Status: v0.2.0 — full endpoint coverage: bills, members, votes, committees, nominations, treaties, amendments, the Congressional Record, and congress sessions, all verified against the live API.

Why this exists

The Congress.gov API is powerful but raw — no official SDK, inconsistent response shapes, pagination quirks, and rate limiting that'll bite you. This client handles all of that so you can focus on building.

Quick start

import { Congress } from '@capitoltrace/congress-api';

const congress = new Congress({ apiKey: process.env.CONGRESS_API_KEY! });

// Get a bill
const bill = await congress.bill(118, 'hr', 1);
console.log(bill.title); // "Lower Energy Costs Act"

// Search members
for await (const member of congress.members.list({ state: 'CA' })) {
  console.log(member.name);
}

// House roll call votes
const vote = await congress.vote(119, 1, 17);
console.log(vote.result); // "Passed"

// How every member voted
const positions = await congress.votes.memberVotes(119, 1, 17);
console.log(positions.results?.length); // 434

// Auto-paginate — no manual offset management
for await (const bill of congress.bills.list({ congress: 118, billType: 'hr' })) {
  console.log(bill.title);
}

// Committees, nominations, treaties, amendments too
const committee = await congress.committee('house', 'hspw00');
for await (const b of congress.committees.bills('house', 'hspw00')) {
  console.log(`${b.type} ${b.number} — ${b.relationshipType}`);
}

const current = await congress.congresses.current();
console.log(current.name); // "119th Congress"

What you get

• Full type safety — Every endpoint returns typed responses, no any
• Auto-pagination — Async iterators follow pagination.next for you
• Rate limit handling — Built-in retry with exponential backoff for 429s and 5xx, honors Retry-After — but fails fast with RateLimitError if the server asks you to wait longer than maxRetryDelayMs (api.data.gov sends Retry-After: 84868 when a daily quota runs out; sleeping a day inside a request helps no one)
• Zero dependencies — Uses native fetch() (Node 18+, Deno, Bun, browsers)
• Tree-shakeable — ESM + CJS dual build, sideEffects: false

Error handling

import { CongressApiError, RateLimitError } from '@capitoltrace/congress-api';

try {
  await congress.bill(118, 'hr', 999999);
} catch (err) {
  if (err instanceof RateLimitError) {
    console.log(`Rate limited — retry after ${err.retryAfterSeconds}s`);
  } else if (err instanceof CongressApiError) {
    console.log(`API error ${err.status}: ${err.message}`);
  }
}

Endpoints

| Resource | Methods | Status | |:---------|:--------|:-------| | 📜 Bills | list, get, actions, cosponsors, subjects, summaries, text, titles | ✅ v0.1 | | 👥 Members | list, get, sponsoredLegislation, cosponsoredLegislation | ✅ v0.1 | | 🗳️ Votes | list, get, memberVotes — House roll calls¹ | ✅ v0.1 | | 🏛️ Committees | list, get, bills, reports, nominations | ✅ v0.2 | | 📋 Nominations | list, get, actions, committees, hearings, nominees | ✅ v0.2 | | 🤝 Treaties | list, get, actions, committees | ✅ v0.2 | | ✏️ Amendments | list, get, actions, cosponsors, amendments, text | ✅ v0.2 | | 📰 Congressional Record | issues (classic), daily (modern) | ✅ v0.2 | | 📅 Congress | list, get, current | ✅ v0.2 |

¹ Via Congress.gov's beta house-vote endpoints. Senate roll call votes are not yet published by the Congress.gov API — they'll be added here the day upstream ships them.

Installation

# npm
npm install @capitoltrace/congress-api

# yarn
yarn add @capitoltrace/congress-api

# pnpm
pnpm add @capitoltrace/congress-api

Works in Deno and Supabase Edge Functions too:

import { Congress } from 'npm:@capitoltrace/congress-api';

Get your API key

Congress.gov API keys are free — sign up here (takes 30 seconds).

Need enriched data?

This client gives you raw Congress.gov data with your own key. If you want cross-referenced intelligence — congressional stock trades, FEC filings, FARA registrations, AI-detected correlations, webhooks — that's the Capitol Trace API.

Contributing

This is an open-source project by Capitol Trace. PRs welcome — especially for:

• Additional endpoint coverage (see the planned rows above)
• Better TypeScript types from real API responses
• Deno / Bun compatibility testing
• Documentation improvements

npm install
npm test         # vitest, no API key needed — tests run against recorded fixtures
npm run build    # tsup → dist/

License

MIT