OmniSQL MCP

Universal database MCP server — give AI assistants read/write access to your databases using connections already saved in your local DB client workspace (DBeaver-compatible).

Database Support

Natively supported (direct driver, fast):

• PostgreSQL (via pg)

• MySQL / MariaDB (via mysql2)

• SQL Server / MSSQL (via mssql)

• SQLite (via sqlite3 CLI)

Postgres-compatible (routed through pg driver automatically):

• CockroachDB, TimescaleDB, Amazon Redshift, YugabyteDB, AlloyDB, Supabase, Neon, Citus

Other databases: Fall back to an external CLI configured via OMNISQL_CLI_PATH. Results vary by CLI.

Custom drivers wrapping any of the above are detected automatically — see Custom and IAM-Authenticated Drivers.

Related MCP server: DuckDB MCP Server

Features

• Reuses connections already configured in your local DB client workspace — no duplicate setup

• Native query execution for PostgreSQL, MySQL/MariaDB, SQLite, SQL Server

• AWS RDS IAM authentication, including custom drivers built on the AWS Advanced JDBC Wrapper

• Connection pooling with configurable pool size and timeouts

• Transaction support (BEGIN/COMMIT/ROLLBACK)

• Query execution plan analysis (EXPLAIN)

• Schema comparison between connections with migration script generation

• Read-only mode with enforced SELECT-only on execute_query

• Connection whitelist to restrict which databases are accessible

• Tool filtering to disable specific operations

• Query validation to block dangerous operations (DROP DATABASE, TRUNCATE, DELETE/UPDATE without WHERE)

• Data export to CSV/JSON

• Graceful shutdown with connection pool cleanup

Requirements

• Node.js 18+

• A local DB client (DBeaver-compatible) with at least one configured connection

Installation

npm install -g omnisql-mcp

Configuration

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS):

{
  "mcpServers": {
    "omnisql": {
      "command": "omnisql-mcp"
    }
  }
}

Claude Code

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "omnisql": {
      "command": "omnisql-mcp"
    }
  }
}

Cursor

Add to Cursor Settings > MCP Servers:

{
  "mcpServers": {
    "omnisql": {
      "command": "omnisql-mcp"
    }
  }
}

Environment Variables

Read-Only Mode

Blocks all write operations. The execute_query tool only allows SELECT, EXPLAIN, SHOW, and DESCRIBE statements. Transaction tools are disabled entirely.

{
  "mcpServers": {
    "omnisql": {
      "command": "omnisql-mcp",
      "env": {
        "OMNISQL_READ_ONLY": "true"
      }
    }
  }
}

Connection Whitelist

Restrict which workspace connections are visible. Accepts connection IDs or display names, comma-separated:

{
  "mcpServers": {
    "omnisql": {
      "command": "omnisql-mcp",
      "env": {
        "OMNISQL_ALLOWED_CONNECTIONS": "dev-postgres,staging-mysql"
      }
    }
  }
}

Disable Specific Tools

{
  "mcpServers": {
    "omnisql": {
      "command": "omnisql-mcp",
      "env": {
        "OMNISQL_DISABLED_TOOLS": "drop_table,alter_table,write_query"
      }
    }
  }
}

Available Tools

Connection Management

• list_connections - List all database connections

• get_connection_info - Get connection details

• test_connection - Test connectivity

Data Operations

• execute_query - Run read-only queries (SELECT, EXPLAIN, SHOW, DESCRIBE only)

• write_query - Run INSERT/UPDATE/DELETE

• export_data - Export to CSV/JSON

Schema Management

• list_tables - List tables and views

• get_table_schema - Get table structure

• create_table - Create tables

• alter_table - Modify tables

• drop_table - Drop tables (requires confirmation)

Transactions

• begin_transaction - Start a new transaction

• execute_in_transaction - Execute query within a transaction

• commit_transaction - Commit a transaction

• rollback_transaction - Roll back a transaction

Query Analysis

• explain_query - Analyze query execution plan

• compare_schemas - Compare schemas between two connections

• get_pool_stats - Get connection pool statistics

Other

• get_database_stats - Database statistics

• append_insight - Store analysis notes

• list_insights - Retrieve stored notes

Security

• Read-only enforcement: execute_query only accepts read-only statements (SELECT, EXPLAIN, SHOW, DESCRIBE, PRAGMA). Write operations must use write_query.

