Universal Database Gateway

npx mcpbar install bytebase/dbhub -c claude

{
  "mcpServers": {
    "Universal Database Gateway": {
      "command": "npx",
      "args": [
        "-y",
        "dbhub"
      ],
      "env": {}
    }
  }
}

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

Resource Name	URI Format	PostgreSQL	MySQL	MariaDB	SQL Server	SQLite	Oracle
schemas	db://schemas	✅	✅	✅	✅	✅	✅
tables_in_schema	db://schemas/{schemaName}/tables	✅	✅	✅	✅	✅	✅
table_structure_in_schema	db://schemas/{schemaName}/tables/{tableName}	✅	✅	✅	✅	✅	✅
indexes_in_table	db://schemas/{schemaName}/tables/{tableName}/indexes	✅	✅	✅	✅	✅	✅
procedures_in_schema	db://schemas/{schemaName}/procedures	✅	✅	✅	✅	❌	✅
procedure_details_in_schema	db://schemas/{schemaName}/procedures/{procedureName}	✅	✅	✅	✅	❌	✅

Database Tools

Tool	Command Name	PostgreSQL	MySQL	MariaDB	SQL Server	SQLite	Oracle
Execute SQL	execute_sql	✅	✅	✅	✅	✅	✅
List Connectors	list_connectors	✅	✅	✅	✅	✅	✅

Prompt Capabilities

Prompt	Command Name	PostgreSQL	MySQL	MariaDB	SQL Server	SQLite	Oracle
Generate SQL	generate_sql	✅	✅	✅	✅	✅	✅
Explain DB Elements	explain_db	✅	✅	✅	✅	✅	✅

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"

# 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:[email protected]: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

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:[email protected]:3306/dbname

DBHub supports the following database connection string formats:

Database	DSN Format	Example
MySQL	mysql://[user]:[password]@[host]:[port]/[database]	mysql://user:password@localhost:3306/dbname
MariaDB	mariadb://[user]:[password]@[host]:[port]/[database]	mariadb://user:password@localhost:3306/dbname
PostgreSQL	postgres://[user]:[password]@[host]:[port]/[database]	postgres://user:password@localhost:5432/dbname?sslmode=disable
SQL Server	sqlserver://[user]:[password]@[host]:[port]/[database]	sqlserver://user:password@localhost:1433/dbname
SQLite	sqlite:///[path/to/file] or sqlite::memory:	sqlite:///path/to/database.db, sqlite:C:/Users/YourName/data/database.db (windows) or sqlite::memory:
Oracle	oracle://[user]:[password]@[host]:[port]/[service_name]	oracle://username:password@localhost:1521/service_name

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

Option	Description	Default
demo	Run in demo mode with sample employee database	false
dsn	Database connection string	Required if not in demo mode
transport	Transport mode: stdio or sse	stdio
port	HTTP server port (only applicable when using --transport=sse)	8080
readonly	Restrict SQL execution to read-only operations	false

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"
   

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

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