What is the 'Neural Link'?

The Neural Link is a bi-directional bridge that connects AI agents (like Gemini or Claude) directly to the Neo.mjs runtime. It allows agents to 'see' the application's Scene Graph, inspect component state, verify event listeners, and even mutate the running application in real-time. This turns the application into a 'glass box' for AI, enabling autonomous debugging and feature development.

Why is Neo.mjs called an 'Application Engine' instead of a framework?

Traditional frameworks are general-purpose libraries (like a Toyota) that help you organize code, but they compile away into ephemeral DOM nodes. Neo.mjs is a precision-engineered runtime (like an F1 car), similar to Unreal Engine for games. It maintains a persistent 'Scene Graph' of objects in a separate worker thread. These objects retain their identity, state, and relationships, allowing for advanced capabilities like multi-window orchestration, runtime permutation, and deep AI introspection that are impossible with 'melted plastic' DOM-based frameworks.

What is 'Context Engineering'?

Context Engineering is the practice of curating the environment and information flow for AI agents to maximize their autonomy. In Neo.mjs, this is implemented via three Model Context Protocol (MCP) servers: a Knowledge Base for semantic code understanding, a Memory Core for learning from past sessions, and a GitHub Workflow server for project management. This ecosystem allows agents to work as fully integrated members of the development team.

What is 'Object Permanence' in the context of Neo.mjs?

In Neo.mjs, UI components are persistent JavaScript objects living in the App Worker, not just transient rendering results. This 'Object Permanence' means a component (like a Dashboard) maintains its state (scroll position, user input, internal logic) even if it is detached from the DOM or moved to a different browser window. This is the 'Lego Technic' approach versus the 'Duplo' approach of traditional frameworks.

What is an 'Agent Operating System'?

Neo.mjs v11 introduced the concept of an Agent OS, where the platform itself provides the tools and interfaces for AI agents to operate. It combines a standalone, type-safe AI SDK for autonomous 'Code Execution' with the Neural Link for runtime control. This enables agents to monitor, debug, and heal the application autonomously, effectively acting as an operating system for synthetic intelligence.

How does Neo.mjs handle multi-window applications?

Neo.mjs uses shared web workers to run a single application instance across multiple browser windows. All windows share the same application state and data in real-time. Components can even move between windows while retaining their JavaScript instances. This enables desktop-class experiences like multi-window IDEs, browser-based email clients, and multi-screen control rooms.

What makes Neo.mjs different from React, Angular, or Vue?

Neo.mjs is fundamentally different in its architecture: (1) It uses True Multithreading via web workers to prevent UI jank, (2) It is an AI-Native Application Engine with built-in bridges for AI collaboration, and (3) It treats components as persistent objects in a Scene Graph, enabling native multi-window support and runtime permutation.

Frontmatter

id	9586
title	Analysis: Robust Multi-Window LivePreview Routing & Base Path Resolution
state	Closed
labels	enhancementaiarchitecture
assignees	tobiu
createdAt	Mar 27, 2026, 4:08 PM
updatedAt	Mar 27, 2026, 6:51 PM
githubUrl	https://github.com/neomjs/neo/issues/9586
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Mar 27, 2026, 6:51 PM

Analysis: Robust Multi-Window LivePreview Routing & Base Path Resolution

Name: Neo.mjs Application Engine
Author: Neo.mjs

Closed v12.1.0 enhancementaiarchitecture

tobiu commented on Mar 27, 2026, 4:08 PM

Background

During v12.1.0 development, we deleted src/code/LivePreview.mjs#beforeSetWindowUrl. This manual path calculation was originally added in #8074 to solve Windows OS path separator issues and nested "recursive" popouts. However, mapping the SharedWorker's basePath upward directly to the repo root fundamentally stripped out environment prefixes like dist/development/.

Current State

The system now relies entirely on the Main thread's native browser relative URL resolution (e.g., evaluating ./childapps/preview/index.html strictly against location.href). Initial macOS testing confirms that this successfully resolves for popouts executed from both the Portal Home route and the Learn route, preventing environment-jumping bugs.

Risk & Verification Plan

We must perform a matrix validation to ensure the native Main thread resolution handles all historical edge cases:

OS Matrix Verification: Ensure the Windows OS path separator (\) bug (#9365) does not regress without the manual split/join logic.
App Depth Verification: Test popping out LivePreview components located in apps with varying structural depths (e.g., apps/portal vs examples/component/button).
Environment Matrix Verification: Test popouts across all environments: development (raw), dist/development (bundled), and dist/production.
Recursive Popout Verification: Verify that popping out a component from inside an already-popped-out childapp (Window 2 -> Window 3) evaluates the deep relative path correctly without generating 404 URL loops (e.g., childapps/preview/childapps/preview/).

tobiu added the enhancement label on Mar 27, 2026, 4:08 PM

tobiu added the ai label on Mar 27, 2026, 4:08 PM

tobiu added the architecture label on Mar 27, 2026, 4:08 PM

tobiu cross-referenced by #9585 on Mar 27, 2026, 4:09 PM

tobiu assigned to @tobiu on Mar 27, 2026, 4:10 PM

tobiu Mar 27, 2026, 6:50 PM

Input from Gemini 3.1 Pro (Antigravity):

✦ > Resolution Summary:

The LivePreview multi-window regression has been successfully resolved.

Root Cause: The issue stemmed from a timing race condition where MainThreadAddons (like ResizeObserver) were not fully imported into the newly spawned popup window before the RemoteMethodAccess (RMA) mixin attempted to interface with them. This occurred because the App worker was caching the addon requests at the application level, bypassing the importAddon step for additional windows once the addon was loaded in the initial window.

Fixes Implemented:

src/worker/App.mjs: Refactored getAddon() to track addon loading on a per-window basis (${addonName}X${windowId}). This guarantees that when a component is moved to a new popout window (e.g., in LivePreview), the worker explicitly invokes Neo.Main.importAddon for that specific windowId.

src/Main.mjs: Ensured the registerAddon() method behaves idempotently. Dynamically importing an addon that is already registered no longer clobbers existing instances, avoiding unnecessary errors.

Validation: Implemented a new Playwright E2E test suite (test/playwright/e2e/LivePreviewMultiWindow.spec.mjs) that structurally validates the popout functionality across all three environments (Dev, Dist Dev, and Dist Prod) and both route contexts (Home and Learn), specifically asserting against "Invalid remote namespace" errors.

All matrix evaluations are currently passing!

tobiu referenced in commit 0c9adee - "test: Add LivePreview multi-window E2E validation (#9586) on Mar 27, 2026, 6:51 PM

tobiu closed this issue on Mar 27, 2026, 6:51 PM

tobiu referenced in commit c34eb32 - "test: Add sequential route validation for LivePreview (#9586)" on Mar 27, 2026, 7:03 PM