Lobbying is a daily event in Washington. It’s a complex stream of activity involving lawmakers, interest groups and individuals who want to influence federal policy. Today we’re releasing a way for developers to tap into that stream to build software applications.

We’re adding new responses to the ProPublica Congress API that allow developers to programmatically access the lobbying data we started publishing last year, including the individuals and organizations who are registered to lobby the federal government, who they’re seeking to influence, and how much they’re being paid.

The data comes from the Clerk of the House of Representatives, which, along with the Secretary of the Senate, collects forms filed by lobbyists. Although both chambers have filings, the data from the House covers both Congress and the executive branch.

The House data is contained in XML files that we load daily into our database, and while we don’t offer every search variation that the House clerk’s site does, the API does give you three different ways to view filings, which we document here.

First, developers can access the most recent filings, 20 at a time, in reverse chronological order. Second, developers can search lobbying filings by keyword or phrase, using the names of lobbyists, clients and issues. For example, you can search for “Facebook” and see lobbying filings where the social media giant is the client and where it is mentioned in the description of the lobbying work. An example of the latter is a 2018 filing from D&D Strategies that references a meeting with Senate committee staff before Facebook CEO Mark Zuckerberg appeared in front of Congress. Finally, developers can see an individual lobbying filing based on its unique ID in the data.

We’ve also made some other changes to the API, including adding a response that returns congressional press releases that mention a specific bill. When we add a new press release to our database, our software scans the text to find any references to bill numbers. Since some statements only refer to bill titles, we don’t catch every mention, but many bills, like a recent one on prison reform, have statements associated with them.

You can check out the full list of changes and fixes in the API’s changelog.

To start using the Congress API, sign up for an API key and we’ll get you on your way. If you have any questions or issues with the API, you can raise them on GitHub or by emailing apihelp@propublica.org.