# x402 Crypto Chain Check API

> x402 Crypto Chain Check API is a paid API for AI agents from x402-crypto.vercel.app, paid per call via x402, $0.144192/call, status unknown (last checked 2026-09-15).

Looks up blockchain chain information (metadata, IDs, status) by chain name or chain ID, accessed via x402 micropayment

## Facts

- Endpoint: POST https://x402-crypto.vercel.app/api/chaincheck/%7Bpath%7D
- Price: $0.144192/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-crypto-chain-check-api-633ac6b4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zMJzJDoht6jgDCxrmMuc_

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-crypto-chain-check-api-633ac6b4 -d '<json body>'
```

Example prompt: What is the chain ID for Polygon — look it up using the crypto chain check service?

## When to prefer this

Use this endpoint when you need quick, programmatic lookup of blockchain chain identifiers or metadata by name or chain ID, especially in a Web3 agent context where x402 micropayment infrastructure is already in use. Prefer this over free alternatives when you need pay-per-call flexibility without API key management.

## Known failure modes

- Unknown or unsupported chain name/ID returns an error or empty data
- Malformed query input may result in a 400 bad request
- Payment failure via x402 micropayment protocol blocks the call
- Network timeout or upstream API unavailability returns a 5xx error
- Ambiguous chain name (e.g. testnets vs mainnets) may return unexpected results

## How this service works

Paid cryptocurrency API endpoints via x402 micropayments

## Output

Returns a data object containing chain metadata such as chain ID, network name, and related details for the queried blockchain chain name or ID. The exact structure may vary but includes identifying and configuration information about the requested chain.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "query": {
   "type": "string",
   "description": "Chain name or ID to look up"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "type": "object",
   "description": "Response payload from the upstream API (structure varies by endpoint)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-crypto-chain-check-api-633ac6b4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-crypto.vercel.app](https://www.zero.xyz/host/x402-crypto.vercel.app/llms.txt)