**Expected behavior:** Emits the atomic amount as a JSON number instead of a string.\n\n**What to watch:** A number-typed amount can silently lose precision; the spec requires a string.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/amount-as-number\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/missing-x402-version": {
      "get": {
        "operationId": "missing-x402-version",
        "summary": "Missing x402Version",
        "description": "**Expected behavior:** The PAYMENT-REQUIRED body omits the x402Version field.\n\n**What to watch:** The client cannot confirm which protocol version it is negotiating.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/missing-x402-version\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/legacy-v1-headers": {
      "get": {
        "operationId": "legacy-v1-headers",
        "summary": "Legacy v1 headers (X-PAYMENT)",
        "description": "**Expected behavior:** Emits the legacy v1 X-PAYMENT header instead of the v2 PAYMENT-REQUIRED challenge.\n\n**What to watch:** v2-only clients ignore it and see no payment prompt.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/legacy-v1-headers\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/empty-accepts": {
      "get": {
        "operationId": "empty-accepts",
        "summary": "Empty accepts array",
        "description": "**Expected behavior:** The PAYMENT-REQUIRED challenge advertises an empty accepts array.\n\n**What to watch:** The client has no payment option to select.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/empty-accepts\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/unsupported-scheme": {
      "get": {
        "operationId": "unsupported-scheme",
        "summary": "Unsupported payment scheme",
        "description": "**Expected behavior:** Advertises a payment scheme the facilitator does not support.\n\n**What to watch:** The client cannot construct a matching payment payload.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/unsupported-scheme\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/wrong-network-mainnet": {
      "get": {
        "operationId": "wrong-network-mainnet",
        "summary": "Advertises mainnet, settles on testnet",
        "description": "**Expected behavior:** Advertises a mainnet network id while the facilitator runs on testnet.\n\n**What to watch:** Testnet wallets find no matching network, so verify fails.\n\n**Status:** Quirk — responsible party if it misbehaves: Network / Chain\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/wrong-network-mainnet\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/wrong-token": {
      "get": {
        "operationId": "wrong-token",
        "summary": "Wrong token contract address",
        "description": "**Expected behavior:** Advertises an asset contract address that is not SBC.\n\n**What to watch:** Verification fails on an asset mismatch.\n\n**Status:** Quirk — responsible party if it misbehaves: Token Issuer\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/wrong-token\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/wrong-decimals": {
      "get": {
        "operationId": "wrong-decimals",
        "summary": "Wrong decimals (18 instead of 6)",
        "description": "**Expected behavior:** Expresses the amount with 18 decimals for a token that has 6.\n\n**What to watch:** Overcharges by roughly a trillion times.\n\n**Status:** Quirk — responsible party if it misbehaves: Token Issuer\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/wrong-decimals\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/wrong-payto": {
      "get": {
        "operationId": "wrong-payto",
        "summary": "Wrong payTo address",
        "description": "**Expected behavior:** Advertises a payTo address that is not the merchant's wallet.\n\n**What to watch:** A successful settlement would route funds to the wrong recipient.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/wrong-payto\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/missing-resource": {
      "get": {
        "operationId": "missing-resource",
        "summary": "Missing resource URL",
        "description": "**Expected behavior:** The PAYMENT-REQUIRED challenge omits the resource object.\n\n**What to watch:** The payment cannot be bound to the specific request.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/missing-resource\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/expired-quote": {
      "get": {
        "operationId": "expired-quote",
        "summary": "Already-expired quote (timeout 0)",
        "description": "**Expected behavior:** Sets maxTimeoutSeconds to 0, so the quote is dead on arrival.\n\n**What to watch:** The signature expires before it can be used.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/expired-quote\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/overlong-validity": {
      "get": {
        "operationId": "overlong-validity",
        "summary": "Overlong validity window (1 year)",
        "description": "**Expected behavior:** Sets maxTimeoutSeconds to a full year, widening the replay window.\n\n**What to watch:** A signed quote stays usable for far too long.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/overlong-validity\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/changing-price": {
      "get": {
        "operationId": "changing-price",
        "summary": "Price changes every request",
        "description": "**Expected behavior:** Increases the advertised amount on every request.\n\n**What to watch:** The quote a client signs may no longer match the server at settle time.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/changing-price\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/dollar-string-price": {
      "get": {
        "operationId": "dollar-string-price",
        "summary": "Dollar-string price ($0.0001)",
