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	9015
title	Fix Regression in Cell Selection Model Cycling (Crash in updateRows)
state	Closed
labels	bugairegression
assignees	tobiu
createdAt	Feb 6, 2026, 5:52 PM
updatedAt	Feb 6, 2026, 5:58 PM
githubUrl	https://github.com/neomjs/neo/issues/9015
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Feb 6, 2026, 5:58 PM

Fix Regression in Cell Selection Model Cycling (Crash in updateRows)

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

Closed v12.0.0 bugairegression

tobiu commented on Feb 6, 2026, 5:52 PM

Cycling through cells (e.g., arrow left on first column to last) causes a crash in BaseModel.updateRows. The error TypeError: Cannot read properties of undefined (reading 'cls') occurs because cellNode can be undefined if the target cell is not currently rendered (unmounted), but the code attempts to access cellNode.cls to determine alreadySelect state before checking if cellNode exists.

Stack Trace:

BaseModel.mjs:72 Uncaught TypeError: Cannot read properties of undefined (reading 'cls')
    at BaseModel.mjs:72:54
    at Array.forEach (<anonymous>)
    at CellModel.updateRows (BaseModel.mjs:54:15)

Proposed Fix:

Safe access cellNode?.cls in BaseModel.mjs.
Ensure aria-selected is applied to cells in src/grid/Row.mjs to ensure unmounted cells get correct attributes when they are eventually rendered.

tobiu added the bug label on Feb 6, 2026, 5:52 PM

tobiu added the ai label on Feb 6, 2026, 5:52 PM

tobiu added the regression label on Feb 6, 2026, 5:52 PM

tobiu referenced in commit 1a2d910 - "bugfix: Fix regression in Cell Selection Model Cycling (Crash in updateRows) (#9015)" on Feb 6, 2026, 5:57 PM

tobiu assigned to @tobiu on Feb 6, 2026, 5:57 PM

tobiu Feb 6, 2026, 5:58 PM

Input from Gemini 3 Pro:

✦ I have resolved the regression causing the crash during cell cycling and added aria-selected support for cell models.

Fixes Implemented:

Crash Fix in BaseModel.updateRows:

The code now safely checks cellNode?.cls before attempting to read includes.

This prevents the TypeError when cycling causes the selection of an unmounted cell (e.g., during a scroll jump).

aria-selected for Cells:

In BaseModel: Added logic to toggle the aria-selected attribute on the cell node during granular updates (updateRows), matching the behavior for rows.

In Row.mjs: Updated applyRendererOutput to strictly check selectedCells.includes(logicalCellId) and apply both the neo-selected class AND aria-selected=true.

Optimization: In Row.mjs, combined the selection check to occur after cellConfig creation, modifying the cls array in-place and setting the attribute in one block. This avoids duplicating the includes check.

The cell selection model should now cycle correctly without errors and properly report accessibility state.

tobiu closed this issue on Feb 6, 2026, 5:58 PM