# Tsdown

> tsdown is a fast and elegant TypeScript library bundler powered by Rolldown and Oxc

- Skill: `franky47/tsdown` (Agent Skill, multi-file: 19 files)
- Install (CLI): `npx skillmds@latest add franky47/tsdown`
- Raw SKILL.md: https://api.skillmd.com/api/skills/franky47/tsdown/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: franky47 (https://skillmd.com/u/franky47)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/franky47/tsdown

---


tsdown is a next-generation TypeScript library bundler built on Rolldown and Oxc. It provides blazing-fast builds, automatic `.d.ts` generation, and seamless migration from tsup. Supports Rolldown/Rollup/Unplugin plugins and features smart dependency handling.

> This documentation is based on **tsdown v0.20.1**.

**Anthony's Preferences:**

- Build pure-ESM packages, avoid CJS
- Always enable `dts` option for type declarations
- Enable `exports` option for auto-generated package exports

## Core

| Topic         | Description                                       | Reference                                |
| ------------- | ------------------------------------------------- | ---------------------------------------- |
| Configuration | Config file setup, defineConfig, multiple configs | [core-config](references/core-config.md) |
| CLI           | Command-line interface and options                | [core-cli](references/core-cli.md)       |
| Entry Points  | Entry files, aliases, glob patterns               | [core-entry](references/core-entry.md)   |

## Build Options

| Topic             | Description                                            | Reference                                                        |
| ----------------- | ------------------------------------------------------ | ---------------------------------------------------------------- |
| Output            | Format (ESM/CJS/IIFE/UMD), directory, target, platform | [options-output](references/options-output.md)                   |
| Declaration Files | .d.ts generation, isolatedDeclarations, sourcemaps     | [options-dts](references/options-dts.md)                         |
| Dependencies      | External, noExternal, dependency bundling              | [options-dependencies](references/options-dependencies.md)       |
| Package Exports   | Auto-generating exports, main, module fields           | [options-package-exports](references/options-package-exports.md) |

## Features

| Topic         | Description                            | Reference                                                    |
| ------------- | -------------------------------------- | ------------------------------------------------------------ |
| Optimization  | Tree shaking, minification, sourcemaps | [features-optimization](references/features-optimization.md) |
| Shims         | CJS/ESM compatibility shims            | [features-shims](references/features-shims.md)               |
| Unbundle Mode | Bundleless transpile-only builds       | [features-unbundle](references/features-unbundle.md)         |
| Watch Mode    | Auto-rebuild on file changes           | [features-watch](references/features-watch.md)               |

## Advanced

| Topic            | Description                                | Reference                                                            |
| ---------------- | ------------------------------------------ | -------------------------------------------------------------------- |
| Plugins          | Rolldown, Unplugin, Rollup, Vite plugins   | [advanced-plugins](references/advanced-plugins.md)                   |
| Hooks            | Build lifecycle hooks                      | [advanced-hooks](references/advanced-hooks.md)                       |
| Programmatic API | Using tsdown from code                     | [advanced-programmatic](references/advanced-programmatic.md)         |
| Rolldown Options | Customizing inputOptions and outputOptions | [advanced-rolldown-options](references/advanced-rolldown-options.md) |

## Recipes

| Topic             | Description                    | Reference                                              |
| ----------------- | ------------------------------ | ------------------------------------------------------ |
| Framework Support | Vue and React library bundling | [recipes-frameworks](references/recipes-frameworks.md) |
| Migration         | Migrating from tsup            | [recipes-migration](references/recipes-migration.md)   |