Lean-lsp-mcp is an MCP server that enables agentic interaction with the Lean theorem prover through the Language Server Protocol using leanclient. It provides a broad toolkit for LLM agents to understand, analyze, and interact with Lean projects. The server exposes rich Lean tooling, including diagnostics, proof goals, term information, and hover documentation, within an LSP-based interface. It also integrates external search tools such as LeanSearch, Loogle, Lean Finder, Lean Hammer, and Lean State Search to locate relevant theorems and definitions. A local search option, lean_local_search (requiring ripgrep), helps agents verify declarations inside the project. A suite of MCP tools supports file outline, diagnostic messages, goals, term goals, hover information, symbol declarations, code completions, and on-demand code execution, plus multi-attempt evaluation to compare proof candidates. The project ships with out-of-the-box setup guidance and configurable environments for editors like VSCode, Cursor, and Claude Code. It supports multiple transports (stdio, streamable-http, sse) and optional bearer authentication via LEAN_LSP_MCP_TOKEN. Optional environment variables tailor project paths, logging, and access control.