mcp_log_window

Top-right floating "MCP" window (zui) that hosts the MCP tool-call log. Wraps mcp_log_ui with its own screen lifecycle — registers via ui.registerScreen, throttles repaints to every 100 ms, and exposes a movable / resizable window pinned to the top-right by default.

Unlike system_tools, this window is a dedicated stand-alone screen rather than a tab host, and uses a fixed screen_id (default "mcp-log-window") so external ui.hideScreen callers keep working.

Exports

• M.createState(opts: MountOpts?) -> McpLogWindowState — build the initial state table from mount opts. Useful for rehydration without going through the full mount flow.
• M.mount(opts: MountOpts?) -> McpLogWindowHandle — register the window, return a handle whose update / onCallback / destroy the caller drives per frame.

Types:

• MountOpts = { title: string?, width: number?, height: number?, screen_id: string? }
• McpLogWindowState = { title: string, width: number, height: number }
• McpLogWindowHandle = { state: McpLogWindowState, update: (dt) -> (), onCallback: (id, data) -> boolean, destroy: () -> () }

Usage

local McpLogWindow = require("@builtin::modules.engine.editor.mcp_log_window")

local handle = McpLogWindow.mount({ title = "Agent" })

-- In your component:
function update(dt) handle.update(dt) end
function onCallback(id, data) return handle.onCallback(id, data) end
function onDestroy() handle.destroy() end

Notes

• Repaints are throttled to MIN_UPDATE_INTERVAL (100 ms) but flush immediately on user interaction so toolbar clicks feel responsive.
• The hosting component owns the screen lifecycle (destroy calls ui.unregisterScreen); leaving a session without calling destroy leaks a screen registration.
• Window position defaults to the top-right via getViewportSize, falling back to 1600x900 if the FFI binding is absent.