v0.21.0 - Notable Changes

Breaking Changes

Dependency options renamed to deps namespace

The dependency-related options have been moved under a new deps namespace with clearer names:

• external -> deps.neverBundle
• noExternal -> deps.alwaysBundle
• inlineOnly -> deps.onlyAllowBundle
• skipNodeModulesBundle -> deps.skipNodeModulesBundle

Before:

export default defineConfig({
  external: ['vue'],
  noExternal: ['lodash'],
})

After:

export default defineConfig({
  deps: {
    neverBundle: ['vue'],
    alwaysBundle: ['lodash'],
  },
})

The old options still work but are deprecated and will emit warnings.

failOnWarn default changed from 'ci-only' to false

If you relied on the previous behavior where warnings would fail the build in CI environments, you now need to explicitly set failOnWarn: true or failOnWarn: 'ci-only' in your config.

Node.js < 22.18.0 deprecated

tsdown now emits a deprecation warning when running on Node.js versions below 22.18.0. Plan to upgrade your Node.js version accordingly.

New Features

Experimental Node.js SEA executable bundling (exe)

tsdown can now bundle your TypeScript project into a standalone executable using Node.js Single Executable Applications (SEA). A new @tsdown/exe package provides cross-platform executable building support. See the exe documentation for details.

export default defineConfig({
  exe: true, // or { useCodeCache: true, useSnapshot: true }
})

Full CSS pipeline with @tsdown/css

CSS handling has been reimplemented as a native Rolldown plugin and extracted into the @tsdown/css package, providing a complete CSS pipeline with Lightning CSS and PostCSS support via the css.transformer option. See the CSS documentation for details.

inlinedDependencies field in package.json

When using the exports feature, tsdown now auto-generates an inlinedDependencies field in your package.json, listing dependencies that are bundled into the output.

Object option for customExports

customExports now supports an object format for more fine-grained control over the generated exports field.

Migration Guide

1. Update dependency options: Rename external -> deps.neverBundle, noExternal -> deps.alwaysBundle, etc.
2. Check failOnWarn: If you need warnings to fail the build in CI, explicitly set failOnWarn: 'ci-only' or failOnWarn: true.
3. Upgrade Node.js: Ensure you're running Node.js >= 22.18.0 to avoid deprecation warnings.

Links

• tsdown Documentation
• v0.21.0-beta.1 Release
• v0.21.0-beta.2 Release
• v0.21.0-beta.3 Release
• v0.21.0-beta.4 Release
• v0.21.0-beta.5 Release
• Full diff from v0.20.3

   🚨 Breaking Changes

• Change failOnWarn default from 'ci-only' to false  -  by @sxzz (ad8db)
• exe: Require Node >=25.7 and default format to esm  -  by @sxzz in #798 (0173c)

   🚀 Features

• Rename dependency options to deps namespace  -  by @sxzz (7f509)
• Upgrade rolldown  -  by @sxzz (7a528)
• Deprecate Node.js versions below 22.18.0  -  by @sxzz (439f1)
• Support bundling .node files by default  -  by @sxzz (944e9)
• css:
  • Implement full CSS pipeline as Rolldown plugin  -  by @sxzz in #787 (dbe3c)
  • Extract CSS pipeline into @tsdown/css package  -  by @sxzz in #790 (e4cbe)
  • Add PostCSS support with css.transformer option  -  by @sxzz in #791 (35bef)
  • Default css.transformer to lightningcss  -  by @sxzz in #797 (288a5)
• exe:
  • Add experimental Node.js SEA executable bundling  -  by @sxzz in #777 (418d5)
  • Add cross-platform executable building via @tsdown/exe  -  by @sxzz in #786 (b6833)
  • Support latest and latest-lts for nodeVersion  -  by @sxzz (ce7ab)
• exports:
  • Support object option for customExports  -  by @Joery-M and @sxzz in #769 (7fb72)
  • Add inlinedDependencies field to package.json  -  by @sxzz in #785 (5c71f)
• migrate:
  • Migrate external/noExternal to deps namespace  -  by @sxzz (c59e7)

   🐞 Bug Fixes

• Apply failOnWarn to rolldown logs  -  by @sxzz (149dc)
• Debounce onSuccess in watch mode to prevent duplicate execution  -  by @sxzz (af748)
• Don't fail on PLUGIN_TIMINGS warnings when failOnWarn is enabled  -  by @sxzz (9872a)
• Resolve css files in node_modules  -  by @ocavue, @sxzz and Rei in #795 (d8a1f)
• config: Handle known Node.js bug in nativeImport error handling  -  by @sxzz (e4230)
• copy: Don't warn if no files specified  -  by @adamlohner, @cursoragent and @sxzz in #780 (afaab)
• css: Remove empty js chunks  -  by @ocavue and @sxzz in #799 (1183a)
• exe: Use runtime semver check for ESM SEA default format  -  by @sxzz (5321c)
• exports: Include non-entry chunks in exports when all is true  -  by @sxzz (79492)
• hooks: Set cwd for onSuccess  -  by @sxzz (c114a)
• node-protocol: Respect alias and tsconfig paths when stripping node: prefix  -  by @lazuee in #773 (b1dd2)
• watch: Re-glob entry files on create/delete events  -  by @sxzz (a1969)

