Library of Congress website screenshot

Library of Congress

The Library of Congress is the largest library in the world, with millions of books, films and video, audio recordings, photographs, newspapers, maps and manuscripts in its collections. The Library is the main research arm of the U.S. Congress and the home of the U.S. Copyright Office. The Library publishes a suite of public APIs that expose its catalog, digital collections, historic newspapers, and legislative information.

Library of Congress publishes 12 APIs on the APIs.io network, including Bills API, Collections API, Committees API, and 9 more. Tagged areas include Cultural Heritage, Federal Government, Library, Legislative, and Newspapers.

Library of Congress’ developer surface includes authentication, documentation, engineering blog, and 7 more developer resources.

🌐 Visit website 📡 Source on GitHub
38.4/100 thin ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreemiumSelf serve⚡ Free to try
12 APIs
Cultural HeritageFederal GovernmentLibraryLegislativeNewspapersSearch

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 38.4/100 · thin
Contract Quality 12.6 / 25
Developer Ergonomics 5.7 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 7.4 / 10
Agent readiness — 31/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/library-of-congress: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 12

Individual APIs this provider publishes, each with its own machine-readable definition.

Library of Congress Bills API

The Bills API from Library of Congress — 3 operation(s) for bills.

Library of Congress Collections API

The Collections API from Library of Congress — 2 operation(s) for collections.

Library of Congress Committees API

The Committees API from Library of Congress — 1 operation(s) for committees.

Library of Congress Congressional Record API

The Congressional Record API from Library of Congress — 1 operation(s) for congressional record.

Library of Congress Issues API

The Issues API from Library of Congress — 1 operation(s) for issues.

Library of Congress Items API

The Items API from Library of Congress — 1 operation(s) for items.

Library of Congress Laws API

The Laws API from Library of Congress — 1 operation(s) for laws.

Library of Congress Members API

The Members API from Library of Congress — 2 operation(s) for members.

Library of Congress Pages API

The Pages API from Library of Congress — 1 operation(s) for pages.

Library of Congress Resources API

The Resources API from Library of Congress — 1 operation(s) for resources.

Library of Congress Search API

The Search API from Library of Congress — 1 operation(s) for search.

Library of Congress Titles API

The Titles API from Library of Congress — 3 operation(s) for titles.

Scroll for all 12

Open Collections 3

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Library of Congress Chronicling America API

OPEN COLLECTION

Library of Congress Congress.gov API

OPEN COLLECTION

Library of Congress loc.gov JSON API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Library Of Congress Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Library Of Congress Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Library Of Congress Finops

FINOPS

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Library Of Congress Authentication

apiKey · 1 scheme

SECURITY

Library Of Congress Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Library Of Congress Vulnerability Disclosure

security.txt · contact published

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Library Of Congress Agentic Access

18 operations

18 operations · 0 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 Reference
Reference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

VulnerabilityDisclosure
VulnerabilityDisclosure
 DomainSecurity
DomainSecurity
 Authentication
Authentication

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: library-of-congress
name: Library of Congress
description: The Library of Congress is the largest library in the world, with millions of books, films and video, audio recordings,
  photographs, newspapers, maps and manuscripts in its collections. The Library is the main research arm of the U.S. Congress
  and the home of the U.S. Copyright Office. The Library publishes a suite of public APIs that expose its catalog, digital
  collections, historic newspapers, and legislative information.
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
position: Producer
access: Public
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/library-of-congress.png
tags:
- Cultural Heritage
- Federal Government
- Library
- Legislative
- Newspapers
- Search
created: '2024-01-01'
modified: '2026-05-19'
url: https://raw.githubusercontent.com/api-evangelist/library-of-congress/refs/heads/main/apis.yml
specificationVersion: '0.19'
apis:
- aid: library-of-congress:library-of-congress-bills-api
  name: Library of Congress Bills API
  description: The Bills API from Library of Congress — 3 operation(s) for bills.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Bills
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-bills-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-collections-api
  name: Library of Congress Collections API
  description: The Collections API from Library of Congress — 2 operation(s) for collections.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Collections
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-collections-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-committees-api
  name: Library of Congress Committees API
  description: The Committees API from Library of Congress — 1 operation(s) for committees.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Committees
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-committees-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-congressional-record-api
  name: Library of Congress Congressional Record API
  description: The Congressional Record API from Library of Congress — 1 operation(s) for congressional record.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Congressional Record
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-congressional-record-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-issues-api
  name: Library of Congress Issues API
  description: The Issues API from Library of Congress — 1 operation(s) for issues.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Issues
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-issues-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-items-api
  name: Library of Congress Items API
  description: The Items API from Library of Congress — 1 operation(s) for items.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Items
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-items-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-laws-api
  name: Library of Congress Laws API
  description: The Laws API from Library of Congress — 1 operation(s) for laws.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Laws
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-laws-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-members-api
  name: Library of Congress Members API
  description: The Members API from Library of Congress — 2 operation(s) for members.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Members
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-members-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-pages-api
  name: Library of Congress Pages API
  description: The Pages API from Library of Congress — 1 operation(s) for pages.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Pages
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-pages-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-resources-api
  name: Library of Congress Resources API
  description: The Resources API from Library of Congress — 1 operation(s) for resources.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Resources
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-resources-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-search-api
  name: Library of Congress Search API
  description: The Search API from Library of Congress — 1 operation(s) for search.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-search-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
- aid: library-of-congress:library-of-congress-titles-api
  name: Library of Congress Titles API
  description: The Titles API from Library of Congress — 3 operation(s) for titles.
  humanURL: https://www.loc.gov/apis/json-and-yaml/
  baseURL: https://www.loc.gov
  tags:
  - Titles
  properties:
  - type: OpenAPI
    url: openapi/library-of-congress-titles-api-openapi.yml
  - type: Documentation
    url: https://www.loc.gov/apis/json-and-yaml/
  - type: Reference
    url: https://www.loc.gov/apis/json-and-yaml/requests/
  - type: Documentation
    url: https://chroniclingamerica.loc.gov/about/api/
  - type: Documentation
    url: https://github.com/LibraryOfCongress/api.congress.gov/
  - type: Signup
    url: https://api.congress.gov/sign-up/
common:
- type: AgenticAccess
  url: agentic-access/library-of-congress-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/library-of-congress-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/library-of-congress-domain-security.yml
- type: Authentication
  url: authentication/library-of-congress-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/library-of-congress
- type: Website
  url: https://www.loc.gov/
- type: Documentation
  url: https://www.loc.gov/apis/
- type: Reference
  url: https://www.loc.gov/apis/json-and-yaml-responses/
- type: GitHubOrganization
  url: https://github.com/LibraryOfCongress
- type: Integrations
  url: https://www.loc.gov/apps
- url: https://blogs.loc.gov/loc/feed/
  type: Blog
integrations:
- name: Facebook
- name: Copy Link
- name: Library of Congress Facebook
- name: Library of Congress X
- name: Library of Congress YouTube
- name: Library of Congress Pinterest
- name: Library of Congress Flickr
- name: Library of Congress Instagram
- name: Library of Congress iTunesU
- name: Library of Congress LinkedIn
- name: Email
- name: Congress.gov
- name: United States Copyright Office
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com