Scouter Server

한국어

An MCP (Model Context Protocol) server that connects AI agents to Scouter APM, enabling natural-language queries against real-time application performance data.

Ask your AI assistant things like "What's the slowest SQL in the last hour?" or "Why is TPS dropping?" and get answers grounded in live monitoring data.

Features

• 32 tools covering the full Scouter API surface
• Dual protocol — connects via HTTP (REST API) or TCP (binary protocol)
• Automatic hash resolution — SQL queries, service names, and error messages are decoded from Scouter's internal hash IDs to human-readable text
• Executable SQL — transaction profiles include SQL with bind parameters substituted, ready for EXPLAIN ANALYZE
• Zero external dependencies — only @modelcontextprotocol/sdk and zod

Quick Start

Using npx (no install needed)

npx scouter-mcp-server

Or install from source

cd scouter.mcp
npm install
npm run build

Configure

Set environment variables to point at your Scouter collector:

Variable	Description	Default
SCOUTER_API_URL	Scouter webapp REST API base URL	http://localhost:6180
SCOUTER_API_ID	API login ID
SCOUTER_API_PASSWORD	API login password
SCOUTER_TCP_HOST	TCP direct connection host
SCOUTER_TCP_PORT	TCP direct connection port	6100
SCOUTER_ENABLE_WRITE	Set to true to enable write tools	(disabled)
SCOUTER_MASK_PII	Set to false to disable PII masking in responses (IP, login, userAgent, SQL params)	true

HTTP mode (recommended) — set SCOUTER_API_URL. Supports all 32 tools (write tools require SCOUTER_ENABLE_WRITE=true). TCP mode — set SCOUTER_TCP_HOST. Lightweight, no webapp needed, but some admin tools are unavailable.

Note: By default, only read-only tools (25) are registered. To enable write tools (set_configure, set_alert_scripting, manage_kv_store, manage_shortener, control_thread, remove_inactive_objects), set SCOUTER_ENABLE_WRITE=true.

3. Add to your MCP client

Claude Desktop (claude_desktop_config.json):

HTTP mode:

{
  "mcpServers": {
    "scouter": {
      "command": "npx",
      "args": ["-y", "scouter-mcp-server"],
      "env": {
        "SCOUTER_API_URL": "http://your-scouter-server:6180",
        "SCOUTER_API_ID": "admin",
        "SCOUTER_API_PASSWORD": "your-password"
      }
    }
  }
}

TCP mode:

{
  "mcpServers": {
    "scouter": {
      "command": "npx",
      "args": ["-y", "scouter-mcp-server"],
      "env": {
        "SCOUTER_TCP_HOST": "your-scouter-server",
        "SCOUTER_TCP_PORT": "6100",
        "SCOUTER_API_ID": "admin",
        "SCOUTER_API_PASSWORD": "your-password"
      }
    }
  }
}

Claude Code (use -s user to register globally across all projects):

# HTTP mode
claude mcp add scouter -s user \
  -e SCOUTER_API_URL=http://your-scouter-server:6180 \
  -e SCOUTER_API_ID=admin \
  -e SCOUTER_API_PASSWORD=your-password \
  -- npx -y scouter-mcp-server

# TCP mode
claude mcp add scouter -s user \
  -e SCOUTER_TCP_HOST=your-scouter-server \
  -e SCOUTER_TCP_PORT=6100 \
  -e SCOUTER_API_ID=admin \
  -e SCOUTER_API_PASSWORD=your-password \
  -- npx -y scouter-mcp-server

To update the configuration later, edit ~/.claude.json directly or remove and re-add:

claude mcp remove scouter -s user
claude mcp add scouter -s user \
  -e SCOUTER_TCP_HOST=new-host \
  -e SCOUTER_TCP_PORT=6100 \
  -e SCOUTER_API_ID=admin \
  -e SCOUTER_API_PASSWORD=your-password \
  -- npx -y scouter-mcp-server

Tools

Performance Investigation

Tool	Description
get_system_overview	Real-time snapshot — TPS, response time, CPU, heap, active services, alerts
diagnose_performance	Automated multi-step diagnosis with severity-ranked findings
get_counter_trend	Historical counter values (TPS, ElapsedTime, CPU, etc.) over time
search_transactions	Find slow/error transactions by time range, service, IP, login
get_transaction_detail	Full transaction profile with executable SQL and API call traces
list_active_services	Currently running requests with thread state

SQL & Database

Tool	Description
get_sql_analysis	SQL performance ranking — count, elapsed, errors, % of total
lookup_text	Resolve hash IDs to SQL/service/error text

