# AgentRXI Bitcoin Timestamp (OpenTimestamps)

> AgentRXI Bitcoin Timestamp (OpenTimestamps) is a paid API for AI agents from agentrxi.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-15).

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

## Facts

- Endpoint: GET https://agentrxi.com/v1/timestamp?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentrxi-bitcoin-timestamp-opentimestamps-a12610d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gHgsH9qdQD9wHofve71d1

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agentrxi-bitcoin-timestamp-opentimestamps-a12610d0
```

Example prompt: Please timestamp this text in the Bitcoin blockchain and give me the .ots proof file so I can prove it existed today: 'This agreement was signed between Alice and Bob on June 1 2025.'

## When to prefer this

Choose this endpoint when you need a trustless, decentralized, tamper-proof record that a specific piece of data existed at a particular moment in time — anchored to the Bitcoin blockchain — without relying on a centralized notary. It is ideal for legal documents, creative works, contracts, software releases, or any content where provenance and timestamp integrity matter. Use it over centralized timestamp services when auditability and censorship-resistance are priorities.

## Known failure modes

- Invalid or missing input (no text, url, sha256, or content_base64 provided) — returns 400 error
- Malformed base64 content — returns parsing error
- OpenTimestamps calendar servers temporarily unavailable — may delay or fail proof generation
- URL provided is unreachable or returns non-200 — content cannot be fetched for hashing
- Payment not completed (x402) — returns 402 Payment Required before processing

## 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 that cryptographically links the SHA-256 hash of the submitted data to a Bitcoin block, which anyone can later verify to confirm the data existed at or before the timestamp. The proof can be independently validated using any OpenTimestamps-compatible verifier.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "url": {
       "type": "string"
      },
      "text": {
       "type": "string"
      },
      "sha256": {
       "type": "string"
      },
      "content_base64": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentrxi-bitcoin-timestamp-opentimestamps-a12610d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentrxi.com](https://www.zero.xyz/host/agentrxi.com/llms.txt)