# Arbor MCP Integration Guide
> Connect Arbor's code graph intelligence to AI agents via Model Context Protocol.
---
## What is the MCP Bridge?
Arbor's MCP (Model Context Protocol) bridge allows AI agents like Claude and Cursor to:
- **Query the code graph** — understand dependencies and relationships
- **Analyze impact** — see blast radius before refactoring
- **Find paths** — trace connections between any two symbols
The bridge communicates over **stdio** using JSON-RPC, following the [MCP specification](https://modelcontextprotocol.io/).
---
## Setup for Cursor
Create or edit `.cursor/mcp.json` in your project root:
```json
{
"mcpServers": {
"arbor": {
"command": "arbor",
"args": ["bridge"],
"cwd": "."
}
}
}
```
Then in Cursor:
1. Open Command Palette (Cmd+Shift+P)
2. Search "MCP: Reload Servers"
3. Arbor tools will appear in the AI assistant
---
## Setup for Claude Desktop
Edit your Claude Desktop config file:
**macOS**: `~/Library/Application Support/Claude/claude_desktop_config.json`
**Windows**: `%APPDATA%\Claude\claude_desktop_config.json`
```json
{
"mcpServers": {
"arbor": {
"command": "arbor",
"args": ["bridge"],
"cwd": "/path/to/your/project"
}
}
}
```
Restart Claude Desktop to load the integration.
---
## Available Tools
| Tool | Description |
|------|-------------|
| `get_logic_path` | Traces call graph from a symbol |
| `analyze_impact` | Returns blast radius with confidence/roles |
| `find_path` | Finds shortest path between two symbols |
### Example: analyze_impact
**Input:**
```json
{
"name": "analyze_impact",
"arguments": {
"node_id": "detect_language",
"max_depth": 5
}
}
```
**Output includes:**
- `confidence.level` — High/Medium/Low
- `confidence.reasons` — Why this confidence
- `role` — Entry Point, Core Logic, Utility, etc.
- `upstream` — Callers that would break
- `downstream` — Dependencies called
- `edges_explained` — Summary of connections
---
## Capabilities
The bridge advertises these capabilities to clients:
```json
{
"streaming": false,
"pagination": false,
"json": true
}
```
---
## Known Limitations
1. **stdio only** — No WebSocket transport currently
2. **Single project** — Point `cwd` to your target project
3. **No hot reload** — Re-index after major changes (`arbor index`)
4. **Static analysis** — Dynamic dispatch marked as uncertain
---
## Troubleshooting
### "arbor: command not found"
Ensure Arbor is installed and in your PATH:
```bash
cargo install arbor-graph-cli
```
### MCP server not responding
Check that your project has been indexed:
```bash
cd /path/to/project
arbor init
arbor index
```
### Tools not appearing in Cursor
1. Check `.cursor/mcp.json` syntax
2. Reload MCP servers from Command Palette
3. Check Cursor's MCP logs for errors
### "Node not found" errors
Use `arbor query <name>` to verify the symbol is indexed.
---
## Version
This guide is for Arbor v1.5.0+ with MCP capabilities.
