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fern-api/fern

Input OpenAPI. Output SDKs and Docs.

TypeScript ◇ api Apache-2.0

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★3.8KSTARS

⑂352FORKS

!345ISSUES

🏆#1,294GLOBAL RANK

🔥5DAYS TRENDING

🚀

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Star History

Continuous Observations

Interactive star growth chart for fern-api/fern

Momentum

+95

STARS · LAST 30 DAYS

PER DAY

#182

MOST-STARRED TypeScript

Window	7 days	30 days	90 days
Stars gained	+21	+95	+270
Per day	3	3	3
Forks gained	+2	+7	+18

fern gained 95 stars in the last 30 days, about 3 a day, and now has 3.8K. It is about 4 years old and has averaged roughly 947 stars a year. It ranks #182 among TypeScript repositories and #1,294 across all languages on GitHubRepo.

Trending Record

fern has maintained a continuous presence across global trending indexes, peaking at #794. Below is the 30-day activity profile:

💡 Overview

fern is an open-source project written in TypeScript: Input OpenAPI. Output SDKs and Docs.

Engineered for speed, consistency, and developer ease, it solves common hurdles in api, docs-as-code, docs-generator. It provides clear interfaces, comprehensive configuration options, and seamless integration with existing tools across the modern development stack.

⚡ Key Features

Optimized execution pipeline written in TypeScript for predictable speed.

Zero-friction configuration with comprehensive sensible defaults out of the box.

Cross-platform runtime support across Linux, macOS, and Windows environments.

Strong typing and modular architecture designed for easy extension and maintainability.

Standardized CLI and API interfaces for smooth integration into CI/CD workflows.

Active community maintenance with regular dependency updates and security patches.

📥 Installation

terminal

$ npm install fern

$ npm install fern # or: pnpm add fern

> npm install fern

⚙ System Requirements

Platforms

• macOS
• Linux
• Windows

Runtime & Dependencies

Node.js >= 18, npm, pnpm or bun

Architecture

x86_64, ARM64 (Apple Silicon & Graviton)

🧠 How It Works

fern coordinates its core functionality through a modular TypeScript pipeline. It parses configuration parameters, validates inputs, and resolves dependencies asynchronously. By minimizing runtime overhead and keeping allocations localized, it delivers predictable performance in both local development environments and automated production workloads.

🎯 Production Use Cases

Production System Integration

Embed fern into TypeScript backend services to handle core application logic.

CI/CD Automated Pipelines

Run automated validation, builds, and integration suites during deployments.

Developer Tooling & Workflows

Accelerate developer onboarding with pre-configured project utilities.

Open Source Extension

Fork and customize internal modules under the repository's open Apache-2.0 license.

🚀 Getting Started

Install fern using your package manager: `npm install fern`

Initialize your project workspace or configuration file for fern.

Import fern into your codebase or invoke it directly from your terminal.

Execute your test suite or run `fern --help` to verify successful setup.

👍 Strengths

Active community backing with 3,783 GitHub stars and verified adoption.

Permissive open-source distribution under the Apache-2.0 license.

Built in TypeScript for high execution speed and developer familiarity.

Cross-platform compatibility across modern Linux, macOS, and Windows environments.

Clean modular design allowing flexible configuration and pipeline integration.

⚠️ Considerations

Requires familiarity with TypeScript and modern CLI workflows.

Ecosystem extensions may require manual configuration depending on environment constraints.

Active development roadmap means breaking API changes may occur across major versions.

⇄ Alternatives & Direct Competitors

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Compare ↗

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DeepSeek Harness: Everything is a Plugin.

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This is the repo for Vue 2. For Vue 3, go to https://github.com/vuejs/core

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anomalyco/opencode ★ 210.4K TypeScript

The open source coding agent.

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👥 Who Should Use This

Developers and engineering teams building with TypeScript, seeking reliable, tested, and actively maintained tooling for production workloads.

🏆 Nearby in the Rankings

fern-api/fern is currently ranked #1,294 by stars across every repository tracked on GitHubRepo. These are adjacent projects:

Rank	Repository	Language	Stars	Action
#1,289	microsoft/kiota	C#	★ 3.8K	Compare ↗
#1,290	Atmosphere/atmosphere	Java	★ 3.8K	Compare ↗
#1,290	MorpheApp/morphe-patches	Java	★ 3.8K	Compare ↗
#1,292	defunkt/gist	Ruby	★ 3.8K	Compare ↗
#1,293	rmm5t/jquery-timeago	JavaScript	★ 3.8K	Compare ↗
#1,294	fern-api/fern This Project	TypeScript	★ 3.8K
#1,295	01mf02/jaq	Rust	★ 3.8K	Compare ↗
#1,296	apple/swift-argument-parser	Swift	★ 3.8K	Compare ↗
#1,296	pipeshub-ai/pipeshub-ai	Python	★ 3.8K	Compare ↗
#1,298	jub0t/Concat	Rust	★ 3.8K	Compare ↗
#1,299	Kuingsmile/PicList	TypeScript	★ 3.8K	Compare ↗

Frequently Asked Questions

What does fern do? +

Input OpenAPI. Output SDKs and Docs.

What language is fern written in? +

The primary language is TypeScript. Topics include: api, docs-as-code, docs-generator, openapi, sdk-generator.

Is fern actively maintained? +

Yes, the last recorded push was on Sep 27, 2026 with 345 open issues being tracked.

How many stars does fern have? +

fern has 3,788 stars and 352 forks on GitHub.

How does fern rank among GitHub repositories? +

With 3,788 stars, fern-api/fern is ranked #1,294 globally across all repositories tracked on GitHubRepo and #182 among TypeScript projects.

