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	8850
title	Fix VDOM ID Mismatch in Cross-Window Move (LivePreview Helix Detach)
state	Closed
labels	bugairegressioncore
assignees	tobiu
createdAt	Jan 21, 2026, 1:46 PM
updatedAt	Jan 21, 2026, 4:18 PM
githubUrl	https://github.com/neomjs/neo/issues/8850
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jan 21, 2026, 4:18 PM

Fix VDOM ID Mismatch in Cross-Window Move (LivePreview Helix Detach)

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

Closed v11.23.0 bugairegressioncore

tobiu commented on Jan 21, 2026, 1:46 PM

The VDOM createDeltas method is failing with an ID mismatch error during a cross-window move operation involving LivePreview.

Scenario:

Open Portal App Home.
Interact with the "Helix" Live Preview (Portal.view.home.parts.Helix), which renders examples.component.multiWindowHelix.
Click "Detach Window" for the Helix Controls panel.
Result: The new window opens and renders correctly, BUT the original content in the main window is NOT removed.
Error: The VDOM worker throws: Error: createDeltas() must be called for the same node. new: {id: neo-container-35, cId: neo-container-35}, old: {id: undefined, cId: neo-container-35}

Analysis: The error old: {id: undefined, cId: neo-container-35} suggests that the vnodeMap lookup for the old node is failing to find the correct VDOM node, likely because id is missing on the stored VNode, even though componentId is present.

This typically happens when moveNode attempts to process a move for a component reference. The Teleportation update might be generating disjoint payloads that interact poorly with moveNode when a component is being moved out of a container (detachment).

We need to investigate vdom.Helper.createDeltas and moveNode logic, specifically how they handle component placeholders during batched updates.

tobiu added the bug label on Jan 21, 2026, 1:46 PM

tobiu added the ai label on Jan 21, 2026, 1:46 PM

tobiu added the regression label on Jan 21, 2026, 1:46 PM

tobiu added the core label on Jan 21, 2026, 1:46 PM

tobiu referenced in commit 37e9a9c - "fix(VdomLifecycle): Fix Teleportation race conditions and cross-window leaks (#8850)" on Jan 21, 2026, 3:11 PM

tobiu assigned to @tobiu on Jan 21, 2026, 3:12 PM

tobiu Jan 21, 2026, 3:12 PM

Input from Gemini 3 Pro:

✦ Fixed critical regressions in VDOM Teleportation and SharedWorker support.

Summary of Fixes:

Race Condition (src/mixin/VdomLifecycle.mjs):

Problem: executeVdomUpdate was synchronously snapshotting the VDOM via collectPayloads before subsequent synchronous DOM mutations (like Container.remove) in the same tick could complete. This resulted in "stale payloads" where removed components persisted as "Ghost Content".

Fix: Added await new Promise(resolve => setTimeout(resolve, 1)) to executeVdomUpdate. This forces a Macrotask yield, ensuring collectPayloads runs after all pending synchronous logic and microtasks have settled, capturing the correct clean state.

Cross-Window Leak (src/mixin/VdomLifecycle.mjs):

Problem: Merged components (children) that moved to a new window were still included in the old parent's update batch. This caused deltas meant for the New Window (e.g., hiding a header) to be applied to the Old Window, corrupting the "Ghost Panel" state.

Fix: Added filtering in collectPayloads to strictly exclude components where component.windowId !== me.windowId.

Blocked Update Registry (src/manager/VDomUpdate.mjs):

Problem: unregisterInFlightUpdate used getParentIds(component) to clear the "in-flight" status from ancestors. If a component moved during the update, this function returned the new parents, leaving the old parent (Viewport) permanently blocked (isChildUpdating = true).

Fix: Refactored to iterate descendantInFlightMap directly, ensuring all registered ancestors are cleared regardless of hierarchy changes.

Component ID Stability (src/manager/Component.mjs):

Problem: Placeholders stored in me.vnode were missing id if they matched componentId, causing strict diffing errors in vdom.Helper.

Fix: Updated addVnodeComponentReferences to always assign id.

Race Condition (examples/component/multiWindowHelix/ViewportController.mjs):

Problem: Logic toggled header.hidden before re-attaching the panel to the viewport, causing an independent update that raced with the insert.

Fix: Swapped order to ensure correct hierarchy merging.

Result: The Helix example now correctly detaches and re-attaches the controls panel across windows without artifacts, ghost content, or errors.

tobiu referenced in commit c3ebf6b - "fix(Gallery): Fix re-attach race condition and add regression test (#8850)" on Jan 21, 2026, 3:17 PM

tobiu closed this issue on Jan 21, 2026, 4:18 PM