# Bitcoin Address Balance & UTXO Lookup

> Bitcoin Address Balance & UTXO Lookup is a paid API for AI agents from api.agentstools.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns confirmed and mempool balance, funded/spent totals, transaction count, and a capped UTXO set for a Bitcoin address (legacy, P2SH, or bech32).

## Facts

- Endpoint: GET https://api.agentstools.dev/btc/address
- 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/bitcoin-address-balance-utxo-lookup-eebe5fd0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_c8kS4nOQgoTaT-hEEu5xf

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 bitcoin-address-balance-utxo-lookup-eebe5fd0
```

Example prompt: What's the current confirmed and mempool balance for the Bitcoin address bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh, and how many UTXOs does it have?

## When to prefer this

Use this endpoint when you need a quick, combined view of a Bitcoin address's balance (both confirmed and mempool), funding history, and available UTXOs without building or querying your own Bitcoin node. Ideal for agents checking wallet balances, verifying incoming payments, or inspecting UTXO availability before constructing transactions. Supports all three major address formats (legacy, P2SH, bech32).

## Known failure modes

- Invalid or malformed Bitcoin address returns a 400 error
- Address not found on mainnet (never used) may return zero balances with empty UTXO set
- Testnet addresses will not be recognized (mainnet only)
- UTXO set is capped — addresses with very large UTXO sets will receive a truncated list
- Network or upstream node unavailability may return 5xx errors
- Missing required 'address' query parameter returns a 400 validation error

## How this service works

Balance and unspent outputs for a Bitcoin address. Returns confirmed and mempool balance, funded and spent totals, transaction count and a capped UTXO set for a legacy, p2sh or bech32 address. Informational, not advice.

## Output

A JSON object containing the confirmed balance, mempool (unconfirmed) balance, total funded amount, total spent amount, transaction count, and a capped list of unspent transaction outputs (UTXOs) for the queried Bitcoin address.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "Bitcoin mainnet address (legacy 1.., p2sh 3.., or bech32 bc1..)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-address-balance-utxo-lookup-eebe5fd0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agentstools.dev](https://www.zero.xyz/host/api.agentstools.dev/llms.txt)