dbhub

DBHub is a universal database gateway implementing the Model Context Protocol (MCP) server interface. This gateway allows MCP-compatible clients to connect to and explore different databases.

 +------------------+    +--------------+    +------------------+
 |                  |    |              |    |                  |
 |                  |    |              |    |                  |
 |  Claude Desktop  +--->+              +--->+    PostgreSQL    |
 |                  |    |              |    |                  |
 |      Cursor      +--->+    DBHub     +--->+    SQL Server    |
 |                  |    |              |    |                  |
 |     Other MCP    +--->+              +--->+     SQLite       |
 |      Clients     |    |              |    |                  |
 |                  |    |              +--->+     MySQL        |
 |                  |    |              |    |                  |
 |                  |    |              +--->+    MariaDB       |
 |                  |    |              |    |                  |
 |                  |    |              +--->+     Oracle       |
 |                  |    |              |    |                  |
 +------------------+    +--------------+    +------------------+
      MCP Clients           MCP Server             Databases

Demo SSE Endpoint

https://demo.dbhub.ai/sse connects a sample employee database. You can point Cursor or MCP Inspector to it to see it in action.

Supported Matrix

Database Resources

Database Tools

Prompt Capabilities

Installation

Docker

# PostgreSQL example
docker run --rm --init \
   --name dbhub \
   --publish 8080:8080 \
   bytebase/dbhub \
   --transport sse \
   --port 8080 \
   --dsn "postgres://user:password@localhost:5432/dbname?sslmode=disable"

# Demo mode with sample employee database
docker run --rm --init \
   --name dbhub \
   --publish 8080:8080 \
   bytebase/dbhub \
   --transport sse \
   --port 8080 \
   --demo

# Oracle example
docker run --rm --init \
   --name dbhub \
   --publish 8080:8080 \
   bytebase/dbhub \
   --transport sse \
   --port 8080 \
   --dsn "oracle://username:password@localhost:1521/service_name"

# Oracle example with thick mode for connecting to 11g or older 
docker run --rm --init \
   --name dbhub \
   --publish 8080:8080 \
   bytebase/dbhub-oracle-thick \
   --transport sse \
   --port 8080 \
   --dsn "oracle://username:password@localhost:1521/service_name"

NPM

# PostgreSQL example
npx @bytebase/dbhub --transport sse --port 8080 --dsn "postgres://user:password@localhost:5432/dbname?sslmode=disable"

# Demo mode with sample employee database
npx @bytebase/dbhub --transport sse --port 8080 --demo

Note: The demo mode includes a bundled SQLite sample "employee" database with tables for employees, departments, salaries, and more.

Claude Desktop

• Claude Desktop only supports stdio transport https://github.com/orgs/modelcontextprotocol/discussions/16

// claude_desktop_config.json
{
  "mcpServers": {
    "dbhub-postgres-docker": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "bytebase/dbhub",
        "--transport",
        "stdio",
        "--dsn",
        // Use host.docker.internal as the host if connecting to the local db
        "postgres://user:password@host.docker.internal:5432/dbname?sslmode=disable"
      ]
    },
    "dbhub-postgres-npx": {
      "command": "npx",
      "args": [
        "-y",
        "@bytebase/dbhub",
        "--transport",
        "stdio",
        "--dsn",
        "postgres://user:password@localhost:5432/dbname?sslmode=disable"
      ]
    },
    "dbhub-demo": {
      "command": "npx",
      "args": ["-y", "@bytebase/dbhub", "--transport", "stdio", "--demo"]
    }
  }
}

Cursor

• Cursor supports both stdio and sse.
• Follow Cursor MCP guide and make sure to use Agent mode.

Usage

SSL Connections

You can specify the SSL mode using the sslmode parameter in your DSN string:

SSL Mode Options:

• sslmode=disable: All SSL/TLS encryption is turned off. Data is transmitted in plaintext.
• sslmode=require: Connection is encrypted, but the server's certificate is not verified. This provides protection against packet sniffing but not against man-in-the-middle attacks. You may use this for trusted self-signed CA.

Without specifying sslmode, most databases default to certificate verification, which provides the highest level of security.

