MCP server (graphlens-mcp)

graphlens is only an analysis engine — it parses code into a graph IR and stops there (see Scope & non-goals). It deliberately ships no long-running server and no agent runtime.

If you want to serve a graph to coding agents (Claude Code, Cursor, and compatible clients) over the Model Context Protocol, use the dedicated project built on top of this engine:

graphlens-mcp — a free, MIT-licensed MCP server. Docs: neko1313.github.io/graphlens-mcp

It is a thin runtime layer over graphlens: the engine provides the mechanisms (parsing, stable node identity, resolvers); graphlens-mcp owns the storage, the freshness model (a filesystem watcher that re-indexes the connected set on every edit) and the agent-facing tool surface — everything graphlens itself is intentionally not.

Quickstart

uv tool install graphlens-mcp          # or: pipx install graphlens-mcp
cd your-project && graphlens-mcp init  # index + configure your agent

init detects the project's languages, indexes the code into a local graph, writes the MCP server entry into your agent's config and installs a navigation skill. Your agent then launches the server itself; restart it and ask things like "what breaks if I change the signature of create_order?".

Agent tools

Tool	Purpose
search_symbols	Full-text search over symbol names — start here
get_node_info	Source snippet + signature + location for a node
get_file_structure	Symbol outline of a file
get_callees	What a function calls (outgoing, up to max_depth)
get_callers	Who calls a function — primary impact-analysis tool
get_neighbors	Nodes within N hops in any direction
find_references	Non-call usages (type annotations, assignments)
get_cross_language_calls	Connections across service boundaries (HTTP/gRPC/queues)

See the graphlens-mcp documentation for the full command set, the freshness model, supported languages and the agent configuration flags.

Using the engine yourself

graphlens-mcp is also a worked example of how to build on the engine: how to drive the adapter registry, persist and refresh the graph, and expose it to a consumer. If you are building your own tool on top of graphlens, it is a good reference. Start from the Library API guide.