Contributing & Building from Source

This page is for contributors who want to build SharpLsp from source. If you just want to use SharpLsp, install the VS Code extension — it ships with everything bundled.

Prerequisites

Rust (stable, latest) — install via rustup
.NET 10.0 SDK — download
Node 20 — for the VS Code extension

Recommended: Dev Container

The fastest path is the included dev container. It comes pre-configured with Rust, .NET 10 SDK, Node 20, and all required tooling.

Install Docker and the Dev Containers extension
Open the repository in VS Code
Click Reopen in Container when prompted

Manual Setup

# Build the Rust LSP host
cargo build

# Run clippy lints
cargo clippy

# Run tests
cargo test

# Build the VS Code extension VSIX
cd editors/vscode && npm install && npm run compile

Repository Structure

sharplsp/
├── src/                  # Rust LSP host
├── sidecars/
│   ├── SharpLsp.Sidecar.FSharp/   # F# sidecar (FSharp.Compiler.Service)
│   ├── SharpLsp.Sidecar.CSharp/   # C# sidecar (Roslyn)
│   └── SharpLsp.Sidecar.Common/   # Shared sidecar code
├── editors/
│   ├── vscode/           # VS Code extension (TypeScript)
│   └── zed/              # Zed extension (Rust → wasm32-wasip1)
├── docs/                 # Specs and implementation plans
├── tests/                # E2E tests
└── website/              # This site

Architecture

Three-tier architecture:

Tier 1 — Rust LSP Host: LSP connection (JSON-RPC over stdio), VFS, tree-sitter incremental parsing, request routing, sidecar lifecycle
Tier 2 — C# Sidecar (Roslyn): MSBuildWorkspace, full Roslyn API (completions, diagnostics, refactorings, formatting)
Tier 3 — F# Sidecar (FCS): FSharp.Compiler.Service, Fantomas, FSharpLint

IPC uses MessagePack over named pipes (Windows) / Unix domain sockets (Linux, macOS).

See Architecture for the full breakdown.

Next: Architecture