        "description": "**Expected behavior:** Advertises the amount as a human dollar string instead of atomic units.\n\n**What to watch:** Atomic-unit parsers reject the value.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/dollar-string-price\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/sensitive-metadata": {
      "get": {
        "operationId": "sensitive-metadata",
        "summary": "Sensitive data in metadata",
        "description": "**Expected behavior:** Leaks fake PII into the resource description before any payment.\n\n**What to watch:** The facilitator and on-chain observers see sensitive intent.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/sensitive-metadata\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/skip-verify": {
      "get": {
        "operationId": "skip-verify",
        "summary": "Skips /verify, settles directly",
        "description": "**Expected behavior:** Goes straight to /settle without a /verify pre-check.\n\n**What to watch:** Bad payloads are only caught at settle time.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/skip-verify\n```",
        "tags": [
          "Verification Gaps"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/verify-only-no-settle": {
      "get": {
        "operationId": "verify-only-no-settle",
        "summary": "Grants on /verify, never settles",
        "description": "**Expected behavior:** Grants access once /verify succeeds and never calls /settle.\n\n**What to watch:** The service is delivered but the merchant is never paid.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/verify-only-no-settle\n```",
        "tags": [
          "Verification Gaps"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/no-facilitator-check": {
      "get": {
        "operationId": "no-facilitator-check",
        "summary": "No verification at all",
        "description": "**Expected behavior:** Grants access on the mere presence of a PAYMENT-SIGNATURE header.\n\n**What to watch:** Any non-empty header unlocks the resource.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/no-facilitator-check\n```",
        "tags": [
          "Verification Gaps"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/trust-client-response": {
      "get": {
        "operationId": "trust-client-response",
        "summary": "Trusts client-supplied result",
        "description": "**Expected behavior:** Believes a client-asserted payment result without checking the facilitator.\n\n**What to watch:** A client can fabricate a 'paid' claim.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/trust-client-response\n```",
        "tags": [
          "Verification Gaps"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/fail-open-timeout": {
      "get": {
        "operationId": "fail-open-timeout",
        "summary": "Fails open when the facilitator is down",
        "description": "**Expected behavior:** Serves the resource anyway when the facilitator is unreachable.\n\n**What to watch:** An availability failure turns into free access.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/fail-open-timeout\n```",
        "tags": [
          "Verification Gaps"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/replay-after-success": {
      "get": {
        "operationId": "replay-after-success",
        "summary": "Replay after success (no binding)",
        "description": "**Expected behavior:** Once a payment settles, the same payload re-serves the resource forever with no re-settle.\n\n**What to watch:** Pay once, fetch many — call it twice with the same wallet.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/replay-after-success\n```",
        "tags": [
          "Replay / Idempotency / Race"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/serve-before-settle": {
      "get": {
        "operationId": "serve-before-settle",
        "summary": "Serves before settlement (verify/settle gap)",
        "description": "**Expected behavior:** Returns 200 immediately and settles in the background.\n\n**What to watch:** The resource leaves before the charge is confirmed.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/serve-before-settle\n```",
        "tags": [
          "Replay / Idempotency / Race"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/cors-hides-headers": {
      "get": {
        "operationId": "cors-hides-headers",
        "summary": "CORS hides payment headers",
        "description": "**Expected behavior:** Does not expose the PAYMENT-REQUIRED and PAYMENT-RESPONSE headers via CORS.\n\n**What to watch:** Browser clients cannot read the challenge or the receipt.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/cors-hides-headers\n```",
        "tags": [
          "Web / HTTP Layer"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/head-leak": {
      "get": {
        "operationId": "head-leak",
        "summary": "HEAD reveals paid metadata",
        "description": "**Expected behavior:** A HEAD request returns 200 with a leak header and no payment.\n\n**What to watch:** Try curl -I against this path.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/head-leak\n```",
        "tags": [
          "Web / HTTP Layer"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/upto-correct": {
      "post": {
        "operationId": "upto-correct",
        "summary": "upto: settles actual usage",
        "description": "**Expected behavior:** Authorizes a maximum but settles only the actual usage (~60%).\n\n**What to watch:** settledAmount is below the authorized max.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/upto-correct -H 'Content-Type: application/json' -d '{\"tokens\":600}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "tokens": 600
              }
            }
          }
        }
      }
    },
    "/api/x402/upto-charges-max": {
      "post": {
        "operationId": "upto-charges-max",
        "summary": "upto: always charges the max",
