Barchart offers streaming market data for a wide range of asset classes which trade on exchanges around the world. Review our market data catalog for details.

This SDK enables your applications to consume real-time market data, as follows:

• A WebSocket connection is established between your application and Barchart's quote servers, then
• Your application requests market data for one or more symbols, then
• Your application receives a market data stream for subscribed symbols.

This library receives market data using a proprietary protocol called DDF. For new development, Barchart has switched to an open-source protocol called Openfeed to transfer market data. Consequently, this library will be marked as deprecated in the near future. You can access new SDK libraries for Openfeed here.

Complete documentation for this SDK can be accessed here:

• https://barchart.github.io/marketdata-api-js/#/

Working demos are available for web browser and Node.js environments. Please refer to the documentation.

This library has been published to NPM as @barchart/marketdata-api-js. Install as follows:

npm install @barchart/marketdata-api-js -S

Source code is written in ES2018. Consequently, transpilation is recommended for use in web browsers.