rust-analyzer-server

A standalone HTTP server for rust-analyzer that keeps the language server warm across requests, with installable Claude Code skills for seamless integration.

How It Works

rust-analyzer-server (persistent HTTP server, rust-analyzer always warm)
  ^  REST API (localhost:15423)
  |
Claude Code skills (.claude/commands/ra-*.md)
  -> curl calls to the HTTP server

The server starts rust-analyzer once and keeps it running. All subsequent requests are fast because the project is already indexed.

Prerequisites

1. rust-analyzer in your PATH:

   rustup component add rust-analyzer
   

2. Rust 1.70+ with Cargo

Installation

From Source

git clone https://github.com/DSmyungjin/rust-analyzer-server.git
cd rust-analyzer-server
cargo build --release

The binary will be at target/release/rust-analyzer-server.

Usage

Start the Server

# Start with default settings (port 15423, current directory as workspace)
rust-analyzer-server

# Specify workspace and port
rust-analyzer-server --workspace /path/to/project --port 4000

# Custom bind address
rust-analyzer-server --bind 0.0.0.0 --port 15423

Environment variable RUST_ANALYZER_PORT can also set the port.

Install Claude Code Skills

Copy skill templates into any project:

rust-analyzer-server install /path/to/your/project

This creates .claude/commands/ra-*.md files that provide slash commands like /ra-hover, /ra-definition, /ra-references, etc.

API Endpoints

Endpoint	Method	Description
/api/v1/health	GET	Server status + workspace info
/api/v1/tools	GET	List available tools
/api/v1/workspace	GET	Current workspace
/api/v1/workspace	POST	Change workspace
/api/v1/shutdown	POST	Graceful shutdown
/api/v1/{tool_name}	POST	Call any tool

All responses use a JSON envelope:

{"ok": true, "result": {...}}
{"ok": false, "error": "..."}

Example API Calls

# Health check
curl http://localhost:15423/api/v1/health

# Get hover info
curl -X POST http://localhost:15423/api/v1/rust_analyzer_hover \
  -H 'Content-Type: application/json' \
  -d '{"file_path":"src/main.rs","line":5,"character":10}'

# Find definition
curl -X POST http://localhost:15423/api/v1/rust_analyzer_definition \
  -H 'Content-Type: application/json' \
  -d '{"file_path":"src/main.rs","line":10,"character":15}'

# Workspace symbol search
curl -X POST http://localhost:15423/api/v1/rust_analyzer_workspace_symbol \
  -H 'Content-Type: application/json' \
  -d '{"query":"MyStruct"}'

Available Tools

Tool	Description
rust_analyzer_hover	Type info + docs at position
rust_analyzer_definition	Go to definition
rust_analyzer_references	Find all references
rust_analyzer_workspace_symbol	Search symbols across workspace
rust_analyzer_symbols	Document symbols for a file
rust_analyzer_diagnostics	File diagnostics (errors/warnings)
rust_analyzer_workspace_diagnostics	All workspace diagnostics
rust_analyzer_incoming_calls	Find callers of a function
rust_analyzer_outgoing_calls	Find callees of a function
rust_analyzer_implementation	Find trait implementations
rust_analyzer_parent_module	Navigate to parent module
rust_analyzer_completion	Code completions
rust_analyzer_format	Format document
rust_analyzer_code_actions	Quick fixes and refactorings
rust_analyzer_inlay_hint	Type annotations for a range
rust_analyzer_set_workspace	Change workspace root

Installed Skills

After running rust-analyzer-server install, these slash commands become available in Claude Code:

Skill	Command	Description
/ra-hover	Hover info	Type info + docs at position
/ra-definition	Go to def	Jump to definition
/ra-references	Find refs	All references to a symbol
/ra-search	Symbol search	Workspace-wide symbol search
/ra-diagnostics	File errors	Diagnostics for a file
/ra-workspace-diagnostics	All errors	Workspace-wide diagnostics
/ra-callers	Callers	Who calls this function?
/ra-callees	Callees	What does this function call?
/ra-implementations	Impls	Find trait implementations
/ra-setup	Health check	Verify server status
/ra-impact	Impact analysis	Multi-step analysis (hover + refs + callers + impls)

Development

cargo build          # Build
cargo test           # Run all 35 tests
cargo run            # Run in dev mode
RUST_LOG=debug cargo run  # Verbose logging

License

MIT