        "description": "**Expected behavior:** Settles the full authorized max even when usage is lower.\n\n**What to watch:** The buyer overpays for light usage.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/upto-charges-max -H 'Content-Type: application/json' -d '{\"tokens\":10}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "tokens": 10
              }
            }
          }
        }
      }
    },
    "/api/x402/upto-override-exceeds-max": {
      "post": {
        "operationId": "upto-override-exceeds-max",
        "summary": "upto: override exceeds the max",
        "description": "**Expected behavior:** Sets the settlement amount above the authorized maximum.\n\n**What to watch:** The server tries to take more than the client allowed.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/upto-override-exceeds-max -H 'Content-Type: application/json' -d '{\"tokens\":5000}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "tokens": 5000
              }
            }
          }
        }
      }
    },
    "/api/x402/upto-zero-free": {
      "post": {
        "operationId": "upto-zero-free",
        "summary": "upto: settles zero (free)",
        "description": "**Expected behavior:** A settlement override of 0 gives the service away by accident.\n\n**What to watch:** A paid scheme yields zero revenue.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/upto-zero-free -H 'Content-Type: application/json' -d '{\"tokens\":600}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "tokens": 600
              }
            }
          }
        }
      }
    },
    "/api/x402/dead-facilitator": {
      "get": {
        "operationId": "dead-facilitator",
        "summary": "Dead facilitator URL",
        "description": "**Expected behavior:** Points /verify and /settle at a facilitator host that does not exist.\n\n**What to watch:** Returns 502 — the payment can never complete.\n\n**Status:** Quirk — responsible party if it misbehaves: Facilitator\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/dead-facilitator\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/unsupported-network-facilitator": {
      "get": {
        "operationId": "unsupported-network-facilitator",
        "summary": "Facilitator can't support the network",
        "description": "**Expected behavior:** Advertises a network the facilitator does not handle.\n\n**What to watch:** Verify fails with an unsupported-network error.\n\n**Status:** Quirk — responsible party if it misbehaves: Facilitator\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/unsupported-network-facilitator\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-rate-limited": {
      "get": {
        "operationId": "facilitator-rate-limited",
        "summary": "Facilitator rate-limits /verify (429 → misclassified 402)",
        "description": "**Expected behavior:** The facilitator returns 429 during /verify; the merchant misclassifies it as a payment failure and returns 402 instead of 503 + Retry-After.\n\n**What to watch:** The client sees 402 and thinks its payment is invalid — it cannot tell a rate limit from a real rejection.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-rate-limited\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-soft-down-503": {
      "get": {
        "operationId": "facilitator-soft-down-503",
        "summary": "Facilitator temporarily unavailable (503)",
        "description": "**Expected behavior:** The facilitator is reachable but returns 503 Service Unavailable — it is not a dead URL, just temporarily down.\n\n**What to watch:** Returns 502. Unlike a dead-facilitator connection error, the facilitator answered; it is temporarily unable to process payments.\n\n**Status:** Quirk — responsible party if it misbehaves: Facilitator\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-soft-down-503\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-settle-500": {
      "get": {
        "operationId": "facilitator-settle-500",
        "summary": "Settle returns 500 (ambiguous paid state)",
        "description": "**Expected behavior:** /verify succeeds but /settle returns 500 Internal Server Error, leaving it unknown whether the payment landed on-chain.\n\n**What to watch:** Returns 502. The client cannot safely retry with the same permit — the charge might already be confirmed on-chain.\n\n**Status:** Quirk — responsible party if it misbehaves: Facilitator\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-settle-500\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-missing-txhash": {
      "get": {
        "operationId": "facilitator-missing-txhash",
        "summary": "Settle succeeds without txHash",
        "description": "**Expected behavior:** /settle reports success: true but omits every transaction-hash field; the PAYMENT-RESPONSE receipt carries no on-chain proof.\n\n**What to watch:** Returns 200 but the PAYMENT-RESPONSE header has no txHash — the client cannot verify the settlement on-chain.\n\n**Status:** Quirk — responsible party if it misbehaves: Facilitator\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-missing-txhash\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-non-json-leaks": {
      "get": {
        "operationId": "facilitator-non-json-leaks",
        "summary": "Non-JSON facilitator response leaked in 402",
        "description": "**Expected behavior:** The facilitator returns an HTML maintenance page instead of JSON; the merchant forwards the raw HTML in the 402 response body, leaking internal infrastructure details.\n\n**What to watch:** The 402 body contains a raw HTML error page with internal build tags and server identifiers.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-non-json-leaks\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-schema-drift": {
      "get": {
        "operationId": "facilitator-schema-drift",
        "summary": "Schema drift: valid vs isValid (loose check grants)",
