# Compose Multiplatform 1.12.0 Released

[Jetbrains](https://yomu.fyi/company/jetbrains) · Elvira Mustafina · Aug 26, 2026

**Type:** Announcement

## Summary

JetBrains has announced the release of Compose Multiplatform 1.12.0 with targeted capabilities for artificial intelligence integrations, web rendering, and desktop application layouts. The update incorporates an experimental Model Context Protocol server inside Compose Hot Reload, allowing AI agents to trigger reloads, capture screenshots, inspect the semantic tree, and simulate user interactions directly. For web deployments, the framework now provides automatic font fallback by downloading necessary Noto font subsets on demand when unresolved characters occur during rendering. Desktop developers receive an experimental v2 window and dialog application programming interface in the androidx.compose.ui.window.v2 package, which distinguishes requested states from actual window states and permits precise control over positioning, sizing constraints, and multi-screen placement. These combined enhancements improve developer workflows and runtime flexibility across multiple target platforms.

## Context

Compose Multiplatform needed better developer tooling for AI coding assistants, simplified international font management on the web without bundling large font files, and finer control over desktop window positioning and sizing states.

## Approach / What changed

JetBrains added an experimental Model Context Protocol server to Compose Hot Reload, implemented on-demand Noto font downloading for web font fallback, and created an experimental v2 WindowState and DialogState API in androidx.compose.ui.window.v2 for desktop.

## Takeaways

- The experimental Model Context Protocol server lets AI agents verify their code changes by triggering reloads, reading logs, inspecting semantic trees, and simulating inputs.
- Automatic web font fallback dynamically downloads matching Noto font subsets upon encountering unresolved characters, enabling scripts like Japanese, Arabic, and Devanagari to render without local bundling.
- The desktop v2 window API explicitly separates requested window states from actual current states while supporting custom sizing providers and parent-relative dialog positioning.

**Tags:** [Developer Experience](https://yomu.fyi/topic/developer-experience), [LLMs](https://yomu.fyi/topic/llm), [Open Source](https://yomu.fyi/topic/open-source)

[Read original post](https://blog.jetbrains.com/kotlin/2026/08/compose-multiplatform-1-12-0)