eCFR

aid: ecfr
name: eCFR
description: Electronic Code of Federal Regulations REST API for accessing the official US Code of Federal Regulations, searching
  regulations, and retrieving regulatory version history.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.19'
tags:
- Federal Regulations
- Government
- Legal
- Compliance
- Open Data
- United States
apis:
- aid: ecfr:versioner
  name: eCFR Versioner API
  description: Provides access to the full text of CFR titles, parts, sections, and appendices at specific dates, as well
    as version history for regulatory content. Supports XML format responses for hierarchical regulatory structure.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.ecfr.gov/developers/documentation/api/v1
  baseURL: https://www.ecfr.gov/api/versioner/v1
  tags:
  - Regulations
  - Version History
  - CFR Titles
  properties:
  - type: Documentation
    url: https://www.ecfr.gov/developers/documentation/api/v1
  - type: OpenAPI
    url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/openapi/ecfr-openapi.json
  contact:
  - FN: eCFR Developer Support
    url: https://www.ecfr.gov/developers
- aid: ecfr:search
  name: eCFR Search API
  description: Full-text search across all Code of Federal Regulations content, with support for filtering by title, agency,
    date ranges, and content type. Returns ranked results with hierarchical context and full-text excerpts.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.ecfr.gov/developers/documentation/api/v1
  baseURL: https://www.ecfr.gov/api/search/v1
  tags:
  - Search
  - Full-Text Search
  - Regulations
  properties:
  - type: Documentation
    url: https://www.ecfr.gov/developers/documentation/api/v1
  - type: OpenAPI
    url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/openapi/ecfr-openapi.json
  contact:
  - FN: eCFR Developer Support
    url: https://www.ecfr.gov/developers
- aid: ecfr:admin
  name: eCFR Admin API
  description: Provides metadata about federal agencies and their CFR references, enabling lookup of which titles and chapters
    correspond to specific agencies.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.ecfr.gov/developers/documentation/api/v1
  baseURL: https://www.ecfr.gov/api/admin/v1
  tags:
  - Agencies
  - Metadata
  - Government
  properties:
  - type: Documentation
    url: https://www.ecfr.gov/developers/documentation/api/v1
  - type: OpenAPI
    url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/openapi/ecfr-openapi.json
  contact:
  - FN: eCFR Developer Support
    url: https://www.ecfr.gov/developers
common:
- type: Website
  url: https://www.ecfr.gov
- type: Documentation
  url: https://www.ecfr.gov/developers/documentation/api/v1
- type: GitHubOrg
  url: https://github.com/usgpo
- type: Blog
  url: https://www.federalregister.gov/blog
- type: Pricing
  url: https://www.ecfr.gov/developers
- type: Plans
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/plans/ecfr-plans-pricing.yml
- type: RateLimits
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/rate-limits/ecfr-rate-limits.yml
- type: FinOps
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/finops/ecfr-finops.yml
- type: OpenAPI
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/openapi/ecfr-openapi.json
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-schema/agency.json
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-schema/cfr-title.json
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-schema/search-result.json
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-schema/content-version.json
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-schema/correction.json
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-schema/cfr-ancestor.json
- type: Vocabulary
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/vocabulary/ecfr-vocabulary.json
- type: JSONLDContext
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/json-ld/ecfr-context.json
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/examples/titles-response.json
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/examples/agencies-response.json
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/examples/search-results-response.json
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/examples/ancestry-response.json
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/ecfr/refs/heads/main/examples/versions-response.json
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com