# Penny Engine — AI Agent Outcome Guard (Ping)

> Penny Engine — AI Agent Outcome Guard (Ping) is a paid API for AI agents from penny-paid-batch-production.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-23).

Returns a deterministic service health ping with timestamp, network identity, and settlement-protection status via x402 payment on Base.

## Facts

- Endpoint: GET https://penny-paid-batch-production.up.railway.app/ping?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/penny-engine-ai-agent-outcome-guard-ping-ff691f22
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5Nt4pnXLl4kk3ZqRU-I1p

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 penny-engine-ai-agent-outcome-guard-ping-ff691f22
```

Example prompt: Ping the Penny Engine diagnostic service and confirm it's live on Base — I need to see that settlementProtected is true and get the current timestamp and requestId back.

## When to prefer this

Choose this endpoint when you need a cheap ($0.001 USDC), machine-readable liveness check for the Penny Engine x402 infrastructure specifically, and want confirmation that the settlement-protection layer on Base is active. Prefer it over generic HTTP health checks when you need a payment-gated proof-of-life with a network identity assertion and requestId for audit trails.

## Known failure modes

- Payment not included or malformed x402 header — returns 402 Payment Required
- Service temporarily unavailable on Railway deployment — returns 500 or connection timeout
- Malformed request — returns 400 Bad Request
- Base network congestion causing settlement confirmation delay

## How this service works

Machine-to-machine result validation via x402. One structured call, deterministic PASS or FAIL and SHA-256 fingerprint, $0.001 USDC on Base.

## Output

Returns a JSON object with: ok (boolean indicating service health), time (ISO-8601 timestamp), network (EIP-155 chain identifier, e.g. eip155:8453 for Base), service name string ('penny-x402-diagnostic'), a unique requestId, and a settlementProtected boolean confirming x402 payment-rail integrity.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "time": "2026-10-17T00:00:00.000Z",
  "network": "eip155:8453",
  "service": "penny-x402-diagnostic",
  "requestId": "example-id",
  "settlementProtected": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/penny-engine-ai-agent-outcome-guard-ping-ff691f22/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from penny-paid-batch-production.up.railway.app](https://www.zero.xyz/host/penny-paid-batch-production.up.railway.app/llms.txt)