# Synthex Forge Receipt Mint (x402)

> Synthex Forge Receipt Mint (x402) is a paid API for AI agents from x402.synthexforge.com, paid per call via x402, $0.25/call, status unknown (last checked 2026-10-23).

Mints a cryptographically signed receipt artifact (Ed25519 + SHA-256) attesting a transaction or action, returning a verifiable on-chain-payment-gated attestation record.

## Facts

- Endpoint: POST https://x402.synthexforge.com/v1/receipts/mint?utm_source=zero.xyz
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthex-forge-receipt-mint-x402-9ef7803c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5PYab2_ho4bJaiTE5x3e2

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 synthex-forge-receipt-mint-x402-9ef7803c -d '<json body>'
```

Example prompt: Mint a signed tx-receipt for transaction hash 0xabc123def456 — the actor is did:ethr:0x789 and the action is 'token transfer approved by governance multisig'.

## When to prefer this

Choose this endpoint when you need a cryptographically signed, tamper-evident receipt or attestation for a specific transaction or agent action — especially in governance, compliance, or audit contexts that require Ed25519-signed artifacts with SHA-256 integrity. Prefer it over generic logging when verifiability and non-repudiation matter, and when paying per-call via atomic USDC on Base is acceptable.

## Known failure modes

- Missing required 'tx' field returns 400 Bad Request
- Missing required 'action' field returns 400 Bad Request
- Insufficient or missing x402 USDC payment on Base mainnet returns 402 Payment Required with payment-required envelope
- Invalid receipt_type enum value may return 422 Unprocessable Entity
- Network or signing service unavailability returns 503 Service Unavailable

## How this service works

Synthex Forge x402 Receive: 41 paid verification, attestation and governance endpoints (Ed25519 + SHA-256 signed artifacts) plus free verify/public-key/standard sibling routes. Paid routes answer HTTP 402 with an x402 v2 `payment-required` envelope (atomic USDC on Base mainnet, chain ID 8453). Free routes are declared with `security: []` per the x402scan discovery spec.

## Output

Returns a JSON object with an 'ok: true' confirmation indicating the signed receipt was successfully minted and stored. The receipt is an Ed25519 + SHA-256 signed artifact anchored to the provided transaction hash and actor identity.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tx": {
   "type": "string",
   "description": "The tx hash / action identifier being attested (required)."
  },
  "actor": {
   "type": "string",
   "description": "Optional DID / address of the acting party."
  },
  "action": {
   "type": "string",
   "description": "Human description of the transaction/action (required)."
  },
  "subject": {
   "type": "string",
   "description": "Optional subject the tx/action pertains to."
  },
  "metadata": {
   "type": "object",
   "description": "Optional structured metadata carried verbatim."
  },
  "receipt_type": {
   "type": "string",
   "description": "Typed receipt schema: 'tx-receipt' | 'action-receipt'."
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthex-forge-receipt-mint-x402-9ef7803c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.synthexforge.com](https://www.zero.xyz/host/x402.synthexforge.com/llms.txt)