# Serena

> An MCP toolkit that gives coding agents IDE-grade powers — symbol-level retrieval and editing via language servers, across 40+ languages.

Serena (MIT, ~25k stars) is 'the IDE for your agent': an MCP server backed by language servers giving agents symbol-level tools — find symbol, find references, replace symbol body, rename — across 40+ languages. Precise, token-efficient edits at the symbol level instead of regex surgery, plus a project memory for cross-session knowledge.

Website: https://oraios.github.io/serena

Serena's tagline — "the IDE for your agent" — is accurate. Where coding agents normally navigate by text search, Serena plugs language servers underneath and exposes **symbol-level tools**: find this function, list every reference to it, replace exactly its body, rename it everywhere. On a large codebase, that's the difference between surgical edits and regex archaeology.

## Highlights

- **Symbolic retrieval** — find symbol, file symbol overview, find referencing symbols, diagnostics: the agent locates code by meaning, not string-matching.
- **Symbolic editing** — replace symbol body, insert before/after symbol, safe deletes, and LSP-powered rename refactoring.
- **40+ languages** — Python, TypeScript/JS, Java, C/C++, C#, Go, Rust, Ruby, PHP, Swift, Kotlin, Elixir, and more via the LSP backend.
- **Token-efficient by design** — symbol overviews and targeted reads keep big-repo work inside a sane context budget.
- **Project memory** — a cross-session knowledge store, so what the agent learns about the codebase persists.
- **Contexts and modes** — `--context claude-code`, `ide-assistant`, and others tune the toolset to the host; stdio or HTTP transport.

## In an AI-assisted workflow

```bash
uv tool install -p 3.13 serena-agent
serena init
claude mcp add --scope user serena -- serena start-mcp-server \
  --context claude-code --project-from-cwd
# then:
# > Find every caller of resolveSession, then rename it to resolveUserSession
# > and update the call sites — use Serena's symbol tools
```

It shines on exactly the work the [refactoring-specialist](/agents/quality-security/refactoring-specialist) agent does: cross-cutting renames, signature changes, dead-code sweeps — now with reference-accurate ground truth instead of grep confidence.

> [!TIP]
> Slow first start? Language servers take a moment to warm up on big repos — launch with `MCP_TIMEOUT=60000 claude` and let `serena init`'s indexing finish once per project.

## Good to know

MIT, Python-based (installed via `uv`; PyPI package `serena-agent`), v1.0 landed April 2026 with the streamlined install flow. Inside Claude Code, Serena's generic file/shell tools are deliberately disabled — its value there is purely the symbolic layer. The optional JetBrains-plugin backend (paid, free trial) unlocks IDE-exclusive operations: move/inline refactorings, type hierarchies, and interactive debugging.

---

_Source: https://agentscamp.com/tools/serena — Tool on AgentsCamp._