Example usage:

# Disable SSL
postgres://user:password@localhost:5432/dbname?sslmode=disable

# Require SSL without certificate verification
postgres://user:password@localhost:5432/dbname?sslmode=require

# Standard SSL with certificate verification (default)
postgres://user:password@localhost:5432/dbname

Read-only Mode

You can run DBHub in read-only mode, which restricts SQL query execution to read-only operations:

# Enable read-only mode
npx @bytebase/dbhub --readonly --dsn "postgres://user:password@localhost:5432/dbname"

In read-only mode, only readonly SQL operations are allowed.

This provides an additional layer of security when connecting to production databases.

Configure your database connection

You can use DBHub in demo mode with a sample employee database for testing:

npx @bytebase/dbhub  --demo

For real databases, a Database Source Name (DSN) is required. You can provide this in several ways:

• Command line argument (highest priority):

  npx @bytebase/dbhub  --dsn "postgres://user:password@localhost:5432/dbname?sslmode=disable"
  

• Environment variable (second priority):

  export DSN="postgres://user:password@localhost:5432/dbname?sslmode=disable"
  npx @bytebase/dbhub
  

• Environment file (third priority):

  • For development: Create .env.local with your DSN
  • For production: Create .env with your DSN

  DSN=postgres://user:password@localhost:5432/dbname?sslmode=disable
  

[!WARNING] When running in Docker, use host.docker.internal instead of localhost to connect to databases running on your host machine. For example: mysql://user:password@host.docker.internal:3306/dbname

DBHub supports the following database connection string formats:

Oracle

If you see the error "NJS-138: connections to this database server version are not supported by node-oracledb in Thin mode", you need to use Thick mode as described below.

Docker

Use bytebase/dbhub-oracle-thick instead of bytebase/dbhub docker image.

npx

1. Download and install Oracle Instant Client for your platform
2. Set the ORACLE_LIB_DIR environment variable to the path of your Oracle Instant Client:

# Set environment variable to Oracle Instant Client directory
export ORACLE_LIB_DIR=/path/to/instantclient_19_8

# Then run DBHub
npx @bytebase/dbhub --dsn "oracle://username:password@localhost:1521/service_name"

SQL Server

Extra query parameters:

authentication

• authentication=azure-active-directory-access-token. Only applicable when running from Azure. See DefaultAzureCredential.

Transport

• stdio (default) - for direct integration with tools like Claude Desktop:

  npx @bytebase/dbhub --transport stdio --dsn "postgres://user:password@localhost:5432/dbname?sslmode=disable"
  

• sse - for browser and network clients:

  npx @bytebase/dbhub --transport sse --port 5678 --dsn "postgres://user:password@localhost:5432/dbname?sslmode=disable"
  

Command line options

The demo mode uses an in-memory SQLite database loaded with the sample employee database that includes tables for employees, departments, titles, salaries, department employees, and department managers. The sample database includes SQL scripts for table creation, data loading, and testing.

Development

1. Install dependencies:

   pnpm install
   

2. Run in development mode:

   pnpm dev
   

3. Build for production:

   pnpm build
   pnpm start --transport stdio --dsn "postgres://user:password@localhost:5432/dbname?sslmode=disable"
   

Testing

The project uses Vitest for testing:

• Run tests: pnpm test
• Run tests in watch mode: pnpm test:watch

Pre-commit Hooks (for Developers)

The project includes pre-commit hooks to run tests automatically before each commit:

1. After cloning the repository, set up the pre-commit hooks:

   ./scripts/setup-husky.sh
   

2. This ensures the test suite runs automatically whenever you create a commit, preventing commits that would break tests.

Debug with MCP Inspector

stdio

# PostgreSQL example
TRANSPORT=stdio DSN="postgres://user:password@localhost:5432/dbname?sslmode=disable" npx @modelcontextprotocol/inspector node /path/to/dbhub/dist/index.js

SSE

# Start DBHub with SSE transport
pnpm dev --transport=sse --port=8080

# Start the MCP Inspector in another terminal
npx @modelcontextprotocol/inspector

Connect to the DBHub server /sse endpoint

Contributors

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