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	9431
title	TreeStore: Fix ARIA desync (siblingIndex and siblingCount) after sort and filter
state	Closed
labels	bugaiarchitecturegrid
assignees	tobiu
createdAt	Mar 10, 2026, 3:26 PM
updatedAt	Mar 10, 2026, 4:02 PM
githubUrl	https://github.com/neomjs/neo/issues/9431
author	tobiu
commentsCount	1
parentIssue	9404
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Mar 10, 2026, 4:02 PM

TreeStore: Fix ARIA desync (siblingIndex and siblingCount) after sort and filter

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

Closed v12.1.0 bugaiarchitecturegrid

tobiu commented on Mar 10, 2026, 3:26 PM

Goal

Ensure siblingIndex and siblingCount are accurately recalculated when the TreeStore is sorted or filtered.

Context

Currently, TreeStore.splice() calculates and writes siblingIndex and siblingCount directly to the record objects for lightning-fast reads during VDOM rendering (crucial for aria-posinset and aria-setsize). However, our custom doSort() and filter() overrides do not trigger this recalculation.

After sorting, the visual order changes, but screen readers read the old index order.
After filtering, the visual count of siblings decreases, but screen readers announce the pre-filtered count.

Acceptance Criteria

Ensure updateSiblingStats() (or a variant) is called appropriately after sorting to update the indices of siblings.
Ensure updateSiblingStats() (or a variant) is called after filtering so the sibling count strictly reflects only the visible siblings.
Write unit tests in TreeStore.spec.mjs verifying that siblingIndex and siblingCount are correct after sorting and filtering.
Ensure the fix remains performant and doesn't break Turbo Mode.

✦ Implementation Guidance for Future Sessions: You can reuse the testing environment in test/playwright/unit/data/TreeStore.spec.mjs. Be aware that updating stats during filtering might require distinguishing between the structural sibling count (in #childrenMap) and the filtered sibling count.

tobiu added the bug label on Mar 10, 2026, 3:26 PM

tobiu added the ai label on Mar 10, 2026, 3:26 PM

tobiu added the architecture label on Mar 10, 2026, 3:26 PM

tobiu added the grid label on Mar 10, 2026, 3:26 PM

tobiu added parent issue #9404 on Mar 10, 2026, 3:26 PM

tobiu assigned to @tobiu on Mar 10, 2026, 3:29 PM

tobiu referenced in commit efe0bb5 - "TreeStore: Fix ARIA desync (siblingIndex and siblingCount) after sort and filter (#9431)" on Mar 10, 2026, 4:01 PM

tobiu Mar 10, 2026, 4:01 PM

Input from Gemini 3.1 Pro:

✦ The ARIA desync issue (#9431) has been fixed!

I've updated doSort() and filter() in TreeStore.mjs to call updateSiblingStats(), which is now capable of correctly ignoring visually hidden nodes (due to filtering). childCount, siblingCount, and siblingIndex are all properly managed. The tests have also been updated to ensure coverage and no regressions. I've pushed the changes to the dev branch.

tobiu closed this issue on Mar 10, 2026, 4:02 PM