# repo-graph

[![repo-graph MCP server](https://glama.ai/mcp/servers/James-Chahwan/repo-graph/badges/card.svg)](https://glama.ai/mcp/servers/James-Chahwan/repo-graph)

**Structural graph memory for AI coding assistants.** Map your codebase. Navigate by structure. Read only what matters.

repo-graph gives LLMs a map of your codebase — entities, relationships, and flows — so they can navigate to the right files without reading everything first.

Instead of flooding an LLM's context window with your entire codebase (or hoping it guesses right), repo-graph builds a lightweight graph of what exists, how things connect, and where the entry points are. The LLM queries the graph, finds the minimal set of files it needs, and reads only those.

## Demo

https://github.com/user-attachments/assets/a1e4171b-b225-40d4-9210-39453e14b76a

https://github.com/user-attachments/assets/fc3191e5-fc35-4bd7-8372-72af55995883

Same bug, same model, same prompt — the only difference is whether repo-graph is installed.

**The task:** fix a reversed comparison operator in a Go + Angular monorepo (566 nodes, 620 edges).

| | Without repo-graph | With repo-graph |
|---|---|---|
| **Tokens used** | 75,308 | 29,838 |
| **Time to fix** | 4m 36s | ~30s |
| **Files explored** | ~15 (grep, read, grep, read...) | 2 (flow lookup + handler file) |
| **Outcome** | Found and fixed the bug | Found and fixed the bug |

**2.5x fewer tokens. ~9x faster. Same correct fix.**

### How the test was run

Both runs used identical conditions to keep the comparison fair:

- **Same model**: Claude Opus, 100% (no Haiku routing)
- **Same prompt**: *"Groups that were created recently are showing as closed, and old groups show as open. This is backwards — new groups should be open for members to join. Find and fix the bug."*
- **Fresh context**: each run started from `/clear` with no prior conversation
- **No other tools**: CLAUDE.md, plugins, hooks, and all other MCP servers were removed for both runs — the only variable was whether repo-graph was installed
- **No hints**: the prompt describes the symptom, not the location — Claude has to find `group_controller.go:57` on its own

Without repo-graph, Claude greps for keywords, reads files, greps again, reads more files, and eventually narrows down to the bug. With repo-graph, Claude calls `flow("groups")`, gets back the exact handler function and file, reads it, and fixes it.

> Browse [pre-generated examples](examples/) for [FastAPI](examples/fastapi/), [Gin](examples/gin/), [Hono](examples/hono/), and [NestJS](examples/nestjs/) — real graph output you can inspect without installing anything.

## The problem

LLMs working on code waste most of their context on orientation:

- Reading files that turn out to be irrelevant
- Missing connections between components in different languages
- Not knowing where a feature starts or what it touches
- Loading 50 files when 5 would do

This is expensive, slow, and gets worse as codebases grow.

## How repo-graph solves it

repo-graph scans your codebase once and builds a graph of:

- **Entities**: modules, packages, classes, functions, routes, services, components
- **Relationships**: imports, calls, handles, defines, contains, cross-stack HTTP
- **Flows**: end-to-end paths from entry point to data layer

Then it exposes 11 MCP tools that let the LLM:

1. **Orient** — "What languages are in this repo? What are the main features?"
2. **Navigate** — "Trace the login flow from route to database" / "What's the shortest path between UserService and the payments API?"
3. **Scope** — "How many lines would I need to read to understand this feature?" / "Give me just the files I need for this bug fix"
4. **Assess** — "What's the blast radius of changing this function?" / "Which files are the biggest maintenance risks?"

The LLM gets structural context in a few hundred tokens instead of reading thousands of lines.

