Real-time visibility to the liquidity across different exchanges for Bitcoin.
You will need a Cryptowatch API key, which should take just a few minutes to obtain (for free).
- Clone this repository.
- Run
npm install - Set the API key here
- Run
nodemon server.js - Open your browser at
http://localhost:8080/
This is a simple a node.js app that uses websockets to connect to the Cryptowatch API to get a live feed of BTC/USD orders across various exchanges.
Note that the websocket connection polls every few seconds and streams a small batch of bids/asks at a time to the UI, as opposed to maintaining an uninterruped real-time feed. This is done to throttle the volume of instantaneous orders and prevent overwhelming the client with thousands data points.
Cryptowatch itself broadcasts the snapshots about once per minute.
For data streaming between the browser client and app's server, socket.io was used so that the incoming data could be immediately rendered in the browser.
Other data sources considered:
For demonstration purposes, only a subset of bid/ask orders (out of hundreds or thousands polled every few seconds) are sent to the client. Ideally, the client should be able to render a more continuous stream of updates. On the client side, a more responsive framework or library could be used instead.
Perhaps a cleaner separation between the app's client and server is to replace the usage of socket.io for communication between the two with a cache or temporary datastore. The server would still maintain a websocket connection with Cryptowatch, but instead of emitting the messages to the client, it would write directly to a cache or table. The client, instead of listening for updates from the server, could periodically read from the cache and update the UI.
Potential additional features include:
- Adding data from more sources and exchanges
- Take action based on the order book data
- Filter for bids/asks by amount and exchange
- Price alerts