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mcp-database

A Node.js MCP (Model Context Protocol) server that provides database operations for AI assistants and agents. Supports 40+ databases through genai-toolbox.

Features

  • Easy Installation: Install via npm/npx - no manual binary downloads
  • Universal Database Support: PostgreSQL, MySQL, MongoDB, Redis, SQLite, and 35+ more
  • Simple Configuration: YAML config or environment variables
  • MCP Standard: Full MCP protocol implementation
  • Production Ready: Connection pooling, auth, and observability built-in

Installation

Install from npm and pick the bundle that fits your environment:

  • Core package (no bundled binaries, ~50KB): npm install -g @adversity/mcp-database
  • Platform-specific (includes binary for one OS/CPU, ~15MB):
    • macOS ARM64: npm install -g @adversity/mcp-database-darwin-arm64
    • macOS Intel: npm install -g @adversity/mcp-database-darwin-x64
    • Linux x64: npm install -g @adversity/mcp-database-linux-x64
    • Windows x64: npm install -g @adversity/mcp-database-win32-x64
  • No install: npx @adversity/mcp-database --help

Quick Start

Using Prebuilt Configurations

The easiest way to get started is with prebuilt database configurations:

# PostgreSQL
DATABASE_HOST=localhost \
DATABASE_NAME=mydb \
DATABASE_USER=user \
DATABASE_PASSWORD=password \
npx @adversity/mcp-database --prebuilt postgres

# MySQL
DATABASE_HOST=localhost \
DATABASE_NAME=mydb \
DATABASE_USER=root \
DATABASE_PASSWORD=password \
npx @adversity/mcp-database --prebuilt mysql

# SQLite (no credentials needed)
DATABASE_NAME=./my-database.db \
npx @adversity/mcp-database --prebuilt sqlite

# MongoDB
DATABASE_HOST=localhost \
DATABASE_NAME=mydb \
DATABASE_USER=user \
DATABASE_PASSWORD=password \
npx @adversity/mcp-database --prebuilt mongodb

Using Custom Configuration

Create a tools.yaml file:

sources:
  my-postgres:
    kind: postgres
    host: ${POSTGRES_HOST:localhost}
    port: ${POSTGRES_PORT:5432}
    database: ${POSTGRES_DATABASE:mydb}
    user: ${POSTGRES_USER:postgres}
    password: ${POSTGRES_PASSWORD}

tools:
  get_user_by_id:
    kind: postgres-sql
    source: my-postgres
    description: Get user by ID
    parameters:
      - name: user_id
        type: number
        description: The user ID
    statement: SELECT * FROM users WHERE id = $1;

Run with custom config:

mcp-database --config tools.yaml

SQLite Built-in Introspection Tools (Recommended for AI)

Designed for AI to explore unknown databases without schema knowledge:

DATABASE_NAME=./your-database.db \
npx @adversity/mcp-database --config prebuilt/sqlite-introspection.yaml

15 Built-in Introspection Tools:

Tool Set Tool Name Function
Basic Exploration sqlite_list_tables List all tables and views
sqlite_describe_table View table structure (columns, types, keys)
sqlite_list_columns List all column information
sqlite_preview_table Preview first N rows of data
sqlite_database_summary Complete database summary (tables, indexes, views)
Advanced Analysis sqlite_list_indexes List all indexes
sqlite_list_table_indexes View indexes for a specific table
sqlite_describe_index View columns in an index
sqlite_list_foreign_keys View foreign key relationships
sqlite_get_table_schema Get table's CREATE statement
Statistics sqlite_count_rows Count total rows in a table
sqlite_table_stats Get statistics for all tables
sqlite_database_info Database basic information
sqlite_get_schema_version Get schema version number

Typical AI Workflow:

1. sqlite_list_tables → Discover users, orders, products tables
2. sqlite_describe_table("users") → Understand column structure
3. sqlite_preview_table("users", 5) → See actual data format
4. sqlite_list_foreign_keys("orders") → Understand table relationships
5. Now AI can confidently construct complex queries!