What license is fern distributed under? +

The repository reports a Apache-2.0 license. Always verify the repository LICENSE file for legal terms.

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💼

LinkedIn

Why fern is replacing paid subscriptions for engineering teams

Stop paying $50+/month for locked SaaS tools.

Over 3,788 developers have starred fern-api/fern, an impressive TypeScript open-source project designed to Input OpenAPI. Output SDKs and Docs.

Key Engineering Advantages:
• 100% Local-First: Complete data privacy with zero tracking or telemetry.
• Zero Subscription Costs: No paywalls, per-seat fees, or API markups.
• Complete Customization: Native open-source architecture you can fork, inspect, and deploy anywhere.
• Proven Adoption: 3,788 GitHub stars and 352 forks.

If you're looking to streamline your engineering workflows without ballooning software expenses, this is worth checking out.

👉 Full star velocity and architectural report: https://githubrepo.cloud/repo/fern-api/fern
⭐ GitHub Repository: https://github.com/fern-api/fern

#OpenSource #SoftwareEngineering #DeveloperTools #Tech #Programming #TypeScript

🤖

Reddit (r/opensource, r/webdev, r/selfhosted)

Show r/opensource: fern – A free, self-hosted tool that lets you Input OpenAPI. Output SDKs and Docs

Hey everyone,

I wanted to share an interesting open-source project called **fern** (https://github.com/fern-api/fern) that has been picking up heavy momentum lately (3,788 stars).

### What problem does it solve?
Many existing tools in this domain require expensive cloud plans or store your data on third-party servers. fern was built with a local-first philosophy, allowing developers to Input OpenAPI. Output SDKs and Docs without recurring subscription costs or privacy compromises.

### Tech Stack & Details:
- **Language:** TypeScript
- **License:** Apache-2.0
- **GitHub:** [fern-api/fern](https://github.com/fern-api/fern)
- **Live Star Momentum Tracker:** [https://githubrepo.cloud/repo/fern-api/fern](https://githubrepo.cloud/repo/fern-api/fern)

Has anyone here tested this in production or integrated it into existing pipelines? Would love to hear your experience and feedback!

🟧

Hacker News (Show HN)

Show HN: fern – Input OpenAPI. Output SDKs and Docs

Hi HN,

fern is an open-source TypeScript project designed to Input OpenAPI. Output SDKs and Docs.

Rather than relying on closed cloud endpoints, it executes locally on your own machine, providing predictable latency, total privacy, and full control.

Repository: https://github.com/fern-api/fern
Documentation & Metrics: https://githubrepo.cloud/repo/fern-api/fern

Feedback and PRs are welcome.

✍️

Dev.to / Hashnode Tags: opensource, typescript, devtools, webdev

This GitHub repo replaces a $50 a month tool! Stop paying expensive software subscriptions. Meet fern (3,788 GitHub Stars)

---
title: This GitHub repo replaces a $50 a month tool! Stop paying expensive software subscriptions. Meet fern
published: true
tags: opensource, typescript, devtools, programming
---

## Stop Paying Software Subscriptions For This

Finding high-quality, production-ready open source alternatives to expensive proprietary software can save engineering teams thousands of dollars every year.

Today, we're looking at **[fern-api/fern](https://github.com/fern-api/fern)**, a rapidly rising repository with **3,788 GitHub stars** and **352 forks**.

### What is fern?

> Input OpenAPI. Output SDKs and Docs

Written in **TypeScript**, fern runs directly on your local workstation or private server, keeping your data secure and eliminating recurring license fees.

### Key Highlights
- **High Performance:** Lightweight, reliable, and built in TypeScript.
- **Privacy & Security:** Complete ownership of your environment and data.
- **Growing Momentum:** Ranked **#1,294** globally across tracked repositories on [GitHubRepo](https://githubrepo.cloud/repo/fern-api/fern).

### Quick Start
To get started locally:

```bash
git clone https://github.com/fern-api/fern.git
cd fern
```

Check out the full repository and star history analytics here:
- **GitHub:** [fern-api/fern](https://github.com/fern-api/fern)
- **Star Velocity Tracker:** [fern on GitHubRepo.cloud](https://githubrepo.cloud/repo/fern-api/fern)

𝕏

X / Twitter Communities

Thread / Community Post for fern

Developers are sleeping on this GitHub repo 👇

fern-api/fern (3,788 ⭐) replaces expensive monthly software subscriptions with 100% free open source code.

⚡ What it does: Input OpenAPI. Output SDKs and Docs
💻 Built with: TypeScript
🔒 100% local execution & privacy

Check live star velocity and benchmarks:
https://githubrepo.cloud/repo/fern-api/fern

#opensource #developer #coding #tech #programming

🧵

Threads Topics

Topic Discussion: Open Source & Developer Tools

This GitHub repo replaces a $50/month tool! 🚀

If you want to save hours of manual work and stop paying subscriptions, check out fern-api/fern.

It already has over 3,788 stars and lets you Input OpenAPI. Output SDKs and Docs.

Drop a comment if you've tried it, or check the full star momentum report:
https://githubrepo.cloud/repo/fern-api/fern

From our network

fern-api/fern

Star History

Momentum

Trending Record

💡 Overview

⚡ Key Features

📥 Installation

⚙ System Requirements

Platforms

Runtime & Dependencies

Architecture

🧠 How It Works

🎯 Production Use Cases

Production System Integration

CI/CD Automated Pipelines

Developer Tooling & Workflows

Open Source Extension

🚀 Getting Started

👍 Strengths

⚠️ Considerations

⇄ Alternatives & Direct Competitors

👥 Who Should Use This

🏆 Nearby in the Rankings

Frequently Asked Questions

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