To connect the Serena MCP server to your client, you typically
* provide the client with a launch command that starts the MCP server, or
* start the Serena MCP server yourself in HTTP mode and provide the client with the URL.
See the [Quick Start](#quick-start) section below for information on how to get started.
## Features
Serena supports two code intelligence backends:
* **Language servers** implementing the language server protocol (LSP) — the free/open-source alternative.
* **The Serena JetBrains Plugin**, which leverages the capabilities of your JetBrains IDE.
Language Servers, while very powerful, have inherent limitations.
The JetBrains variant is the more advanced solution, as detailed below. It is also more memory-efficient, especially in
multi-agent scenarios.
### Language Support
#### Language Servers
When using Serena's language server backend, we provide **support for over 40 programming languages**, including
AL, Ansible, Bash, C#, C/C++, Clojure, Dart, Elixir, Elm, Erlang, Fortran, F# (currently with some bugs), GLSL, Go, Groovy (partial support), Haskell, HLSL, Java, Javascript, Julia, Kotlin, Lean 4, Lua, Luau, Markdown, MATLAB, Nix, OCaml, Perl, PHP, PowerShell, Python, R, Ruby, Rust, Scala, Solidity, Swift, TOML, TypeScript, WGSL, YAML, and Zig.
#### The Serena JetBrains Plugin
The [Serena JetBrains Plugin](https://plugins.jetbrains.com/plugin/28946-serena/)
leverages the powerful code analysis capabilities of your JetBrains IDE.
The plugin naturally supports all programming languages and frameworks that are supported by JetBrains IDEs,
including IntelliJ IDEA, PyCharm, Android Studio, WebStorm, PhpStorm, RubyMine, GoLand, and potentially others (Rider and CLion are unsupported though).
See our [documentation page](https://oraios.github.io/serena/02-usage/025_jetbrains_plugin.html) for further details and instructions on how to apply the plugin.
### Retrieval
Serena's retrieval tools allow agents to explore codebases at the symbol level, understanding structure and relationships
without reading entire files.
| Capability | Language Servers | JetBrains Plugin |
|----------------------------------|------------------|------------------|
| find symbol | yes | yes |
| symbol overview (file outline) | yes | yes |
| find referencing symbols | yes | yes |
| search in project dependencies | -- | yes |
| type hierarchy | -- | yes |
| find declaration | -- | yes |
| find implementations | -- | yes |
| query external projects | yes | yes |
### Refactoring
Without precise refactoring tools, agents are forced to resort to unreliable and expensive search and replace operations.
| Capability | Language Servers | JetBrains Plugin |
|-------------------------------------------|--------------------|-----------------------------------|
| rename | yes (only symbols) | yes (symbols, files, directories) |
| move (symbol, file, directory) | -- | yes |
| inline | -- | yes |
| propagate deletions (remove unused code) | -- | yes |
### Symbolic Editing
Serena's symbolic editing tools are less error-prone and much more token-efficient than typical alternatives.
| Capability | Language Servers | JetBrains Plugin |
|------------------------|-------------------|------------------|
| replace symbol body | yes | yes |
| insert after symbol | yes | yes |
| insert before symbol | yes | yes |
| safe delete | yes | yes |
### Basic Features
Beyond its semantic capabilities, Serena includes a set of basic utilities for completeness.
When Serena is used inside an agentic harness such as Claude Code or Codex, these tools are typically disabled by default,
since the surrounding harness already provides overlapping file, search, and shell capabilities.
- **`search_for_pattern`** – flexible regex search across the codebase
- **`replace_content`** – agent-optimised regex-based and literal text replacement
- **`list_dir` / `find_file`** – directory listing and file search
- **`read_file`** – read files or file chunks
- **`execute_shell_command`** – run shell commands (e.g. builds, tests, linters)
### Memory Management
A memory system is elemental to long-lived agent workflows, especially when knowledge is to be shared across
sessions, users and projects.
Despite its simplicity, we received positive feedback from many users who tend to combine Serena's memory management system with their
agent's internal system (e.g., `AGENTS.md` files).
It can easily be disabled if you prefer to use something else.
### Configurability
Active tools, tool descriptions, prompts, language backend details and many other aspects of Serena
can be flexibly configured on a per-case basis by simply adjusting a few lines of YAML.
To achieve this, Serena offers multiple levels of (composable) configuration:
* global configuration
* MCP launch command (CLI) configuration
* per-project configuration (with local overrides)
* execution context-specific configuration (e.g. for particular clients)
* dynamically composable configuration fragments (modes)
## Serena in Action
#### Demonstration 1: Efficient Operation in Claude Code
A demonstration of Serena efficiently retrieving and editing code within Claude Code, thereby saving tokens and time. Efficient operations are not only useful for saving costs, but also for generally improving the generated code's quality. This effect may be less pronounced in very small projects, but often becomes of crucial importance in larger ones.
https://github.com/user-attachments/assets/ab78ebe0-f77d-43cc-879a-cc399efefd87
#### Demonstration 2: Serena in Claude Desktop
A demonstration of Serena implementing a small feature for itself (a better log GUI) with Claude Desktop.
Note how Serena's tools enable Claude to find and edit the right symbols.
https://github.com/user-attachments/assets/6eaa9aa1-610d-4723-a2d6-bf1e487ba753
## Quick Start
**Prerequisites**. Serena is managed by *uv*. If you don’t already have it, you need to [install uv](https://docs.astral.sh/uv/getting-started/installation/) before proceeding.
> [!NOTE]
> Some language servers require additional dependencies to be installed; see the [Language Support](https://oraios.github.io/serena/01-about/020_programming-languages.html) page for details.
**Starting the MCP Server**. The easiest way to start the Serena MCP server is by running the latest version from GitHub using uvx.
Issue this command to see available options:
```bash
uvx -p 3.13 --from git+https://github.com/oraios/serena serena start-mcp-server --help
```
**Configuring Your Client**. To connect Serena to your preferred MCP client, you typically need to [configure a launch command in your client](https://oraios.github.io/serena/02-usage/030_clients.html).
Follow the link for specific instructions on how to set up Serena for Claude Code, Codex, Claude Desktop, MCP-enabled IDEs and other clients (such as local and web-based GUIs).
> [!TIP]
> While getting started quickly is easy, Serena is a powerful toolkit with many configuration options.
> We highly recommend reading through the [user guide](https://oraios.github.io/serena/02-usage/000_intro.html) to get the most out of Serena.
>
> Specifically, we recommend to read about ...
> * [Serena's project-based workflow](https://oraios.github.io/serena/02-usage/040_workflow.html) and
> * [configuring Serena](https://oraios.github.io/serena/02-usage/050_configuration.html).
## User Guide
Please refer to the [user guide](https://oraios.github.io/serena/02-usage/000_intro.html) for detailed instructions on how to use Serena effectively.
## Acknowledgements
A significant part of Serena, especially support for various languages, was contributed by the open source community.
We are very grateful for the many contributors who made this possible and who played an important role in making Serena
what it is today.