        "description": "**Expected behavior:** The facilitator returns { valid: true } instead of the spec's { isValid: true }; the merchant's loose field-name check grants access on the wrong key.\n\n**What to watch:** Returns 200 despite the field-name mismatch — a compliant client relying on isValid would have denied access.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-schema-drift\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-no-verify-timeout": {
      "get": {
        "operationId": "facilitator-no-verify-timeout",
        "summary": "No timeout on /verify (hangs indefinitely)",
        "description": "**Expected behavior:** The merchant's /verify fetch has no AbortController or timeout; when the facilitator is slow the handler ties up the connection forever.\n\n**What to watch:** The request hangs — no response arrives. You will need to Ctrl+C or wait for your client's own timeout to fire.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-no-verify-timeout\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-wrong-payto-at-settle": {
      "get": {
        "operationId": "facilitator-wrong-payto-at-settle",
        "summary": "Wrong payTo used at settle time",
        "description": "**Expected behavior:** The merchant calls /settle with a payTo address different from the one advertised in the challenge; the facilitator rejects it because the payment was signed for a different recipient.\n\n**What to watch:** Returns 402. The facilitator rejects the mismatched payTo — funds would have gone to the wrong address if the call had succeeded.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-wrong-payto-at-settle\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-already-settled-grants": {
      "get": {
        "operationId": "facilitator-already-settled-grants",
        "summary": "Grants access despite settle failure",
        "description": "**Expected behavior:** When /settle returns a failure (e.g., already used), the merchant grants access anyway — a replay attacker can reuse any previously-rejected permit for free.\n\n**What to watch:** Returns 200 even though settle failed. The merchant is giving away the resource without confirmed payment.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-already-settled-grants\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/facilitator-settle-concurrent-race": {
      "get": {
        "operationId": "facilitator-settle-concurrent-race",
        "summary": "Concurrent settle race (second racer gets 402)",
        "description": "**Expected behavior:** Two concurrent requests carry the same PAYMENT-SIGNATURE; without a per-permit lock the merchant lets both race to /settle. The facilitator accepts only one — the second racer is charged but gets a confusing 402.\n\n**What to watch:** Returns 402 with an 'already used' detail — the client paid but the second concurrent call lost the settle race.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/facilitator-settle-concurrent-race\n```",
        "tags": [
          "Facilitator Dependency"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/settle-then-fail": {
      "get": {
        "operationId": "settle-then-fail",
        "summary": "Settles, then the handler fails",
        "description": "**Expected behavior:** The payment settles on-chain, then the handler returns 500.\n\n**What to watch:** The buyer is charged but receives nothing — check the txHash.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/settle-then-fail\n```",
        "tags": [
          "Paid-but-Denied / Unpaid-Service"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/missing-payment-response": {
      "get": {
        "operationId": "missing-payment-response",
        "summary": "Success without PAYMENT-RESPONSE",
        "description": "**Expected behavior:** Settles and returns 200 but omits the PAYMENT-RESPONSE header.\n\n**What to watch:** The client cannot read its settlement receipt.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/missing-payment-response\n```",
        "tags": [
          "Paid-but-Denied / Unpaid-Service"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/joke-api": {
      "get": {
        "operationId": "joke-api",
        "summary": "Joke API (pay-per-call)",
        "description": "**Expected behavior:** A compliant GET that returns a joke after a real settlement.\n\n**What to watch:** Real verify and settle, then 200 with a PAYMENT-RESPONSE.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/joke-api\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/dictionary-api": {
      "get": {
        "operationId": "dictionary-api",
        "summary": "Dictionary API (pay-per-call)",
        "description": "**Expected behavior:** A compliant GET that returns a definition after settlement.\n\n**What to watch:** Behaves like a genuine paid lookup.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/dictionary-api\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/quote-api": {
      "get": {
        "operationId": "quote-api",
        "summary": "Quote API (pay-per-call)",
        "description": "**Expected behavior:** A compliant GET that returns a quote after settlement.\n\n**What to watch:** Real verify and settle before the quote is returned.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/quote-api\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/wrong-transfer-method": {
      "get": {
        "operationId": "wrong-transfer-method",
        "summary": "Wrong asset transfer method",
        "description": "**Expected behavior:** Sets extra.assetTransferMethod to something other than permit2, so the facilitator can't move funds.\n\n**What to watch:** Verification fails on a transfer-method mismatch.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/wrong-transfer-method\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/zero-price-gated": {
      "get": {
        "operationId": "zero-price-gated",
