---
title: "Introducing Forge: the open source pipeline for generating SDKs, CLIs, docs, and more"
description: "Cloudflare introduced Forge, an open source, pluggable generation pipeline for producing SDKs, CLIs, documentation, and other API surfaces from API definitions. Forge runs in CI on each team’s API repositories, linting every change and generating preview builds of the CLI, docs, and SDKs with only the changes highlighted, similar to Workers Previews. It supports OpenAPI as input and can chain transformers to produce outputs like Cap’n Web bindings, TanStack Query, or MCP servers, enabling generation of bindings from Workers to other APIs. Forge is designed to reduce coordination overhead across Cloudflare’s hundreds of services and repos, and to enable better API versioning without breaking existing clients or SDKs. It is available under the Apache 2.0 license and can be run for free, privately or publicly, and already generates the output required for the cf CLI."
---

# Introducing Forge: the open source pipeline for generating SDKs, CLIs, docs, and more

[Cloudflare](https://yomu.fyi/company/cloudflare) · Samuel Macleod · Sep 28, 2026

**Type:** Announcement

## Summary

Cloudflare introduced Forge, an open source, pluggable generation pipeline for producing SDKs, CLIs, documentation, and other API surfaces from API definitions. Forge runs in CI on each team’s API repositories, linting every change and generating preview builds of the CLI, docs, and SDKs with only the changes highlighted, similar to Workers Previews. It supports OpenAPI as input and can chain transformers to produce outputs like Cap’n Web bindings, TanStack Query, or MCP servers, enabling generation of bindings from Workers to other APIs. Forge is designed to reduce coordination overhead across Cloudflare’s hundreds of services and repos, and to enable better API versioning without breaking existing clients or SDKs. It is available under the Apache 2.0 license and can be run for free, privately or publicly, and already generates the output required for the cf CLI.

## Context

Cloudflare’s API has over 3,500 operations across hundreds of services written in Rust, Go, TypeScript, and Python. They needed a flexible generation pipeline that could handle this scale, reduce coordination overhead between teams, generate preview builds on every pull request across hundreds of repos, and extend to generate more than just SDKs. Existing hosted products did not solve these problems and some shut down entirely, leading Cloudflare to build Forge.

## Approach / What changed

Forge is a pluggable generation pipeline that runs in CI on each team’s API repositories. It lints every change and generates preview builds of the CLI, docs, and SDKs with only the changes highlighted, similar to Workers Previews. It supports OpenAPI as input and allows chaining transformers to produce outputs like Cap’n Web bindings, TanStack Query, or MCP servers. Forge is open source under the Apache 2.0 license and can be run for free, privately or publicly.

## Takeaways

- Forge runs in CI on each team’s API repos, linting every change and generating preview builds of CLI, docs, and SDKs before merge, similar to Workers Previews.
- Forge transformers can be chained: the OpenAPI definition is built into the TypeScript SDK, which is then used to generate the cf CLI and Cap’n Web specifications.
- Forge is designed to enable better API versioning, allowing release of new major API versions without breaking old clients or SDKs, addressing Cloudflare’s v4 API challenges.

## FAQ

### What input formats does Forge support?

Forge currently supports OpenAPI as an input type, but is designed to allow AsyncAPI, GraphQL, Cap'n Proto, Protobuf, or other input formats in the future.

### How does Forge handle handwritten CLI commands?

Forge allows feeding handwritten commands back into the documentation so they can be documented alongside generated output, solving a problem Cloudflare faced with the cf CLI's local-only behaviors like cf dev and cf build.

### Under what license is Forge available?

Forge is available open source under the permissive Apache 2.0 license, allowing anyone to run it for any purpose, with custom modifications, for free, in private.

**Tags:** [API](https://yomu.fyi/topic/api), [CI/CD](https://yomu.fyi/topic/ci-cd), [CLI](https://yomu.fyi/topic/cli), [Open Source](https://yomu.fyi/topic/open-source), [SDK](https://yomu.fyi/topic/sdk)

- Source: [Cloudflare](https://blog.cloudflare.com/forge-open-source-generation-pipeline)
- Source URL: https://blog.cloudflare.com/forge-open-source-generation-pipeline
- Ingested by Yomu: 2026-09-28T15:00:11.824Z

[Read original post](https://blog.cloudflare.com/forge-open-source-generation-pipeline)