Top of page

Introducing the API

Share this post:

This post was originally co-authored for the In Custodia Legis blog by Margaret Wood and Andrew Weber. is a fantastic source of legislative information, and a marvelous source for investigating specific legislation and exploring the legislative history of a bill. also contains large amounts of data and various users have expressed interest in having additional access to download this data. Certain entities or persons have “scraped” the website over the years and the Government Publishing Office (GPO) has also offered bulk data downloads for some collections, but these have all been somewhat imperfect measures. However, today we are introducing the beta API which will provide access to accurate and structured congressional data. We are very excited about this release and a great deal of hard work has gone on behind the scenes this year to make this happen.

So what is an API? It is a method by which structured data can be shared when an application submits a request and receives the data back. The API is a REST API and presents data in a hierarchical browse format with responses provided in XML or JSON. The XML format is the default for the API.

The API will cover many of the collections out of the gate, including bills, amendments, summaries, Congress, members, the Congressional Record, committee reports, nominations, treaties, and House Communications. Over time we will be adding other collection endpoints, such as hearing transcripts and Senate Communications

a screen shot of the API details
Items in the beta API

As with all products, we have worked to provide documentation about the API as well. In this case there is documentation, user guides, a change log that details changes to the API, and opportunities for feedback. To use the API you must first get an API key.

screenshot of the form to get a API key
Sign up to get a API key

There is a GitHub page for the API where you can get additional information and provide feedback if you encounter any problems. We encourage users to look at the issues section for information which can help answer possible queries. And, as always, we are here to help through our Ask a Librarian service.

A screenshot of the API GitHub space
Learn more at the API GitHub space


Be sure to join us for the Virtual Public Forum on September 21st where we will talk more about the new beta API. And if you’re interested in any other APIs provided by the Library of Congress, check out 

Subscribe to In Custodia Legis – it’s free! – to receive interesting posts drawn from the Law Library of Congress’s vast collections and our staff’s expertise in U.S., foreign, and international law.

Add a Comment

Your email address will not be published. Required fields are marked *