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Citiview Blockchain Timestamp (OpenTimestamps)
x402
Citiview Blockchain Timestamp (OpenTimestamps) is a paid API for AI agents from agents.citiviewgroup.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-14).
Anchors the SHA-256 hash of any text, file, or URL in the Bitcoin blockchain via OpenTimestamps calendars and returns a .ots proof file for later verification
Price / call$0.01
Success—
StatusUnknown
How this service works
Proof of existence: anchor the SHA-256 of any text, file or URL in the Bitcoin blockchain through OpenTimestamps calendars and get the .ots proof file, so anyone can later verify the data existed at that time. Also callable as GET with the same fields as query parameters.
Output
A .ots (OpenTimestamps) proof file containing cryptographic attestation that links the SHA-256 hash of the submitted content to a Bitcoin blockchain block, allowing anyone to independently verify that the data existed at the timestamped moment using the OpenTimestamps protocol.
Example use cases
Intellectual property timestamping
“I just wrote a new song lyric and need to prove I authored it today — can you timestamp this text in the Bitcoin blockchain and get me an OpenTimestamps .ots proof file? The text is: 'Stars align when rivers run dry, midnight whispers under neon sky.'”
Legal document proof of existence
“Please anchor the SHA-256 hash of this contract in the Bitcoin blockchain so we have proof it existed before signing — the hash is a9f3c2b1d8e74f6a2c5b9d1e3f7a0c4b2d6e8f1a3c5b7d9e2f4a6c8b0d2e4f6.”
Webpage snapshot notarization
“I need to prove this webpage existed as-is today — can you create a blockchain timestamp for this URL and return the .ots proof file? The URL is https://example.com/announcement/2025-product-launch.”
Technical details
Endpoint
GEThttps://agents.citiviewgroup.com/v1/timestamp?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need cryptographic, decentralized proof of existence anchored to the Bitcoin blockchain without relying on any central authority. Ideal for legal notarization, intellectual property protection, contract timestamping, or any scenario requiring trustless verification that data existed at a specific point in time. Prefer over centralized timestamping services when immutability and third-party-verifiability via the open OpenTimestamps protocol are required.
Side effects
- Invalid or malformed SHA-256 hash returns an error
- Base64-encoded content that is too large may be rejected
- Inaccessible URL (404, timeout) cannot be fetched and hashed
- OpenTimestamps calendar servers temporarily unavailable causing delay
- Missing required input field (text, url, sha256, or content_base64) returns validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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