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	8870
title	Investigate VNode.getById(null) error in Container.onScrollCapture
state	Closed
labels	bugaicore
assignees	tobiu
createdAt	Jan 23, 2026, 9:00 PM
updatedAt	Jan 23, 2026, 10:35 PM
githubUrl	https://github.com/neomjs/neo/issues/8870
author	tobiu
commentsCount	2
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jan 23, 2026, 10:35 PM

Investigate VNode.getById(null) error in Container.onScrollCapture

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

Closed v11.24.0 bugaicore

tobiu commented on Jan 23, 2026, 9:00 PM

Description: During a feasibility analysis for Card Layout optimization, a runtime error was observed in the Portal App when switching tabs quickly or triggering layout updates:

VNode.mjs:132 Uncaught TypeError: Cannot read properties of null (reading 'id')
    at VNode.getById (VNode.mjs:132:27)
    at Container.onScrollCapture (Abstract.mjs:423:31)
    at Container.onScrollCapture (Base.mjs:1454:15)

Context: The error occurs in onScrollCapture, which attempts to look up a VDOM node by ID using VDomUtil.getById(me._vdom, data.target.id). The error message "Cannot read properties of null (reading 'id')" inside VNode.getById suggests that me._vdom (passed as the root) might be valid, but traversal encounters a null node, or me._vdom itself is unexpectedly null/invalid in a way that getById doesn't handle gracefully.

Hypothesis: This might be related to removeDom transitions where _vdom state on the component might be in flux or partially synced (e.g. _vnode vs _vdom mismatch, or _vdom containing null children due to template processing or other factors).

Goal: Investigate the root cause of this error and harden onScrollCapture or VDomUtil.getById against null/invalid inputs.

tobiu added the bug label on Jan 23, 2026, 9:00 PM

tobiu added the ai label on Jan 23, 2026, 9:00 PM

tobiu added the core label on Jan 23, 2026, 9:00 PM

tobiu Jan 23, 2026, 9:03 PM

Input from Gemini 3 Pro:

✦ Clarification: This error was observed during an experimental branch where _vnode state was being actively modified/nullified during updates. It may not be currently reproducible on the dev branch.

However, the fact that onScrollCapture can crash if the VDOM state is slightly out of sync with the Event target suggests a vulnerability. The fix should focus on graceful handling (e.g., checking if vdomNode exists before accessing properties) rather than assuming deep structural corruption in the stable codebase. This is a hardening task.

tobiu referenced in commit 4f62336 - "fix: Harden getById against null nodes (#8870)" on Jan 23, 2026, 10:35 PM

tobiu Jan 23, 2026, 10:35 PM

Input from Gemini 3 Pro:

✦ I have applied the hardening fix to both src/util/VNode.mjs and src/util/VDom.mjs.

Both getById methods now gracefully handle null nodes during traversal, returning null instead of throwing a TypeError. This ensures stability in scenarios where VDOM/VNode state might be transiently inconsistent or contain null placeholders (e.g., during unmounts or race conditions).

Changes committed and pushed to feat/card-incremental-updates. Closing ticket.

tobiu assigned to @tobiu on Jan 23, 2026, 10:35 PM

tobiu closed this issue on Jan 23, 2026, 10:35 PM