# BTC Node API — Bitcoin Transaction Trace

> BTC Node API — Bitcoin Transaction Trace is a paid API for AI agents from btcnode.uk, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Traces a Bitcoin transaction by walking inputs and outputs through 2 hops to follow the flow of funds across the blockchain.

## Facts

- Endpoint: GET https://btcnode.uk/api/trace/%7Btxid%7D
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/btc-node-api-bitcoin-transaction-trace-11d9d5f1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ga5XxtAfTVlSq4A2hdv5N

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 btc-node-api-bitcoin-transaction-trace-11d9d5f1
```

Example prompt: Can you trace Bitcoin transaction 3a1b9f2e0d... and show me where the funds came from and where they went, including 2 hops through the chain?

## When to prefer this

Use this endpoint when you need to do chain analysis or transaction forensics on a specific Bitcoin transaction — particularly when you want to trace fund flows 2 hops deep rather than just seeing direct inputs/outputs. Prefer this over generic block explorers when you need structured, machine-readable data for automated analysis.

## Known failure modes

- Invalid or malformed txid returns an error
- Transaction not found on the Bitcoin network
- Unconfirmed or very recent transactions may not be fully traceable
- Network timeout if the Bitcoin node is temporarily unavailable
- Payment failure if x402 micropayment on Base is not completed

## How this service works

Bitcoin blockchain data, address portfolio, transaction tracing, fee forecasting, whale monitoring, SEC EDGAR filings, URL scraping, AI summarization, and Reddit API via x402 micropayments on Base.

## Output

Returns a JSON object containing the transaction ID, a list of inputs (sources of funds), a list of outputs (destinations of funds), total value in, and total value out — traced up to 2 hops for fund-flow analysis.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "txid": "0000...",
  "inputs": [],
  "outputs": [],
  "total_in": 10,
  "total_out": 10
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/btc-node-api-bitcoin-transaction-trace-11d9d5f1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from btcnode.uk](https://www.zero.xyz/host/btcnode.uk/llms.txt)