# Bitcoin UTXO Lookup by Address

> Bitcoin UTXO Lookup by Address is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-01).

Returns all spendable unspent transaction outputs (UTXOs) for a given Bitcoin address

## Facts

- Endpoint: POST https://twin.unykorn.org/btc-utxos?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-utxo-lookup-by-address-90fce880
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Qs5Tk6msTeWkpaZAagMmP

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-utxo-lookup-by-address-90fce880 -d '<json body>'
```

Example prompt: What are all the spendable UTXOs for Bitcoin address bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh? I need the full list of unspent outputs before I build a transaction.

## When to prefer this

Choose this endpoint when you need a complete, current list of all spendable UTXOs for a Bitcoin address — particularly useful before constructing a raw transaction, performing coin selection, or auditing a wallet's spendable balance. It is part of the UnyKorn operator network alongside complementary Bitcoin utilities (fee rates, block height, script identification), making it a good fit when you are already using that network for other Bitcoin on-chain queries.

## Known failure modes

- Invalid Bitcoin address format returns an error response
- Address with no UTXOs returns an empty list
- Network or node connectivity issues may return a timeout or service error
- Malformed request body (missing params.address) returns a validation error
- Payment failure via x402 protocol prevents the call from being processed

## How this service works

Every spendable UTXO at a Bitcoin address — Genesis402 / UnyKorn Operator Network

## Output

A JSON object with ok:true, a type of 'btc-utxos', a receipt object containing the transaction hash, USD amount charged, and receipt ID, plus a generated_at ISO8601 timestamp. The core payload lists all spendable UTXOs associated with the queried Bitcoin address, enabling coin selection, balance calculation, or transaction construction.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "address": {
     "type": "string"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "btc-utxos",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.005,
   "receipt_id": "g402-<16hex>"
  },
  "generated_at": "<iso8601>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-utxo-lookup-by-address-90fce880/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)