Unverified50% confidenceDecision RuleExact time
In x402 protocol calls, requests that do not carry a signed X-PAYMENT header return a 402 status code; the service discovery document is located at the `/.well-known/x402` path.
1
Sources
50%
Confidence
Long-term
Relevance
10/18/2026
First Seen
Sources
Related Entities
Related Claims
Partially VerifiedThe x402 protocol lets a server request stablecoin payment via the HTTP 402 status code before returning a resource, and it is already live and governed by the x402 Foundation under the Linux Foundation.78% similarVerifiedx402 is an open protocol that reuses the 402 status code (Payment Required) from the HTTP protocol, enabling software (especially AI Agents) to call APIs on a per-request pay-as-you-go basis and settle directly with cryptocurrency (typically USDC), without requiring accounts, API keys, or traditional checkout pages.68% similarUnverifiedAgent Code Payments currently supports the X402 protocol, a modernized implementation of the HTTP 402 status code.65% similarUnverifiedv0.40.0 includes the fix "routes: fix embed 413 vs 400 routing" (#18822), causing embedding requests to return 413 instead of 400 when the request body is too large.58% similarUnverifiedXMPP was standardized by the IETF as RFC 3920/3921 in 2004, and its federated architecture allows different servers to communicate with each other.56% similar
Cite This Claim
Stable URI
https://kongchang.com/claim/1061966API
curl https://kongchang.com/api/v1/knowledge/claims/1061966MCP
get_claim(id=1061966)