{"format":"forge-attestation/0.1","policy_id":"forge-policy/2026-08-17","signing":{"available":true,"algorithm":"ed25519","public_key_spki_b64":"MCowBQYDK2VwAyEAZEusEICmKN4SuzVRUb942tTy0MdipoPy0MhdE4LuT84="},"canonicalization":"sorted-key JSON of every field except `id` and `signature`; sign the UTF-8 bytes","verify_offline":"id = first 32 hex chars of sha256(canonical payload); signature = ed25519 over the same bytes","verify_hosted":"POST https://forgesignals.org/attestations/verify with the attestation as the body (free)","falsifiability":"Every claim carries a `falsifiable_by` field naming the observation that would refute it. On-chain claims are re-derivable forever (re-run the query). Probe claims are not re-derivable at all and say so - corroborate them with independent witnesses, where disagreement is the failure signature. A claim that cannot name what would refute it is a press release, not evidence.","evidence_classes":{"witnessed":"Forge observed this directly (endpoint probe, on-chain settlement lookup).","asserted":"A party told Forge this and Forge notarised the claim. Includes any response hash submitted after the call. It is not proof of delivery."},"guarantee_levels":{"consistency":"supported - the offer and the settlement are bound and cannot be rewritten later","conformance":"supported - payment-schema validity, advertised price and payee agreement","correctness":"NOT supported by any third-party witness, including this one"},"privacy":"Response bodies are never sent to or stored by Forge. Hashes only. A witness that logged bodies would be a surveillance service.","openness":"This format is published so it can become an x402 extension rather than a private moat. Implement it, fork it, or compete with it on retention and dispute UX. If the x402 working group adopts a delivery-receipt extension, Forge will implement that instead of this.","open_problem":"A hash submitted after a call only notarises a claim. Witnessing delivery as it happens needs either a seller-signed delivery receipt, an in-path observer, or redundancy across independent buyers of the same deterministic call. None of those exist yet; this format labels the gap instead of hiding it."}