---
title: "MCP Servers"
sidebarTitle: "MCP Servers"
description: "Connect external data sources to Siclaw via Model Context Protocol."
---

[Model Context Protocol (MCP)](https://modelcontextprotocol.io/) lets you extend Siclaw with external tools and data sources. During investigation, the agent discovers and uses MCP tools automatically — querying Prometheus metrics, searching GitHub issues, reading files, or calling any custom API.

## Supported Transports

| Transport | Use Case | Config |
|-----------|----------|--------|
| **stdio** | Local processes (npx packages, Python scripts) | `command` + `args` |
| **SSE** | Remote servers (Server-Sent Events) | `url` |
| **streamable-http** | Remote servers (bidirectional HTTP) | `url` |

## Configuration

### Via Web UI (Recommended)

In Gateway mode, go to **Settings** > **MCP Servers**:

1. Click **New Server**
2. Select transport type
3. Enter a unique name and optional description
4. Fill in transport-specific fields (command/args or URL)
5. Add environment variables or HTTP headers as needed
6. Save

Changes take effect immediately — all active sessions reload automatically.

<Note>
Creating and managing MCP servers requires **admin** role. All users can use the tools they provide.
</Note>

### Via settings.json (CLI mode)

For TUI / single-user mode, add MCP servers to `.siclaw/config/settings.json`:

```json
{
  "mcpServers": {
    "prometheus": {
      "transport": "stdio",
      "command": "npx",
      "args": ["-y", "@prom-mcp/server"],
      "env": {
        "PROMETHEUS_URL": "http://prometheus:9090"
      }
    }
  }
}
```

## Examples

### Prometheus Metrics

```json
{
  "mcpServers": {
    "prometheus": {
      "transport": "stdio",
      "command": "npx",
      "args": ["-y", "@prom-mcp/server"],
      "env": {
        "PROMETHEUS_URL": "http://prometheus.monitoring:9090"
      }
    }
  }
}
```

The agent can then query metrics during investigation:

```
Phase 1: Context Gathering
  [mcp:prometheus] rate(http_request_duration_seconds_sum{service="payment"}[5m])
  [kubectl] get pods -n payments
```

### Filesystem Access

```json
{
  "mcpServers": {
    "filesystem": {
      "transport": "stdio",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/workspace"]
    }
  }
}
```

### GitHub

```json
{
  "mcpServers": {
    "github": {
      "transport": "stdio",
      "command": "npx",
      "args": ["-y", "@github/mcp-server"],
      "env": {
        "GITHUB_TOKEN": "your-token"
      }
    }
  }
}
```

### Custom HTTP Service

Any service implementing the MCP protocol can be connected:

```json
{
  "mcpServers": {
    "my-service": {
      "transport": "streamable-http",
      "url": "https://mcp.internal.example.com/v1",
      "headers": {
        "Authorization": "Bearer your-token"
      }
    }
  }
}
```

## How It Works

### Tool Discovery

When a session starts, Siclaw connects to all enabled MCP servers and discovers their tools. MCP tools appear alongside built-in tools with a `mcp__` prefix:

```
mcp__prometheus__query        ← from Prometheus MCP server
mcp__github__search_issues    ← from GitHub MCP server
mcp__filesystem__read_file    ← from Filesystem MCP server
```

The agent decides which tools to use based on the investigation context — no manual tool selection needed.

### Config Sync (Gateway Mode)

In multi-user deployments, MCP configuration syncs automatically:

```
Admin creates/edits MCP server in Web UI
  → Saved to database
  → Gateway notifies all active AgentBoxes
  → Each AgentBox fetches merged config
  → Active sessions reload with new tools
```

The merge strategy: DB entries (managed via Web UI) override local seed entries with the same name. Disabling a DB entry removes it from the merged config.

### Kubernetes Considerations

<Warning>
In Kubernetes mode, `stdio` MCP servers run inside AgentBox pods. Make sure the required binaries or packages are available in that runtime image, or use HTTP-based MCP transports instead.
</Warning>

For HTTP-based transports (`sse`, `streamable-http`), the MCP server runs externally — the AgentBox pod only needs network access to the URL.
