Congress API Client

A C++ application that fetches data from the Congress API using HTTPS.

https://gpo.congress.gov/

Live demo

https://pedro-vicente.net:9445/

Prerequisites

This project requires CMake, a C++ compiler, OpenSSL, and the ASIO library.

Installation Instructions

macOS

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
brew install cmake openssl asio
export OPENSSL_ROOT_DIR=$(brew --prefix openssl)
export PKG_CONFIG_PATH=$(brew --prefix openssl)/lib/pkgconfig:$PKG_CONFIG_PATH

Linux (Ubuntu/Debian)

sudo apt install build-essential cmake libssl-dev libasio-dev

Windows

1. Install CMake from https://cmake.org/download/
2. Download OpenSSL pre-compiled binaries from https://slproweb.com/products/Win32OpenSSL.html 3 Set environment variable:

set OPENSSL_ROOT_DIR=C:\OpenSSL-Win64

Building the Project

On a bash shell (on Windows, Git bash shell), run

chmod a+x build.cmake.sh 
build.cmake.sh

Setup

1. Create a key.txt file in the project root with your Congress API key. Obtain key from

https://gpo.congress.gov/sign-up/

Edit file config.json with the API key

{
  "API_KEY": "MY_API_KEY",
  "RESPONSE_FORMAT": "json",
  "LIMIT": "2"
}

2. Run the application:

./congress 

The application will fetch member data and save it to member.json.

HTTP

An HTTP GET request with the following format is made

GET /v3/member?api_key=API_KEY&limit=1 HTTP/1.1
Host: api.congress.gov
Accept: */*
Connection: close

Example JSON response

{
    "members": [
        {
            "bioguideId": "Y000064",
            "depiction": {
                "attribution": "Image courtesy of the Member",
                "imageUrl": "https://www.congress.gov/img/member/y000064_200.jpg"
            },
            "name": "Young, Todd",
            "partyName": "Republican",
            "state": "Indiana",
            "terms": {
                "item": [
                    {
                        "chamber": "House of Representatives",
                        "endYear": 2017,
                        "startYear": 2011
                    },
                    {
                        "chamber": "Senate",
                        "startYear": 2017
                    }
                ]
            },
            "updateDate": "2025-09-20T10:30:32Z",
            "url": "https://api.congress.gov/v3/member/Y000064?format=json"
        }
    ],
    "pagination": {
        "count": 2598,
        "next": "https://api.congress.gov/v3/member?offset=1&limit=1&format=json"
    },
    "request": {
        "contentType": "application/json",
        "format": "json"
    }
}

Web interface

The web interface display retrieved data on a web browser. It uses the Wt framework

Wt is a C++ library for developing web applications.

Usage

Build dependencies Boost and Wt on a bash shell (Linux, Mac, Windows) with

./build.boost.sh 
./build.wt.sh 

Build with

./build.cmake.sh 

Run with

On a bash shell

./build/congress/web --http-address=0.0.0.0 --http-port=8080  --docroot=.

Access the web interface at http://localhost:8080