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	8885
title	fix: Resolve JS errors when filtering in Big Data Grid example
state	Closed
labels	bugai
assignees	tobiu
createdAt	Jan 26, 2026, 7:58 PM
updatedAt	Jan 26, 2026, 8:07 PM
githubUrl	https://github.com/neomjs/neo/issues/8885
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jan 26, 2026, 8:07 PM

fix: Resolve JS errors when filtering in Big Data Grid example

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

Closed v11.24.0 bugai

tobiu commented on Jan 26, 2026, 7:58 PM

The Big Data Grid example (@examples/grid/bigData/ControlsContainer.mjs) throws a TypeError when using the filter field:

Filter.mjs:208 Uncaught TypeError: Cannot read properties of undefined (reading 'firstname')
    at Filter.isFiltered (Filter.mjs:208:27)
    at MainStore.filter (Base.mjs:727:40)
    ...

This appears to be related to the recent change to lazy records, where the filter logic might be attempting direct property access on undefined values or raw data objects in a way that is no longer valid.

Task:

Investigate src/collection/Filter.mjs, src/data/Store.mjs, and src/collection/Base.mjs.
Identify the root cause in Filter.isFiltered.
Implement a fix to ensure safe property access during filtering.

tobiu added the bug label on Jan 26, 2026, 7:58 PM

tobiu added the ai label on Jan 26, 2026, 7:58 PM

tobiu referenced in commit 424cb51 - "fix: Resolve JS errors when filtering in Big Data Grid example (#8885)" on Jan 26, 2026, 8:06 PM

tobiu assigned to @tobiu on Jan 26, 2026, 8:06 PM

tobiu Jan 26, 2026, 8:06 PM

Input from Gemini 3 Pro:

✦ Fixed the issue by adding guard checks for undefined items in both Neo.collection.Filter and Neo.collection.Base.

Changes:

src/collection/Filter.mjs: Added a check in isFiltered to return true (exclude) if the item is undefined. This prevents the crash when accessing properties on undefined items.

src/collection/Base.mjs: Added a check in afterSetItems to skip undefined items when populating the collection map. This prevents crashes during collection initialization or bulk updates if the items array contains gaps.

test/playwright/unit/collection/Base.spec.mjs: Added a regression test case "Filter collection with undefined items" to verify that filtering handles data corruption gracefully.

tobiu closed this issue on Jan 26, 2026, 8:07 PM