        "summary": "Advertises a zero price but still gates",
        "description": "**Expected behavior:** Advertises an amount of 0 yet still demands a payment header.\n\n**What to watch:** The client signs a zero-value permit that settles nothing.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0 SBC (0 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/zero-price-gated\n```",
        "tags": [
          "402 / Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/batch-settlement-correct": {
      "post": {
        "operationId": "batch-settlement-correct",
        "summary": "batch-settlement: deposit, then reconcile usage",
        "description": "**Expected behavior:** Advertises the batch-settlement scheme: the client authorizes a 5x deposit, and the server settles only the actual (much lower) usage.\n\n**What to watch:** settledAmount is far below authorizedDeposit, and reconciled is true.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/batch-settlement-correct -H 'Content-Type: application/json' -d '{\"calls\":3}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "calls": 3
              }
            }
          }
        }
      }
    },
    "/api/x402/batch-settlement-overcharge-deposit": {
      "post": {
        "operationId": "batch-settlement-overcharge-deposit",
        "summary": "batch-settlement: settles beyond the deposit",
        "description": "**Expected behavior:** Settles more than the deposit the client authorized under the batch scheme.\n\n**What to watch:** Settlement exceeds authorizedDeposit — the facilitator should reject the overcharge.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/batch-settlement-overcharge-deposit -H 'Content-Type: application/json' -d '{\"calls\":3}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "calls": 3
              }
            }
          }
        }
      }
    },
    "/api/x402/batch-settlement-never-reconciles": {
      "post": {
        "operationId": "batch-settlement-never-reconciles",
        "summary": "batch-settlement: never reconciles down",
        "description": "**Expected behavior:** Holds the full authorized deposit and never settles the lower real usage.\n\n**What to watch:** settledAmount equals authorizedDeposit and reconciled is false — the buyer overpays.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/batch-settlement-never-reconciles -H 'Content-Type: application/json' -d '{\"calls\":1}'\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "calls": 1
              }
            }
          }
        }
      }
    },
    "/api/x402/client-scheme-mismatch": {
      "get": {
        "operationId": "client-scheme-mismatch",
        "summary": "exact: canonical scheme identifier (client sends the wrong one)",
        "description": "**Expected behavior:** A fully compliant exact endpoint. The scheme identifier in the payment payload MUST be the canonical \"exact\" — a client that instead sends a non-canonical name like \"exact-evm\" is rejected by the facilitator with invalid_exact_evm_scheme even though its signature recovers a valid payer.\n\n**What to watch:** Pay with the canonical scheme \"exact\" and it settles. Send scheme:\"exact-evm\" and the facilitator returns 402 with PAYMENT-RESPONSE invalidReason \"invalid_exact_evm_scheme\" and the recovered payer — the fix is on the client.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/client-scheme-mismatch\n```",
        "tags": [
          "Schemes (exact / upto / batch)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/multi-network-accepts": {
      "get": {
        "operationId": "multi-network-accepts",
        "summary": "Genuine multi-entry accepts (match by network)",
        "description": "**Expected behavior:** Advertises two EVM entries — Base Sepolia first, Radius testnet second — so the client must match by network instead of taking accepts[0].\n\n**What to watch:** A correct client skips accepts[0] (Base Sepolia) and pays the eip155:72344 entry.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/multi-network-accepts\n```",
        "tags": [
          "Multi-Network Selection (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/svm-requirement": {
      "get": {
        "operationId": "svm-requirement",
        "summary": "SVM-only requirement (solana:*)",
        "description": "**Expected behavior:** Advertises only a Solana (solana:*) requirement, which an EVM testnet client cannot satisfy.\n\n**What to watch:** An EVM wallet finds no compatible entry; surfaces SVM network selection.\n\n**Status:** Quirk — responsible party if it misbehaves: Network / Chain\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/svm-requirement\n```",
        "tags": [
          "Multi-Network Selection (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/cross-vm-accepts": {
      "get": {
        "operationId": "cross-vm-accepts",
        "summary": "Cross-VM accepts (EVM and SVM together)",
        "description": "**Expected behavior:** Advertises a Solana entry and a Radius testnet EVM entry together, forcing the client to select the VM and network it can settle on.\n\n**What to watch:** A correct client picks the EVM eip155:72344 entry and ignores the solana:* one.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/cross-vm-accepts\n```",
        "tags": [
          "Multi-Network Selection (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/overpriced-vs-cap": {
      "get": {
        "operationId": "overpriced-vs-cap",
        "summary": "Overpriced vs per-call cap",
        "description": "**Expected behavior:** Advertises a price far above a sane per-call cap that an MCP policy gate would enforce.\n\n**What to watch:** A max-amount policy check rejects this before signing; a capless client overpays.\n\n**Status:** Quirk — responsible party if it misbehaves: Client\n**Price:** 1 SBC (1000000 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/overpriced-vs-cap\n```",
