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	9287
title	[Documentation] Document the ''undefined'' sentinel value for reactive config initialization
state	Closed
labels	documentationaicore
assignees	tobiu
createdAt	Feb 24, 2026, 11:09 AM
updatedAt	Feb 24, 2026, 11:10 AM
githubUrl	https://github.com/neomjs/neo/issues/9287
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Feb 24, 2026, 11:10 AM

[Documentation] Document the 'undefined' sentinel value for reactive config initialization

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

Closed v12.0.0 documentationaicore

tobiu commented on Feb 24, 2026, 11:09 AM

Context The Neo.mjs config system relies on an elegant and highly performant architectural pattern for reactive configs: undefined acts as a strict, immutable sentinel value representing "initial instantiation".

The Problem If a developer is unaware of this, they might try to reset a config to undefined during the component's lifecycle. Doing so would break the guarantee that oldValue === undefined exclusively means the component is initializing, forcing every afterSet hook in the framework to implement complex boolean logic instead of a simple if (oldValue !== undefined) check.

The Solution Update the JSDoc for static config in src/core/Base.mjs to explicitly document this sentinel concept, enhancing the AI Knowledge Base and guiding developers to use null (not undefined) when explicitly clearing a state.

tobiu added the documentation label on Feb 24, 2026, 11:09 AM

tobiu added the ai label on Feb 24, 2026, 11:09 AM

tobiu added the core label on Feb 24, 2026, 11:09 AM

tobiu assigned to @tobiu on Feb 24, 2026, 11:09 AM

tobiu Feb 24, 2026, 11:09 AM

Input from Gemini 3.1 Pro:

✦ I have implemented the JSDoc enhancement in src/core/Base.mjs.

The static config documentation now explicitly describes the undefined sentinel value mechanism. It clarifies that oldValue === undefined during an afterSet hook guarantees that the component is undergoing its initial setup phase. It also warns developers that they should never explicitly set() a reactive config to undefined later in its lifecycle, but should instead use null to clear its state.

This documentation will be indexed by the Knowledge Base, providing essential context to both human developers and future AI sessions.

tobiu referenced in commit 408c83c - "docs(core): Document the 'undefined' sentinel value for reactive config initialization (#9287)" on Feb 24, 2026, 11:10 AM

tobiu closed this issue on Feb 24, 2026, 11:10 AM