# MCP in Claude Code

Claude Code is Anthropic's terminal-based coding agent. With Synapse MCP,
Claude Code gains persistent memory across coding sessions — it remembers
your project context, past decisions, and codebase patterns.

## Setup

### Method 1: CLI Command (recommended)

```bash
# Add Synapse as an MCP server
claude mcp add synapse -- npx -y synapse-mcp-api@latest

# Set your Mind Key as env var (add to ~/.bashrc or ~/.zshrc)
export SYNAPSE_MIND_KEY="mk_YOUR_MIND_KEY_HERE"
export SYNAPSE_URL="https://synapse.schaefer.zone"  # optional, defaults to synapse.schaefer.zone
```

### Method 2: Edit Config File

Edit `~/.claude/config.json`:

```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"
      }
    }
  }
}
```

## Verify It Works

Start Claude Code:

```bash
claude
```

In the Claude Code prompt, type:

```
recall all my memories
```

Claude should call `memory_recall` and respond with your stored memories.

## Common Patterns

### Project context persistence

At the start of a coding session:

```
recalling my memories — what projects am I working on?
```

Claude calls `memory_recall`, sees your project list, and continues work
where you left off.

### Codebase decisions

When you make an architectural decision:

```
store this: "We chose PostgreSQL over SQLite because of concurrent write
performance. Decision made on 2026-06-27."
```

Claude calls `memory_store` with category `project`, priority `high`.

### Avoiding past mistakes

```
what mistakes have I made with this codebase?
```

Claude searches memories with category `mistake` and reminds you of past errors.

### Task tracking

```
create a task: "Refactor auth module to use JWT refresh tokens"
```

Claude calls `task_create`, and the task persists across sessions.

## Tool Profiles

For coding sessions where you don't need all 119 tools:

```bash
# Set profile via env var
export MCP_PROFILE="standard"  # 25 tools, ~2500 tokens

# Or in config.json
"env": {
  "SYNAPSE_MIND_KEY": "mk_...",
  "MCP_PROFILE": "standard"
}
```

## Troubleshooting

### MCP server not starting

```bash
# Test the MCP server manually
npx -y synapse-mcp-api@latest

# Should print:
# [info] synapse-mcp Streamable HTTP server ready
# [info]   MCP:      http://localhost:13100/mcp
```

### Mind Key not recognized

```bash
# Verify env var is set
echo $SYNAPSE_MIND_KEY

# Test directly
curl -H "Authorization: Bearer $SYNAPSE_MIND_KEY" \
     https://synapse.schaefer.zone/memory/recall
```

### Claude Code doesn't see tools

- Restart Claude Code after config changes
- Check `claude mcp list` to verify Synapse is registered
- See [MCP Troubleshooting](/docs/mcp/troubleshooting)

## Next Steps

- [Claude Desktop Setup](/docs/mcp/claude-desktop)
- [Cursor Setup](/docs/mcp/cursor)
- [Persistent LLM Agent Guide](/docs/guides/persistent-llm-agent)