# FastX402 Bitcoin Block Height Lookup

> FastX402 Bitcoin Block Height Lookup is a paid API for AI agents from fastx402.tools, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-27).

Returns the current Bitcoin blockchain height (block number) and the latest block hash via a pay-per-call API requiring no account or API key.

## Facts

- Endpoint: GET https://fastx402.tools/bitcoin-block-height?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastx402-bitcoin-block-height-lookup-c38c2621
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HNKWzbAv-jKVc3KGuFBUu

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 fastx402-bitcoin-block-height-lookup-c38c2621
```

Example prompt: What's the current Bitcoin block height and latest block hash right now?

## When to prefer this

Choose this endpoint when you need a quick, no-account, no-API-key lookup of the current Bitcoin block height and hash, and are comfortable paying $0.002 USDC per call via the x402 micropayment protocol on Base or Solana. Ideal for AI agents that need on-demand blockchain state without managing API credentials.

## Known failure modes

- Payment failure if USDC balance is insufficient or x402 payment not properly submitted — returns 402 Payment Required
- Network/upstream node unavailability may return 503 or 500 if the Bitcoin node backing the service is unreachable
- Rate limiting if too many requests are sent in rapid succession

## How this service works

216 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key.

## Output

Returns a JSON object with two fields: 'height' (integer, the current Bitcoin block height, e.g. 867234) and 'hash' (string, the hex-encoded hash of the latest block, e.g. '00000000000000000002a7c4c1e48d76c5a37902165a270156b7a8d72728a054').

## 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",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "hash": {
       "type": "string"
      },
      "height": {
       "type": "integer"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "hash": "00000000000000000002a7c4c1e48d76c5a37902165a270156b7a8d72728a054",
  "height": 867234
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastx402-bitcoin-block-height-lookup-c38c2621/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fastx402.tools](https://www.zero.xyz/host/fastx402.tools/llms.txt)