\n OpenAPI 3 and 3.1 schema generator and validator for Hono, itty-router and more!\n
\n\n\n\n**Documentation**: chanfana.pages.dev\n\n**Source Code**: github.com/cloudflare/chanfana\n\n\n\n## Overview\n\n[chanfana](https://github.com/cloudflare/chanfana) **(previously known as itty-router-openapi)** is a library that adds\nOpenAPI schema generation and validation to any router (\nHono, itty-router, etc), meant to be a\npowerful and lightweight\nlibrary for Cloudflare Workers but runs on any runtime supported by the base router.\n\nThe key features are:\n\n- OpenAPI 3 and 3.1 schema generator and validator\n- Zod v4 compatible with full TypeScript inference\n- Fully written in typescript\n- [Class-based endpoints](https://chanfana.pages.dev/endpoints/defining-endpoints)\n- Query, Path, Headers, and Body typescript inference, see [Parameters](https://chanfana.pages.dev/endpoints/parameters) and [Request Validation](https://chanfana.pages.dev/endpoints/request-validation)\n- Extend existing [Hono](https://chanfana.pages.dev/router-adapters), [itty-router](https://chanfana.pages.dev/router-adapters), etc application, without touching old routes\n- CLI to extract the schema.json from your code (npx chanfana) - see [CLI Documentation](https://chanfana.pages.dev/cli)\n\n## AI Skills\n\nChanfana provides AI coding assistant skills to help you build OpenAPI endpoints faster. Install them using [npx skills](https://www.npmjs.com/package/skills):\n\n```bash\nnpx skills install cloudflare/chanfana\n```\n\nAvailable skills:\n- **write-endpoints** - Comprehensive guide for building OpenAPI endpoints with schema definition, request validation, CRUD operations, and D1 integration\n\n## Getting started\n\n[](https://deploy.workers.cloudflare.com/?url=https://github.com/cloudflare/chanfana/tree/main/template)\n\nOr scaffold it locally with the `create-cloudflare` CLI:\n\n```bash\nnpm create cloudflare@latest -- --template https://github.com/cloudflare/chanfana/tree/main/template\n```\n\nThe template includes a complete Task API with Hono, D1, and Zod v4 — full CRUD endpoints, a custom endpoint example, integration tests, and auto-generated docs at `/api/docs`.\n\nSee [`template/README.md`](template/README.md) for full setup instructions.\n\n## Installation\n\n```bash\nnpm i chanfana --save\n```\n\n## Command-Line Interface (CLI)\n\nChanfana includes a CLI tool to help you extract the OpenAPI schema from your Cloudflare Worker project. This is useful for generating a static schema file, for example, in CI/CD pipelines.\n\nThe basic command is:\n```bash\nnpx chanfana\n```\nThis will start your worker using `wrangler dev`, fetch the schema from `/openapi.json`, and save it to `schema.json`.\n\nFor more details on options and usage, please refer to the [**CLI Documentation**](https://chanfana.pages.dev/cli).\n\n## Minimal Hono Example\n\n```ts\nimport { fromHono, OpenAPIRoute } from 'chanfana'\nimport { Hono } from 'hono'\nimport { z } from 'zod'\n\nexport type Env = {\n // Example bindings\n DB: D1Database\n BUCKET: R2Bucket\n}\nexport type AppContext = Context<{ Bindings: Env }>\n\nexport class GetPageNumber extends OpenAPIRoute {\n schema = {\n request: {\n params: z.object({\n id: z.string().min(2).max(10),\n }),\n query: z.object({\n page: z.number().int().min(0).max(20),\n }),\n },\n }\n\n async handle(c: AppContext) {\n const data = await this.getValidatedData()\n\n return c.json({\n id: data.params.id,\n page: data.query.page,\n })\n }\n}\n\n// Start a Hono app\nconst app = new Hono<{ Bindings: Env }>()\n\n// Setup OpenAPI registry\nconst openapi = fromHono(app)\n\n// Register OpenAPI endpoints (this will also register the routes in Hono)\nopenapi.get('/entry/:id', GetPageNumber)\n\n// Export the Hono app\nexport default app\n```\n\n## Feedback and contributions\n\n[chanfana](https://github.com/cloudflare/chanfana) aims to be at the core of new APIs built using\nWorkers and define a pattern to allow everyone to\nhave an OpenAPI-compliant schema without worrying about implementation details or reinventing the wheel.\n\nchanfana is considered stable and production ready and is being used with\nthe [Radar 2.0 public API](https://developers.cloudflare.com/radar/) and many other Cloudflare products.\n\nYou can also talk to us in the [Cloudflare Community](https://community.cloudflare.com/) or\nthe [Radar Discord Channel](https://discord.com/channels/595317990191398933/1035553707116478495)\n","readmeFilename":"README.md"}
![\"chanfana\"/](\"https://raw.githubusercontent.com/cloudflare/chanfana/refs/heads/main/docs/public/assets/logo.png\"){kind=logo}
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