Db2 for i MCP Server

mcp-server-db2i is a Model Context Protocol (MCP) server for IBM Db2 for i (Db2i) on IBM i (AS/400). It enables AI assistants like Claude and Cursor to query and inspect IBM i databases through the IBM i Access ODBC driver, or optionally the JT400 JDBC driver or Mapepire over SSH.

Listed in the MCP Registry as io.github.Strom-Capital/mcp-server-db2i.

Website: db2i-mcp.com, with a blog that explains each release. Docs: docs.db2i-mcp.com.

Architecture

AI clients connect to the MCP Server in one of two ways. Local clients such as Claude Desktop, Claude Code and Cursor can start it as a process and talk over stdio. Remote clients connect over Streamable HTTP at /mcp, signing in with OAuth 2.1 (claude.ai custom connectors) or a bearer token (custom agents). Local clients can also use the HTTP endpoint. The server executes read-only queries against Db2 for i using the IBM i Access ODBC driver (default, no Java), the optional JT400 JDBC driver (DB2I_DRIVER=jt400), or Mapepire over SSH (DB2I_DRIVER=mapepire) for systems where only SSH is reachable. One server can reach several IBM i systems through connection profiles, each with its own driver.

graph LR
    subgraph clients ["AI Clients"]
        local("Claude Desktop, Claude Code, Cursor")
        remote("claude.ai connectors")
        agents("Custom Agents")
    end

    subgraph server ["MCP Server"]
        stdio["stdio"]
        http["Streamable HTTP + Auth"]
        tools[["MCP Tools"]]
        profiles{{"System profiles"}}
        odbc["IBM i Access ODBC"]
        jdbc["JT400 JDBC (optional)"]
        mapepire["Mapepire over SSH (optional)"]
    end

    subgraph prod ["IBM i: prod"]
        db2prod[("Db2 for i")]
    end

    subgraph test ["IBM i: test"]
        db2test[("Db2 for i")]
    end

    subgraph dev ["IBM i: dev"]
        db2dev[("Db2 for i")]
    end

    local -->|local process| stdio
    local -.->|remote URL| http
    remote -->|OAuth 2.1| http
    agents -->|bearer token| http
    stdio & http --> tools
    tools --> profiles
    profiles --> odbc & jdbc & mapepire
    odbc -->|ODBC| db2prod
    jdbc -->|JDBC| db2test
    mapepire -->|SSH| db2dev

Features

• Read-only SQL queries - Execute SELECT statements safely with automatic result limiting, and a query timeout that cancels runaway statements on the IBM i
• Schema inspection - List all schemas/libraries with optional filtering
• Table metadata - List tables, describe columns, view indexes and constraints
• View inspection - List and explore database views
• Secure by design - Only SELECT queries allowed, credentials via environment variables
• Docker support - Run as a container for easy deployment
• HTTP Transport - MCP over Streamable HTTP with token authentication for remote clients and agents
• OAuth for Remote Clients - Built-in OAuth 2.1 sign-in with the user's own IBM i profile, so claude.ai custom connectors can connect
• Current MCP spec - Speaks 2026-07-28 and still serves stateless 2025-era clients
• Dual Transport - Run stdio and HTTP simultaneously
• Multiple systems - Reach several IBM i systems from one server with DB2I_PROFILES, each with its own driver, credentials, and library allowlist. Tools take an optional system argument. See Multiple systems
• SSH-only systems - With DB2I_DRIVER=mapepire, reach an IBM i where only SSH is open. Mapepire starts inside the SSH session, with no server install and a host key check. See Using the Mapepire driver
• Tool selection - Enable or disable individual tools, e.g. a metadata-only mode without execute_query
• Business SQL tools - Load read-only ERP queries and table notes from YAML, and check the files with mcp-server-db2i validate-tools before the server starts. See Business SQL tools
• Compact responses - Compact JSON by default, or markdown tables to save tokens
• Statement checks and DDL - Validate object names, return the SQL that recreates an object, and list what depends on a table
• Catalog search and profiling - Find tables and columns across libraries, check journaling, and profile a table's row counts and value ranges
• Column masking - Redact sensitive columns, or show only their last four characters, in query results. See Column masking
• Query exports - Hand the user a CSV or Excel file of a query's results, as a file path over stdio or a short-lived download link over HTTP. The rows never pass through the model. See Query exports
• Audit log - Record every tool call as one JSON line, with the SQL hashed by default. See Audit log
• Tool reload - Reload YAML tool files when they change, with MCP_CUSTOM_TOOLS_WATCH=true
• Resources and prompts - Read table columns and DDL as MCP resources, and start from prompts that explore a library, explain a table, or write a query. See Resources and prompts

Quick Start

Installation

npm install -g mcp-server-db2i

The default odbc driver needs unixODBC and the IBM i Access ODBC Driver on the machine. No Java is needed. The other drivers' packages are not installed by default, so add them next to the server:

npm install -g mcp-server-db2i node-jt400              # DB2I_DRIVER=jt400, needs a JDK to install and a JRE to run
npm install -g mcp-server-db2i @ibm/mapepire-js ssh2   # DB2I_DRIVER=mapepire, when only SSH reaches the IBM i

With npx, pass them with -p, for example npx -y -p mcp-server-db2i@latest -p node-jt400 mcp-server-db2i. See Installing the jt400 and mapepire packages.

Or with Docker:

docker build -t mcp-server-db2i .                  # odbc image (amd64; add --platform linux/amd64 on arm64)
docker build --target jt400 -t mcp-server-db2i .   # jt400 image (builds natively on arm64)

Configuration

Create a .env file with your IBM i credentials:

DB2I_HOSTNAME=your-ibm-i-host.com
DB2I_USERNAME=your-username
DB2I_PASSWORD=your-password
DB2I_SCHEMA=your-default-schema  # Optional

Client Setup

Add to your MCP client config (e.g., ~/.cursor/mcp.json):

{
  "mcpServers": {
    "db2i": {
      "command": "npx",
      "args": ["-y", "mcp-server-db2i@latest"],
      "env": {
        "DB2I_HOSTNAME": "${env:DB2I_HOSTNAME}",
        "DB2I_USERNAME": "${env:DB2I_USERNAME}",
        "DB2I_PASSWORD": "${env:DB2I_PASSWORD}"
      }
    }
  }
}

This uses environment variable expansion to keep credentials out of config files. Set the variables in your shell profile (~/.zshrc or ~/.bashrc).

See the Client Setup Guide for Cursor, Claude Desktop, Claude Code, and Docker setup options.

Available Tools