code-graph-mcp

Local code-intelligence MCP server for mono-repos. It indexes your repo once into a knowledge graph — packages, components, frontend routes, HTTP calls, backend routes, handlers — and lets any MCP client (Claude Code, Cursor, Codex CLI, OpenCode…) query structure directly instead of grepping and re-reading files on every question.

Ask "where does LoginPage land in the backend?" and get LoginPage → POST /api/auth/login → auth.login in one tool call, from a graph that's already in memory. No file reads, no grep round-trips.

Why

Agents burn most of their tokens re-discovering structure: listing directories, grepping for usages, opening five files to trace one request path. This server front-loads that discovery into a single index pass and then answers structural questions from memory, with output engineered to be cheap:

• Compact line-oriented output — no pretty-printed JSON, no prose padding.

• Hard token budgets per response (default ~2k tokens, tunable per call) with …+N more (refine query) truncation instead of overflow.

• Path compression — repo-relative paths, common prefixes stripped in lists.

• Incremental re-index — content-hash manifest; unchanged files are never reparsed.

• Savings tracking — repo_summary reports how many tokens of raw file reads the session avoided.

• Zero query-time I/O — every tool answers from in-memory indexes; only reindex touches disk.

Related MCP server: code-context-mcp

What it detects

Parsing is regex/heuristic (deliberately: fast, zero native deps). It won't catch every dynamic pattern — that's the tradeoff for indexing thousands of files in milliseconds with two pure-JS dependencies.

Install

Claude Code: install as a plugin (recommended)

Two commands inside any Claude Code session — no config files:

/plugin marketplace add dorkian/code-graph-mcp
/plugin install code-graph@code-graph-mcp

The plugin bundles the MCP server (starts automatically, indexing whatever project you're in) and the skill that teaches Claude to query the graph instead of grepping. Update later with /plugin update, remove with /plugin uninstall — nothing to hand-edit. When Claude Code asks you to approve the plugin's MCP server on first use, that's the standard trust gate for plugin-declared servers.

Same thing from the terminal (no session needed)

Every /plugin command is also a claude plugin CLI command, so the install is scriptable — dotfiles, onboarding scripts, CI:

claude plugin marketplace add dorkian/code-graph-mcp
claude plugin install code-graph@code-graph-mcp

Pick where it lands with --scope:

claude plugin install code-graph@code-graph-mcp                  # user: all your projects (default)
claude plugin install code-graph@code-graph-mcp --scope project  # this repo, shared with the team via VCS
claude plugin install code-graph@code-graph-mcp --scope local    # this repo, just you

Verify and manage:

claude plugin list                                # installed plugins + status
claude plugin marketplace list                    # registered marketplaces
claude plugin marketplace update code-graph-mcp   # pull latest catalog
claude plugin update code-graph                   # update the plugin itself
claude plugin disable code-graph                  # keep installed, turn off
claude plugin uninstall code-graph                # remove

Inside a session, /mcp should list the code-graph server and /plugin opens the manager UI. If claude plugin prints "unknown command", update Claude Code first (claude --version to check).

Or: let the CLI configure your client

# Claude Code — writes .mcp.json AND installs the companion skill
npx -y @ashkand/code-graph-mcp install claude-code --repo .

# Cursor — writes .cursor/mcp.json
npx -y @ashkand/code-graph-mcp install cursor --repo .

# anything else — prints ready-to-paste config for Claude Desktop, Codex CLI, …
npx -y @ashkand/code-graph-mcp install

No npm? Every command also works straight from the repo by swapping @ashkand/code-graph-mcp for github:dorkian/code-graph-mcp.

That's it — restart your client and ask "where does LoginPage land in the backend?"

Or: let your AI install it

Paste this into Claude Code, Cursor, Codex, or any coding agent with shell access, from inside the repo you want indexed:

Install the code-graph-mcp server in this repo:
1. Run: npx -y @ashkand/code-graph-mcp install claude-code --repo .
   (if this isn't Claude Code, run `npx -y @ashkand/code-graph-mcp install`
   and apply the printed config for the client you are instead)
2. Add `.codegraph/` to .gitignore if it isn't there.
3. Run: npx -y @ashkand/code-graph-mcp --repo . --index
   and show me the node/edge counts it reports.
4. From now on, prefer the code-graph MCP tools (repo_summary,
   find_component_relations, map_frontend_to_backend, search_symbols,
   impact_of_change, visualize_graph) over grep/read_file for questions
   about repo structure, and call reindex after you edit files.

Step 4 is a summary of the bundled skill — Claude Code users get the full version automatically at .claude/skills/code-graph/SKILL.md.