Error & Alert Analysis

Tool	Description
get_error_summary	Errors ranked by frequency with per-service error rates
get_alert_summary	Alert statistics within a time range
get_alert_scripting	Read alert rule scripts
set_alert_scripting	Create/update alert rules (HTTP only)

Service & Traffic

Tool	Description
get_service_summary	Service-level stats with external API call breakdown
get_ip_summary	Request distribution by client IP
get_user_agent_summary	Request distribution by browser/user-agent
get_visitor_stats	Unique visitor counts (realtime, daily, hourly)
get_interaction_counters	Service-to-service call relationships

Infrastructure

Tool	Description
get_thread_dump	Thread dump with stack traces
get_host_info	Host-level top processes and disk usage
get_agent_info	Agent runtime info (threads, env, sockets)
get_server_info	Collector server metadata and counter model

Distributed Tracing

Tool	Description
get_distributed_trace	Trace a transaction across services via GXID
get_realtime_xlogs	Real-time transaction stream
get_raw_xlog	Raw XLog data (5 query modes)
get_raw_profile	Raw profile steps with hash IDs

Configuration & Management

Tool	Description
get_configure	Read server/agent configuration
set_configure	Modify configuration (HTTP only)
control_thread	Suspend/resume/interrupt threads
manage_kv_store	Global, namespaced, and private key-value store
manage_shortener	URL shortener service
remove_inactive_objects	Clean up dead agents (HTTP only)

Architecture

┌─────────────────────────────┐
│  AI Agent (Claude, etc.)    │
│  "Why is the app slow?"     │
└──────────┬──────────────────┘
           │ MCP (stdio)
┌──────────▼──────────────────┐
│  Scouter MCP Server         │
│  ┌────────────────────────┐ │
│  │ Tool Hub (31 tools)    │ │
│  │ Hash Resolution Engine │ │
│  │ SQL Param Binding      │ │
│  └────────────────────────┘ │
└──────────┬──────────────────┘
           │ HTTP REST or TCP Binary
┌──────────▼──────────────────┐
│  Scouter Collector Server   │
│  + Webapp (REST API)        │
└──────────┬──────────────────┘
           │
    ┌──────▼──────┐
    │ Java Agents │
    │ Host Agents │
    └─────────────┘

Project Structure

scouter.mcp/
├── index.ts                 # Entry point — stdio transport + SIGINT handler
├── server/
│   └── index.ts             # createServer() factory → { server, cleanup }
├── tools/
│   ├── index.ts             # registerAllTools() hub — explicit imports of all tools
│   ├── shared-utils.ts      # Hash resolution, SQL param binding
│   └── ... (31 tool files)
├── client/
│   ├── index.ts             # Client facade — exports client, jsonStringify, catchWarn
│   ├── interface.ts         # ScouterClient interface + types
│   ├── http.ts              # HTTP/REST implementation
│   └── tcp.ts               # TCP binary protocol implementation
├── protocol/
│   ├── tcp-connection.ts    # TCP connection with handshake/auth
│   ├── packs.ts             # Scouter binary pack definitions
│   ├── values.ts            # Value type serialization
│   ├── data-input.ts        # Binary deserialization
│   ├── data-output.ts       # Binary serialization
│   └── constants.ts         # Protocol constants
├── time-utils.ts            # Time parsing utilities
├── __tests__/               # Vitest test suites
├── vitest.config.ts         # Test config (v8 coverage)
├── tsconfig.json            # NodeNext modules
└── package.json

Development

npm run dev          # Watch mode (tsc --watch)
npm test             # Run tests
npm run test:coverage  # Coverage report
npm run build        # Production build

Adding a New Tool

1. Create tools/my-tool.ts exporting register(server: McpServer) with server.registerTool()
2. Add import { register as registerMyTool } from "./my-tool.js" to tools/index.ts
3. Call registerMyTool(server) inside registerAllTools()
4. Use shared-utils.ts for hash resolution and SQL binding

Protocol Details

HTTP Mode

Connects to Scouter's webapp REST API (/scouter/v1/*). Supports all 32 tools including write operations (configuration, alert scripting, thread control).

Authentication: username/password login with bearer token auto-refresh on 401.

TCP Mode

Connects directly to the Scouter collector using the binary protocol (port 6100). Handshake uses NetCafe magic number (0xCAFE2001), login with SHA-256 hashed password.

Supports read-only tools. Write operations (config, alerts, KV store, URL shortener) throw UnsupportedOperationError.

Text hash resolution uses GET_TEXT_100 command with per-date caching.

Requirements

• Node.js >= 18
• Scouter Collector >= 2.x with webapp enabled (for HTTP mode)

License

Apache License 2.0 — same as the Scouter project.