A stable systems interface for the native TypeScript compiler — over stdio, with no forks and no patches.

---

corsa-bind is a multi-crate workspace for talking to Corsa (the native TypeScript 7 implementation line) from Rust and JavaScript runtimes. Hot paths live in Rust and stay zero-cost; napi-rs, Rustler, and a shared C ABI carry that performance to JS/TS, Elixir, C, C++, Go, Zig, C#, Swift, and MoonBit — so you can author custom checker tooling and lint rules without reimplementing the checker.

It is deliberately not a reimplementation of the TypeScript Compiler API. It is the layer between upstream's checker and everything that wants to use it:

  Vize · Oxlint · Node · Rust · C · Go · Swift · …
                       │
  ┌────────────────────▼────────────────────┐
  │              corsa-bind                 │
  │  stable API/ABI · worker pools          │
  │  snapshot + process lifecycle           │
  │  virtual projects · cancellation        │
  │  backpressure · observability           │
  └────────────────────┬────────────────────┘
                       │
        upstream native compiler service
                 TypeScript 7+

As upstream's own API matures, this layer should get thinner — and more important. See the Architecture charter.

Warning

This repository is still evolving. The local Rust and Node API/LSP surfaces are hardened for production-style use, but some upstream-facing endpoints remain explicitly experimental.

Important

corsa-bind is built around upstream-supported Corsa workflows. We follow Corsa's recommended stdio/API/LSP integration points, keep ref/corsa-upstream as an exact upstream checkout, and preserve a strict no forks, no patches policy.

The second half of that policy is own integration, not TypeScript semantics: checker semantics are never ours, checker lifecycle is aggressively ours, and when upstream ships something we approximate today, we delete ours and wrap theirs. The Architecture charter spells out what that rules in and out.

Quick start

Enter the Nix dev shell and build the workspace:

nix develop
vp install
vp run -w build

A first program in Rust — no Corsa binary required:

use corsa::{
    lsp::{VirtualChange, VirtualDocument},
    runtime::block_on,
};
use lsp_types::{Position, Range};

fn main() -> Result<(), corsa::CorsaError> {
    block_on(async {
        let mut doc =
            VirtualDocument::untitled("/virtual/minimal.ts", "typescript", "const answer = 41;\n")?;
        doc.apply_changes(&[VirtualChange::splice(
            Range::new(Position::new(0, 15), Position::new(0, 17)),
            "42",
        )])?;
        Ok(())
    })
}

cargo run -p corsa --example minimal_start

The Getting started guide covers the Node.js and type-aware Oxlint entry points and how to run against the real pinned Corsa binary.

Documentation

Full guides live under docs/:

Guide	What it covers
Getting started	First program in Rust, Node.js, and Oxlint
Architecture charter	The ownership boundary and the rules that follow from it
Architecture	Workspace shape, upstream policy, extension points, naming
Node.js binding	@corsa-bind/napi for Node, Deno, and Bun
Language bindings	Native bindings for Elixir, C, C++, Go, Zig, C#, Swift, MoonBit
Type-aware Oxlint	corsa-oxlint rule authoring and native rules
Native rules	The type-aware Rust lint rules and their options
Performance	Benchmark entry points and measured numbers
CI and local checks	Reproduce the GitHub checks locally
Production readiness	Runtime controls and release gates
Support policy	Supported platforms, bindings, and experimental scope

The generated documentation site starts at docs/index.md and is built with vp run -w docs_build.

Status

• License: MIT
• Upstream: ref/corsa-upstream is pinned by exact commit in corsa_ref.lock.toml, with no local patching
• Default transport: SyncMsgpackStdio (msgpack-first)
• Runtime: custom in-house runtime, no tokio
• Published packages: @corsa-bind/napi and corsa-oxlint (both expect a caller-provided Corsa executable)
• Process isolation: every checker query crosses a process boundary on purpose — crash, GC, ABI, and TypeScript-version isolation, plus timeouts, cancellation, restart, and memory kill
• Scaling: single-machine worker pools with project affinity, and repo-level sharding above that; the Raft-backed replication layer was removed in 2.0

Public APIs are still 0.x, so treat compatibility as conservative. See Known limitations for the current experimental scope.

Sponsors

CI/CD runners for this project are supported by Blacksmith.