Library of Congress Items API

openapi: 3.2.0
info:
  title: loc.gov JSON/YAML Items API
  description: The loc.gov JSON/YAML API provides structured, machine-readable data about Library of Congress digital collections — books, photographs, maps, manuscripts, archived websites, videos, and more. No authentication is required. Responses are available in JSON or YAML format via the fo= query parameter.
  version: '1.0'
  contact:
    name: Library of Congress
    url: https://www.loc.gov/about/contact-us/
  license:
    name: U.S. Government Work
    url: http://www.loc.gov/text-us-government-work
servers:
- url: https://www.loc.gov
  description: Production server
tags:
- name: Items
  description: Access individual item details
paths:
  /item/{itemId}/:
    get:
      tags:
      - Items
      summary: Get item details
      description: Returns bibliographic information and digital resources for a single item identified by its identifier. The item ID can be obtained from the id field in search results. Many items are composed of one or more resources; the item endpoint provides summary information about each resource and how to access it.
      operationId: getItem
      parameters:
      - name: itemId
        in: path
        description: The item identifier (from the id field in search results, excluding the base URL)
        required: true
        schema:
          type: string
        example: 2003623100
      - name: fo
        in: query
        description: Output format
        required: false
        schema:
          type: string
          enum:
          - json
          - yaml
        example: json
      - name: at
        in: query
        description: Limit response to specific attribute(s)
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Item bibliographic data and digital resources
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ItemResponse'
        '404':
          description: Item not found
components:
  schemas:
    ResourceFile:
      type: object
      description: A specific digital file for a resource
      properties:
        height:
          type: integer
          description: Height of the image in pixels
        levels:
          type: integer
          description: Number of zoom levels available
        mimetype:
          type: string
          description: MIME type of the file
        size:
          type: integer
          description: File size in bytes
        url:
          type: string
          description: URL to access the file
        width:
          type: integer
          description: Width of the image in pixels
    ItemResponse:
      type: object
      description: Detailed item response from the loc.gov item endpoint
      properties:
        cite_this:
          type: object
          description: 'Experimental feature providing citation text in Chicago Manual of Style, MLA, and APA formats. Should be used as a starting point only.

            '
          additionalProperties: true
        item:
          type: object
          description: Bibliographic information for the requested item
          additionalProperties: true
        resources:
          type: array
          description: 'Digital resources associated with the item (digitized images, audio files, video files, web archive links, etc.)

            '
          items:
            $ref: '#/components/schemas/Resource'
    Resource:
      type: object
      description: A discrete digital representation or element of a collection item
      properties:
        caption:
          type: string
          description: Caption for the resource
        files:
          type: array
          description: Digital files associated with the resource
          items:
            type: array
            items:
              $ref: '#/components/schemas/ResourceFile'
        image:
          type: string
          description: URL of the resource image
        url:
          type: string
          description: URL of the resource
externalDocs:
  description: API Documentation
  url: https://www.loc.gov/apis/json-and-yaml/