> ## Documentation Index
> Fetch the complete documentation index at: https://developers.openalex.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Get changefile for a date

> Get details for a specific date's changefile, including which entity types changed, how many records, and download links in JSONL and Parquet formats. For a full guide on using changefiles to keep your local data current, see [Download Changefiles](/download/changefiles). **Requires a paid plan** — contact sales@openalex.org or see [pricing](https://openalex.org/pricing).



## OpenAPI

````yaml /api-reference/openapi.json get /changefiles/{date}
openapi: 3.1.0
info:
  title: OpenAlex API
  description: >-
    The OpenAlex API provides access to a comprehensive catalog of scholarly
    works, authors, sources, institutions, topics, keywords, publishers, and
    funders. OpenAlex indexes over 250 million scholarly works.
  version: 1.0.0
  contact:
    name: OpenAlex Support
    email: support@openalex.org
    url: https://openalex.org
  license:
    name: CC0
    url: https://creativecommons.org/publicdomain/zero/1.0/
servers:
  - url: https://api.openalex.org
    description: OpenAlex Production API
security:
  - apiKey: []
tags:
  - name: Works
    description: Scholarly documents like journal articles, books, datasets, and theses
  - name: Authors
    description: People who create scholarly works
  - name: Sources
    description: Journals, repositories, and other venues where works are hosted
  - name: Institutions
    description: Universities, research organizations, and other affiliations
  - name: Topics
    description: Research topics automatically assigned to works
  - name: Keywords
    description: Short phrases identified from works' topics
  - name: Publishers
    description: Companies and organizations that publish scholarly works
  - name: Funders
    description: Organizations that fund research
  - name: Autocomplete
    description: Fast typeahead search for any entity type
  - name: Domains
    description: Top-level categories in the topic hierarchy (4 total)
  - name: Fields
    description: Second-level categories in the topic hierarchy (26 total)
  - name: Subfields
    description: Third-level categories in the topic hierarchy (254 total)
  - name: SDGs
    description: UN Sustainable Development Goals (17 total)
  - name: Countries
    description: Geographic countries for filtering research by location
  - name: Continents
    description: Geographic continents (7 total)
  - name: Languages
    description: Languages of scholarly works
  - name: Awards
    description: Research grants and funding awards
  - name: Concepts
    description: Legacy taxonomy of research areas (deprecated - use Topics instead)
  - name: Work Types
    description: Types of scholarly works (article, book, dataset, etc.)
  - name: Source Types
    description: Types of sources (journal, repository, conference, etc.)
  - name: Institution Types
    description: Types of institutions (education, healthcare, company, etc.)
  - name: Licenses
    description: Open access licenses (CC BY, CC BY-SA, etc.)
paths:
  /changefiles/{date}:
    get:
      tags:
        - Changefiles
      summary: Get changefile for a date
      description: >-
        Get details for a specific date's changefile, including which entity
        types changed, how many records, and download links in JSONL and Parquet
        formats. For a full guide on using changefiles to keep your local data
        current, see [Download Changefiles](/download/changefiles). **Requires a
        paid plan** — contact sales@openalex.org or see
        [pricing](https://openalex.org/pricing).
      operationId: getChangefile
      parameters:
        - name: date
          in: path
          required: true
          description: The changefile date in YYYY-MM-DD format
          schema:
            type: string
            format: date
          example: '2026-02-19'
        - $ref: '#/components/parameters/api_key'
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                type: object
                properties:
                  meta:
                    type: object
                    properties:
                      count:
                        type: integer
                        description: Number of entity types with changes
                      date:
                        type: string
                        format: date
                        description: The changefile date
                  results:
                    type: array
                    items:
                      type: object
                      properties:
                        entity:
                          type: string
                          description: The entity type (e.g., works, authors, institutions)
                        records:
                          type: integer
                          description: Number of created or modified records
                        formats:
                          type: object
                          properties:
                            jsonl:
                              type: object
                              properties:
                                size_bytes:
                                  type: integer
                                  description: File size in bytes
                                size_display:
                                  type: string
                                  description: Human-readable file size
                                url:
                                  type: string
                                  format: uri
                                  description: Download URL for gzipped JSONL file
                            parquet:
                              type: object
                              properties:
                                size_bytes:
                                  type: integer
                                  description: File size in bytes
                                size_display:
                                  type: string
                                  description: Human-readable file size
                                url:
                                  type: string
                                  format: uri
                                  description: Download URL for Parquet file
        '429':
          $ref: '#/components/responses/RateLimited'
components:
  parameters:
    api_key:
      name: api_key
      in: query
      description: >-
        Your OpenAlex API key (required). Get a free key at
        https://openalex.org/settings/api
      required: true
      schema:
        type: string
  responses:
    RateLimited:
      description: Rate limit exceeded
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    Error:
      type: object
      properties:
        error:
          type: string
          description: Error type
        message:
          type: string
          description: Human-readable error message
  securitySchemes:
    apiKey:
      type: apiKey
      in: query
      name: api_key
      description: >-
        Your OpenAlex API key. Get a free key at
        https://openalex.org/settings/api

````