# Tollex x402 Payment Requirements Validator

> Tollex x402 Payment Requirements Validator is a paid API for AI agents from api.tollex.org, paid per call via x402, $0.0079/call, status unknown (last checked 2026-10-11).

Validates whether an x402 payment requirements object from a merchant URL is well-formed, policy-compliant, and safe to pay before any funds are committed.

## Facts

- Endpoint: POST https://api.tollex.org/tools/x402_validate_requirements?utm_source=zero.xyz
- Price: $0.0079/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tollex-x402-payment-requirements-validator-0852bd5b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zEN_lYkxPMDcrbfFaDnDf

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 tollex-x402-payment-requirements-validator-0852bd5b -d '<json body>'
```

Example prompt: Before paying this API, check if the x402 payment requirements from https://merchant.example/v1/quote are valid and policy-safe — the requirements say asset USDC, payTo 0xABC…, amount 0.01, scheme exact, network base, maxTimeoutSeconds 30.

## When to prefer this

Use this endpoint when an AI agent has received x402 payment requirements from a merchant and needs to validate them against policy rules before committing any funds. This is the pre-payment safety gate in an x402-based autonomous purchasing flow — prefer it over proceeding directly to payment when you need to enforce spending policies, verify address formats, confirm network/asset compatibility, or audit suspicious merchant payment headers.

## Known failure modes

- Malformed URL or unreachable merchant endpoint returns validation error
- Payment requirements object missing required fields triggers schema validation failure
- Asset or network not supported by policy returns policy rejection
- Amount exceeds configured spending limit returns policy violation
- maxTimeoutSeconds outside acceptable range returns timeout policy error
- Invalid payTo address format returns address validation failure

## How this service works

Tollex lets software agents buy APIs and tools under rules you set: it finds a capability that fits, checks your policy before anything is signed, pays with x402 in USDC on Base or USDG on Robinhood Chain, reconciles uncertain payments and returns a signed receipt.

## Output

Returns a structured validation result indicating whether the x402 payment requirements are well-formed, policy-compliant, and safe to proceed with. May include field-level error details, policy violation reasons, and a signed receipt or authorization token if validation passes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "pattern": "^https?://",
   "examples": [
    "https://merchant.example/v1/quote"
   ],
   "maxLength": 2048
  },
  "requirements": {
   "type": "object",
   "properties": {
    "asset": {
     "type": "string"
    },
    "payTo": {
     "type": "string"
    },
    "amount": {
     "type": "string"
    },
    "scheme": {
     "type": "string"
    },
    "network": {
     "type": "string"
    },
    "maxTimeoutSeconds": {
     "type": "integer"
    }
   },
   "additionalProperties": true
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "tool": {
   "id": "x402_validate_requirements",
   "version": "1.0.0",
   "provider": "tollex.robinhood-chain"
  },
  "result": {
   "results": [
    {
     "ok": true,
     "amount": "7800",
     "issues": [],
     "scheme": "exact",
     "network": "eip155:8453"
    }
   ]
  },
  "evidence": [],
  "untrustedOutput": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tollex-x402-payment-requirements-validator-0852bd5b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.tollex.org](https://www.zero.xyz/host/api.tollex.org/llms.txt)