MCP Client Configuration Example:

{
  "mcpServers": {
    "database": {
      "command": "npx",
      "args": ["@adversity/mcp-database", "--config", "prebuilt/sqlite-introspection.yaml"],
      "env": {
        "DATABASE_NAME": "./your-database.db"
      }
    }
  }
}

SQLite Custom YAML Example

  1. Copy the example: cp tools.example.yaml tools.yaml
  2. Verify sample database exists: ls sample.sqlite
  3. Run:
    DATABASE_NAME=$(pwd)/sample.sqlite \
    npx @adversity/mcp-database --config tools.yaml --verbose
  4. The MCP client can access sqlite_crud toolset from tools.example.yaml:
    • sqlite_list_recent_users: List recent 20 user records
    • sqlite_get_user_by_id: Query by ID
    • sqlite_find_user_by_email: Search by email
    • sqlite_create_user / sqlite_update_user_email / sqlite_delete_user: Create/Update/Delete

Example YAML snippet (from tools.example.yaml):

tools:
  sqlite_list_recent_users:
    kind: sqlite-sql
    source: my-sqlite
    description: List recent 20 users ordered by creation time
    statement: |
      SELECT id, name, email, created_at
      FROM users
      ORDER BY datetime(created_at) DESC
      LIMIT 20;

  sqlite_create_user:
    kind: sqlite-sql
    source: my-sqlite
    description: Create new user and return result
    parameters:
      - { name: name, type: string }
      - { name: email, type: string }
    statement: |
      INSERT INTO users (name, email, created_at)
      VALUES (?1, ?2, CURRENT_TIMESTAMP)
      RETURNING id, name, email, created_at;

toolsets:
  sqlite_crud:
    - sqlite_list_recent_users
    - sqlite_get_user_by_id
    - sqlite_find_user_by_email
    - sqlite_create_user
    - sqlite_update_user_email
    - sqlite_delete_user

Unified Environment Variables and CLI Override

All prebuilt databases use simple, unified environment variables:

  • DATABASE_HOST - Database host (default: localhost)
  • DATABASE_PORT - Database port (default: depends on database type)
  • DATABASE_NAME - Database name
  • DATABASE_USER - Database user
  • DATABASE_PASSWORD - Database password

You can also override via CLI:

mcp-database --prebuilt postgres \
  --db-host prod-db.internal \
  --db-port 6543 \
  --db-name inventory \
  --db-user readonly

自定义 toolbox 端口

默认使用 STDIO 模式,不占用 TCP 端口;当需要切换到 HTTP(例如调试或远程访问)时,可指定传输方式与端口:

npx @adversity/mcp-database --prebuilt sqlite \
  --transport http \
  --toolbox-host 0.0.0.0 \
  --toolbox-port 5900

对应环境变量:

变量 说明
MCP_TOOLBOX_TRANSPORT stdio(默认)或 http
MCP_TOOLBOX_HOST HTTP 监听地址,默认 127.0.0.1
MCP_TOOLBOX_PORT HTTP 端口,默认 5000

CLI 也保留 --stdio(布尔)用于兼容旧脚本;推荐使用 --transport 来切换模式。

MCP Integration

Claude Code / Claude Desktop

Add to your .mcp.json or claude_desktop_config.json:

{
  "mcpServers": {
    "database": {
      "command": "npx",
      "args": ["@adversity/mcp-database", "--prebuilt", "postgres"],
      "env": {
        "DATABASE_HOST": "localhost",
        "DATABASE_PORT": "5432",
        "DATABASE_NAME": "mydb",
        "DATABASE_USER": "postgres",
        "DATABASE_PASSWORD": "your-password"
      }
    }
  }
}

Cursor IDE

Create .cursor/mcp.json:

{
  "mcpServers": {
    "database": {
      "command": "npx",
      "args": ["@adversity/mcp-database", "--prebuilt", "mysql"],
      "env": {
        "DATABASE_HOST": "localhost",
        "DATABASE_NAME": "mydb",
        "DATABASE_USER": "root",
        "DATABASE_PASSWORD": "your-password"
      }
    }
  }
}

VS Code (Copilot)

Create .vscode/mcp.json:

{
  "servers": {
    "database": {
      "command": "npx",
      "args": ["@adversity/mcp-database", "--prebuilt", "postgres"],
      "env": {
        "DATABASE_HOST": "localhost",
        "DATABASE_NAME": "mydb"
      }
    }
  }
}

Windsurf

Configure via the Cascade assistant's MCP settings with the same JSON format as Cursor.

