CongressMCP Documentation

30 MCP tools for searching, analyzing, and understanding U.S. congressional data. Bills, members, votes, committees, hearings, amendments, nominations, and AI-powered enrichments.

Getting Started

1. Register for an API key

Create a free account at /register to get your API key. No credit card required. The free tier includes 100 requests per month.

2. Add to Claude Code

Run this command to register CongressMCP as an MCP server in Claude Code:

claude mcp add congressmcp \ --transport http \ https://www.congressmcp.com/mcp \ --header "Authorization: Bearer YOUR_KEY"

3. Add to Claude Desktop

Add the following to your Claude Desktop settings.json:

{ "mcpServers": { "congressmcp": { "type": "streamable-http", "url": "https://www.congressmcp.com/mcp", "headers": { "Authorization": "Bearer YOUR_KEY" } } } }

Replace YOUR_KEY with the API key you received during registration.

Authentication

All requests to the MCP endpoint require an Authorization header with a Bearer token:

Authorization: Bearer sk_live_...

API keys are prefixed with sk_live_. Keep your key secret and never share it publicly.

Rate Limits

Free tier: 100 requests/month, 10 requests/minute
Pro tier: 10,000 requests/month, 60 requests/minute

When you exceed your monthly limit, the API returns 429 Too Many Requests with an upgrade prompt. Rate limits reset on the first of each month.

Bills

Search, retrieve, and explore legislation from Congress.

search_bills

Search congressional bills by keyword, or browse by date, policy area, and type. Omit query to browse by filters alone (e.g. "bills introduced today").

Parameter	Type	Required	Description
query	string	optional	Search keyword or phrase. Omit to browse by date or filters.
congress	number	optional	Filter by congress number (e.g. 119)
introduced_after	string	optional	Bills introduced on or after this date (YYYY-MM-DD)
introduced_before	string	optional	Bills introduced on or before this date (YYYY-MM-DD)
policy_area	string	optional	Filter by policy area (e.g. "Health", "Education")
type	string	optional	Bill type: hr, s, hjres, sjres, hconres, sconres, hres, sres
is_law	boolean	optional	If true, only return bills that became law
sort_by	string	optional	"introduced_date" (default) or "latest_action_date"
limit	number	optional	Max results to return (default: 20, max: 50)
offset	number	optional	Pagination offset (default: 0)

Show example response

[
  {
    "congress": 119,
    "type": "hr",
    "number": 1234,
    "title": "Example Act of 2025",
    "sponsor_name": "John Smith",
    "sponsor_party": "D",
    "sponsor_state": "CA",
    "latest_action": "Referred to committee",
    "latest_action_date": "2025-03-15"
  }
]

get_bill

Get detailed information about a specific bill including sponsor, cosponsors count, subjects, and latest summary.

Parameter	Type	Required	Description
congress	number	required	Congress number (e.g. 119)
type	string	required	Bill type (e.g. "hr", "s", "hjres", "sjres")
number	number	required	Bill number

Show example response

{
  "congress": 119,
  "type": "hr",
  "number": 1234,
  "title": "Example Act of 2025",
  "introduced_date": "2025-01-10",
  "sponsor_bioguide_id": "S000123",
  "sponsor_name": "John Smith",
  "sponsor_party": "D",
  "cosponsor_count": 42,
  "latest_action": "Passed House",
  "latest_action_date": "2025-06-12",
  "policy_area": "Health",
  "subjects": ["Medicare", "Drug prices"]
}

get_bill_actions

Get the legislative timeline/actions for a bill.

Parameter	Type	Required	Description
congress	number	required	Congress number
type	string	required	Bill type
number	number	required	Bill number
limit	number	optional	Max actions to return (default: 25)

Show example response

[
  {
    "action_date": "2025-06-12",
    "action_text": "Passed/agreed to in House: On passage Passed by Yea-Nay Vote: 275 - 160.",
    "action_type": "Floor",
    "action_code": "H37300"
  },
  {
    "action_date": "2025-03-15",
    "action_text": "Referred to the Committee on Energy and Commerce.",
    "action_type": "IntroReferral",
    "action_code": "H11100"
  }
]

get_bill_cosponsors

Get the list of cosponsors for a bill with party affiliation.

Parameter	Type	Required	Description
congress	number	required	Congress number
type	string	required	Bill type
number	number	required	Bill number

Show example response

[
  {
    "bioguide_id": "J000123",
    "first_name": "Jane",
    "last_name": "Doe",
    "party": "R",
    "state": "TX",
    "cosponsor_date": "2025-02-01"
  }
]

get_bill_text

Get available text versions for a bill with download URLs.

