# Relaystation PDF Signature Verifier

> Relaystation PDF Signature Verifier is a paid API for AI agents from api.relaystation.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Verifies a PDF's digital signatures with structural and digest checks, returning results as JSON

## Facts

- Endpoint: POST https://api.relaystation.ai/v1/pdf/verify-signatures
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/relaystation-pdf-signature-verifier-dc6cdf5e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__5tdRH58LlcHYX96Cm_Wi

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 relaystation-pdf-signature-verifier-dc6cdf5e -d '<json body>'
```

Example prompt: Can you check whether the digital signatures on this PDF contract are valid and intact — run both structural and digest checks and give me the full results?

## When to prefer this

Choose this endpoint when you need programmatic, per-call PDF signature verification at very low cost ($0.001/call) without managing your own cryptographic infrastructure. Ideal for agents that need to validate signed documents as part of onboarding, compliance, or contract workflows. Prefer this over general-purpose document APIs when the specific requirement is digital signature integrity checking with structured JSON output.

## Known failure modes

- PDF has no digital signatures — returns empty or zero-signature result
- PDF is corrupted or malformed — parsing error returned
- URL to PDF is inaccessible or returns non-PDF content
- Signature uses an unsupported or proprietary signature format
- Certificate chain cannot be resolved — indeterminate validity
- Payment not included or insufficient — x402 payment required error
- Request times out for very large PDFs

## How this service works

$0.001/call. Verify a PDF's digital signatures — structural + digest checks, results as JSON. 1¢ x402 min; remainder auto-credits — relaystation.ai/penny

## Output

A JSON object containing the results of digital signature verification for the submitted PDF, including structural validity checks, cryptographic digest verification, signer identity information, certificate status, and an overall validity verdict for each signature found in the document.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "file": {
       "type": "object",
       "description": "cputools input-source: { inline: <base64 ≤ 4 MiB> } or { inputKey: <scratch key from /v1/cputools/upload-url, ≤ 50 MB> }."
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "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/relaystation-pdf-signature-verifier-dc6cdf5e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.relaystation.ai](https://www.zero.xyz/host/api.relaystation.ai/llms.txt)