# MCP in Claude Desktop

Claude Desktop is Anthropic's desktop app for macOS and Windows. With the
Synapse MCP server configured, Claude gets native access to all 79 Synapse
tools — it can store memories, recall them, manage tasks, chat with you, and
more.

## Prerequisites

- Claude Desktop app (macOS or Windows)
- Node.js 18+ installed (`node --version`)
- Your Synapse Mind Key

## Step 1: Open the Config File

- **macOS:** `~/Library/Application Support/Claude/claude_desktop_config.json`
- **Windows:** `%APPDATA%\Claude\claude_desktop_config.json`

If the file doesn't exist, create it.

## Step 2: Add Synapse MCP Server

```json
{
  "mcpServers": {
    "synapse": {
      "command": "npx",
      "args": ["-y", "synapse-mcp-api@latest"],
      "env": {
        "SYNAPSE_MIND_KEY": "mk_YOUR_MIND_KEY_HERE",
        "SYNAPSE_URL": "https://synapse.schaefer.zone"
      }
    }
  }
}
```

> [!TIP]
> If you already have other MCP servers configured, just add the `"synapse"`
> block inside the existing `"mcpServers"` object.

## Step 3: Restart Claude Desktop

1. Fully quit Claude Desktop (Cmd+Q on macOS, not just close window)
2. Reopen Claude Desktop
3. Start a new chat
4. Look for the 🔌 plug icon in the bottom-left — it should say "79 tools"

## Step 4: Test It

In a new chat, type:

```
memory_recall aufrufen
```

Claude should call the `memory_recall` tool and respond with a summary of your
stored memories (or "No memories yet" if your mind is empty).

## Available Tools (Selection)

| Tool | Description |
|------|-------------|
| `memory_recall` | Recall all memories |
| `memory_store` | Store a new memory |
| `memory_search` | Search memories |
| `task_list` | List tasks |
| `task_create` | Create a task |
| `chat_poll` | Check for new messages |
| `chat_reply` | Reply to a message |
| `browser_new` | Open a browser tab |
| `computer_list` | List registered computers |

Full list: [What is MCP?](/docs/mcp/what-is-mcp)

## Troubleshooting

### No tools appear in Claude Desktop

1. Verify Node.js version: `node --version` (must be ≥ 18)
2. Check the config file is valid JSON (no trailing commas)
3. Restart Claude Desktop fully (Cmd+Q, not just close)
4. Check Claude Desktop logs: `~/Library/Logs/Claude/mcp.log` (macOS)

### "Mind Key invalid" error

- Verify `SYNAPSE_MIND_KEY` starts with `mk_`
- Get a fresh key via `POST /minds` (requires JWT from `/login`)
- No quotes around the key in the JSON

### npx not found

- Install Node.js 18+: <https://nodejs.org/>
- Restart terminal after install
- On macOS with Homebrew: `brew install node`

### Tools show but calls fail

- Check `SYNAPSE_URL` is reachable: `curl https://synapse.schaefer.zone/health`
- Verify your Mind Key works: `curl -H "Authorization: Bearer mk_..." https://synapse.schaefer.zone/memory/recall`
- See [MCP Troubleshooting](/docs/mcp/troubleshooting)

## Tool Profiles (Save Tokens)

If you're using a smaller LLM or want to save context tokens, set a tool profile:

```json
{
  "mcpServers": {
    "synapse": {
      "command": "npx",
      "args": ["-y", "synapse-mcp-api@latest"],
      "env": {
        "SYNAPSE_MIND_KEY": "mk_...",
        "SYNAPSE_URL": "https://synapse.schaefer.zone",
        "MCP_PROFILE": "standard"
      }
    }
  }
}
```

Profiles: `minimal` (8 tools), `standard` (25), `full` (119, default).

## Next Steps

- [Claude Code Setup](/docs/mcp/claude-code)
- [Cursor Setup](/docs/mcp/cursor)
- [MCP Troubleshooting](/docs/mcp/troubleshooting)