# Blockchain.com

Blockchain.com exchange historical data for **all its currency pairs** is available since **2023-02-23**.

{% embed url="<https://api.tardis.dev/v1/exchanges/blockchain-com>" %}
See Blockchain.com exchange historical data coverage: available symbols, channels, date ranges and incidents
{% endembed %}

### Downloadable **CSV** files

Historical CSV datasets for the first day of each month are **available to download without API key**. See [downloadable CSV files documentation](https://docs.tardis.dev/downloadable-csv-files/overview).

| data type             | symbol  | date       |                                                                                                                |
| --------------------- | ------- | ---------- | -------------------------------------------------------------------------------------------------------------- |
| incremental\_book\_L2 | BTC-USD | 2023-03-01 | [Download sample](https://datasets.tardis.dev/v1/blockchain-com/incremental_book_L2/2023/03/01/BTC-USD.csv.gz) |
| trades                | BTC-USD | 2023-03-01 | [Download sample](https://datasets.tardis.dev/v1/blockchain-com/trades/2023/03/01/BTC-USD.csv.gz)              |
| quotes                | BTC-USD | 2023-03-01 | [Download sample](https://datasets.tardis.dev/v1/blockchain-com/quotes/2023/03/01/BTC-USD.csv.gz)              |

### API Access and data format

Historical data format is the same as provided by real-time Blockchain.com Exchange WebSocket **Market Data API v1** (<https://exchange.blockchain.com/api/#websocket-api>) with addition of local timestamps. If you'd like to work with **normalized data format** instead (same format for each exchange) see [downloadable CSV files](https://docs.tardis.dev/downloadable-csv-files/overview) or official [client libs](https://docs.tardis.dev/api/quickstart) that can perform data normalization client-side.

{% tabs %}
{% tab title="Python" %}

```python
# pip install tardis-dev
import asyncio
from tardis_dev import Channel, replay

async def main():
    async for local_timestamp, message in replay(
        exchange="blockchain-com",
        from_date="2023-03-01",
        to_date="2023-03-02",
        filters=[Channel(name="l2", symbols=["BTC-USD"])],
        api_key="YOUR_API_KEY",
    ):
        # messages as provided by Blockchain.com exchange real-time stream
        print(message)

asyncio.run(main())
```

See [Python client docs](https://docs.tardis.dev/python-client/quickstart).
{% endtab %}

{% tab title="Node.js" %}

```javascript
// npm install tardis-dev
import { replay } from 'tardis-dev';

const messages = replay({
  exchange: 'blockchain-com',
  from: '2023-03-01',
  to: '2023-03-02',
  filters: [{ channel: 'l2', symbols: ['BTC-USD'] }],
  apiKey: 'YOUR_API_KEY'
});

// messages as provided by Blockchain.com exchange real-time stream
for await (const { localTimestamp, message } of messages) {
  console.log(localTimestamp, message);
}
```

See [Node.js client docs](https://docs.tardis.dev/node-client/quickstart).
{% endtab %}

{% tab title="cURL & HTTP API" %}

```bash
curl --compressed -g 'https://api.tardis.dev/v1/data-feeds/blockchain-com?from=2023-03-01&filters=[{"channel":"l2","symbols":["BTC-USD"]}]&offset=0'
```

{% embed url="<https://api.tardis.dev/v1/data-feeds/blockchain-com?from=2023-03-01&filters=[{%22channel%22:%22l2%22,%22symbols%22:[%22BTC-USD%22]}]&offset=0>" %}
Example API response for Blockchain.com exchange historical market data request
{% endembed %}

See [HTTP API docs](https://docs.tardis.dev/api/http-api-reference).
{% endtab %}

{% tab title="cURL & tardis-machine" %}

```bash
curl -g 'localhost:8000/replay?options={"exchange":"blockchain-com","filters":[{"channel":"l2","symbols":["BTC-USD"]}],"from":"2023-03-01","to":"2023-03-02"}'
```

[Tardis-machine](https://docs.tardis.dev/tardis-machine/quickstart) is a locally runnable server that exposes API allowing efficiently requesting historical market data for whole time periods in contrast to [HTTP API](https://docs.tardis.dev/api/http-api-reference) that provides data only in minute by minute slices.

See [tardis-machine](https://docs.tardis.dev/tardis-machine/quickstart) docs.
{% endtab %}
{% endtabs %}

### Captured real-time channels

{% embed url="<https://exchange.blockchain.com/api/#websocket-api>" %}
See Blockchain.com exchange docs providing documentation for each captured channel's format
{% endembed %}

{% hint style="info" %}
Click any channel below to see [HTTP API](https://docs.tardis.dev/api/http-api-reference#data-feeds-exchange) response with historical data recorded for it.
{% endhint %}

* [trades](https://api.tardis.dev/v1/data-feeds/blockchain-com?from=2025-01-01\&filters=\[{%22channel%22:%22trades%22}]) Public trade executions stream
* [l2](https://api.tardis.dev/v1/data-feeds/blockchain-com?from=2024-01-01\&filters=\[{%22channel%22:%22l2%22}]) Level 2 order book snapshots and deltas
* [l3](https://api.tardis.dev/v1/data-feeds/blockchain-com?from=2024-01-01\&filters=\[{%22channel%22:%22l3%22}]) Level 3 order book updates stream
* [ticker](https://api.tardis.dev/v1/data-feeds/blockchain-com?from=2024-01-01\&filters=\[{%22channel%22:%22ticker%22}]) Ticker updates with best bid and ask plus 24h stats

### Market data collection details

[Market data collection infrastructure](https://docs.tardis.dev/faq/general#what-is-your-infrastructure-setup) for Blockchain.com exchange is located in GCP europe-west2 region (London, UK).

Real-time market data is captured via **multiple WebSocket connections** to `wss://ws.blockchain.info/mercury-gateway/v1/ws`.

{% hint style="info" %}
Blockchain.com exchange public APIs are proxied through Cloudflare.
{% endhint %}