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	8625
title	Fragment Move Operation Instability
state	Closed
labels	bugairegression
assignees	tobiu
createdAt	Jan 14, 2026, 1:15 AM
updatedAt	Jan 14, 2026, 1:59 AM
githubUrl	https://github.com/neomjs/neo/issues/8625
author	tobiu
commentsCount	1
parentIssue	8601
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jan 14, 2026, 1:59 AM

Fragment Move Operation Instability

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

Closed v11.21.0 bugairegression

tobiu commented on Jan 14, 2026, 1:15 AM

The Fragment example app (examples/container/fragment/) reveals a bug where repeatedly clicking the "Move Field 1 into Fragment" button (attempting to insert an item that is already at the target index in the Fragment) causes random reordering of items and eventual data loss (Fragment becomes empty).

Steps to Reproduce:

Open the Fragment example app.
Click "Move Field 1 into Fragment". (Works correctly).
Click "Move Field 1 into Fragment" again.
Repeat.

Expected Behavior: Subsequent clicks should be a no-op as the item is already in place.

Actual Behavior: Items randomly reshuffle, and the Fragment eventually loses its content.

Root Cause Analysis:

DeltaUpdates likely mishandles move operations involving Fragments when the source and target are effectively the same or when the operation should be a no-op.
Potential index corruption in Fragment or Container during repeated re-insertion.

See Also:

Issue #8627 (No-op fix for Container.insert)
Issue #8616 (Parent Task)

tobiu added the bug label on Jan 14, 2026, 1:15 AM

tobiu added the ai label on Jan 14, 2026, 1:15 AM

tobiu added the regression label on Jan 14, 2026, 1:15 AM

tobiu added parent issue #8601 on Jan 14, 2026, 1:15 AM

tobiu referenced in commit d433c61 - "test: Verify Container.insert no-op stability (#8625)" on Jan 14, 2026, 1:58 AM

tobiu assigned to @tobiu on Jan 14, 2026, 1:59 AM

tobiu Jan 14, 2026, 1:59 AM

Input from Gemini 3 Pro:

✦ I have verified that the fix implemented in #8626 (Container.insert no-op optimization) successfully resolves the instability reported here.

Verification:

Created a new unit test test/playwright/unit/container/InsertNoOp.spec.mjs which confirms that repeatedly inserting an item into its current index is now a no-op and does not corrupt the Container's items array or VDOM structure.

This prevents the "Fragment empty" and random reordering issues caused by redundant insert operations.

Changes committed and pushed.

tobiu closed this issue on Jan 14, 2026, 1:59 AM