ra-mcp

rust-analyzer MCP Server - Rust code intelligence for AI assistants.

Why ra-mcp?

Beyond standard LSP features, ra-mcp provides:

Feature	Description
Macro Expansion	ra_expand_macro to analyze macro output, ra_view_hir for IR inspection
Symbol Index	Build persistent index with ra_build_index, fast queries with ra_query_index
Concurrent Access	Thread-safe design supports multiple AI agents simultaneously
Extended Analysis	ra_runnables, ra_related_tests, ra_ssr structural search-replace
Test Relations	ra_related_tests finds tests for any function

Installation

git clone https://github.com/your-org/ra-mcp.git
cd ra-mcp
cargo build --release

Configure in MCP client:

{
  "mcpServers": {
    "ra-mcp": {
      "command": "target/release/ra-mcp",
      "args": ["--workspace", "/path/to/rust/project"]
    }
  }
}

CLI Options

Argument	Default
--workspace <PATH>	Current directory
--log-level <LEVEL>	info
--timeout <MS>	30000

Tools

Navigation

Tool	Parameters
ra_hover	file_path, line, character
ra_definition	file_path, line, character
ra_type_definition	file_path, line, character
ra_implementation	file_path, line, character
ra_references	file_path, line, character, include_declaration?
ra_call_hierarchy	file_path, line, character
ra_parent_module	file_path, line, character

Intellisense

Tool	Parameters
ra_completion	file_path, line, character
ra_signature_help	file_path, line, character
ra_inlay_hints	file_path, start_line, start_character, end_line, end_character

Symbols

Tool	Parameters
ra_document_symbols	file_path, limit?, kind?
ra_outline	file_path
ra_find	file_path, query, kind?, limit?
ra_workspace_symbols	query, kind?, limit?

Refactoring

Tool	Parameters
ra_rename	file_path, line, character, new_name
ra_code_actions	file_path, start_line, start_character, end_line, end_character

Diagnostics

Tool	Parameters
ra_diagnostics	file_path
ra_workspace_diagnostics	-

rust-analyzer Extensions

Tool	Parameters
ra_expand_macro	file_path, line, character
ra_runnables	file_path, line?, character?
ra_related_tests	file_path, line, character
ra_open_docs	file_path, line, character
ra_ssr	query, parse_only?
ra_syntax_tree	file_path
ra_view_hir	file_path, line, character
ra_crate_graph	full?

Index Management

Tool	Parameters
ra_build_index	-
ra_query_index	query, kind?, limit?
ra_clear_index	-

SymbolKind Values

file, module, namespace, package, class, method, property, field, constructor, enum, interface, function, variable, constant, struct, enum_member, trait, type_parameter, operator, event

License

MIT