graphindex

An MCP server that gives AI coding assistants a structured, queryable view of your codebase. graphindex parses your repository with tree-sitter, stores symbols and call relationships in a local SQLite database, and exposes them through the Model Context Protocol so tools like Claude Code can navigate code by meaning instead of by grep.

The index updates incrementally as files change, so it stays accurate while you work.

Why

LLM agents spend a lot of tokens reading files just to figure out where a symbol lives or who calls it. graphindex answers those questions directly:

• "Where is parseConfig defined?" → one tool call, one row.
• "What breaks if I change this function?" → transitive callers up to depth 3.
• "Give me a summary of this file." → counts and last-indexed time without opening it.

Supported languages

• Go
• TypeScript / JavaScript
• Angular templates

More can be added by dropping a tree-sitter grammar binding into internal/parser/.

Install

go install github.com/254binaryninja/graphindex@latest

This places a graphindex binary in $GOBIN (usually ~/go/bin). Make sure that directory is on your PATH.

Requires Go 1.26 or newer.

Usage

graphindex speaks MCP over stdio. You normally don't run it by hand — you point an MCP client at it.

With Claude Code

Add it to your MCP config (~/.claude/mcp.json or project-local .mcp.json):

{
  "mcpServers": {
    "graphindex": {
      "command": "graphindex",
      "args": ["--repo", "/absolute/path/to/your/repo"]
    }
  }
}

Flags

Flag	Default	Description
--repo	.	Path to the repository root to index
--db	<repo>/.graphindex.db	Path to the SQLite database file

On startup graphindex performs a full index, then watches the repo for changes via fsnotify and re-indexes touched files in the background.

Add .graphindex.db to your .gitignore.

MCP tools exposed

Tool	Purpose
search_symbols	Find functions, classes, variables, and types by name. Optional kind filter.
get_definition	Return the source location and signature for an exact symbol name.
analyze_impact	Direct callers and transitive dependents up to depth 3 — blast radius before refactors.
get_module_summary	Per-file symbol/function/dependency counts and last index time.
explore_symbol	One-shot: definition + signature + callers + impact + module stats in a single call.

How it works

                ┌──────────────────────┐
                │  fsnotify watcher    │
                └──────────┬───────────┘
                           │ file events
                           ▼
   ┌─────────────────────────────────────────────┐
   │  indexer  →  tree-sitter parser per language │
   └─────────────────────┬───────────────────────┘
                         │ symbols, refs, edges
                         ▼
                 ┌────────────────┐         ┌─────────────┐
                 │  SQLite (WAL)  │ ◀────── │  query/*    │
                 └────────────────┘         └──────┬──────┘
                                                   │ MCP
                                                   ▼
                                          ┌────────────────┐
                                          │  AI assistant  │
                                          └────────────────┘

• internal/parser — tree-sitter bindings for each supported language.
• internal/indexer — full and incremental indexing, file hashing, fsnotify watcher.
• internal/db — SQLite schema, separate read/write handles.
• internal/query — the queries that back each MCP tool.

Building from source

git clone https://github.com/254binaryninja/graphindex.git
cd graphindex
go build ./...
go test ./...

License

MIT