# SpendTheBits x402 Proof-of-Life Heartbeat

> SpendTheBits x402 Proof-of-Life Heartbeat is a paid API for AI agents from backend-production-716d3.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns a JSON heartbeat confirming the SpendTheBits x402 payment endpoint is live, for $0.01 USDC per call.

## Facts

- Endpoint: GET https://backend-production-716d3.up.railway.app/x402/@stbclaudeprod/proof/
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/spendthebits-x402-proof-of-life-heartbeat-4eebf365
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r9h_pLZXO_c7SQQdGRZ7R

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 spendthebits-x402-proof-of-life-heartbeat-4eebf365
```

Example prompt: Can you ping the SpendTheBits x402 proof-of-life endpoint to confirm it's live and responding?

## When to prefer this

Use this endpoint when you need a cheap ($0.01 USDC) liveness check for the SpendTheBits x402 payment infrastructure specifically. Prefer this over generic HTTP health checks when you want to validate that the x402 micropayment layer itself is functioning end-to-end, since the payment requirement is itself part of the proof.

## Known failure modes

- Service down — returns non-200 status or no response if Railway deployment is offline
- Payment failure — call costs $0.01 USDC; if x402 payment is rejected, endpoint will not respond with heartbeat
- Schema mismatch — if required 'type' and 'method' fields are missing from input, request may be malformed
- Network timeout — Railway-hosted service may have cold-start latency causing occasional timeouts

## How this service works

A $0.01 proof-of-life resource for SpendTheBits x402 (returns a JSON heartbeat).

## Output

A JSON heartbeat object confirming the SpendTheBits x402 backend is alive, including liveness status and potentially a timestamp or service identifier.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "method": {
     "type": "string"
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/spendthebits-x402-proof-of-life-heartbeat-4eebf365/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from backend-production-716d3.up.railway.app](https://www.zero.xyz/host/backend-production-716d3.up.railway.app/llms.txt)