# Notary Digital Signer MCP

> Notary Digital Signer MCP is a paid API for AI agents from api.m2mcent.com, paid per call via x402, $0.2/call, status unknown (last checked 2026-10-17).

Digitally signs and notarizes data or documents, producing a cryptographic attestation of authenticity and integrity.

## Facts

- Endpoint: POST https://api.m2mcent.com/notary-digital-signer-mcp/api/process?utm_source=zero.xyz
- Price: $0.2/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/notary-digital-signer-mcp-9faa4125
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TSDhoyn1JNSGNcD2Rdc_K

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 notary-digital-signer-mcp-9faa4125 -d '<json body>'
```

Example prompt: Can you digitally sign and notarize this document text for me so I have a cryptographic proof of its authenticity? Here's the content: 'This agreement between Alice and Bob dated June 1, 2025 confirms the transfer of 500 USDC.'

## When to prefer this

Choose this endpoint when you need a cryptographic, tamper-proof digital signature or notarization of arbitrary string data or document content — especially in agentic workflows requiring provenance, audit trails, or legally-relevant attestations. Prefer this over simple hashing when you need a trusted third-party signing authority rather than just a checksum.

## Known failure modes

- Empty or missing data field returns a validation error
- Malformed input payload causes a 400 Bad Request
- Service unavailability or timeout returns a 5xx error
- Insufficient payment or x402 payment failure blocks the request
- Excessively large data payloads may be rejected

## How this service works

The premier global index of 1,069 monetized MCP nodes across 205 specialized subdomains. Gasless USDC runtime settlements via x402 V2 Spec on Base L2. Save 95% token context.

## Output

Returns a cryptographic digital signature and/or notarized attestation for the submitted data, proving its integrity and authenticity at the time of signing. Typically includes the signature value, signing timestamp, and metadata about the signing authority.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "success": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/notary-digital-signer-mcp-9faa4125/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.m2mcent.com](https://www.zero.xyz/host/api.m2mcent.com/llms.txt)