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	8898
title	Fix VDOM ID Corruption during Component Recycling (Structural Shifts)
state	Closed
labels	bugcore
assignees	[]
createdAt	Jan 27, 2026, 10:18 PM
updatedAt	Jan 27, 2026, 10:36 PM
githubUrl	https://github.com/neomjs/neo/issues/8898
author	tobiu
commentsCount	2
parentIssue	8891
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jan 27, 2026, 10:21 PM

Fix VDOM ID Corruption during Component Recycling (Structural Shifts)

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

Closed v11.24.0 bugcore

tobiu commented on Jan 27, 2026, 10:18 PM

Problem: During rapid updates or complex component recycling (like Buffered Grid scrolling), Neo.util.VDom.syncVdomState can corrupt VDOM IDs. This happens because the function synchronizes IDs from the Worker (VNode) to the App (VDOM) using an index-based loop, assuming structural identity.

When components are recycled (e.g., Row A moves to Row B's position), the App's VDOM structure shifts (New Order), but the Worker's response might reflect the Old Order. syncVdomState blindly maps IDs from the Old Order to the New Order. While top-level IDs (like the Row itself) are protected by an existence check, the function descends into the children, corrupting the internal IDs of stable components (like Buttons inside cells). This leads to "Node Stealing" and duplicate DOM nodes.

Solution: Modify src/util/VDom.mjs to abort child synchronization if the parent IDs mismatch.

if (vnode.id && vdom.id && vnode.id !== vdom.id) {
    return; // Stop recursion
}

This ensures that IDs are only synced into a subtree if the root of that subtree matches the Worker's view, preventing cross-contamination during structural shifts.

Impact: Fixes node duplication and "Recursive Move" anomalies in high-performance grids and other recycling views.

tobiu added the bug label on Jan 27, 2026, 10:18 PM

tobiu added the core label on Jan 27, 2026, 10:18 PM

tobiu cross-referenced by #8893 on Jan 27, 2026, 10:19 PM

tobiu referenced in commit 4f223a7 - "Fix VDOM ID Corruption during Component Recycling (Structural Shifts) #8898" on Jan 27, 2026, 10:20 PM

tobiu added parent issue #8891 on Jan 27, 2026, 10:20 PM

tobiu Jan 27, 2026, 10:21 PM

Input from Gemini 3 Pro:

✦ This issue was identified during the investigation of #8893.

Resolution: The fix was implemented in src/util/VDom.mjs to abort child synchronization when parent IDs mismatch. Regression tests were added in test/playwright/unit/vdom/SyncVdomIds.spec.mjs.

Fixed in commit referencing #8893. Closing as resolved.

tobiu closed this issue on Jan 27, 2026, 10:21 PM

tobiu referenced in commit cfd7dde - "fix: Add length mismatch guard to syncVdomState to prevent ID corruption #8898" on Jan 27, 2026, 10:36 PM

tobiu Jan 27, 2026, 10:36 PM

Input from Gemini 3 Pro:

✦ ### Additional Fix: Length Mismatch Guard

Further analysis revealed a second corruption vector: Scenario: A stable component (Parent ID matches) updates its structure asynchronously (e.g., adds a child) while an older update is in-flight.

Worker (Old): Parent has 1 child (Text).

App (New): Parent has 2 children (Icon, Text).

Sync:

Parent IDs match. Recursion proceeds.

Index 0: Text (Worker) vs Icon (App).

Icon gets Text ID. Corruption.

Solution: Added a Length Mismatch Guard to src/util/VDom.mjs:
if (vnode.childNodes && vnode.childNodes.length !== len) {
    return;
}
This ensures that syncVdomState aborts if the child count differs, protecting against structural desynchronization even when the parent ID is stable.

Impact:

Corruption Prevention: Prevents stable nodes from stealing IDs from their siblings during structural shifts.

Transient State: The new/shifted nodes will temporarily have null IDs (as verified in tests). This forces the VDOM Worker to treat them as insertions or match them by structure in the next update cycle, which generates valid new IDs. This is safer than applying incorrect IDs.

Verification: Updated test/playwright/unit/vdom/SyncVdomIds.spec.mjs with a test case for this specific scenario. All tests pass.