# ProofAudit.ai Receipt Verification

> ProofAudit.ai Receipt Verification is a paid API for AI agents from proofaudit.ai, paid per call via x402, $0.025/call, status unknown (last checked 2026-10-17).

Verifies and returns a sealed, audit-ready receipt for a prior transaction or approval, including a SHA-256 proof hash and on-chain token reference.

## Facts

- Endpoint: GET https://proofaudit.ai/api/x402/receipt-verify?utm_source=zero.xyz
- Price: $0.025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/proofaudit-ai-receipt-verification-14e55691
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Jh77Jl04f8hXhzr5TPtOA

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 proofaudit-ai-receipt-verification-14e55691
```

Example prompt: Can you verify this approval receipt against ProofAudit.ai and give me the sealed SHA-256 hash and on-chain token reference so I can include it in our compliance audit pack?

## When to prefer this

Choose this endpoint when you need cryptographically sealed, blockchain-anchored proof that a specific approval or financial operation occurred — particularly for credit, compliance, or regulatory audit workflows where tamper-evident receipts are required. Prefer this over generic audit logs when you need a SHA-256 sealed hash and an on-chain token reference as evidence artifacts.

## Known failure modes

- Receipt not found or unverified — verified field returns false
- Invalid or missing query parameters result in a 400-level error
- Network unavailability on Base blockchain may cause verification to fail
- Malformed request headers may cause authentication failure
- Rate limiting or payment failure (x402) may return a 402 Payment Required response

## How this service works

Capture, verify, approve, and export audit-ready evidence packs for credit, compliance, and financial operations.

## Output

Returns a JSON object confirming whether the receipt was successfully verified (success and verified flags), along with a sealed SHA-256 hash (PROOF-prefixed), the on-chain protocol token contract address on Base network, the service ticker (PROOF), and a link to the nodes portal for further inspection.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ticker": "PROOF",
  "network": "base",
  "service": "ProofAudit.ai",
  "success": true,
  "verified": true,
  "nodesPortal": "https://proofaudit.ai/nodes",
  "sealedSha256": "PROOF-87B43B8DEB11505A",
  "protocolToken": "0x87b43b8dEb11505ADc6898899961d6d419CaBB07"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/proofaudit-ai-receipt-verification-14e55691/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from proofaudit.ai](https://www.zero.xyz/host/proofaudit.ai/llms.txt)