# split_window

Source: https://libtmux.org/en/dotnet/latest/mcp/tools/split_window/

> Start a pane's configured process; accepts no command payload. Split a pane and return the NEW pane's id. Use that id for what you put in it — pane ids stay valid across layout changes, where window names and indexes do not.

MCP is in development

Server behavior and tool contracts may change. Tool availability depends on the server configuration.

Start a pane’s configured process; accepts no command payload. Split a pane and return the NEW pane’s id. Use that id for what you put in it — pane ids stay valid across layout changes, where window names and indexes do not.

[All .NET tools](../) · [JSON](../split_window.json) · [Source](https://github.com/libtmux/libtmux-dotnet/blob/320dc64f4b8b7815842471327a5e6b84a1499bf8/src/LibTmux.Mcp/Policy/CapabilityModel.cs#L594)

## Arguments

* `direction` optional · string

  Below, Above, Left, or Right.

  Default: `"Below"`.

* `paneId` optional · string | null

  The pane to split. Omit for the active pane.

  Default: `null`.

* `percentage` optional · integer | null

  Percentage of the space for the new pane.

  Default: `null`.

* `startDirectory` optional · string | null

  The literal starting directory.

  Default: `null`.

## Schemas

The schema defines required fields, nested values, defaults, and validation constraints.