Simple app that displays contact information for US Congress representatives by district.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.

Call My Congress

Greenkeeper badge

Build Status

Call My Congress is a small application that helps US citizens quickly find contact information for their congressional representatives.

It is built using data freely provided by the US Census Geocoding Services and ProPublica.

The app consists of an Ember client app and an Express server. All the front end application code can be found in app/. The back end application code can be found in backend/app/.


You will need the following things properly installed on your computer.


  • git clone this repository
  • cd call-my-congress
  • npm install

Running / Development

Since this application includes both a front end and a back end, you will need to start up two servers to begin development.

Note: Running the backend requires access to ProPublica. You'll need to obtain an API key for the ProPublica Congress API to make valid requests.

  • PROPUBLICA_API_KEY=[...] npm run backend
  • npm run frontend
  • Visit http://localhost:4200 to see the app running locally.

Both of these servers will automatically reload whenever you save changes.

Running Tests

To run all tests once (used for Travis CI builds):

  • npm test

This runs both the front end and back end test suites. You can also run either suite just once with:

  • npm run test:backend
  • npm run test:frontend

To develop against tests:

  • npm run test-server:backend
  • npm run test-server:frontend

This will start a test server for the test suite in question, and will reload your tests whenever you save either app or test code.

Pro tip for front end tests: the tests will be opened in your browser. You can use the filter query param to run a subset of tests. I.e. ?filter=Integration | Component will only run the component integration tests.


  • ember build (development)
  • ember build --environment production (production)


Changes pushed to master are automatically deployed to Heroku once they have a passing build.

This app is deployed to two separate dynos on Heroku. The first (call-my-congress) is configured to run only the front end Ember application. The second (call-my-congress-backend) runs the Express server.

call-my-congress proxies all /api/ requests to call-my-congress-backend, which is defined in static.json.

Caching Strategy

Call My Congress relies on third-party APIs to serve district and congressional data. When Call My Congress is experiencing a high volume of traffic, we want to ensure we don't overwhelm our third-party APIs with requests or hit their designated rate limits.

Since most of the response data (congressional representatives, their contact information, and mapping zip codes to districts) does not change on a frequent basis, we can cache the responses and avoid making additional requests for the same data.

Zip code to district data is cached by zip code lookup, and held for one week.

Congressional representative data is cached by either House or Senate, and held for one day.

The current cache implementation uses only app memory (which means each server starts with a completely empty cache when it refreshes, and multiple servers running the app cannot share a cache). We should consider adding a database (like Redis) to further enable Call My Congress to scale in the future if the app-memory cache hits the top of its constraints.

Note: We will never cache or log district lookup by street address, as this is personally-identifiable information and unique to the point that there aren't any gains to be made. Zip code lookups are sufficiently de-anonymized and general to warrant caching.


PRs and improvements are welcome! If you'd like to contribute but aren't sure where to start, here's a short wish list of small contributions:

  • Improve high-level documentation (particularly around getting started or running locally)
  • Document a component with its expected inputs and behavior
  • Add another test for a case that's missing
  • Try out the app on a different browser or operating system, and if there are any bugs then file an issue and consider trying to fix it
  • Translate helper text and error messages into a new language (original English strings)