# Genesis402 Proof Receipt Verifier

> Genesis402 Proof Receipt Verifier is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-29).

Verifies a genesis402 proof receipt by checking its Ed25519 signature and hash-chain position within the UnyKorn Operator Network

## Facts

- Endpoint: POST https://twin.unykorn.org/verify-receipt?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/genesis402-proof-receipt-verifier-df9a4c3e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_auADYAlbif9AW1kcIkAU3

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 genesis402-proof-receipt-verifier-df9a4c3e -d '<json body>'
```

Example prompt: Can you verify genesis402 receipt ID 'rK3xZ9mQpL7vB2wY' to confirm its signature is valid and check where it sits in the hash chain?

## When to prefer this

Choose this endpoint when you need to cryptographically validate a genesis402-format proof receipt, specifically checking Ed25519 signature authenticity and hash-chain sequence position within the UnyKorn Operator Network. Prefer it over generic hash-check tools when you need structured truth labels (ATTESTED, VERIFIED) and issuer key metadata from the genesis402 receipt schema.

## Known failure modes

- Receipt ID not found — found: false returned
- Invalid receiptId format (must match ^[A-Za-z0-9_\-]{4,80}$) — request rejected
- Signature verification failure — verdict: invalid, signature_valid: false
- Network or upstream node unavailability — HTTP 5xx error
- Malformed or tampered receipt data causing hash mismatch

## How this service works

Verify a genesis402 proof receipt — signature and hash-chain position — Genesis402 / UnyKorn Operator Network

## Output

Returns a JSON object with: a boolean verdict ('valid'/'invalid'), signature_valid flag, the receipt's sequence number and SHA-256 hash, truth labels (e.g. ATTESTED, VERIFIED), the issuer's algorithm and key ID, chain anchor status, total receipts on chain, and the receipt version string.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "receiptId": {
     "type": "string",
     "pattern": "^[A-Za-z0-9_\\-]{4,80}$"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "verify-receipt",
  "chain": {
   "anchor": "UNANCHORED",
   "receipts_on_chain": 3
  },
  "found": true,
  "issuer": {
   "alg": "ed25519",
   "keyId": "g402-key-<16hex>"
  },
  "receipt": {
   "seq": 3,
   "sha256": "<64hex>",
   "truthLabels": [
    "ATTESTED",
    "VERIFIED"
   ],
   "receiptVersion": "genesis402-receipt-v1"
  },
  "verdict": "valid",
  "signature_valid": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/genesis402-proof-receipt-verifier-df9a4c3e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)