ibmi-mcp

Give your AI Agent terminal access to your IBM i system via TN5250.

ibmi-mcp is an MCP server that lets AI Agents like Claude interact with IBM i the same way a human would through a 5250 green-screen terminal.

Installation

Install and register with Claude Code:

claude mcp add ibmi-5250 -- uvx ibmi-mcp

Configuration

Configure the connection using environment variables:

| Variable | Description | Required | Default | |----------|-------------|----------|---------| | IBMI_HOST | IBM i hostname or IP | Yes | — | | IBMI_PORT | TN5250 port | No | 23 | | IBMI_SSL | Enable TLS | No | false | | IBMI_USER | Username for auto-signon | No | — | | IBMI_PASSWORD | Password for auto-signon | No | — | | IBMI_DEVICE_NAME | Virtual device name | No | — | | IBMI_CODEPAGE | EBCDIC codepage | No | cp037 | | IBMI_TERMINAL_TYPE | Terminal type | No | IBM-3179-2 |

When IBMI_USER and IBMI_PASSWORD are set, ibmi-mcp will automatically sign on when it detects a login screen after connecting.

Tools

| Tool | Description | |------|-------------| | connect | Connect to an IBM i system via TN5250 | | disconnect | Disconnect the active session | | read_screen | Read the current screen content and input fields | | send_keys | Type text into the current input field | | send_key | Send a function/attention key (Enter, F1-F24, PageUp, PageDown, Tab, etc.) | | set_cursor | Position the cursor at a specific row and column |

Features

• Auto-signon — Automatically detects sign-on screens and logs in with configured credentials
• Full key support — Enter, F1-F24, PageUp, PageDown, Tab, Backtab, Clear, Help, Print, Attn
• Local editing — Backspace, Delete, Field Exit, Home, and End handled locally for responsive editing
• Structured screen data — Returns screen text, cursor position, and input field metadata
• Configurable codepage — Supports EBCDIC codepage translation (default: CP037)

License

BSD 2-Clause. See LICENSE for details.

About Whitehorn Ltd. Co.

ibmi-mcp is developed and maintained by Whitehorn Ltd. Co., a legacy system modernization firm. We specialize in IBM i, RPG, COBOL, and midrange platforms. We help our clients protect what they can't afford to break while building a path forward.

Learn more about how Whitehorn Ltd. Co. can help you modernize your IBM midrange systems at whitehorn.ltd.