Serena

What is Serena?

Serena is an MCP server that provides AI coding agents with IDE-level semantic code retrieval, editing, refactoring, and debugging tools. It operates at the symbol level, exploiting relational code structure, and integrates with any MCP-compatible client or LLM.

How to use Serena?

Install Serena via the uv package manager, then connect it to your AI client either by providing a launch command that starts the MCP server, or by running the server in HTTP mode and providing the URL. Supported clients include Claude Code, Codex, VSCode, Cursor, JetBrains IDEs, Claude Desktop, and others.

Key features of Serena

• Symbol-level code retrieval (find symbol, references, type hierarchy)
• Cross-file refactoring (rename, move, inline, remove unused code)
• Symbolic editing (replace body, insert before/after, safe delete)
• Interactive debugging (JetBrains plugin exclusive)
• Memory management for long-lived agent workflows
• Supports over 40 languages via language servers or JetBrains IDE

Use cases of Serena

• Faster semantic navigation and editing in large, complex codebases
• Cross-file renames and refactorings that would otherwise require many error-prone steps
• Monorepo dependency jumps and reference lookups
• Interactive debugging sessions controlled by the agent

FAQ from Serena

How is Serena different from search-and-replace or line-number based tools?

Serena operates at the symbol level, exploiting code structure and relationships. This makes the agent faster, more efficient, and more reliable, especially in larger projects, compared to low‑level text manipulations.

What programming languages does Serena support?

When using language servers, Serena supports over 40 languages including Python, Java, C/C++, TypeScript, Rust, Go, and many more. With the paid JetBrains plugin, it supports all languages and frameworks covered by JetBrains IDEs (excluding Rider and CLion).

Do I need a paid plugin to use Serena?

No. The default backend uses free/open‑source language servers. A paid JetBrains plugin is available as an alternative, offering additional features like interactive debugging and advanced refactoring (free trial available).

What clients can I use Serena with?

Any client that supports the Model Context Protocol (MCP) can connect to Serena. This includes terminal‑based clients (Claude Code, Codex, OpenCode, Gemini‑CLI), IDE plugins (VSCode, Cursor, JetBrains), and desktop/web clients (Claude Desktop, OpenWebUI).

What are the runtime requirements for Serena?

Serena requires the uv package manager to be installed. It can work with system language servers (automatically managed) or a JetBrains IDE with the Serena plugin. No additional runtime dependencies beyond a Python environment managed by uv.