## Supported languages

| Language | Detection | What it extracts |
|----------|-----------|-----------------|
| **Go** | `go.mod` | Packages, functions, HTTP routes (gin/echo/chi/stdlib), imports |
| **Rust** | `Cargo.toml` | Crates, modules, structs, traits, functions, routes (Actix/Rocket/Axum) |
| **TypeScript** | `tsconfig.json` / `package.json` | Modules, classes, functions, import relationships |
| **React** | `react` in `package.json` | Components, hooks, context providers, React Router routes, fetch/axios calls, flows |
| **Angular** | `@angular/core` in `package.json` | Components, services, guards, DI injection, HTTP calls, feature flows |
| **Vue** | `vue` in `package.json` | SFCs, composables, Vue Router routes, fetch/axios calls |
| **Python** | `pyproject.toml` / `setup.py` / `requirements.txt` | Packages, modules, classes, functions, routes (Flask/FastAPI/Django) |
| **Java/Kotlin** | `pom.xml` / `build.gradle` | Packages, classes, routes (Spring/JAX-RS/Ktor/WebFlux/Micronaut) |
| **Scala** | `build.sbt` | Packages, objects/classes/traits, routes (Play/Akka HTTP/http4s) |
| **Clojure** | `project.clj` / `deps.edn` | Namespaces, defn/defprotocol/defrecord, routes (Compojure/Reitit) |
| **C#/.NET** | `.csproj` / `.sln` | Namespaces, classes, routes (ASP.NET/Minimal API) |
| **Ruby** | `Gemfile` / `.gemspec` | Files, classes, modules, Rails routes |
| **PHP** | `composer.json` | Namespaces, classes, interfaces, routes (Laravel/Symfony) |
| **Swift** | `Package.swift` / `.xcodeproj` | Files, types (class/struct/enum/protocol/actor), Vapor routes |
| **C/C++** | `CMakeLists.txt` / `Makefile` / `meson.build` | Sources, headers, classes, structs, enums, namespaces, includes |
| **Dart/Flutter** | `pubspec.yaml` | Modules, classes, widgets, go_router/shelf routes |
| **Elixir/Phoenix** | `mix.exs` | Modules, functions, Phoenix router scopes + routes |
| **Solidity** | `.sol` files / `foundry.toml` / `hardhat.config.*` | Contracts, interfaces, libraries, events, inheritance |
| **Terraform** | `.tf` files | Modules, resources, variables, outputs, module sources |
| **SCSS** | `.scss` files present | File-level bloat analysis |

Cross-cutting extractors (work across all languages):

- **Data sources** — DB/cache/queue/blob/search/email client detection
- **CLI entrypoints** — Python click, JS commander/yargs, Go cobra, Rust clap
- **gRPC** — service/method definitions from `.proto` files
- **Queue consumers** — Celery, Dramatiq, BullMQ, Sidekiq, Oban, NATS
- **Cross-stack HTTP** — frontend `fetch`/`axios` calls linked to backend routes

Multiple languages can match one repo (e.g., Go backend + Angular frontend + SCSS). Each contributes its nodes and edges into a single unified graph.

## Install

The package name **is** the run command — `uvx mcp-repo-graph` just works. No prior
`pip install`, nothing to keep on `PATH`. This is the same command VS Code, Cursor,
and the MCP registry use under the hood.

**Requirements:** Python 3.11+, and [`uv`](https://docs.astral.sh/uv/) if you use the
`uvx` path. Prebuilt wheels ship for the Rust engine on Linux (x86_64, aarch64),
macOS (Intel + Apple Silicon), and Windows (x86_64) — no Rust toolchain needed.

### Claude Code

```bash
claude mcp add repo-graph -- uvx mcp-repo-graph --repo .
```

(`--repo .` points the graph at the current project; use an absolute path to pin it.)

### VS Code

One command — adds the server to your user config:

```bash
code --add-mcp '{"name":"repo-graph","command":"uvx","args":["mcp-repo-graph","--repo","${workspaceFolder}"]}'
```

Or click **Install** on the [MCP gallery](https://code.visualstudio.com/mcp) entry,
or add it to `.vscode/mcp.json` manually (see below).

### Cursor / any MCP client — manual config

Add this to your client's MCP config (`.mcp.json`, `.cursor/mcp.json`,
`.vscode/mcp.json`, or `~/.claude.json`):

```json
{
  "mcpServers": {
    "repo-graph": {
      "command": "uvx",
      "args": ["mcp-repo-graph", "--repo", "/path/to/your/project"]
    }
  }
}
```

Prefer a persistent install? `pip install mcp-repo-graph` (or `uv tool install
mcp-repo-graph`) puts a `mcp-repo-graph` / `repo-graph` command on your `PATH`; then
use `"command": "mcp-repo-graph"` in the config above.

