# Foundry Agent Services — x402 Preflight Checker

> Foundry Agent Services — x402 Preflight Checker is a paid API for AI agents from foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Checks whether a Foundry pay-per-request endpoint is reachable and returns its payment challenge details before committing funds

## Facts

- Endpoint: POST https://foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/v2/x402/preflight
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/foundry-agent-services-x402-preflight-checker-686b96bf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OgdAtsb3gyjnVZg0B-viP

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 foundry-agent-services-x402-preflight-checker-686b96bf -d '<json body>'
```

Example prompt: Before I pay, can you preflight check the Foundry CSV profile endpoint at https://foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/v1/csv/profile using a POST method to confirm it's reachable and show me the USDC payment challenge details?

## When to prefer this

Use this endpoint when you need to inspect a Foundry x402-gated route's payment requirements before committing USDC. It is the correct preflight step in any agentic workflow that uses Foundry pay-per-request data tools (CSV validation, DNS evidence, weather, earthquake, vehicle, company, or study records). Prefer this over direct calls when you want to confirm reachability, validate the payment amount, or retrieve the pay-to address programmatically without spending funds.

## Known failure modes

- Target URL is unreachable — reachable field returns false
- Malformed target URL — request rejected with validation error
- Target endpoint does not return a 402 challenge — challenge_header_present is false
- Network timeout reaching the target worker
- Invalid method enum value — schema validation error

## How this service works

Pay-per-request evidence and data tools: CSV validation and reconciliation, DNS/email configuration evidence, and bounded official weather, earthquake, vehicle, company and study records. Exact USDC prices, explicit JSON contracts and source provenance. No mailbox, ownership, medical or safety guarantees.

## Output

A JSON object containing the target URL, HTTP method, HTTP status (typically 402), a payment challenge with accepted asset details (token address, USDC amount, pay-to address, payment scheme, network), reachability boolean, whether payment was sent, whether the challenge header was present, and an observed_at timestamp. Also includes any warnings about missing input or output schemas.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "maxLength": 2048
  },
  "body": {
   "type": "object",
   "propertyNames": {
    "type": "string"
   },
   "additionalProperties": {}
  },
  "method": {
   "enum": [
    "GET",
    "POST"
   ],
   "type": "string",
   "default": "GET"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "route": "preflight",
  "result": {
   "url": "https://foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/v1/csv/profile",
   "method": "POST",
   "status": 402,
   "challenge": {
    "accepts": [
     {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "amount": "10000",
      "pay_to": "0x25e8245f07d5e4873987293dad666afbe56a9608",
      "scheme": "exact",
      "network": "eip155:8453"
     }
    ],
    "version": 2,
    "resource": null,
    "warnings": [
     "INPUT_SCHEMA_MISSING",
     "OUTPUT_SCHEMA_MISSING"
    ],
    "declared_input": null,
    "declared_output": null
   },
   "reachable": true,
   "observed_at": "2026-09-06T00:00:00Z",
   "payment_sent": false,
   "challenge_header_present": true
  },
  "observed_at": "2026-09-06T00:00:00Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/foundry-agent-services-x402-preflight-checker-686b96bf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev](https://www.zero.xyz/host/foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/llms.txt)