        "tags": [
          "Client Policy Gate (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/resource-host-mismatch": {
      "get": {
        "operationId": "resource-host-mismatch",
        "summary": "Resource host mismatch",
        "description": "**Expected behavior:** The advertised resource origin differs from the server actually being called.\n\n**What to watch:** An expected-resource-server policy check rejects the mismatched origin before signing.\n\n**Status:** Quirk — responsible party if it misbehaves: Client\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/resource-host-mismatch\n```",
        "tags": [
          "Client Policy Gate (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/tool-operation-mismatch": {
      "get": {
        "operationId": "tool-operation-mismatch",
        "summary": "Tool / operation mismatch",
        "description": "**Expected behavior:** The requirement authorizes a different, more privileged tool than the one being requested.\n\n**What to watch:** A tool-name binding check rejects the requirement before signing.\n\n**Status:** Quirk — responsible party if it misbehaves: Client\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/tool-operation-mismatch\n```",
        "tags": [
          "Client Policy Gate (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/session-price-escalation": {
      "get": {
        "operationId": "session-price-escalation",
        "summary": "Session price escalation",
        "description": "**Expected behavior:** The price climbs call over call (1x, 2x, 3x...) to defeat a per-session spend limit.\n\n**What to watch:** Each call may slip under a per-call cap, but a per-session budget check catches the running total.\n\n**Status:** Quirk — responsible party if it misbehaves: Client\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/session-price-escalation\n```",
        "tags": [
          "Client Policy Gate (MCP)"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-correct-headers": {
      "get": {
        "operationId": "edge-correct-headers",
        "summary": "Correct edge cache headers (compliant)",
        "description": "**Expected behavior:** The 402 challenge is no-store; the paid 200 is private, no-store with Vary: PAYMENT-SIGNATURE — and it still does a real verify and settle.\n\n**What to watch:** curl -i: the 402 carries Cache-Control: no-store; the paid 200 is private and Vary.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-correct-headers\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-cacheable-challenge": {
      "get": {
        "operationId": "edge-cacheable-challenge",
        "summary": "Cacheable 402 challenge",
        "description": "**Expected behavior:** Sends the 402 with Cache-Control: public, max-age, so a shared cache stores and replays a stale challenge.\n\n**What to watch:** curl -i: the 402 carries public, max-age=300; the nonce, quote, and price go stale in cache.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-cacheable-challenge\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-cacheable-paid": {
      "get": {
        "operationId": "edge-cacheable-paid",
        "summary": "Cacheable paid response (shared cache)",
        "description": "**Expected behavior:** Sends the paid 200 publicly cacheable, so a shared edge serves paid content to unpaid clients on the same URL.\n\n**What to watch:** curl -i: the paid 200 carries public, max-age — a paywall bypass via the CDN.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-cacheable-paid\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-missing-vary": {
      "get": {
        "operationId": "edge-missing-vary",
        "summary": "Missing Vary on payment",
        "description": "**Expected behavior:** Caches the paid 200 but ignores the payment header in the cache key (no Vary), so one payer's response is served to another.\n\n**What to watch:** curl -i: public, max-age with NO Vary header on the paid 200.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-missing-vary\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-swr-leak": {
      "get": {
        "operationId": "edge-swr-leak",
        "summary": "stale-while-revalidate leak",
        "description": "**Expected behavior:** A stale-while-revalidate directive lets the edge serve cached protected content without payment during revalidation.\n\n**What to watch:** curl -i: the paid 200 carries stale-while-revalidate — protected content is served stale and unpaid.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-swr-leak\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-oversized-header": {
      "get": {
        "operationId": "edge-oversized-header",
        "summary": "Oversized challenge header",
        "description": "**Expected behavior:** Pads the PAYMENT-REQUIRED header beyond common proxy header-size caps, so an edge truncates, drops, or 431s it.\n\n**What to watch:** curl -i: the PAYMENT-REQUIRED header is over 12KB — a proxy may strip it before the client sees it.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-oversized-header\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-conditional-304": {
      "get": {
        "operationId": "edge-conditional-304",
        "summary": "Conditional 304 replay",
        "description": "**Expected behavior:** The paid resource carries an ETag, and a later conditional request is answered 304 from cache without re-payment.\n\n**What to watch:** The first paid call returns an ETag; a replay with -H 'If-None-Match: \"paid-resource-v1\"' (no payment) returns 304.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-conditional-304\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-rate-limited": {
      "get": {
        "operationId": "edge-rate-limited",
        "summary": "Rate-limited before payment",
