specification: API Commons Plans
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/Plans
provider: Chronicling America
providerId: chroniclingamerica
created: '2026-06-13'
modified: '2026-06-13'
tags:
  - Newspapers
  - Historical
  - Archives
  - Library of Congress
  - Government
  - Digitized
  - OCR
  - Search
description: >-
  Chronicling America is a free public service of the Library of Congress funded by the US federal
  government through the National Digital Newspaper Program (NDNP). There are no paid tiers, API keys,
  registration requirements, or commercial licensing fees. All API endpoints are open and free to use.
plans:
  - id: chroniclingamerica-free
    name: Free Public Access
    type: free
    description: >-
      Unrestricted free access to all Chronicling America API endpoints including full-text search,
      title metadata, issue listings, page records, OCR text, and image downloads. No registration,
      API key, or authentication required.
    entries:
      - label: Page Search Requests
        description: Full-text search requests against the newspaper page index
        name: page_search_requests
        type: quota
        metric: requests
        limit: -1
        timeFrame: month
        geo: global
        domains:
          - https://chroniclingamerica.loc.gov
        unit: 1
        price: '0.00'
        userMultiplied: false
      - label: Rate Limit
        description: >-
          Requests are rate-limited to prevent abuse. Chronicling America enforces a rate limit
          in line with general LOC policy; sustained high-volume crawling may result in temporary
          blocks. A conservative guideline is 150 requests per minute for text and metadata endpoints.
        name: rate_limit
        type: rate
        metric: requests_per_minute
        limit: 150
        timeFrame: minute
        geo: global
        domains:
          - https://chroniclingamerica.loc.gov
        unit: 1
        price: '0.00'
        userMultiplied: false
    elements:
      - name: Full-Text Newspaper Search
      - name: Title and LCCN Metadata
      - name: Issue and Batch Listings
      - name: Page-Level OCR Text
      - name: JP2, PDF, and TIFF Image Downloads
      - name: IIIF Image Service
      - name: Atom Feed Responses
      - name: JSON Responses
      - name: Community/Self-Service Support
pricing:
  model: Free only; no paid tiers or commercial plans
  notes: >-
    All Chronicling America services are funded by the US federal government and are provided at
    no cost. There are no premium tiers, enterprise contracts, or commercial licensing fees. The
    digitized newspaper content and associated metadata are in the public domain or openly licensed
    where applicable, though some historic newspaper pages may contain third-party material whose
    copyright status should be individually evaluated.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com