**`--repo` also accepts a git URL.** Point it at any public repo without cloning
first — it shallow-clones and maps it (requires `git`):

```bash
uvx mcp-repo-graph --repo https://github.com/org/repo
```

## Quick start

### 1. Initialise the target repo (optional)

```bash
uvx --from mcp-repo-graph repo-graph-init --repo /path/to/your/project
# or, if installed:  repo-graph-init --repo /path/to/your/project
```

This generates the graph, writes `.mcp.json` and CLAUDE.md instructions, and gets your
AI assistant ready to use repo-graph. If you used the one-liners above, you can skip
this — the server builds the graph on first connect.

### 2. Use it

The AI assistant now has access to all 13 tools. Example queries it can answer:

- *"What does this codebase do?"* → `status` tool
- *"Trace the checkout flow"* → `flow` tool
- *"What would break if I change UserService?"* → `impact` tool
- *"Which nodes are relevant to this bug?"* → `activate` / `find` tools
- *"Here's a stacktrace — where do I look?"* → `locate` tool
- *"Show me that function's source"* → `read` tool
- *"Give me the full graph context cheaply"* → `dense_text` tool
- *"Show me the auth flow visually"* → `graph_view` tool

### 3. Keep it fresh with a git hook (recommended)

The graph auto-refreshes on cold start whenever the source tree has changed since the
cached `.gmap` was written, so it's never stale when your assistant connects. To
pre-warm the cache on every commit instead — so even the first query is instant — add
a pre-commit hook:

```bash
# .git/hooks/pre-commit (or add to your existing hook)
#!/bin/sh
uvx --from mcp-repo-graph repo-graph-init --repo .   # or: repo-graph-init --repo .
git add .ai/repo-graph/
```

```bash
chmod +x .git/hooks/pre-commit
```

Every commit keeps the graph current. The LLM always has a fresh map without wasting a single token on `generate`.

> **Tip:** If you don't want graph data in version control, add `.ai/repo-graph/` to `.gitignore` and skip the `git add` line — the graph will just live locally.

## MCP tools reference

repo-graph exposes **13 tools** across four tiers.

### Generation

| Tool | Parameters | Description |
|------|-----------|-------------|
| `generate` | `repo_path` *(optional)*, `incremental` | Scan the codebase with tree-sitter, rebuild the graph, run cross-stack resolvers, and cache it. Incremental by default — only changed files re-parse |

### Navigation

| Tool | Parameters | Description |
|------|-----------|-------------|
| `status` | *(none)* | Repo overview: node/edge counts, detected kinds, entry points, dense preview. Call this first to orient |
| `flow` | `feature` | End-to-end flow for a feature — entry point → service layer → data store, in layered tiers |
| `trace` | `from_node`, `to_node` | Shortest path between two nodes, hop by hop with tier transitions |
| `impact` | `nodes` *(comma-separated)*, `direction`, `depth`, `mode` | Blast radius — what nodes affect (downstream) or depend on (upstream). Pass several nodes for a whole-diff radius |
| `neighbours` | `node` | All direct connections to and from a node, one hop each way |
| `read` | `node`, `context_lines` | Return a node's source code, sliced from its file by the graph's line span — read the exact code without grepping |

### Activation & context

| Tool | Parameters | Description |
|------|-----------|-------------|
| `activate` | `seeds`, `top_k`, `profile`, `mode` | Spreading activation (Personalized PageRank) from seed nodes — the most relevant nodes to your seeds. `profile` retunes for repair/review/onboard |
| `find` | `query` | Find nodes by name or qualified-name pattern |
| `locate` | `signal`, `kind` (`stacktrace`/`test`/`diff`/`auto`), `top_k`, `mode` | Resolve a stacktrace, failing-test id, or diff to the most relevant nodes — paste the error, get the code that matters |
| `dense_text` | `seed` *(optional)*, `budget` | The graph in dense sigil notation — the primary context tool. With `seed`, returns just that node's neighbourhood (scoped map) |

### Health & admin

| Tool | Parameters | Description |
|------|-----------|-------------|
| `graph_view` | `node` *(optional)*, `depth` | Visual ASCII map — a node's tree/neighbourhood, or the full overview |
| `reload` | `incremental` | Re-generate the graph from source after code changes. Incremental by default |

Most read tools also take a `budget` (max chars) so a result fits a small-model context window. `activate` / `impact` / `locate` take `mode=prose` to return the ranked subgraph as primed prose instead of a table.

