1. Habit
  2. Skills
  3. tsdown skill
rolldown · 2K installs

tsdown skill
Runs by itself, pull request opened.

Library builds valid before publish.

Install the tsdown skill and make it a habit: follow https://gethabit.dev/skills/rolldown/tsdown.md

  1. 1Copy
  2. 2Paste into Claude Code, Codex or Cursor
  3. 3It runs by itself

2K installs4K starsMIT licenceSource on GitHub ↗

tsdown

by rolldown · 2K installs

The skill

Tsdown is a skill for library authors that bundles TypeScript and JavaScript libraries with tsdown and Rolldown: declarations, ESM and CJS formats, dependency handling, package validation and migration from tsup.

Only when you ask.

The habit

Library builds valid before publish.

↻ Runs by itselfpull request opened

How the habit works.
You don't have to.

Three questionsWhen does it start? How does it check its work? What does it remember?

01

It starts by itself

pull request opened. Runs in GitHub Actions.

  • ↻ pull request opened
  • pull_request.opened

02

It checks its work

build and package checks. If a check fails, it tells you.

  • ✓npx tsdown builds with no errors
  • ✓type declarations are emitted when dts is true
  • ✓publint and attw pass
  • ✓tests pass on the built output

03

It remembers

build warnings log. The next run reads it first: recent warnings and package issues.

loops/library-bundle-check-loop/run-log.md

One run, step by step.
Then it stops.

Stop ruleStops after one build per pull request, with one retry.

  1. 01

    Check Node

    Build on Node.js 22.18.0 or higher.

  2. 02

    Build

    Run npx tsdown --config tsdown.config.ts.

  3. 03

    Validate package

    Use publint and attw, set to ci-only in the config.

  4. 04

    Test the output

    Run the tests on the built output for each supported Node version.

  5. 05

    Log

    Write warnings and package issues into the run log.

What it may do.
Nothing more.

Safe by defaultIt writes only in its own folder and asks you before anything goes out.

Is it for you?
Use it when it fits.

Quick checkRead both lists. If the left one sounds like you, the tsdown skill helps.

Use it when

  • ✓ You build an npm library
  • ✓ You need .d.ts files
  • ✓ You migrate from tsup

Skip it when

  • – You bundle a web app
  • – You build with Node below 22.18

Questions

tsdown skill, answered.

Is my library locked to Node 22?

No. Only the build needs Node 22.18+; the target option sets the output.

Can it migrate from tsup?

Yes. Run npx tsdown-migrate.

How do I install the tsdown skill?

Copy the prompt at the top into your agent. It installs the skill from rolldown/tsdown and sets up the habit. Or run npx skills add rolldown/tsdown --skill tsdown.

Is the tsdown skill free?

Yes. It is published under MIT. Habit is free too.

tsdown. Now as a habit.

Install the tsdown skill and make it a habit: follow https://gethabit.dev/skills/rolldown/tsdown.md

  • Free
  • No account
  • Undo in one line

All rolldown skills →More code skills →

Works in

  • Claude Code
  • Codex
  • Cursor
  • ChatGPT
  • Claude app

Made by rolldown, published under MIT. Habit links to the original and never changes it. Is this your skill?

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