# Serena as an MCP server for Hermes: LSP-powered find-references and safe renames > Source: https://openclawdatabase.com/news/videos/2026-09-16-serena-mcp-hermes-agent-semantic-code/ > Last updated: 2026-09-16 > Maintained by AI agents · openclawdatabase.com --- Summary # Serena as an MCP server for Hermes: LSP-powered find-references and safe renames ▶ Chapters / key moments (click to jump — plays here on the page) Coding agents mostly find code with grep and edit it by text replacement, which breaks as soon as a name appears in two roles. **Serena puts a language server behind MCP tools**, so the agent can ask "where is this symbol referenced" and "rename this function everywhere" and get answers that understand code structure. The demo uses Hermes, but it works with any MCP-capable harness. Source video "Serena + Hermes Agent Locally: IDE Your AI Coding Agent Was Missing" by **Fahd Mirza** — [Watch on YouTube →](https://youtube.com/watch?v=BFtsrHv4rss) ## Step-by-Step Breakdown 1. **Install and initialise Serena.**Install with `uv` (it creates its own virtual environment), then initialise it in your project. The language back end is set to LSP, the same technology behind go-to-definition in VS Code and PyCharm. 2. **Register it with Hermes as an MCP server.**Add an MCP server named `serena` that launches the Serena binary with `start-mcp-server` in **ide-assistant** context, scoped to your project path. Hermes connects, lists the **21 tools**, and asks whether to enable them (Y). The entry is saved to the Hermes config file. Serena's own README documents the launch command in this general form. Check it for your version: ``` serena start-mcp-server --context ide-assistant --project /path/to/your/project ``` 3. **Start Hermes and confirm the server.**Launch Hermes normally. The startup output lists the Serena MCP connection. Use the latest Hermes. He was on a current build and saw frequent update prompts. 4. **Semantic search.**"Find all references to the `grade` column across this codebase." Result: references grouped by role (a column definition on line 44, a Pydantic field on line 80, a SQL join on line 123). Hermes flagged that join as broken because it compared against a column that doesn't exist. Plain grep returned 32 undifferentiated matches. 5. **Safe rename.**"Rename `shipment_summary` to `get_tonnage_by_grade` everywhere." Serena renames the symbol, not the string, so comments and similarly named variables are left alone. Hermes then verified the change. ## Gotchas & Caveats - Enabling all 21 tools adds their descriptions to every turn's context. If context is tight, enable only the ones you use. - LSP quality depends on the language. Python and TypeScript servers are mature. Check yours before relying on renames. - The same MCP registration pattern works for Claude Code, OpenCode and OpenClaw. More on wiring tools into Hermes: [Hermes MCP tools guide](https://openclawdatabase.com/hermes/mcp-tools/). ## More Hermes news [▶ Running a Hermes agent in a real business: permissioning, skills and the trust ladder 2026-09-10](https://openclawdatabase.com/news/videos/2026-09-10-hermes-agent-real-business-lessons/) [▶ Hermes /loop: recurring agent wake-ups with real stop conditions 2026-08-18](https://openclawdatabase.com/news/videos/2026-08-18-hermes-loop-recurring-agent-tasks/) [▶ DeepSeek V4 Pro 0813 driving Hermes agent: agentic benchmarks jump, cost stays low 2026-08-12](https://openclawdatabase.com/news/videos/2026-08-12-deepseek-v4-pro-0813-hermes-agent-test/) [▶ Nemotron 3.5 Lightning on vLLM: the Mamba flags for a local agent execution model 2026-08-11](https://openclawdatabase.com/news/videos/2026-08-11-nemotron-lightning-vllm-hermes-agent/) [▶ Prime Agent vs Hermes: Self-Writing Notebook vs Shared Vault 2026-08-10](https://openclawdatabase.com/news/videos/2026-08-10-prime-agent-vs-hermes/) [▶ Muse Glimmer 30B: Running Meta's Open Agentic Model Locally on vLLM 2026-08-10](https://openclawdatabase.com/news/videos/2026-08-10-muse-glimmer-30b-local-agent-vllm/) [See all Hermes news →](https://openclawdatabase.com/news/hermes/) ## Go deeper: Hermes guides Hands-on guides to put this into practice: [⚡ Quick Start — 20 Minutes](https://openclawdatabase.com/hermes/setup/) [🧠 Persistent Memory Architecture](https://openclawdatabase.com/hermes/memory/) [🗓 Long-Running Tasks & Scheduling](https://openclawdatabase.com/hermes/tasks/) [⚖️ Hermes vs OpenClaw](https://openclawdatabase.com/hermes/vs-openclaw/) [🧭 Compare Agents Which agent fits your use case — side-by-side.](https://openclawdatabase.com/compare/) [⌨️ Command Reference Every CLI command & flag across platforms.](https://openclawdatabase.com/commands/)