Fern
Platform and open-source CLI that generates SDKs, API documentation and CLIs from API definitions such as OpenAPI.
buildwithfern.comrepositorydocspricing
Fern turns an API definition into SDKs, API reference documentation and command-line tools. The open source part is the fern-api command-line tool, installed with npm, which needs Node.js 18 or later. Documentation sites are written as Markdown kept in Git and are hosted by Fern by default. A Docker container for self-hosting the docs is offered on the Enterprise plan. Birch Solutions, Inc., a Postman company, maintains it.
Worth knowing
The README of the open source repository says the project is no longer maintained and points to the hosted product, which the company still publishes.
Identity
Rendering and deploy
- Install with
- npm install -g fern-api7
Releases
Adoption
Sources
- 2026-10-22: links
buildwithfern.com - 2026-10-22: links, Written in, GitHub stars
api.github.com/repos/fern-api/fern - 2026-10-22: links, Maintainer, Categories, Admin interface, Multilingual
buildwithfern.com/learn/docs/getting-started/overview - 2026-10-22: links
buildwithfern.com/pricing - 2026-10-22: Owned by
buildwithfern.com/terms-of-service - 2026-10-22: First release, Current major version
api.github.com/repos/fern-api/fern/releases - 2026-10-22: Runtime, Minimum runtime, Install with
raw.githubusercontent.com/fern-api/fern/main/README.md - 2026-10-22: License, License model
raw.githubusercontent.com/fern-api/fern/main/LICENSE - 2026-10-22: Last release
api.github.com/repos/fern-api/fern/releases/latest - 2026-10-22: Contributors
api.github.com/repos/fern-api/fern/contributors - 2026-10-22: npm downloads a week
api.npmjs.org/downloads/point/last-week/fern-api - 2026-10-25: Dependent repositories, Dependent packages
packages.ecosyste.ms/api/v1/registries/npmjs.org/packages/fern-api