Supported Databases

Relational Databases

  • PostgreSQL
  • MySQL
  • SQL Server
  • SQLite
  • Oracle
  • Cloud SQL (Postgres, MySQL, SQL Server)
  • AlloyDB for PostgreSQL
  • Spanner
  • TiDB
  • OceanBase
  • YugabyteDB

NoSQL Databases

  • MongoDB
  • Redis
  • Valkey
  • Firestore
  • Bigtable
  • Cassandra
  • Couchbase
  • Neo4j
  • Dgraph

Analytics & Warehouses

  • BigQuery
  • ClickHouse
  • Trino
  • Serverless Spark
  • Elasticsearch
  • SingleStore

Cloud Services

  • Looker
  • MindsDB
  • Dataplex
  • Cloud Healthcare API
  • Cloud Monitoring

See genai-toolbox documentation for complete list and configuration details.

Available Tools

When connected via MCP, the following tools are available to AI assistants:

list_tables

List all tables in the database with their descriptions.

Example:

Show me all tables in the database

execute_sql

Execute any SQL statement on the database.

Parameters:

  • sql (string, required): The SQL statement to execute

Example:

Get all users from the users table where age > 25

Environment Variables

All database types use the same unified environment variables:

  • DATABASE_HOST - Database host (default: localhost)
  • DATABASE_PORT - Database port (default: varies by database type)
    • PostgreSQL: 5432
    • MySQL: 3306
    • MongoDB: 27017
    • Redis: 6379
    • MSSQL: 1433
  • DATABASE_NAME - Database name or file path
  • DATABASE_USER - Database user
  • DATABASE_PASSWORD - Database password

For cloud services (Cloud SQL, AlloyDB, BigQuery, Spanner, Firestore), additional GCP-specific variables are required:

  • GCP_PROJECT - GCP project ID
  • GCP_REGION - GCP region (default: us-central1)
  • CLOUD_SQL_INSTANCE / ALLOYDB_CLUSTER / etc. - Service-specific identifiers

CLI Reference

mcp-database [OPTIONS]

OPTIONS:
  -c, --config <path>    Path to tools.yaml configuration file
  -p, --prebuilt <type>  Use prebuilt config for database type
      --db-host <value>  Override MCP_DATABASE_HOST(所有预置类型通用)
      --db-port <value>  Override MCP_DATABASE_PORT
      --db-name <value>  Override MCP_DATABASE_NAME(对应 database/schema)
      --db-user <value>  Override MCP_DATABASE_USER
      --db-password <value> Override MCP_DATABASE_PASSWORD
      --transport <mode> Transport between wrapper 与 toolbox:`stdio`(默认) / `http`
      --toolbox-host <value> 当 transport=http 时的监听地址(默认 127.0.0.1)
      --toolbox-port <value> 当 transport=http 时的端口(默认 5000)
      --stdio            Use stdio transport (default: true)
  -v, --version          Print version
  -h, --help             Print help
      --verbose          Enable verbose logging

PREBUILT TYPES:
  postgres, mysql, sqlite, mongodb, redis, mssql,
  cloud-sql-postgres, cloud-sql-mysql, alloydb-pg,
  bigquery, spanner, firestore

Programmatic Usage

You can also use mcp-database programmatically:

import { startServer, generatePrebuiltConfig } from '@adversity/mcp-database';

const config = generatePrebuiltConfig('postgres');

const server = await startServer({
  binaryPath: '/path/to/toolbox',
  config,
  verbose: true,
});

// Server is now running

Testing

The project includes comprehensive test coverage, especially for SQLite features:

# Run all tests
npm test

# Run only SQLite tests
npm test -- sqlite

# Run with coverage
npm run test:coverage

SQLite Test Coverage:

  • ✅ 63 test cases, 100% passing
  • ✅ Configuration loading and environment variable handling
  • ✅ 15 built-in introspection tools validation
  • ✅ CRUD operations and parameterized queries
  • ✅ Toolset integration tests

Development

# Install dependencies
npm install

# Build
npm run build

# Watch mode
npm run dev

# Run tests
npm test

# Lint
npm run lint

# Format
npm run format

How It Works

This package wraps the genai-toolbox binary and exposes it as an MCP server:

  1. Binary Management: Automatically downloads the correct genai-toolbox binary for your platform
  2. Configuration: Generates or loads YAML configuration with environment variable substitution
  3. MCP Protocol: Implements MCP server protocol over stdio
  4. Tool Execution: Proxies tool calls to genai-toolbox subprocess

Requirements

  • Node.js 18 or higher
  • Internet connection (for initial binary download)
  • Database credentials for your target database

License

MIT

Related Projects

Contributing

Contributions are welcome! Please open an issue or pull request.

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