New to APIs? Start here.

No experience required.

What is an API?

An API (Application Programming Interface) is a way for programs to talk to each other. Instead of visiting a website and copying data by hand, your code can request data directly and get it back in a structured format (JSON) that's easy to work with.

What does the Capitol Trace API do?

We pull data from 15+ government sources — Congress.gov, the FEC, Senate lobbying records, and more — normalize it into a single, consistent format, and serve it through one API. One key, one schema, all the data.

Who is this for?

Students building class projects. Journalists investigating corruption. Researchers studying polarization. Developers building civic tech apps. Anyone who wants to work with congressional data without spending weeks figuring out government APIs.

How do I get started?

1. Sign up for a free API key below. 2. Pick an endpoint from the reference. 3. Make your first request using any language — JavaScript, Python, R, or even just cURL in your terminal. 4. Get back clean JSON data. That's it.

Response Format

Every endpoint returns the same structure.

GET /v1/members?state=TX&party=R

{
  "data": [
    {
      "bioguide_id": "C001098",
      "name": "Ted Cruz",
      "party": "R",
      "state": "TX",
      "chamber": "Senate",
      "ideology_score": 0.891,
      "committees": ["Commerce", "Judiciary", "Foreign Relations"]
    }
  ],
  "meta": {
    "source": "congress.gov + voteview.com",
    "updated_at": "2026-03-16T12:00:00Z",
    "cache_ttl": 3600,
    "api_version": "v1"
  },
  "pagination": {
    "total": 25,
    "page": 1,
    "per_page": 50,
    "next": null
  }
}

API Reference

Filter by tier:

Capitol Trace API catalog34 endpoints · All responses return JSON with consistent schema

Simple, Transparent Pricing

Free for citizens. Paid for power users. No hidden fees. No "contact sales" games.

Free

$0/mo

For students, hobbyists, and civic tech experiments.

100 requests/day

Member profiles & search
Bill search & status
Roll call votes
JSON responses
Community support

Starter

$9/mo

For hobbyists, side projects, and Quiver-style dashboards.

1,000 requests/day

Everything in Free
Donors, trades, ideology & lobbying
JSON responses
Email support

Researcher

$29/mo

For academics, journalists, and data analysts.

5,000 requests/day + CSV exports

Everything in Starter
CSV & JSON export
Historical data access
Bulk data downloads
Email support

Widget

$49/mo

For commercial applications using Capitol Trace embeddable widgets.

10,000 requests/day

Everything in Researcher
Embeddable data widgets
Commercial use license
White-label options
Email support

Pro

$79/mo

For developers, side projects, and power users.

25,000 requests/day + webhooks

Everything in Researcher
Webhook alerts (real-time)
Bulk downloads
Priority support
Multiple API keys

Newsroom

$299/mo

For media organizations and advocacy groups.

100,000 requests/day + SLA

Everything in Pro
Embeddable widgets
Team accounts (5 keys)
Custom alert rules
Dedicated support
SLA guarantee

Need enterprise-grade access? Custom endpoints, SLA, white-label data? Let's talk.

Built for every level of expertise

Students

Build class projects with real congressional data. The free tier has everything you need. No credit card required.

Journalists

Stop spending 3 days pulling FEC data. Get a member's full donor breakdown, stock trades, and voting record in one API call.

Researchers

Research-ready political data. Bulk CSV downloads, historical records, ideology scores. No more wrestling with 14 different formats.

Developers

Build civic tech on top of our data layer. We handle the government APIs — you build the experience. Full OpenAPI spec included.

Ready to build?

Get your free API key in 30 seconds. 100 requests/day, no credit card, no strings attached. Upgrade when you need to.

Get Free API Key →← Back to Capitol Trace