Zed MySQL Context Server

A Model Context Server for MySQL that integrates with Zed AI assistant.

Prerequisites

• Rust (latest stable version)
• MySQL/MariaDB database
• Zed

Installation

1. Clone and build:

git clone <repository-url>
cd mcp-server-mysql
cargo build --release

2. Configure Zed (see Configuration section)

Configuration

Click on the "Toggle Agent Menu" -> "Add custom Server"

{
  /// The name of your MCP server
  "mysql-mcp-server": {
    /// The command which runs the MCP server
    "command": "/path/to/mcp-server-mysql/target/release/mcp-server-mysql",
    /// The arguments to pass to the MCP server
    "args": [
        "--username", "your_username",
        "--password", "your_password",
        "--database", "your_database",
        "--host", "localhost",
        "--port", "3306"
    ],
    /// The environment variables to set
    "env": {}
  }
}

To allow dangerous queries (INSERT, UPDATE, DELETE, etc.), add the flag:

{
  "mysql-mcp-server": {
    "command": "/path/to/mcp-server-mysql/target/release/mcp-server-mysql",
    "args": [
        "--username", "your_username",
        "--password", "your_password",
        "--database", "your_database",
        "--host", "localhost",
        "--port", "3306",
        "--allow-dangerous-queries"
    ],
    "env": {}
  }
}

Options

• --host <HOST>: MySQL host (default: localhost)
• --port <PORT>: MySQL port (default: 3306)
• --username <USERNAME>: MySQL username (required)
• --password <PASSWORD>: MySQL password (default: empty)
• --database <DATABASE>: MySQL database name (required)
• --allow-dangerous-queries: Allow dangerous SQL keywords in queries (INSERT, UPDATE, DELETE, etc.)

Logging

The server uses standard Rust logging. Control log levels with the RUST_LOG environment variable:

• RUST_LOG=error - Only show errors
• RUST_LOG=warn - Show warnings and errors
• RUST_LOG=info - Show info, warnings and errors (recommended for production)
• RUST_LOG=debug - Show all messages including detailed debug info

Testing

Test manually with your database:

# Test initialization (with info logging)
RUST_LOG=info echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' | cargo run --bin mcp-server-mysql -- --username admin --database mydb

# Test schema retrieval (quiet mode)
echo '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"mysql","arguments":{"table_name":"users"}}}' | cargo run --bin mcp-server-mysql -- --username admin --database mydb

# Test with debug output (for troubleshooting)
RUST_LOG=debug echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' | cargo run --bin mcp-server-mysql -- --username admin --database mydb

Or use the test script:

./test-stdio.sh

Building

# Development
cargo build

# Production
cargo build --release

Available Tools

The server provides the following tools:

• mysql: Retrieve MySQL database schema information for tables
• query: Execute SQL queries (SELECT only by default, all queries with --allow-dangerous-queries)
• insert: Insert data into a specified table
• update: Update data in a specified table based on conditions
• delete: Delete data from a specified table based on conditions

Query Tool

The query tool executes SQL queries on the database.

Parameters

• query (required): The SQL query to execute
• database (optional): Database name to use for this query. If specified, the query will be executed in the context of this database.

Database Context

Each query can specify which database to use via the optional database parameter. This is useful when working with multiple databases or when you need to query a database different from the default.

Example with database parameter:

{
  "name": "query",
  "arguments": {
    "query": "SELECT * FROM crm_sites LIMIT 10",
    "database": "dev_smartConnect_za"
  }
}

Example without database parameter (uses default):

{
  "name": "query",
  "arguments": {
    "query": "SELECT * FROM users WHERE active = 1 LIMIT 10"
  }
}

Multiple databases in one session:

// Query from production database
{
  "query": "SELECT COUNT(*) FROM customers",
  "database": "production_db"
}

// Query from test database
{
  "query": "SELECT COUNT(*) FROM test_data",
  "database": "test_db"
}

Query Safety

By default, only SELECT queries are allowed:

SELECT COUNT(*) as count FROM accounts WHERE primary_category = 'Medical';
SELECT * FROM users WHERE active = 1 LIMIT 10;

With --allow-dangerous-queries flag, you can execute any SQL:

CREATE TABLE new_table (id INT PRIMARY KEY, name VARCHAR(255));
ALTER TABLE users ADD COLUMN last_login TIMESTAMP;
DROP TABLE old_data;
TRUNCATE TABLE logs;

Notes

• When no database parameter is provided, the query uses the default database specified in --database
• The database parameter allows you to query any database you have permissions for
• Each query with a database parameter acquires its own connection to ensure proper database context
• Database names with special characters are automatically escaped

License

Apache-2.0