Rslib is an MIT-licensed library development tool built on Rsbuild that lets developers create JavaScript libraries and UI component libraries with zero configuration, across React, Vue, Svelte, and Solid.

What it is

Rslib is a library development tool based on Rsbuild, and it belongs to Rstack, the unified JavaScript toolchain that also holds the Rspack bundler, the Rsbuild build tool, the Rspress static site generator, the Rsdoctor build analyzer, the Rstest testing framework, and the Rslint linter. It supplies tool integrations and best practices that run across building, debugging, documentation, and testing for the whole life of a library, rather than stopping at the bundling step. It is written in TypeScript and is decoupled from frontend UI frameworks, so React, Vue, Svelte, Solid, and other targets can be built through plugins under one consistent configuration and workflow. Its build engine is Rspack, and it brings in Rust-based community tooling including SWC and Lightning CSS.

The concrete problem it solves is the configuration burden of packaging a library. Authors must otherwise decide output formats, targets for different runtimes, distribution methods, and compatibility with downstream build tools, then maintain that setup themselves as the project grows. Rslib replaces that per-project bundler configuration with out-of-the-box tooling that builds libraries with zero configuration, while offering a set of semantic build configurations that extend as needs appear. Because it accepts Rsbuild plugins, Rspack plugins, and webpack plugins, existing plugin choices and engineering practices carry over instead of being rewritten. In the JavaScript and TypeScript ecosystem this makes Rslib the library-facing layer of the Rstack toolchain, sitting above Rspack and Rsbuild and complementing Rspress, Rstest, and Rsdoctor.

Key capabilities

• Zero-configuration library builds, with semantic build configurations that extend as project requirements grow.
• Performance-oriented builds powered by Rspack, integrating the Rust-based SWC and Lightning CSS tools.
• Plugin compatibility across the Rsbuild plugin ecosystem, Rspack plugins, and webpack plugins.
• Flexible output configuration for different runtimes, distribution methods, and downstream build tools, covering varied library publishing and consumption patterns.
• Framework-agnostic component library builds for React, Vue, Svelte, and Solid through plugins.
• Membership in the Rstack toolchain alongside Rspack, Rsbuild, Rspress, Rsdoctor, Rstest, and Rslint.
• Documentation split by major version, with Rslib v1 docs at https://rslib.rs and Rslib v0 docs at https://v0.rslib.rs.

Who uses it and how

• JavaScript and TypeScript library authors who publish packages and want build, debugging, documentation, and testing integrations in one place.
• UI component library maintainers shipping for React, Vue, Svelte, or Solid who want one configuration and workflow across frameworks.
• Teams already invested in webpack plugins, or in Rspack and Rsbuild plugins, who reuse those plugins rather than changing build approach.
• Adopters of the wider Rstack toolchain, pairing Rslib for library output with Rsbuild for builds, Rspress for docs, Rstest for testing, Rsdoctor for build analysis, and Rslint for linting.
• Documentation and demo workflows built on the Rsbuild-powered Storybook builder, storybook-rsbuild, or drawing on rstack-examples and agent-skills.

Getting started

Rslib is installed and configured through the Rslib v1 documentation at https://rslib.rs, while projects staying on the earlier major version should follow the Rslib v0 docs at https://v0.rslib.rs. The repository's Contributing Guide covers contribution setup, and the Rstack Discord is the community channel.

How it compares

Within the tools named here, Rslib sits above the Rspack bundler and the Rsbuild build tool in the same Rstack toolchain, serving library publishing rather than application bundling or app build orchestration. It reaches across to webpack through plugin support, so existing webpack plugin choices stay usable inside an Rslib build. The project also credits esbuild and mini-css-extract-plugin among the open source projects its work derives from or is inspired by.

When to use it — and when not to

Choose Rslib when the deliverable is a library or component library that must be built into several output shapes, and when the Rsbuild, Rspack, and webpack plugin ecosystems matter to the setup. Do not pick it for application builds, which are the job of Rsbuild and Rspack, nor if the project sits outside the JavaScript toolchain or cannot adopt Node-based build tooling. There is no service to self-host, so the running cost is the CI and developer machines that execute the build rather than any database or storage; note also that documentation is split between the v1 and v0 sites, which matters when maintaining code written against the older version.