        "description": "**Expected behavior:** Returns 429 (short Retry-After, no challenge) before the 402, so a willing payer can't tell a rate limit from a paywall.\n\n**What to watch:** curl -i (no payment): 429 with Retry-After and no PAYMENT-REQUIRED header.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-rate-limited\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-waf-blocks-payment": {
      "get": {
        "operationId": "edge-waf-blocks-payment",
        "summary": "WAF blocks the payment payload",
        "description": "**Expected behavior:** The large base64 PAYMENT-SIGNATURE trips a managed WAF rule and is rejected with 403 before the payment logic runs.\n\n**What to watch:** The paid call returns 403 (WAF) instead of verifying — the payment never reaches the origin logic.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-waf-blocks-payment\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-body-too-large": {
      "post": {
        "operationId": "edge-body-too-large",
        "summary": "Body too large (413)",
        "description": "**Expected behavior:** A paid POST is rejected by a small edge body cap with 413 before reaching the payment logic.\n\n**What to watch:** The paid POST returns 413 before any verify or settle — the edge body limit fires first.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 post http://127.0.0.1:8080/api/x402/edge-body-too-large -H 'Content-Type: application/json' -d '{\"query\":\"radius\"}'\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        },
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "additionalProperties": true
              },
              "example": {
                "query": "radius"
              }
            }
          }
        }
      }
    },
    "/api/x402/edge-timeout-settle": {
      "get": {
        "operationId": "edge-timeout-settle",
        "summary": "Edge timeout during settle",
        "description": "**Expected behavior:** Settlement is slow and the edge returns 504 while the charge may have completed on-chain — an ambiguous paid state.\n\n**What to watch:** The paid call returns 504 after a valid verify — the charge may still settle on-chain.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/x402/edge-timeout-settle\n```",
        "tags": [
          "Edge / CDN Controls"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-push-happy": {
      "get": {
        "operationId": "mpp-push-happy",
        "summary": "MPP push happy path (EIP-3009)",
        "description": "**Expected behavior:** Compliant MPP push flow: server issues WWW-Authenticate: Payment challenge, client submits EIP-3009 authorization credential, server validates structure and returns 200 with Payment-Receipt.\n\n**What to watch:** Returns 200 with Payment-Receipt header. Submit Authorization: Payment credential=\"<base64-push-payload>\" to pass.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-push-happy\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-permit-happy": {
      "get": {
        "operationId": "mpp-permit-happy",
        "summary": "MPP permit happy path (EIP-2612)",
        "description": "**Expected behavior:** Compliant MPP permit flow: challenge requests an EIP-2612 permit credential. Client submits signed permit in Authorization: Payment, server validates and returns 200.\n\n**What to watch:** Returns 200 with Payment-Receipt. Credential must have type:\"permit\" with owner/spender/value/deadline/nonce/v/r/s fields.\n\n**Status:** Compliant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-permit-happy\n```",
        "tags": [
          "Happy Path"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-wrong-status": {
      "get": {
        "operationId": "mpp-wrong-status",
        "summary": "MPP challenge returns 401 instead of 402",
        "description": "**Expected behavior:** Issues the MPP payment challenge with HTTP 401 Unauthorized instead of the required 402 Payment Required.\n\n**What to watch:** Clients that key on status 402 to start the MPP flow never see the payment prompt.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-wrong-status\n```",
        "tags": [
          "Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-missing-authenticate": {
      "get": {
        "operationId": "mpp-missing-authenticate",
        "summary": "MPP 402 without WWW-Authenticate",
        "description": "**Expected behavior:** Returns 402 but omits the WWW-Authenticate: Payment header entirely. The client receives a payment signal but no challenge to respond to.\n\n**What to watch:** Client stalls — no challenge means no credential can be constructed.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-missing-authenticate\n```",
        "tags": [
          "Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-raw-json-authenticate": {
      "get": {
        "operationId": "mpp-raw-json-authenticate",
        "summary": "WWW-Authenticate challenge is raw JSON (not Payment scheme)",
        "description": "**Expected behavior:** Emits WWW-Authenticate with the challenge embedded as raw JSON instead of the \"Payment method=\\\"evm/charge\\\" challenge=\\\"<base64>\\\"\" format.\n\n**What to watch:** Strict MPP parsers reject the malformed auth-scheme and cannot extract the challenge.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-raw-json-authenticate\n```",
        "tags": [
          "Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-bearer-authenticate": {
      "get": {
        "operationId": "mpp-bearer-authenticate",
        "summary": "WWW-Authenticate uses Bearer instead of Payment scheme",
        "description": "**Expected behavior:** Returns WWW-Authenticate: Bearer realm=\"...\" — the OAuth scheme — instead of the Payment scheme. MPP clients have no credential type to submit.\n\n**What to watch:** An OAuth client might initiate a token flow; an MPP client sees no payment challenge.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-bearer-authenticate\n```",
