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Agent Vending Machine - Hash Attestation
x402
Agent Vending Machine - Hash Attestation is a paid API for AI agents from agent-vending-machine.avm-7301.workers.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).
Submits a SHA-256 hash or raw payload and receives a signed Ed25519 receipt binding the hash to a timestamp, providing third-party existence attestation.
Price / call$0.05
Success—
StatusUnknown
How this service works
Third-party existence attestation: submit a sha256 hash (or a payload to hash) and receive an Ed25519-signed receipt binding the hash to an issuance timestamp. Verify any receipt for free at /verify; signing public key published at /.
Output
An Ed25519-signed receipt object binding the submitted hash (or the server-side hash of the provided payload) to an issuance timestamp, serving as cryptographic third-party proof of existence at that moment. The receipt can be independently verified for free at the /verify endpoint.
Example use cases
Notarize contract before deadline
“I need to prove this contract existed before the submission deadline — please attest the SHA-256 hash b7e2d1f3a4c56789abcdef0987654321fedcba9876543210fedcba9876543210fe and give me a signed timestamped receipt I can show as third-party proof it was finalized before the cutoff.”
Attest dataset without revealing contents
“I want to prove I had this proprietary dataset before I shared it publicly, but without exposing the actual data — please submit this hash 9c3e5a1d2b4f6789012345678901234567890123456789012345678901234567ab to the attestation service and get me a signed Ed25519 receipt I can keep as evidence.”
Audit trail for software build
“For our compliance audit I need a tamper-proof record that this software build artifact existed at this exact moment — please attest the SHA-256 hash f1a2b3c4d5e6f7089876543210abcdef1234567890abcdef1234567890abcdef12 and return a third-party-signed timestamped receipt I can attach to the audit log.”
Technical details
Endpoint
POSThttps://agent-vending-machine.avm-7301.workers.dev/attestWhen to prefer
Use this endpoint when you need a cryptographically signed, third-party-attested timestamp receipt for a hash or payload — especially for legal, audit, or compliance purposes where you need an independent party's Ed25519 signature binding content to a moment in time. Prefer this over self-signed or chain-based solutions when you want a lightweight, verifiable receipt without blockchain overhead.
Side effects
- Invalid sha256 format (not 64 lowercase hex chars) — returns 400 error
- Neither sha256 nor payload provided — returns 400 missing parameter error
- Both sha256 and payload provided simultaneously — may return 400 ambiguous input error
- Payment not included or insufficient USDC — returns 402 Payment Required
- Service temporarily unavailable — returns 503
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| sha256 | string | Lowercase hex sha256 digest to attest (64 chars). Provide this or `payload`. |
| payload | string | Raw UTF-8 payload; the service hashes it server-side. Provide this or `sha256`. |
Tags
x402
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