MCP Debug Mode: Expose UI State and Widget Tree

### Use case

Flutter has no built-in way for AI tools or external developer agents to understand what the app looks like at runtime. When the app runs in debug mode, AI-assisted tools cannot access a screenshot, widget tree, or layout information. This makes it difficult for AI to help with UI debugging, layout analysis, and automatic test generation.

I am requesting a feature that allows Flutter to expose runtime UI state to AI tools or debugging tools.

Problem

AI agents currently only have access to source code — not the live UI.
They cannot:

See what the screen looks like

Inspect the widget hierarchy

Analyze layout constraints or bounds

This limits AI-assisted development that relies on understanding the actual rendered UI.

Alternatives considered

Screenshot packages exist, but they don't expose a full widget tree or structured data.

Devtools inspector is visual-only and not accessible programmatically.

No package on pub.dev provides a standardized protocol like MCP for structured tool communication.

There is no existing solution that exposes the UI in a safe, standardized, debug-only way.

### Proposal

Allow Flutter apps (in debug mode only) to run a lightweight MCP (Model Context Protocol) server. This would let tools request structured information about the current UI.

What Flutter should support

`getScreenshot` → return current screen pixel buffer

`getWidgetTree` → return the rendered widget/element tree

`getLayoutInfo` → return bounding boxes and constraints

This would allow AI agents and development tools to understand what is currently rendered on screen.

Why MCP

MCP is a simple, standardized protocol designed for safe tool-to-application communication.
Using it avoids building custom RPC systems and enables compatibility with modern AI tools.

Should Flutter provide this directly?

Yes — because:

Flutter already has access to the widget tree and render tree

Screenshot and inspector logic exist internally

A framework-level implementation is more reliable and consistent than a third-party package

A package could attempt this, but it would be much more limited.