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. The sign-in page can carry your company's name, logo, colors and language (Customize for your company)
- 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 optionalsystemargument. 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-toolsbefore the server starts. See Business SQL tools - Server instructions - Send the rules no query may miss, such as which flag marks a deleted row, to the model at the start of every session. See
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.
No MCP client? The example web app is a browser chat with result tables, exports and the business SQL tools. Users sign in with their IBM i user profile and bring their own model API key.
Available Tools
In hosts that support MCP Apps, results from execute_query, profile_table and business SQL tools open as a grid and a chart under the tool call. See Result view.
Filter Syntax
The list tools support pattern matching:
CUST- Contains "CUST"CUST*- Starts with "CUST"*LOG- Ends with "LOG"
Resources and prompts
Clients that support MCP resources can read a table's context without a tool call, and complete library and table names as you type.
resources/list offers the annotated tables, for example db2i://MYLIB/ORDERS. Percent-encode # and other reserved characters in names (ORD%23X for ORD#X). A library outside QUERY_ALLOWED_SCHEMAS is rejected with the same message execute_query gives, and completion offers only allowed libraries. Reads and completions that query IBM i count against the rate limit, and reads are written to the audit log. Completion fetches a library's name list once and reuses it for 60 seconds, so typing a name costs one query rather than one per keystroke.
A prompt is listed only when the tools it tells the model to call are enabled: explore_library needs list_tables and describe_table, and the other two need describe_table. None of them asks for a write.
Use cases
I've used this server on projects where the source system was the Iptor DC1 ERP on IBM i. The same patterns work with any IBM i ERP.
- Building REST APIs - The agent finds the ERP tables and keys, checks its SQL with
validate_query, tests it on sample rows, and then writes the endpoint. - ETL and ELT pipelines for BI - Profile source tables, generate staging DDL with
get_object_ddl, and draft incremental extracts and code mappings for the warehouse. - Near-real-time replication to BI - Check which tables are journaled, and with which images, before a journal-based tool such as Fivetran streams changes to the warehouse.
- Ad-hoc analysis - Connect Claude or Cursor directly to the ERP and ask business questions in plain language, with vetted Business SQL tools and column masking for sensitive fields.
See Use cases for sample prompts and the guardrails that go with each one.
Example Usage
Once connected, you can ask the AI assistant:
- "List all schemas that contain 'PROD'"
- "Show me the tables in schema MYLIB"
- "Describe the columns in MYLIB/CUSTOMERS"
- "What indexes exist on the ORDERS table?"
- "Run this query: SELECT * FROM MYLIB.CUSTOMERS WHERE STATUS = 'A'"
- "Find the order header and line tables in MYLIB and write a GET /orders/:orderNo endpoint"
- "Draft an incremental extract of MYLIB.ORDERHDR rows changed since yesterday"
Documentation
Compatibility
- IBM i V7R3 and later (V7R5 recommended)
validate_queryand theexecute_queryparse check needQSYS2.PARSE_STATEMENT(IBM i 7.3 with Db2 PTF group SF99703 level 3, or 7.4 and later)get_related_objectsneeds IBM i 7.3 Technology Refresh 9, IBM i 7.4 Technology Refresh 3, or a later releaseget_journal_infoneeds the journal columns ofQSYS2.OBJECT_STATISTICS(IBM i 7.3 Technology Refresh 2 or later)search_ibmi_servicesneedsQSYS2.SERVICES_INFO, which ships with the Db2 for i PTF group- The
causeandrecoveryon a failed statement come fromSYSTOOLS.SQLCODE_INFO. Without it, errors return the SQLSTATE, SQLCODE and message only - Node.js 22 or higher
- unixODBC with the IBM i Access ODBC Driver for the default
odbcdriver, a JDK at install time and a JRE 11 or higher at runtime for the optionaljt400driver, or SSH access and Java 8 or higher on the IBM i for the optionalmapepiredriver (see Database Drivers) - MCP spec 2026-07-28, plus stateless clients from the 2025-era revisions (through 2025-11-25)
Related Projects
- IBM ibmi-mcp-server - IBM's official MCP server for IBM i systems. Offers YAML-based SQL tool definitions and AI agent frameworks. Requires Mapepire. This project's
mapepiredriver uses Mapepire's SSH mode, which needs no Mapepire server running on the IBM i.
Contributing
Contributions are welcome! See the Development Guide for setup instructions.
License
MIT License - see LICENSE for details.
Trademarks
IBM, IBM i and Db2 are trademarks of International Business Machines Corporation. This project is not affiliated with or endorsed by IBM.
Acknowledgments
- node-jt400 - JT400 JDBC driver wrapper for Node.js
- node-odbc - ODBC bindings for Node.js, maintained by IBM
- mapepire-js - Mapepire client for Node.js, maintained by IBM
- Model Context Protocol - The protocol specification
- @modelcontextprotocol/server - Official TypeScript SDK (spec 2026-07-28, with stateless 2025-era clients)
