Oversized challenge header

Quirk · GET /api/x402/edge-oversized-header · Edge / CDN Controls

Pads the PAYMENT-REQUIRED header beyond common proxy header-size caps, so an edge truncates, drops, or 431s it.

Explanation

The PAYMENT-REQUIRED header is padded beyond common proxy header-size caps (often around 8KB), so an edge truncates or drops it — or rejects the response with 431 Request Header Fields Too Large — before the client can read the challenge. The merchant must keep the challenge header within proxy limits, or move the payload into the body.

What to watch

curl -i: the PAYMENT-REQUIRED header is over 12KB — a proxy may strip it before the client sees it.

Facilitator

Settled against the live Radius testnet facilitator (https://facilitator.testnet.radiustech.xyz). A valid payment runs a real /verify and /settle on-chain.

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