• Query validation: Blocks DROP DATABASE, DROP SCHEMA, TRUNCATE, DELETE/UPDATE without WHERE, GRANT, REVOKE, and user management statements.

• Connection whitelist: Restrict which connections are exposed via OMNISQL_ALLOWED_CONNECTIONS.

• Tool filtering: Disable any tool via OMNISQL_DISABLED_TOOLS.

• Input sanitization: Connection IDs and SQL identifiers are sanitized to prevent injection.

• Recommendation: For production use, also use a database-level read-only user for defense in depth.

Workspace Format Support

Supports both configuration formats written by DBeaver-compatible DB clients:

• Legacy: XML config in .metadata/.plugins/org.jkiss.dbeaver.core/

• Modern: JSON config in General/.dbeaver/

The project/workspace folder name (General by default) is configurable via OMNISQL_PROJECT, so workspaces using a custom or renamed DBeaver project (e.g. DataPlatform) are discovered without needing to rename the project or symlink the folder.

Connection modes

DBeaver connections are configured either manually (host, port, database fields) or by URL (a JDBC URL). Both work. In URL mode DBeaver leaves the host/port fields at placeholder values — usually localhost — and reads only the URL, so the URL is what is used here too.

SSH tunnels

Connections that DBeaver reaches through an SSH tunnel are tunneled here as well. The tunnel is opened on first use and reused for the lifetime of the server, with a loopback-only local forward, and the connection's host/port are treated the way DBeaver treats them: as the database as seen from the SSH server.

• Agent, password and public-key authentication are supported, taken from the connection's SSH tab. Credentials saved in the workspace (including the tunnel's own, stored separately from the database credentials) are decrypted and used.

• Agent authentication needs SSH_AUTH_SOCK set in the MCP server's environment. MCP clients usually do not inherit your shell, so set it explicitly in the client's server config if you use an agent.

• The SSH host key is checked against known_hosts. A host recorded there must match, or the tunnel is refused; a host that is not recorded is accepted, unless OMNISQL_SSH_STRICT_HOST_KEY=true.

• If a tunnel cannot be opened the connection fails with that reason. It never falls back to connecting directly to the recorded host, which would reach an unrelated local database.

Querying another database on the same server

A connection id may carry a database override — my-connection/analytics — to run against a different database on the same server without adding a second connection in DBeaver. This does not apply to file-backed engines such as SQLite, where the "database" is a file path.

With OMNISQL_ALLOWED_CONNECTIONS set, whitelisting a connection allows the databases its credentials can reach. To pin it to specific databases, list connection/database entries instead of the bare connection.

Credentials are automatically decrypted from the workspace credentials-config.json.

Custom and IAM-Authenticated Drivers

Custom drivers

Native routing normally keys off the driver id (postgres-jdbc, mysql8). Custom drivers often use an opaque id instead — a UUID, say — which names no engine. Those connections are resolved by falling back to the connection's provider (postgresql, mysql, …) and then to the JDBC URL's sub-protocol, including wrapped ones such as jdbc:aws-wrapper:postgresql://…. A custom driver wrapping a supported engine therefore works with no extra configuration.

If an engine still cannot be identified, the resulting error names both the driver id and the provider so you can see what was missing.

AWS RDS IAM authentication

Connections that authenticate with an RDS IAM token instead of a stored password are detected and handled automatically. Both shapes are recognised:

• AWS Advanced JDBC Wrapper drivers, which record wrapperPlugins: "iam" alongside awsProfile and iamRegion.

• The DB client's own AWS IAM auth models.

For these connections OmniSQL:

1. Mints a token with aws rds generate-db-auth-token (via the AWS CLI, so SSO and role-chained profiles work as configured) and uses it as the password.

2. Caches each token for 13 minutes, under its 15-minute lifetime, and re-mints per physical connection so long-lived pools keep working.

3. Forces TLS, which RDS requires for IAM tokens.

4. Resolves the database username from the connection when present. Where it is absent, the username is derived from your AWS identity: either the per-developer role name (<profile>-<user>) or the assumed SSO session name.

Requirements: the AWS CLI on PATH (or OMNISQL_AWS_CLI_PATH), a valid session for the connection's profile (aws sso login --profile <profile>), and network reachability to the endpoint. An expired SSO session produces an error naming the profile to re-authenticate.

Development

git clone https://github.com/srthkdev/omnisql-mcp.git
cd omnisql-mcp
npm install
npm run build
npm test
npm run lint

License

MIT