mcp-server-db2-luw

MCP server for IBM DB2 LUW (Linux/Unix/Windows) 11.x.

Connects via JDBC using a persistent Java subprocess (Db2Gateway), so no native Node.js modules are required — only a standard JRE ≥ 11.

Tools

| Tool | Description | |------|-------------| | list_schemas | List all schemas in the database | | list_tables | List tables in a schema (supports % wildcard filter) | | describe_table | Column details for a table (types, lengths, nullability, defaults) | | list_views | List views in a schema | | list_indexes | List indexes for a table | | get_table_constraints | PK / FK / unique constraints for a table | | execute_query | Execute a read-only SELECT query (row limit enforced) |

Requirements

• Node.js ≥ 18
• Java JDK ≥ 11 (javac and java on PATH) — only needed to build; consumers who install via npm/npx only need the JRE

Installing Java

| Platform | Command | |----------|---------| | Windows (winget) | winget install Microsoft.OpenJDK.21 | | Windows (manual) | Download .msi from adoptium.net | | macOS (Homebrew) | brew install --cask temurin | | Ubuntu / Debian | sudo apt install default-jdk | | RHEL / Fedora | sudo dnf install java-21-openjdk-devel |

After installing, restart your terminal so PATH is updated, then verify:

javac -version   # should print: javac 21.x.x (or 11+)
java  -version

JDBC Driver

The IBM DB2 JDBC driver (db2jcc4.jar) is not committed to git and not published in npm tarballs due to its IBM license.

At runtime, the server resolves the driver in this order:

1. DB2_JDBC_JAR (user-provided path)
2. Local legacy paths (java/db2jcc4.jar or java/jcc-<version>.jar)
3. Cache path ~/.mcp-server-db2-luw/jdbc/jcc-<version>.jar
4. Download com.ibm.db2:jcc from Maven Central into the cache path

Manual override

If you want to supply your own driver or control where downloads are cached:

DB2_JDBC_JAR=/path/to/db2jcc4.jar npx -y mcp-server-db2-luw
DB2JCC_MAVEN_VERSION=11.5.8.0 npx -y mcp-server-db2-luw
DB2JCC_CACHE_DIR=/custom/cache/dir npx -y mcp-server-db2-luw

Usage

GitHub Copilot / Claude (mcp.json)

{
  "servers": {
    "db2-luw": {
      "type": "stdio",
      "command": "node",
      "args": ["/path/to/mcp-server-db2-luw/index.js"],
      "env": {
        "DB2_HOSTNAME": "127.0.0.1",
        "DB2_PORT":     "50000",
        "DB2_DATABASE": "db_name",
        "DB2_USERNAME": "db_username",
        "DB2_PASSWORD": "your_password",
        "DB2_SCHEMA":   "db_schema"
      }
    }
  }
}

npx (after publish to npm)

{
  "command": "npx",
  "args": ["-y", "mcp-server-db2-luw"]
}

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | DB2_HOSTNAME | ✓ | localhost | DB2 server hostname | | DB2_PORT | | 50000 | DB2 port | | DB2_DATABASE | | trunkdb | Database name | | DB2_USERNAME | ✓ | — | DB2 username | | DB2_PASSWORD | ✓ | — | DB2 password | | DB2_SCHEMA | | — | Default schema for metadata tools | | DB2_JDBC_JAR | | auto-resolved/downloaded | Path to a custom db2jcc4.jar | | QUERY_MAX_LIMIT | | 1000 | Maximum rows returned per query | | DB2JCC_MAVEN_VERSION | | 11.5.9.0 | Driver version to download if not found locally | | DB2JCC_CACHE_DIR | | ~/.mcp-server-db2-luw/jdbc | Directory for downloaded JDBC jars |