# Delx Commerce — Rate Limit Window Check

> Delx Commerce — Rate Limit Window Check is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Checks whether a requested number of API calls falls within the current rate limit quota window, returning deficit, quota status, and seconds until reset.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/rate-limit-window-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-rate-limit-window-check-c6dc327e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YBya2ALPyoNBU-mGkY9iK

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 delx-commerce-rate-limit-window-check-c6dc327e -d '<json body>'
```

Example prompt: I have 45 calls remaining in my current rate limit window that resets at epoch 1720000060, and it's currently epoch 1720000000 — can you check if I can safely make 30 more requests right now?

## When to prefer this

Choose this endpoint when you need a cryptographically evidenced, pay-per-result rate limit window check with no signup or persistent state — particularly useful for AI agents that need verifiable proof of computation (SHA-256 input hash, zero external calls, no data retained) as part of an auditable workflow. Prefer this over building your own arithmetic when you need tamper-evident, on-chain-payment-gated quota validation on Base or Solana.

## Known failure modes

- Missing required fields (now_epoch, remaining, requested, reset_epoch) result in a validation error
- Non-integer values for epoch or count fields cause schema rejection
- reset_epoch earlier than now_epoch may produce undefined or negative reset_in_seconds
- Payment failure via x402 protocol blocks the request before computation
- Malformed JSON body returns a 400-level error

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object with: 'within_quota' (boolean indicating if the request fits within the limit), 'deficit' (number of calls over quota, 0 if within), 'reset_in_seconds' (time until quota window resets), plus an evidence block with input SHA-256 hash, retained=false flag, and external_calls=0 confirming the computation is purely in-memory with no data retention.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "now_epoch": {
   "type": "integer",
   "description": "Now Epoch supplied to Rate Limit Window Check; used only for this bounded calculation and processed in memory without retention."
  },
  "remaining": {
   "type": "integer",
   "description": "Remaining supplied to Rate Limit Window Check; used only for this bounded calculation and processed in memory without retention."
  },
  "requested": {
   "type": "integer",
   "description": "Requested supplied to Rate Limit Window Check; used only for this bounded calculation and processed in memory without retention."
  },
  "reset_epoch": {
   "type": "integer",
   "description": "Reset Epoch supplied to Rate Limit Window Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "deficit": 0,
   "within_quota": true,
   "reset_in_seconds": 60
  },
  "schema": "delx/util-rate-limit-window-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "e12bef43e7d52fe13e28d9a9200483561a533bc0eed1e48f817303d9e23b66ee",
   "external_calls": 0
  },
  "operation": "web_reliability:rate_limit_window_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-rate-limit-window-check-c6dc327e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)