Code Bundling

txiki.js supports ES modules natively, but when deploying applications you may want to bundle all your source files into a single JavaScript file. This is especially useful for standalone executables and for projects written in TypeScript.

esbuild is the recommended bundler for txiki.js projects. It's fast and handles both bundling and TypeScript type stripping in a single step.

Using tjs bundle

txiki.js ships with a built-in bundle command that automatically downloads esbuild (if needed) and runs it with the right flags for txiki.js compatibility. No extra tools or dependencies required.

Basic usage

tjs bundle my-app/index.js bundle.js

If you omit the output file, it defaults to <name>.bundle.js:

tjs bundle my-app/index.js
# produces my-app/index.bundle.js

TypeScript support

esbuild natively strips TypeScript types during bundling, so .ts and .tsx files work as input without any extra configuration. Note that esbuild does not perform type checking. You should use tsc --noEmit separately if you need that.

tjs bundle my-app/index.ts bundle.js

Minification

Add --minify (or -m) to reduce the output size:

tjs bundle --minify my-app/index.ts bundle.js

This is especially useful when creating standalone executables, as the bundled code is embedded in the resulting binary.

How it works

The first time you run tjs bundle, the esbuild binary is downloaded from the npm registry and cached in ~/.tjs/esbuild/<version>/. Subsequent runs reuse the cached binary. The download requires no system tools since it uses the built-in fetch API and DecompressionStream to stream the tarball directly to disk.

Under the hood, esbuild is invoked with the following flags:

Flag	Purpose
--bundle	Resolve all imports and bundle into a single file
--external:tjs:*	Don't bundle tjs:* standard library imports — they are provided by the runtime
--target=esnext	Use the latest JavaScript syntax (txiki.js supports ES2025)
--platform=neutral	Don't assume Node.js or browser globals
--format=esm	Output ES module format
--main-fields=main,module	Prefer the module entry point in package.json

Using esbuild directly

If you need more control over the bundling process, you can invoke esbuild directly:

npx esbuild my-app/index.ts \
    --bundle \
    --outfile=bundle.js \
    --external:tjs:* \
    --target=esnext \
    --platform=neutral \
    --format=esm \
    --main-fields=main,module

There are other interesting options available, check the API documentation.