    View changes on GitHub

v0.21.0-beta.5 - Notable Changes

Breaking Changes

Dependency options renamed to deps namespace

The dependency-related options have been moved under a new deps namespace with clearer names:

• external -> deps.neverBundle
• noExternal -> deps.alwaysBundle
• inlineOnly -> deps.onlyAllowBundle
• skipNodeModulesBundle -> deps.skipNodeModulesBundle

Before:

export default defineConfig({
  external: ['vue'],
  noExternal: ['lodash'],
})

After:

export default defineConfig({
  deps: {
    neverBundle: ['vue'],
    alwaysBundle: ['lodash'],
  },
})

The old options still work but are deprecated and will emit warnings.

failOnWarn default changed from 'ci-only' to false

If you relied on the previous behavior where warnings would fail the build in CI environments, you now need to explicitly set failOnWarn: true or failOnWarn: 'ci-only' in your config.

Node.js < 22.18.0 deprecated

tsdown now emits a deprecation warning when running on Node.js versions below 22.18.0. Plan to upgrade your Node.js version accordingly.

New Features

Experimental Node.js SEA executable bundling (exe)

tsdown can now bundle your TypeScript project into a standalone executable using Node.js Single Executable Applications (SEA). A new @tsdown/exe package provides cross-platform executable building support. See the exe documentation for details.

export default defineConfig({
  exe: true, // or { useCodeCache: true, useSnapshot: true }
})

Full CSS pipeline with @tsdown/css

CSS handling has been reimplemented as a native Rolldown plugin and extracted into the @tsdown/css package, providing a complete CSS pipeline with Lightning CSS and PostCSS support via the css.transformer option. See the CSS documentation for details.

inlinedDependencies field in package.json

When using the exports feature, tsdown now auto-generates an inlinedDependencies field in your package.json, listing dependencies that are bundled into the output.

Object option for customExports

customExports now supports an object format for more fine-grained control over the generated exports field.

Migration Guide

1. Update dependency options: Rename external -> deps.neverBundle, noExternal -> deps.alwaysBundle, etc.
2. Check failOnWarn: If you need warnings to fail the build in CI, explicitly set failOnWarn: 'ci-only' or failOnWarn: true.
3. Upgrade Node.js: Ensure you're running Node.js >= 22.18.0 to avoid deprecation warnings.

Links

• tsdown Documentation
• v0.21.0-beta.1 Release
• v0.21.0-beta.2 Release
• v0.21.0-beta.3 Release
• v0.21.0-beta.4 Release
• v0.21.0-beta.5 Release
• Full diff from v0.20.3

   🚨 Breaking Changes

• exe: Require Node >=25.7 and default format to esm  -  by @sxzz in #798 (0173c)

   🚀 Features

• css: Default css.transformer to lightningcss  -  by @sxzz in #797 (288a5)

   🐞 Bug Fixes

• Resolve css files in node_modules  -  by @ocavue, @sxzz and Rei in #795 (d8a1f)

    View changes on GitHub

   🚀 Features

• css:
  • Extract CSS pipeline into @tsdown/css package  -  by @sxzz in #790 (e4cbe)
  • Add PostCSS support with css.transformer option  -  by @sxzz in #791 (35bef)

    View changes on GitHub

v0.21.0-beta.3 - Notable Changes

Breaking Changes

Dependency options renamed to deps namespace

The dependency-related options have been moved under a new deps namespace with clearer names:

• external -> deps.neverBundle
• noExternal -> deps.alwaysBundle
• inlineOnly -> deps.onlyAllowBundle
• skipNodeModulesBundle -> deps.skipNodeModulesBundle

Before:

export default defineConfig({
  external: ['vue'],
  noExternal: ['lodash'],
})

After:

export default defineConfig({
  deps: {
    neverBundle: ['vue'],
    alwaysBundle: ['lodash'],
  },
})

The old options still work but are deprecated and will emit warnings.

failOnWarn default changed from 'ci-only' to false

If you relied on the previous behavior where warnings would fail the build in CI environments, you now need to explicitly set failOnWarn: true or failOnWarn: 'ci-only' in your config.

Node.js < 22.18.0 deprecated

tsdown now emits a deprecation warning when running on Node.js versions below 22.18.0. Plan to upgrade your Node.js version accordingly.

New Features

Experimental Node.js SEA executable bundling (exe)

tsdown can now bundle your TypeScript project into a standalone executable using Node.js Single Executable Applications (SEA). A new @tsdown/exe package provides cross-platform executable building support. See the exe documentation for details.

export default defineConfig({
  exe: true, // or { useCodeCache: true, useSnapshot: true }
})

Full CSS pipeline as Rolldown plugin

CSS handling has been reimplemented as a native Rolldown plugin, providing a complete CSS pipeline with Lightning CSS integration for transforms, minification, and bundling. See the CSS documentation for details.

inlinedDependencies field in package.json

When using the exports feature, tsdown now auto-generates an inlinedDependencies field in your package.json, listing dependencies that are bundled into the output.

