lynx — Claude Code MCP server: code search and call graph
A local MCP server that answers what grep cannot: who calls this, what breaks if I change it, where the code behind a behaviour lives.
claude mcp add lynx -- uvx lynx-mcpWhat lynx does
LynxMCP indexes your repository and hands the agent retrieval tools: hybrid BM25 plus dense search, AST-aware chunking, and an optional code knowledge graph. Ask who inherits from Field or what breaks when ApplyDamage changes, and you get file:line on every edge plus the tests worth re-running. Library docs and PDFs can sit in the same index as your code, so the version you actually ship is what the agent reads.
Nothing leaves the machine. Install with pipx install lynx-mcp or uv tool install lynx-mcp, then run lynx manager init, add a source, and build the index with lynx build. The first build pulls a 130 MB embedding model, and the install itself takes roughly 460 MB on disk — no PyTorch. Python 3.10+ is required.
The tool set stays fixed no matter how many sources you add. Three profiles ship: core with 5 tools, standard with 10, and full with 17; pick one via tools.profile in config.json or lynx serve --profile full. Every tool also exists as a CLI command with the same name and output, and --json makes it scriptable. On a small repo that already fits the agent's context, the built-in tools are enough — Lynx earns its place on large codebases and stale framework docs.
What it helps with
- trace every subclass of a class through the call graph instead of grep rounds
- work out which tests to re-run after touching a function
- find code by described behaviour when nothing matches literally
- index the docs of the exact library version in use
- search only files changed against a base branch
Example prompts for the agent
- Who calls
ApplyDamage, and what breaks if I change its signature? - Find where session tokens get validated — by meaning, not by name.
- Show me everything that inherits from
Field, with file and line for each class.
How to install lynx
Platform CLI
claude mcp add lynx -- uvx lynx-mcpuvx runs the command named after the package; if the README names another one, use uvx --from lynx-mcp <command>
Platform CLI
codex mcp add lynx -- uvx lynx-mcpuvx runs the command named after the package; if the README names another one, use uvx --from lynx-mcp <command>
Config file
{
"mcpServers": {
"lynx": {
"command": "uvx",
"args": [
"lynx-mcp"
]
}
}
}uvx runs the command named after the package; if the README names another one, use uvx --from lynx-mcp <command>
Config file
{
"servers": {
"lynx": {
"type": "stdio",
"command": "uvx",
"args": [
"lynx-mcp"
]
}
}
}uvx runs the command named after the package; if the README names another one, use uvx --from lynx-mcp <command>
Platform CLI
gemini mcp add lynx uvx lynx-mcpuvx runs the command named after the package; if the README names another one, use uvx --from lynx-mcp <command>
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about lynx
How do I install lynx in Claude Code?
Run claude mcp add lynx -- uvx lynx-mcp. Install the server first with pipx install lynx-mcp or uv tool install lynx-mcp.
What does lynx do?
It indexes a repository and gives the agent hybrid search plus call-graph queries: definitions, usages, subclasses, and the blast radius of a change.
Which tools does the agent get?
The standard profile exposes 10 tools, among them search, impact, graph_query and deep_search. core trims that to 5, full expands it to 17.
