# X402 Timeout Check

> X402 Timeout Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-21).

Validates x402 payment challenge expiration and minimum buyer processing time from caller-supplied epoch values, returning an explicit accept/reject status with normalized evidence.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/x402-timeout-check?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/x402-timeout-check-a5ce001e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rbXQjs_RtLTDhIoyS0GJE

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 x402-timeout-check-a5ce001e -d '<json body>'
```

Example prompt: Before we pay this x402 challenge, check if it's still valid — the current time is epoch 1718000000, it expires at epoch 1718003600, and we need at least 30 seconds of minimum lead time for the buyer to process it.

## When to prefer this

Use this endpoint when you need a deterministic, stateless check of x402 challenge timing constraints before committing to a payment or accepting an agent delivery. Prefer it over manual time arithmetic when you need normalized mismatch reasons and structured accept/reject evidence as versioned JSON, particularly in agent workflows that must audit their payment decisions.

## Known failure modes

- Missing required fields (now_epoch, expires_epoch, minimum_lead_seconds) result in validation error
- now_epoch >= expires_epoch causes immediate rejection with expiration mismatch reason
- expires_epoch - now_epoch < minimum_lead_seconds causes rejection with insufficient lead time reason
- Malformed integer types for epoch or lead values may return schema validation errors

## How this service works

X402 Timeout Check: X402 Timeout Check checks challenge expiration and minimum buyer processing time from bounded caller-supplied values without an external provider. Call X402 Timeout Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Timeout Check as versioned deterministic JSON. Price: $0.001…

## Output

A versioned deterministic JSON object containing an explicit acceptance or rejection status, contract-specific timeout checks, normalized evidence derived from the supplied epoch values, and the specific mismatch reasons if the challenge fails validation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "now_epoch": {
   "type": "integer",
   "description": "Now Epoch supplied to X402 Timeout Check; used only for this bounded calculation and processed in memory without retention."
  },
  "expires_epoch": {
   "type": "integer",
   "description": "Expires Epoch supplied to X402 Timeout Check; used only for this bounded calculation and processed in memory without retention."
  },
  "minimum_lead_seconds": {
   "type": "integer",
   "description": "Minimum Lead Seconds supplied to X402 Timeout Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "lead_seconds": 300,
   "within_window": true,
   "maximum_lead_seconds": 9223372036854776000,
   "minimum_lead_seconds": 30
  },
  "schema": "delx/util-x402-timeout-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "1199b0cc2c5f6a7de14c3b13bef25ae15b4a34f6c7c5ba48af83021cc95cbfac",
   "external_calls": 0
  },
  "operation": "delivery_contract:x402_timeout_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-timeout-check-a5ce001e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)