Parameter	Type	Required	Description
congress	number	required	Congress number
type	string	required	Bill type
number	number	required	Bill number

Show example response

[
  {
    "date": "2025-03-15",
    "type": "Introduced in House",
    "url": "https://www.congress.gov/119/bills/hr1234/BILLS-119hr1234ih.xml",
    "formats": ["xml", "pdf", "htm"]
  }
]

get_bill_summary

Get CRS summaries for a bill at different legislative stages. Returns plain-language explanations of what the bill does.

Parameter	Type	Required	Description
congress	number	required	Congress number
type	string	required	Bill type
number	number	required	Bill number

get_bill_subjects

Get the legislative subjects/topics assigned to a bill by the Library of Congress.

Parameter	Type	Required	Description
congress	number	required	Congress number
type	string	required	Bill type
number	number	required	Bill number

Members

Search and retrieve information about members of Congress.

search_members

Search for members of Congress by name. Supports fuzzy matching.

Parameter	Type	Required	Description
query	string	required	Name to search for (supports fuzzy matching)
chamber	string	optional	"House" or "Senate"
party	string	optional	Party filter (e.g. "D", "R")
state	string	optional	State abbreviation (e.g. "CA")
current_only	boolean	optional	Only current members (default: true)
limit	number	optional	Max results (default: 20)

Show example response

[
  {
    "bioguide_id": "P000197",
    "first_name": "Nancy",
    "last_name": "Pelosi",
    "party": "D",
    "state": "CA",
    "district": 11,
    "chamber": "House",
    "current_member": true
  }
]

get_member

Get detailed information about a member of Congress including terms served, bills sponsored/cosponsored, and vote count.

Parameter	Type	Required	Description
bioguide_id	string	required	Bioguide identifier (e.g. "P000197")

Show example response

{
  "bioguide_id": "P000197",
  "first_name": "Nancy",
  "last_name": "Pelosi",
  "party": "D",
  "state": "CA",
  "chamber": "House",
  "terms_served": 19,
  "bills_sponsored": 312,
  "bills_cosponsored": 4521,
  "total_votes": 14892,
  "current_member": true
}

get_member_legislation

Get bills sponsored or cosponsored by a member.

Parameter	Type	Required	Description
bioguide_id	string	required	Bioguide identifier
type	string	required	"sponsored" or "cosponsored"
congress	number	optional	Filter by congress number
limit	number	optional	Max results (default: 25)

Show example response

[
  {
    "congress": 119,
    "type": "hr",
    "number": 456,
    "title": "Infrastructure Investment Act",
    "introduced_date": "2025-02-14",
    "latest_action": "Referred to committee"
  }
]

Votes

Access voting records and roll call data.

get_member_votes

Get voting record for a member of Congress. Returns their votes on recorded roll calls.

Parameter	Type	Required	Description
bioguide_id	string	required	Bioguide identifier
congress	number	optional	Congress number (default: 119)
limit	number	optional	Max results (default: 50, max: 100)
offset	number	optional	Pagination offset (default: 0)

Show example response

[
  {
    "vote_cast": "Yea",
    "question_text": "On Passage - H.R. 1234",
    "result": "Passed",
    "vote_date": "2025-06-12",
    "vote_congress": 119,
    "vote_chamber": "House",
    "vote_session": 1,
    "vote_roll_call": 287
  }
]

get_vote_detail

Get details of a specific recorded vote including party breakdown.

Parameter	Type	Required	Description
chamber	string	required	"House" or "Senate"
congress	number	required	Congress number
session	number	required	Session number (1 or 2)
roll_call	number	required	Roll call number

Show example response

{
  "congress": 119,
  "chamber": "House",
  "session_number": 1,
  "roll_call_number": 287,
  "question_text": "On Passage - H.R. 1234",
  "result": "Passed",
  "vote_date": "2025-06-12",
  "yea_total": 275,
  "nay_total": 160,
  "not_voting": 0,
  "democrat_yea": 200,
  "democrat_nay": 12,
  "republican_yea": 75,
  "republican_nay": 148
}

score_members_on_votes

Score all members on a set of votes. Provide vote IDs with your preferred position (yea/nay) to generate a scorecard.

Parameter	Type	Required	Description
yea_vote_ids	number[]	required	Roll call vote IDs where you prefer a Yea
nay_vote_ids	number[]	required	Roll call vote IDs where you prefer a Nay

Show example response

[
  {
    "bioguide_id": "S000123",
    "name": "John Smith",
    "party": "D",
    "state": "CA",
    "score": 0.92,
    "votes_counted": 12,
    "aligned_votes": 11
  }
]

get_recent_votes

Browse recent recorded votes (roll calls) by date range and chamber. Great for "what votes happened today/this week".

