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	9403
title	Performance: Eliminate Path scrollTop Layout Thrashing in getTargetData
state	Closed
labels	enhancementaiperformance
assignees	tobiu
createdAt	Mar 8, 2026, 11:44 PM
updatedAt	Mar 8, 2026, 11:59 PM
githubUrl	https://github.com/neomjs/neo/issues/9403
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Mar 8, 2026, 11:59 PM

Performance: Eliminate Path scrollTop Layout Thrashing in getTargetData

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

Closed v12.1.0 enhancementaiperformance

tobiu commented on Mar 8, 2026, 11:44 PM

Problem: Profiling the Main Thread during rapid Grid scrolling reveals a secondary massive layout thrashing penalty:

Recalculate style: 50.6% total time
get scrollTop: 13.1% total time

This occurs because getTargetData unconditionally reads node.scrollTop and node.scrollLeft for every node in the event bubble path. When a grid row scrolls, the style tree is invalidated by VDOM delta mutations (set innerHTML, style.transform). Reading scrollTop on 15 ancestor elements immediately after these mutations forces the browser to synchronously recalculate layout 15 times per frame.

Proposed Solution: Pass an isTarget boolean into getTargetData(). For high-frequency continuous events like scroll and wheel, we only need the layout state of the actual node that generated the event (isTarget === true).

For all other elements in the event path (isTarget === false), we will skip reading scrollTop and scrollLeft and return undefined. By returning undefined rather than 0, we prevent the VDOM engine from misinterpreting the omission as a command to reset scroll positions to zero.

Additionally, we will convert the previous dimension skips (clientHeight, etc.) to return undefined rather than 0 for structural safety.

tobiu added the enhancement label on Mar 8, 2026, 11:44 PM

tobiu added the ai label on Mar 8, 2026, 11:44 PM

tobiu added the performance label on Mar 8, 2026, 11:44 PM

tobiu referenced in commit b10acf8 - "perf: Eliminate Path scrollTop Layout Thrashing in getTargetData (#9403)" on Mar 8, 2026, 11:57 PM

tobiu assigned to @tobiu on Mar 8, 2026, 11:58 PM

tobiu Mar 8, 2026, 11:58 PM

Input from Gemini 3.1 Pro:

✦ Task Completed:

Updated getTargetData to accept an isTarget boolean flag.

For high-frequency layout-thrashing events (scroll and wheel), the framework now skips reading scrollTop and scrollLeft for all nodes in the event's bubble path (isTarget === false).

Instead of returning 0 (which implies a valid coordinate that could reset scroll state in the VDOM engine), skipped geometric properties now return undefined to cleanly drop them from the serialized JSON payload.

The event.target continues to return its actual scrollTop, preserving critical scroll behavior for the components generating the event.

This targeted excision addresses the secondary layout thrashing bottleneck identified in the benchmarking, eliminating forced synchronous layouts on ancestor wrappers during grid scroll cycles.

tobiu closed this issue on Mar 8, 2026, 11:59 PM