greptimedb-mcp-server

greptimedb-mcp-server

A Model Context Protocol (MCP) server for GreptimeDB — an open-source observability database that handles metrics, logs, and traces in one engine.

Enables AI assistants to query and analyze GreptimeDB using SQL, TQL (PromQL-compatible), and RANGE queries, with built-in security features like read-only enforcement and data masking.

Quick Start

# Install
pip install greptimedb-mcp-server

# Run (connects to localhost:4002 by default)
greptimedb-mcp-server --host localhost --database public

For Claude Desktop, add this to your config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "greptimedb": {
      "command": "greptimedb-mcp-server",
      "args": ["--host", "localhost", "--database", "public"]
    }
  }
}

Features

Tools

Pipeline Management

Resources & Prompts

• Resources: Browse tables via greptime://<table>/data URIs
• Prompts: Built-in templates for common tasks — pipeline_creator, log_pipeline, metrics_analysis, promql_analysis, iot_monitoring, trace_analysis, table_operation

For LLM integration and prompt usage, see docs/llm-instructions.md.

Configuration

Environment Variables

GREPTIMEDB_HOST=localhost      # Database host
GREPTIMEDB_PORT=4002           # MySQL protocol port (default: 4002)
GREPTIMEDB_USER=root           # Database user
GREPTIMEDB_PASSWORD=           # Database password
GREPTIMEDB_DATABASE=public     # Database name
GREPTIMEDB_TIMEZONE=UTC        # Session timezone

# Optional
GREPTIMEDB_HTTP_PORT=4000      # HTTP API port for pipeline management
GREPTIMEDB_HTTP_PROTOCOL=http  # HTTP protocol (http/https)
GREPTIMEDB_POOL_SIZE=5         # Connection pool size
GREPTIMEDB_MASK_ENABLED=true   # Enable sensitive data masking
GREPTIMEDB_MASK_PATTERNS=      # Additional patterns (comma-separated)
GREPTIMEDB_AUDIT_ENABLED=true  # Enable audit logging

# Transport (for HTTP server mode)
GREPTIMEDB_TRANSPORT=stdio     # stdio, sse, or streamable-http
GREPTIMEDB_LISTEN_HOST=0.0.0.0 # HTTP server bind host
GREPTIMEDB_LISTEN_PORT=8080    # HTTP server bind port
GREPTIMEDB_ALLOWED_HOSTS=      # DNS rebinding protection (comma-separated)
GREPTIMEDB_ALLOWED_ORIGINS=    # CORS allowed origins (comma-separated)

CLI Arguments

greptimedb-mcp-server \
  --host localhost \
  --port 4002 \
  --database public \
  --user root \
  --password "" \
  --timezone UTC \
  --pool-size 5 \
  --mask-enabled true \
  --transport stdio

HTTP Server Mode

For containerized or Kubernetes deployments. Requires mcp>=1.8.0:

# Streamable HTTP (recommended for production)
greptimedb-mcp-server --transport streamable-http --listen-port 8080

# SSE mode (legacy)
greptimedb-mcp-server --transport sse --listen-port 3000

DNS Rebinding Protection

By default, DNS rebinding protection is disabled for compatibility with proxies, gateways, and Kubernetes services. To enable it, use --allowed-hosts:

# Enable DNS rebinding protection with allowed hosts
greptimedb-mcp-server --transport streamable-http \
  --allowed-hosts "localhost:*,127.0.0.1:*,my-service.namespace:*"

# With custom allowed origins for CORS
greptimedb-mcp-server --transport streamable-http \
  --allowed-hosts "my-service.namespace:*" \
  --allowed-origins "http://localhost:*,https://my-app.example.com"

# Or via environment variables
GREPTIMEDB_ALLOWED_HOSTS="localhost:*,my-service.namespace:*" \
GREPTIMEDB_ALLOWED_ORIGINS="http://localhost:*" \
  greptimedb-mcp-server --transport streamable-http

If you encounter 421 Invalid Host Header errors, either disable protection (default) or add your host to the allowed list.

Security

Read-Only Database User (Recommended)

Create a read-only user in GreptimeDB using static user provider:

mcp_readonly:readonly=your_secure_password

Application-Level Security Gate

All queries go through a security gate that:

• Blocks: DROP, DELETE, TRUNCATE, UPDATE, INSERT, ALTER, CREATE, GRANT, REVOKE, EXEC, LOAD, COPY
• Blocks: Encoded bypass attempts (hex, UNHEX, CHAR)
• Allows: SELECT, SHOW, DESCRIBE, TQL, EXPLAIN, UNION

Data Masking

Sensitive columns are automatically masked (******) based on column name patterns:

• Authentication: password, secret, token, api_key, credential
• Financial: credit_card, cvv, bank_account
• Personal: ssn, id_card, passport

Configure with --mask-patterns phone,email to add custom patterns.

Audit Logging

All tool invocations are logged:

2025-12-10 10:30:45 - greptimedb_mcp_server.audit - INFO - [AUDIT] execute_sql | query="SELECT * FROM cpu LIMIT 10" | success=True | duration_ms=45.2

Disable with --audit-enabled false.

Development

# Clone and setup
git clone https://github.com/GreptimeTeam/greptimedb-mcp-server.git
cd greptimedb-mcp-server
uv venv && source .venv/bin/activate
uv sync

# Run tests
pytest

# Format & lint
uv run black .
uv run flake8 src

# Debug with MCP Inspector
npx @modelcontextprotocol/inspector uv --directory . run -m greptimedb_mcp_server.server

License

MIT License - see LICENSE.md.

Acknowledgement

Inspired by:

• ktanaka101/mcp-server-duckdb
• designcomputer/mysql_mcp_server
• mikeskarl/mcp-prompt-templates