# Bitcoin Research Kit (BRK)

> Open-source Bitcoin on-chain analytics API. Thousands of metrics, block explorer, address index — all computed from a Bitcoin Core node, including the price.

Base URL: https://bitview.space

## API

Free, no auth required. JSON and CSV output. Mempool.space compatible for block/tx/address endpoints.

- [Interactive docs](https://bitview.space/api)
- [OpenAPI spec (compact, LLM-optimized)](https://bitview.space/api.json)
- [OpenAPI spec (full)](https://bitview.space/openapi.json)

## Discover

Search for metrics by keyword:

    GET /api/metrics/search?q={query}

Get metric info (available indexes, value type):

    GET /api/metric/{metric}

Browse all available metrics:

    GET /api/metrics/list

List available indexes (date, height, etc.):

    GET /api/metrics/indexes

Browse the full metric catalog as a tree:

    GET /api/metrics

## Query

Get a metric by name and index:

    GET /api/metric/{metric}/{index}
    GET /api/metric/{metric}/{index}?start=2025-01-01&end=2025-06-01
    GET /api/metric/{metric}/{index}?start=-30

Get just the data array (no wrapper):

    GET /api/metric/{metric}/{index}/data

Get the latest value:

    GET /api/metric/{metric}/{index}/latest

Get the data length or version:

    GET /api/metric/{metric}/{index}/len
    GET /api/metric/{metric}/{index}/version

Example — last 30 days of Bitcoin closing price:

    GET /api/metric/price/day?start=-30

Fetch multiple metrics at once:

    GET /api/metrics/bulk?index={index}&metrics={metric1},{metric2}

Range parameters `start` and `end` accept integers, dates (YYYY-MM-DD), or ISO 8601 timestamps. See the [OpenAPI spec](https://bitview.space/api.json) for full details.

## Block Explorer

    GET /api/block-height/{height}
    GET /api/block/{hash}
    GET /api/tx/{txid}
    GET /api/address/{address}

## Mempool

    GET /api/mempool/price
    GET /api/mempool/info
    GET /api/v1/fees/recommended

## Client Libraries

- JavaScript: https://www.npmjs.com/package/brk-client
- Python: https://pypi.org/project/brk-client/
- Rust: https://crates.io/crates/brk_client

## Metric Categories

Market, supply, mining, network activity, UTXO age bands, cointime economics, holder cohorts, cost basis distributions, and more. Use the discovery endpoints above to explore.

## Source

- GitHub: https://github.com/bitcoinresearchkit/brk
- License: MIT