        "tags": [
          "Challenge Construction"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-bad-credential": {
      "get": {
        "operationId": "mpp-bad-credential",
        "summary": "MPP server rejects every credential",
        "description": "**Expected behavior:** The server always returns 401 on any Authorization: Payment credential, even structurally valid ones. No credential can satisfy this endpoint.\n\n**What to watch:** Payment flow loops: server issues challenge, client submits valid credential, server rejects with 401 every time.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-bad-credential\n```",
        "tags": [
          "Credential Validation"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-skip-validation": {
      "get": {
        "operationId": "mpp-skip-validation",
        "summary": "MPP grants on credential presence (no validation)",
        "description": "**Expected behavior:** Grants access on the mere presence of an Authorization: Payment header — any credential value, even random bytes, unlocks the resource.\n\n**What to watch:** Submit Authorization: Payment credential=\"anyrandomstring\" to obtain the resource without a valid payment.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-skip-validation\n```",
        "tags": [
          "Credential Validation"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-paid-denied": {
      "get": {
        "operationId": "mpp-paid-denied",
        "summary": "MPP paid-but-denied (403 after valid credential)",
        "description": "**Expected behavior:** Accepts a structurally valid push credential but returns 403 Forbidden with a Payment-Receipt failure header. The payment credential was consumed without delivering the resource.\n\n**What to watch:** Returns 403 with Payment-Receipt even after a correct credential is submitted.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-paid-denied\n```",
        "tags": [
          "Paid-but-Denied"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    },
    "/api/mpp/mpp-replay-accepted": {
      "get": {
        "operationId": "mpp-replay-accepted",
        "summary": "MPP replay accepted (no idempotency check)",
        "description": "**Expected behavior:** The server accepts a previously-used push credential without checking for replay. A single credential can be reused indefinitely to obtain the resource.\n\n**What to watch:** Send the same Authorization: Payment credential twice — both succeed with Replay-Warning header on second call.\n\n**Status:** Quirk — responsible party if it misbehaves: Merchant\n**Price:** 0.0001 SBC (100 atomic units)\n\nImporting this request demonstrates the endpoint and surfaces the 402 challenge. To actually pay and receive the 200 resource, run it with radius-cli (the only client that can sign an x402 payment):\n\n```\nradius-cli --network testnet wallet x402 get http://127.0.0.1:8080/api/mpp/mpp-replay-accepted\n```",
        "tags": [
          "Credential Validation"
        ],
        "responses": {
          "200": {
            "description": "Paid resource. On success the PAYMENT-RESPONSE header carries the settlement receipt (including a real testnet txHash for compliant endpoints).",
            "headers": {
              "PAYMENT-RESPONSE": {
                "description": "Base64-encoded settlement receipt returned after a successful payment.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "additionalProperties": true
                }
              }
            }
          },
          "402": {
            "description": "Payment Required — the x402 challenge. The PAYMENT-REQUIRED response header carries the base64-encoded requirements (accepts, amount, asset, payTo, network) to sign.",
            "headers": {
              "PAYMENT-REQUIRED": {
                "description": "Base64-encoded x402 v2 PAYMENT-REQUIRED challenge describing what to pay.",
                "schema": {
                  "type": "string"
                }
              }
            },
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/PaymentRequired"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "PaymentRequirement": {
        "type": "object",
        "properties": {
          "scheme": {
            "type": "string"
          },
          "network": {
            "type": "string"
          },
          "amount": {
            "type": "string",
            "description": "Atomic-unit amount as a string."
          },
          "asset": {
            "type": "string"
          },
          "payTo": {
            "type": "string"
          },
          "maxTimeoutSeconds": {
            "type": "integer"
          },
          "resource": {
            "type": "string"
          }
        }
      },
      "PaymentRequired": {
        "type": "object",
        "properties": {
          "x402Version": {
            "type": "integer"
          },
          "error": {
            "type": "string"
          },
          "resource": {
            "type": "object",
            "additionalProperties": true
          },
          "accepts": {
            "type": "array",
            "items": {
              "$ref": "#/components/schemas/PaymentRequirement"
            }
          },
          "extensions": {
            "type": "object",
            "description": "Optional protocol extensions. Every challenge from this server includes `eip2612GasSponsoring` and a builder-code entry under the ERC-8021 key (`https://x402.org/extensions/builder-code`) declaring the `grug402` builder code for on-chain attribution.",
            "example": {
              "eip2612GasSponsoring": {
                "info": {
                  "version": "1"
                }
              },
              "https://x402.org/extensions/builder-code": {
                "builderCode": "grug402"
              }
            }
          }
        }
      }
    }
  }
}