API Reference

Complete reference for the Legisletter API. Look up legislators by address, get contact info, and build civic engagement tools.

The Legisletter API provides programmatic access to legislator data. Look up federal representatives by address and get comprehensive contact information, social media handles, and more.

Base URL

https://api.legisletter.org/v1

Authentication

All API requests require authentication via API key. Include your key in the Authorization header:

Authorization: Bearer ll-sk-your-api-key-here

Get your free API key at api.legisletter.org.

Rate Limits

Plan	Lookups/Month	Price	Coverage
Free	100	$0	Federal
Pro	2,000	$20/mo	Federal + State
National	25,000	$200/mo	Federal + State + Local

Rate limit headers are included in every response:

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 99
X-RateLimit-Reset: 1703980800

Endpoints

District Lookup

Look up legislators by address. Returns senators and house representative for the given location.

GET /api/v1/lookup
POST /api/v1/lookup

Parameters

Parameter	Type	Required	Description
`address`	string	Yes	Full US address (street, city, state, zip)

Example Request

curl "https://api.legisletter.org/v1/lookup?address=350+5th+Ave,+New+York,+NY+10118" \
  -H "Authorization: Bearer ll-sk-your-api-key"

Example Response

{
  "success": true,
  "address": {
    "input": "350 5th Ave, New York, NY 10118",
    "normalized": "350 5th Ave, New York, NY 10118"
  },
  "coordinates": {
    "lat": 40.7484,
    "lng": -73.9857
  },
  "district": {
    "state": "NY",
    "congressionalDistrict": "12",
    "districtCode": "NY12"
  },
  "representatives": {
    "senators": [
      {
        "name": "Chuck Schumer",
        "firstName": "Chuck",
        "lastName": "Schumer",
        "chamber": "senate",
        "party": "Democrat",
        "state": "NY",
        "district": null,
        "phone": "(202) 224-6542",
        "website": "https://www.schumer.senate.gov",
        "contactForm": "https://www.schumer.senate.gov/contact/email-chuck",
        "avatar": "https://bioguide.congress.gov/...",
        "twitter": "SenSchumer",
        "facebook": "saborchuck",
        "bioguideId": "S000148"
      },
      {
        "name": "Kirsten Gillibrand",
        "firstName": "Kirsten",
        "lastName": "Gillibrand",
        "chamber": "senate",
        "party": "Democrat",
        "state": "NY",
        "district": null,
        "phone": "(202) 224-4451",
        "website": "https://www.gillibrand.senate.gov",
        "contactForm": "https://www.gillibrand.senate.gov/contact/email-me",
        "avatar": "https://bioguide.congress.gov/...",
        "twitter": "SenGillibrand",
        "facebook": "KirstenGillibrand",
        "bioguideId": "G000555"
      }
    ],
    "representative": {
      "name": "Jerry Nadler",
      "firstName": "Jerry",
      "lastName": "Nadler",
      "chamber": "house",
      "party": "Democrat",
      "state": "NY",
      "district": "12",
      "phone": "(202) 225-5635",
      "website": "https://nadler.house.gov",
      "contactForm": "https://nadler.house.gov/contact",
      "avatar": "https://bioguide.congress.gov/...",
      "twitter": "RepJerryNadler",
      "facebook": "CongressmanNadler",
      "bioguideId": "N000002"
    }
  },
  "authenticated": true,
  "tier": "FREE"
}

Response Fields

Representative Object

Field	Type	Description
`name`	string	Full name
`firstName`	string	First name
`lastName`	string	Last name
`chamber`	string	`"senate"` or `"house"`
`party`	string	Party affiliation
`state`	string	Two-letter state code
`district`	string	District number (House only)
`phone`	string	DC office phone
`website`	string	Official website URL
`contactForm`	string	Contact form URL
`avatar`	string	Photo URL
`twitter`	string	Twitter/X handle
`facebook`	string	Facebook page
`bioguideId`	string	Bioguide ID

Error Responses

400 Bad Request

{
  "success": false,
  "error": "Missing required parameters",
  "message": "Provide either \"address\" or both \"lat\" and \"lng\" parameters"
}

401 Unauthorized

{
  "error": "Invalid API key",
  "message": "The provided API key is invalid, inactive, or expired."
}

429 Rate Limited

{
  "error": "Rate limit exceeded",
  "message": "Rate limit exceeded. Resets at 2024-01-01T00:00:00.000Z",
  "limit": 100,
  "reset": 1704067200000
}

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