# Agent Transaction Trust - x402 Authorization

> Agent Transaction Trust - x402 Authorization is a paid API for AI agents from json-repair-api-9ybv.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-21).

Validates and authorizes an autonomous agent's x402 merchant payment challenge against an operator-issued policy before the transaction is allowed to proceed.

## Facts

- Endpoint: POST https://json-repair-api-9ybv.onrender.com/trust/x402/authorize?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-transaction-trust-x402-authorization-2f51f3b0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DPnjE7drmnWysIHejEJFd

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 agent-transaction-trust-x402-authorization-2f51f3b0 -d '<json body>'
```

Example prompt: Before my agent pays this merchant, check the x402 PAYMENT-REQUIRED payload against my operator policy token — the payer address is 0xABC123, merchant ID is 'merchant-42', and the purchase category is 'software-subscription'.

## When to prefer this

Use this endpoint when an autonomous agent needs to validate an incoming x402 PAYMENT-REQUIRED merchant challenge against an operator-issued policy credential before committing funds. It is specifically designed for the x402 protocol flow where the payment settles only on successful authorization, making it suitable for agentic purchase gating, spend-policy enforcement, and multi-agent fleet spend controls. Prefer this over generic auth endpoints when you need policy-token-based authorization tightly integrated with x402 merchant challenge verification.

## Known failure modes

- Invalid or expired policy token — returns authorization denied with policy validation error
- Merchant ID not recognized or not covered by policy — returns policy mismatch error
- Purchase category not permitted under the operator mandate — returns category denial
- Malformed x402 payment-required payload — returns parsing or schema validation error
- Payer EVM address does not match the policy credential — returns identity mismatch error
- Network timeout or upstream handler failure — payment does not settle, request may be retried
- Invalid nonce or replay detected — returns nonce validation failure

## How this service works

Authorize an AI-agent payment under a predelegated spending policy before funds move. Verify that the merchant's exact x402 challenge, amount, payer, payee and HTTP request are within authority already delegated to the agent. No synchronous human approval is required when the predelegated policy permits the purchase. Includes signed authorization plus post-payment on-chain settlement verification and receipt; this is not merchant reputation scoring.

## Output

Returns an authorization decision indicating whether the agent's intended payment satisfies the operator-issued policy. On success, the trust check confirms the x402 merchant challenge is valid and the transaction is approved; on failure, it returns a denial with policy violation details. The $0.001 USDC fee only settles upon a successful authorization handler response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "nonce": {
   "type": "string"
  },
  "payer": {
   "type": "string",
   "description": "EVM address that would sign/pay the merchant transaction."
  },
  "request": {
   "type": "object",
   "required": [
    "method",
    "url"
   ],
   "properties": {
    "url": {
     "type": "string"
    },
    "body": {},
    "method": {
     "type": "string"
    }
   },
   "description": "Exact HTTP request the agent intends to make after authorization."
  },
  "category": {
   "type": "string",
   "description": "Purchase category used by the operator policy."
  },
  "merchant_id": {
   "type": "string",
   "description": "Stable merchant identifier used by the operator policy."
  },
  "ap2_evidence": {
   "type": "object",
   "description": "Optional AP2 v0.2 mandate evidence and challenge token for native verification."
  },
  "policy_token": {
   "type": "string",
   "description": "Operator-issued signed policy credential for the buying agent."
  },
  "payment_required": {
   "oneOf": [
    {
     "type": "object"
    },
    {
     "type": "string"
    }
   ],
   "description": "The merchant's real x402 PAYMENT-REQUIRED payload, as decoded JSON or its encoded string."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-transaction-trust-x402-authorization-2f51f3b0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from json-repair-api-9ybv.onrender.com](https://www.zero.xyz/host/json-repair-api-9ybv.onrender.com/llms.txt)