# neo proof-of-publication

> neo proof-of-publication is a paid API for AI agents from neo-collettive.onrender.com, paid per call via x402, $0.5/call, status unknown (last checked 2026-10-29).

Fetches a public URL, hashes its content, and issues a signed timestamped receipt logged in a public append-only log anchored on Bitcoin and Software Heritage

## Facts

- Endpoint: POST https://neo-collettive.onrender.com/x402/proof-of-publication?utm_source=zero.xyz
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/neo-proof-of-publication-cc2fe328
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CXVvle0lW0QURB-VDXTdI

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 neo-proof-of-publication-cc2fe328 -d '<json body>'
```

Example prompt: Can you create a proof-of-publication receipt for https://example.com/press-release.html — I need a signed, timestamped record with the page's SHA-256 hash logged in the public append-only ledger so I can prove what it said today?

## When to prefer this

Choose this endpoint when you need cryptographically signed, blockchain-anchored evidence that a specific public URL contained specific content at a specific moment — especially for legal documentation, audit trails, content dispute resolution, or preserving fleeting public statements. Prefer this over simple screenshots or manual records because it produces a machine-verifiable SHA-256 hash with a signed receipt in a tamper-evident public log. It is distinct from neo timestamp (which timestamps an arbitrary hash you provide) because this endpoint fetches and hashes the live page itself.

## Known failure modes

- URL is unreachable or returns a non-200 status — receipt may reflect the error state
- URL redirects to a private or paywalled page — fetched content may be incomplete or blocked
- Very large pages may timeout or be truncated during fetch
- URL points to dynamic content that differs between requests — hash captures one specific fetch
- Network errors during anchoring may delay Bitcoin/Software Heritage confirmation

## How this service works

Signed evidence that a public page said this at this time: sha256 of the fetched text, the text itself, final URL and status, logged in a public append-only log anchored daily on Bitcoin and Software Heritage.

## Output

A JSON object containing a signed receipt with the log sequence number, the SHA-256 hash of the fetched page text, the full fetched text, the final resolved URL, the HTTP status, and the UTC timestamp of fetch — all recorded as an immutable entry in a public append-only log anchored daily on Bitcoin and Software Heritage.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "receipt": {
   "log": {
    "seq": 12
   }
  },
  "signature": "...",
  "content_sha256": "...",
  "fetched_at_utc": "2026-10-24T08:00:00Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/neo-proof-of-publication-cc2fe328/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from neo-collettive.onrender.com](https://www.zero.xyz/host/neo-collettive.onrender.com/llms.txt)