Manual

git clone https://github.com/dorkian/code-graph-mcp.git
cd code-graph-mcp && npm install
node bin/code-graph-mcp.js --repo /path/to/your/repo

The graph lives at <repo>/.codegraph/ — add it to your repo's .gitignore. Pre-warm the cache (e.g. in CI or a git hook):

code-graph-mcp --repo . --index          # incremental
code-graph-mcp --repo . --index --full   # rebuild from scratch

Client setup (manual configs)

{
  "mcpServers": {
    "code-graph": {
      "command": "npx",
      "args": ["-y", "@ashkand/code-graph-mcp", "--repo", "."]
    }
  }
}

Then copy skills/code-graph/ into .claude/skills/ (the install claude-code command does both).

{
  "mcpServers": {
    "code-graph": {
      "command": "npx",
      "args": ["-y", "@ashkand/code-graph-mcp", "--repo", "${workspaceFolder}"]
    }
  }
}

{
  "mcpServers": {
    "code-graph": {
      "command": "npx",
      "args": ["-y", "@ashkand/code-graph-mcp", "--repo", "/abs/path/to/repo"]
    }
  }
}

[mcp_servers.code-graph]
command = "npx"
args = ["-y", "@ashkand/code-graph-mcp", "--repo", "/abs/path/to/repo"]

Any other MCP client: it's a plain stdio server — run node bin/code-graph-mcp.js --repo <path> and speak MCP over stdin/stdout.

Use it as a Claude custom connector (claude.ai / Desktop / mobile)

Claude's custom connectors only accept remote MCP servers: Claude connects to your server URL from Anthropic's cloud, not from your machine, so a local stdio process can't be added directly — the server must be reachable on the public internet over Streamable HTTP. That's what --http mode is for:

# on your VPS, next to a checkout of the repo you want indexed
npx -y @ashkand/code-graph-mcp --repo /srv/my-monorepo \
  --http --port 3333 --auth-token "$(openssl rand -hex 24)"

Put it behind your reverse proxy with TLS (Caddy example):

graph.yourdomain.com {
    reverse_proxy 127.0.0.1:3333
}

Then in Claude: Settings → Connectors → Add custom connector and paste

https://graph.yourdomain.com/mcp/<your-token>

The token-in-URL form exists exactly for this: the connector UI takes a plain URL (or OAuth), so the secret rides in the path; API/CLI clients can send Authorization: Bearer <token> instead. Keep in mind what you're exposing — the graph reveals your repo's structure (routes, endpoints, file names), so treat the URL like a password, rotate the token if it leaks, and never run --http without a token on anything internet-facing. Run it as a systemd service and add a cron/git-hook --index call to keep the graph fresh after pushes.

Who can use your hosted URL — and what they get. Anyone you share https://graph.yourdomain.com/mcp/<token> with can add it as a custom connector in their own Claude (Settings → Connectors → Add custom connector; available on all plans — Free accounts can add one custom connector). But be clear about the model: one running instance indexes one repo on your server, and every connected user queries that same shared graph. It is not multi-tenant — users can't point your instance at their own codebases. Host it to demo the tool or to give a team a shared brain for one codebase; for their own repos, users run their own instance (stdio locally via the install command, or --http on their own box).

Tools

Every tool accepts max_tokens (response budget) and, where lists appear, detail: "compact" | "full".

Example output (map_frontend_to_backend, name: "LoginPage"):

LoginPage -> POST /api/auth/login -> POST /api/auth/login (services/api/app/auth.py) -> auth.login

Example diagram (visualize_graph, kind: "fe-to-be"):

graph LR
  n1(("route /login")) --> n2["LoginPage"]
  n2 -- calls --> n3["POST /api/auth/login"]
  n3 -- hits --> n4[/"POST /api/auth/login"/]
  n4 -- handled by --> n5[["fn login"]]

Storage format

.codegraph/graph.json — versioned node/edge lists, loaded into in-memory Maps (by id, name, file, endpoint path) at startup; a ~1k-file repo loads in well under a second. .codegraph/manifest.json — sha1 per indexed file, drives incremental re-index and deleted-file pruning. Corrupted or missing graph files trigger a clean full re-index, never a crash.

Development

npm install
npm test   # 57 unit assertions against a bundled fixture mono-repo,
           # an MCP smoke test speaking real JSON-RPC over stdio,
           # and an HTTP smoke test covering --http mode + token auth

The fixture under test/fixture/ is a miniature mono-repo (React app, FastAPI service, Express service) exercising every detection path including include_router alias resolution and template-literal endpoints.

Publishing this repo to GitHub

Credentials never leave your machine, so push it yourself:

cd code-graph-mcp
git init && git add -A && git commit -m "code-graph-mcp v0.2.0"
git branch -M main
git remote add origin https://github.com/dorkian/code-graph-mcp.git
git push -u origin main

# optional: publish to npm so npx works
npm login
npm publish --access public

License

MIT © dorkian