Connect to an IBM i system via TN5250.

Args: host: IBM i hostname or IP. Defaults to IBMI_HOST env var. port: TN5250 port. Defaults to IBMI_PORT env var or 23. use_ssl: Enable TLS. Defaults to IBMI_SSL env var.

Returns the initial screen after connection.

Disconnect the active TN5250 session.

Read the current 5250 screen content.

Returns structured data with:

• screen: list of text rows (the visible display)

• cursor: current cursor position {row, col} (1-based)

• fields: list of input fields with position, length, value, and type

• dimensions: screen size {rows, cols}

Type text into the current input field at the cursor position.

Args: text: The text to type.

Returns the updated screen state.

Send an attention/function key and wait for the host response.

Args: key: Key name. Valid values: Enter, F1-F24, PageUp, PageDown, Tab, Backtab, Clear, Help, Print, Attn.

Returns the updated screen after the host processes the key.

Position the cursor at the specified location.

Args: row: Row number (1-based, top row is 1). col: Column number (1-based, leftmost column is 1).

Returns the updated screen state.