Object option for customExports

customExports now supports an object format for more fine-grained control over the generated exports field.

Migration Guide

1. Update dependency options: Rename external -> deps.neverBundle, noExternal -> deps.alwaysBundle, etc.
2. Check failOnWarn: If you need warnings to fail the build in CI, explicitly set failOnWarn: 'ci-only' or failOnWarn: true.
3. Upgrade Node.js: Ensure you're running Node.js >= 22.18.0 to avoid deprecation warnings.

Links

• tsdown beta Documentation
• v0.21.0-beta.1 Release
• v0.21.0-beta.2 Release
• v0.21.0-beta.3 Release
• Full diff from v0.20.3

   🚀 Features

• Upgrade rolldown  -  by @sxzz (7a528)
• Deprecate Node.js versions below 22.18.0  -  by @sxzz (439f1)
• css: Implement full CSS pipeline as Rolldown plugin  -  by @sxzz in #787 (dbe3c)
• exe: Add cross-platform executable building via @tsdown/exe  -  by @sxzz in #786 (b6833)
• exports: Add inlinedDependencies field to package.json  -  by @sxzz in #785 (5c71f)

   🐞 Bug Fixes

• Don't fail on PLUGIN_TIMINGS warnings when failOnWarn is enabled  -  by @sxzz (9872a)
• hooks: Set cwd for onSuccess  -  by @sxzz (c114a)
• watch: Re-glob entry files on create/delete events  -  by @sxzz (a1969)

    View changes on GitHub

   🚨 Breaking Changes

• Change failOnWarn default from 'ci-only' to false  -  by @sxzz (ad8db)

    View changes on GitHub

   🚀 Features

• Rename dependency options to deps namespace  -  by @sxzz (7f509)
• exe: Add experimental Node.js SEA executable bundling  -  by @sxzz in #777 (418d5)
• exports: Support object option for customExports  -  by @Joery-M and @sxzz in #769 (7fb72)
• migrate: Migrate external/noExternal to deps namespace  -  by @sxzz (c59e7)

   🐞 Bug Fixes

• Apply failOnWarn to rolldown logs  -  by @sxzz (149dc)
• Debounce onSuccess in watch mode to prevent duplicate execution  -  by @sxzz (af748)
• config: Handle known Node.js bug in nativeImport error handling  -  by @sxzz (e4230)
• copy: Don't warn if no files specified  -  by @adamlohner, @cursoragent and @sxzz in #780 (afaab)
• exe: Use runtime semver check for ESM SEA default format  -  by @sxzz (5321c)
• exports: Include non-entry chunks in exports when all is true  -  by @sxzz (79492)
• node-protocol: Respect alias and tsconfig paths when stripping node: prefix  -  by @lazuee in #773 (b1dd2)

    View changes on GitHub

   🐞 Bug Fixes

• package: Ignore scripts when packing  -  by @sxzz (0b10b)

    View changes on GitHub

   🚀 Features

• Upgrade rolldown to 1.0.0-rc.3  -  by @sxzz (0beea)
• dep: Keep inlineOnly clean with hint message on unused  -  by @jycouet and @sxzz in #725 (13f1c)
• pkg: Optimize attw and publint packing  -  by @sxzz in #736 (375cf)

   🐞 Bug Fixes

• Throw error when skipNodeModulesBundle and noExternal are used together  -  by @sxzz in #746 (656d5)
• External type only packages @types/*  -  by @kalvenschraut (0be7c)
• exports: Move import before require  -  by @sxzz (3027a)

    View changes on GitHub

   🚀 Features

• inline-only: Show warnings if bundled deps  -  by @sxzz (1e0e7)

    View changes on GitHub

   🚨 Breaking Changes

• Upgrade dts plugin, remove dts.resolve option  -  by @sxzz (16655)

   🚀 Features

• Add option to disable legacy CJS warning  -  by @sxzz (9fada)
• Apply inlineOnly option for dts files  -  by @sxzz (7d89d)
• Upgrade rolldown to 1.0.0-beta.60  -  by @sxzz (bb3ee)
• Upgrade rolldown to rc 1  -  by @sxzz (1959f)
• entry: Support mixed array and object entries  -  by @sxzz (a8083)

   🐞 Bug Fixes

• Optional parseEnv  -  by @sxzz (be1b6)
• Reload config on restart  -  by @sxzz (1756b)
• Config extensions typo  -  by @aryaemami59 in #722 (d2bb7)
• windows: Normalize path separators in build output  -  by @ryuapp in #719 (c4525)

   🏎 Performance

• Native filter for external plugin  -  by @sxzz (8764e)

    View changes on GitHub