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)
chamber	string	optional	"House" or "Senate"
from_date	string	optional	Votes on or after this date (YYYY-MM-DD). Defaults to last 7 days.
to_date	string	optional	Votes on or before this date (YYYY-MM-DD)
limit	number	optional	Max results (default: 20, max: 50)
offset	number	optional	Pagination offset (default: 0)

Committees

Explore congressional committees and their membership.

get_committees

List congressional committees. Filter by chamber or congress.

Parameter	Type	Required	Description
chamber	string	optional	"House", "Senate", or "Joint"
congress	number	optional	Congress number (default: 119)
limit	number	optional	Max results (default: 50)

Show example response

[
  {
    "system_code": "SSFI",
    "congress": 119,
    "name": "Committee on Finance",
    "chamber": "Senate",
    "type_code": "Standing",
    "subcommittees": [
      { "code": "SSFI01", "name": "Subcommittee on Health Care" }
    ]
  }
]

get_committee_members

Get members of a specific committee.

Parameter	Type	Required	Description
committee_code	string	required	The system_code of the committee (e.g. "SSFI")
congress	number	optional	Congress number (default: 119)

Show example response

[
  {
    "bioguide_id": "W000123",
    "name": "Ron Wyden",
    "party": "D",
    "state": "OR",
    "rank": 1,
    "role": "Chair"
  }
]

Enrichments Pro

AI-generated insights layered on top of raw congressional data. These tools require a Pro tier subscription.

get_bill_enrichment Pro

Get AI-generated enrichment for a bill including topic classification, significance rating, impact assessment, and plain-language summary.

Parameter	Type	Required	Description
congress	number	required	Congress number
type	string	required	Bill type
number	number	required	Bill number

Show example response

{
  "bill_ref": "119-hr-1234",
  "primary_topic": "Healthcare",
  "secondary_topics": ["Medicare", "Prescription Drugs"],
  "significance": "major",
  "impact_summary": "Would cap insulin costs at $35/month for all insured Americans.",
  "plain_language_summary": "This bill limits how much insurance companies can charge patients for insulin...",
  "issue_tags": ["insulin price cap", "drug pricing", "medicare reform"]
}

get_legislator_profile Pro

Get AI-generated legislator impact profile including archetype, topic authority, and vote courage.

Parameter	Type	Required	Description
bioguide_id	string	required	Bioguide identifier
congress	number	optional	Congress number (default: 119)

Show example response

{
  "bioguide_id": "P000197",
  "congress": 119,
  "archetype": "Coalition Builder",
  "topic_authority": ["Trade", "Foreign Affairs", "Immigration"],
  "vote_courage_score": 0.78,
  "legislative_effectiveness": "high",
  "bipartisan_index": 0.45
}

search_by_topic Pro

Search bills by AI-classified topic. Returns enriched bills matching a policy topic.

Parameter	Type	Required	Description
topic	string	required	Policy topic to search (e.g. "healthcare", "climate")
significance	string	optional	"landmark", "major", "moderate", "minor", or "routine"
congress	number	optional	Filter by congress number
limit	number	optional	Max results (default: 20)

Show example response

[
  {
    "bill_ref": "119-hr-1234",
    "primary_topic": "Healthcare",
    "significance": "major",
    "impact_summary": "Would cap insulin costs at $35/month...",
    "api_bills": {
      "title": "Example Act of 2025",
      "congress": 119
    }
  }
]

search_by_issue_tag Pro

Search bills by specific issue tag (e.g., "student loan forgiveness", "border wall", "insulin price cap").

Parameter	Type	Required	Description
tag	string	required	Issue tag to search for
limit	number	optional	Max results (default: 20)

Show example response

[
  {
    "bill_ref": "119-hr-5678",
    "primary_topic": "Education",
    "issue_tags": ["student loan forgiveness", "higher education"],
    "significance": "major",
    "api_bills": {
      "title": "Student Debt Relief Act",
      "congress": 119,
      "type": "hr",
      "number": 5678
    }
  }
]

Analysis Pro

Advanced analytical tools for comparing members, scoring votes, and reviewing aggregate statistics. The first three tools below require a Pro tier subscription.

get_party_unity Pro

Calculate party unity score for a member -- how often they vote with their party.

Parameter	Type	Required	Description
bioguide_id	string	required	Bioguide identifier
congress	number	optional	Congress number (default: 119)

Show example response

{
  "bioguide_id": "P000197",
  "party": "D",
  "congress": 119,
  "total_party_votes": 245,
  "votes_with_party": 232,
  "unity_score": 0.947
}

compare_members Pro

Compare two members of Congress -- shared cosponsored bills and voting alignment.