## How it works

`mcp-repo-graph` is a thin Python MCP server that wraps **glia**, a Rust engine.

1. **Parse** — per-language tree-sitter parsers extract raw nodes and unresolved references
2. **Extract** — cross-cutting extractors layer on HTTP routes, data sources, CLI entrypoints, gRPC services, queue consumers
3. **Resolve** — graph builder resolves intra-repo references; cross-graph resolvers link stacks (frontend HTTP calls → backend routes, etc.)
4. **Store** — merged graph lands in `.ai/repo-graph/` as a zero-copy `.gmap` (rkyv + mmap) plus JSON projections for portability
5. **Serve** — the MCP server loads the graph into memory and exposes the 13 tools

The Rust engine lives in its own [`glia`](https://github.com/James-Chahwan/glia) repo; `mcp-repo-graph` is the MCP-facing thin wrapper.

## Config (optional escape hatch)

If auto-detection misses a weird layout, drop `.ai/repo-graph/config.yaml` in the target repo:

```yaml
skip:
  - legacy       # directory basenames excluded from the walk
  - scratch

roots:           # explicit roots heuristics miss — added on top of auto-detection
  - path: apps/weird-layout
    kind: python
  - path: services/custom
    kind: go
```

`kind` values: `go`, `rust`, `python`, `typescript`, `react`, `vue`, `angular`, `java`, `scala`, `clojure`, `csharp`, `ruby`, `php`, `swift`, `c_cpp`, `dart`, `elixir`, `solidity`, `terraform`. `config.json` works too if you prefer.

## Graph data format

Generated files live in `.ai/repo-graph/` inside the target repo:

- **`nodes.json`** — `[{id, type, name, file_path, confidence, ...}, ...]`
- **`edges.json`** — `[{from, to, type}, ...]`
- **`flows/*.yaml`** — named feature flows with ordered step sequences and `kind` (`http`/`page`/`cli`/`grpc`/`queue`)
- **`state.md`** — human-readable snapshot for quick orientation

Common edge types: `imports`, `defines`, `contains`, `uses`, `calls`, `handles`, `handled_by`, `exports`, `includes`, `tests`, cross-stack HTTP links.

## Privacy Policy

repo-graph runs on your machine and is built to keep your code there. Full text: [PRIVACY.md](PRIVACY.md).

- **Telemetry / analytics:** None. No tracking, no update checks, no phone-home.
- **Data collection & sharing:** None. Your source code and graph data are never sent to repo-graph, its author, or any third party.
- **Local processing & storage:** Scanning and graph-building happen locally; the graph is cached in your project's `.ai/repo-graph/` directory and stays on your device.
- **Network access — only two cases, both user-initiated:**
  1. *Installation* — `uvx`/`pip` downloads the package and its prebuilt engine wheel from PyPI.
  2. *Git-URL targets* — if you pass a git URL to `--repo`, repo-graph runs `git clone` against the URL **you** specified; nothing is sent to repo-graph or its author. A local `--repo` path (the default) makes zero network calls.
- **Data retention:** The local cache persists until you delete it — fully under your control.
- **Contact:** [GitHub issues](https://github.com/James-Chahwan/repo-graph/issues)

## License

MIT

## Support

If repo-graph saved you time, consider buying me a coffee.

<p align="center">
  <a href="https://buymeacoffee.com/polycrisis">
    <img src="docs/bmc-qr.png" alt="Buy Me a Coffee" width="200">
  </a>
  <br>
  <a href="https://buymeacoffee.com/polycrisis">buymeacoffee.com/polycrisis</a>
</p>

<!-- mcp-name: io.github.James-Chahwan/repo-graph -->
