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witnessd.vip Witness Endpoint
x402
witnessd.vip Witness Endpoint is a paid API for AI agents from witnessd.vip, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-11).
Independently fetches, hashes, timestamps, and Merkle-anchors any URL or API response on Base as a neutral third-party witness record
Price / call$0.02
Success—
StatusUnknown
How this service works
Independently fetch, hash, timestamp and archive a URL or API response; returns a signed certificate. Merkle-anchored on Base hourly. Neutral third-party evidence for agent commerce disputes.
Output
Returns a JSON object containing a unique witness ID (e.g. ws_76cae2b76822b099d37882c4), a retrieve_url to access the archived response content, and a certificate_url linking to the Merkle-anchored proof on Base that verifies the fetch was performed at a specific time by a neutral third party.
Example use cases
AI agent output audit trail
“Witness the response from https://myagent.io/api/decision/123 right now and give me a certificate I can show auditors proving exactly what the model returned at this moment.”
Legal evidence of webpage content
“I need to prove what's currently published at https://competitor.com/claims — can you have an independent service fetch it, timestamp it, and anchor it on the blockchain so I have tamper-proof evidence?”
Regulatory compliance snapshot
“Before this market data feed changes, fetch and certify https://datavendor.com/api/rates/live right now so we have a neutral third-party record of today's published rates for our compliance files.”
Technical details
Endpoint
POSThttps://witnessd.vip/api/witness?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a neutral, independent, blockchain-anchored proof that a specific URL or API endpoint had particular content at a specific moment in time — especially for audit trails, legal evidence, compliance snapshots, or AI agent output verification. Prefer this over simple screenshots or self-hosted archiving when tamper-proof third-party attestation and Merkle anchoring on Base are required. Best suited for single-URL, point-in-time witnessing rather than ongoing monitoring.
Side effects
- Target URL is unreachable or returns a non-2xx status — witness may still be created but content reflects the error response
- Invalid or malformed URL input — API returns a validation error
- Payment of $0.02 USDC not fulfilled via x402 — request rejected before fetch is attempted
- Target URL requires authentication or blocks external fetchers — returns partial or access-denied content
- Network timeout on the target URL — witness may record a timeout rather than content
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| url | string | The http(s) URL or API endpoint to witness right now |
Output
Schema · Response
{
"type": "json",
"example": {
"id": "ws_76cae2b76822b099d37882c4",
"retrieve_url": "https://witnessd.vip/api/retrieve/ws_76cae2b76822b099d37882c4",
"certificate_url": "https://witnessd.vip/api/certificate/ws_76cae2b76822b099d37882c4"
}
}Tags
x402
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