Parameter	Type	Required	Description
member1_bioguide	string	required	First member's bioguide ID
member2_bioguide	string	required	Second member's bioguide ID
limit	number	optional	Max shared bills to return (default: 10)

Show example response

{
  "shared_cosponsored_bills": [
    {
      "congress": 119,
      "type": "s",
      "number": 100,
      "title": "Bipartisan Infrastructure Act"
    }
  ],
  "member1_party_unity": { "unity_score": 0.947 },
  "member2_party_unity": { "unity_score": 0.891 }
}

get_legislation_stats

Get aggregate legislation statistics for a congress -- bill counts by type and status.

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)

Show example response

{
  "congress": 119,
  "total_bills": 12450,
  "by_type": {
    "hr": 8200,
    "s": 3100,
    "hjres": 150,
    "sjres": 80
  },
  "by_status": {
    "introduced": 10200,
    "passed_one_chamber": 1500,
    "became_law": 120
  }
}

get_vote_stats

Get voting statistics for a congress -- total votes, breakdowns by chamber.

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)

Show example response

{
  "congress": 119,
  "total_votes": 1245,
  "house_votes": 820,
  "senate_votes": 425
}

get_data_freshness

Check data freshness across all domains -- shows when each data type was last updated.

Parameter	Type	Required	Description
No parameters required.

Show example response

{
  "bills": {
    "last_updated": "2025-06-12T14:30:00Z",
    "total_records": 285000
  },
  "members": {
    "last_updated": "2025-06-12T14:30:00Z",
    "total_records": 13200
  },
  "votes": {
    "last_updated": "2025-06-12T12:00:00Z",
    "total_records": 52000
  }
}

Extended

Amendments, hearings, nominations, public laws, and member term history with contact info.

get_amendments

Get amendments for a specific bill, or browse amendments by congress, chamber, or date. Returns descriptions, sponsors, and status.

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)
bill_type	string	optional	Bill type to get amendments for (e.g. "hr", "s")
bill_number	number	optional	Bill number to get amendments for
chamber	string	optional	"House" or "Senate"
submitted_after	string	optional	Amendments submitted on or after (YYYY-MM-DD)
submitted_before	string	optional	Amendments submitted on or before (YYYY-MM-DD)
limit	number	optional	Max results (default: 20, max: 50)
offset	number	optional	Pagination offset (default: 0)

get_hearings

Browse congressional hearings by date, chamber, or committee. Returns titles, dates, committees, and witnesses.

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)
chamber	string	optional	"House" or "Senate"
committee_code	string	optional	Committee system code (e.g. "SSJU" for Senate Judiciary)
from_date	string	optional	Hearings on or after (YYYY-MM-DD)
to_date	string	optional	Hearings on or before (YYYY-MM-DD)
query	string	optional	Search hearing titles by keyword
limit	number	optional	Max results (default: 20, max: 50)

get_nominations

Browse presidential nominations sent to the Senate. Includes nominee info, organization, committee referrals, and status.

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)
query	string	optional	Search by description or organization keyword
from_date	string	optional	Received on or after (YYYY-MM-DD)
to_date	string	optional	Received on or before (YYYY-MM-DD)
limit	number	optional	Max results (default: 20, max: 50)

get_public_laws

Browse public laws (bills signed into law) by congress or date. Returns law numbers, titles, signing dates, and source bill info.

Parameter	Type	Required	Description
congress	number	optional	Congress number (default: 119)
from_date	string	optional	Laws signed on or after (YYYY-MM-DD)
to_date	string	optional	Laws signed on or before (YYYY-MM-DD)
limit	number	optional	Max results (default: 20, max: 50)

get_member_terms

Get term history for a member of Congress including chamber, state, district, party, dates, and contact info (phone, address, website).

Parameter	Type	Required	Description
bioguide_id	string	required	Member's Bioguide ID

REST API

In addition to the MCP interface, CongressMCP exposes standard REST endpoints for account management and billing.

POST /auth/register

Create a new account and receive an API key. Send { "email": "...", "name": "..." } as JSON body.

POST /auth/key Auth Required

Regenerate your API key. The old key is immediately revoked. Returns a new key.

GET /usage Auth Required

Get your current usage statistics: tier, requests this month, monthly limit, and rate limits.

POST /billing/checkout Auth Required

Create a Stripe checkout session to upgrade to the Pro tier. Returns a checkout_url.

POST /billing/portal Auth Required

Create a Stripe customer portal session to manage your subscription. Returns a portal_url.

Rate Limits & Pricing

Feature	Free	Pro
Price	$0/month	$20/month
Monthly Requests	100	10,000
Rate Limit	10 req/min	60 req/min
Bills, Members, Votes, Committees	All tools	All tools
Enrichments (AI-generated insights)	--	All 4 tools
Analysis (party unity, compare members)	--	All 5 tools
Support	Community	Priority email

Limits reset on the 1st of each month at midnight UTC. If you exceed your monthly quota, the API returns HTTP 429. Upgrade anytime at /billing/checkout.