> For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt.

# tools

Options for low-level tools.

## tools.bundlerChain [![tools.bundlerChain](https://assets.rspack.rs/rsbuild/rsbuild-logo.svg)tools.bundlerChain](https://rsbuild.rs/config/tools/bundler-chain)
[rspack-chain](https://github.com/rstackjs/rspack-chain) is a utility library for configuring Rspack. By using `rspack-chain`, you can more easily modify and extend Rspack configurations.

## tools.rspack [![tools.rspack](https://assets.rspack.rs/rsbuild/rsbuild-logo.svg)tools.rspack](https://rsbuild.rs/config/tools/rspack)
`tools.rspack` is used to configure [Rspack](https://rspack.rs/config/index).

## tools.swc [![tools.swc](https://assets.rspack.rs/rsbuild/rsbuild-logo.svg)tools.swc](https://rsbuild.rs/config/tools/swc)
You can set the options of [builtin:swc-loader](https://rspack.rs/guide/features/builtin-swc-loader) through `tools.swc`.