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	8823
title	test: Investigate RealWorldUpdates Regression
state	Closed
labels	bugaitesting
assignees	tobiu
createdAt	Jan 20, 2026, 4:25 AM
updatedAt	Jan 20, 2026, 12:08 PM
githubUrl	https://github.com/neomjs/neo/issues/8823
author	tobiu
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jan 20, 2026, 12:08 PM

test: Investigate RealWorldUpdates Regression

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

Closed v11.23.0 bugaitesting

tobiu commented on Jan 20, 2026, 4:25 AM

The recent VDOM race condition fixes (Ticket #8814) introduced a regression in test/playwright/unit/vdom/RealWorldUpdates.spec.mjs.

Symptoms:

Tests fail with 0 or 1 delta received instead of expected 2.
Specifically, child updates are not being merged into the parent update or are being serialized such that promiseUpdate() only captures the parent's delta.

Root Cause Analysis: The fix enforces serialization (isChildUpdating) to prevent race conditions. RealWorldUpdates.spec.mjs seems to rely on an implicit merging behavior or parallel execution assumption that allowed it to capture both updates in a single promiseUpdate call (or expected them to be bundled). The new logic forces the parent to wait, potentially splitting the updates into separate transactions that the test doesn't capture correctly.

Action Item: Investigate if RealWorldUpdates.spec.mjs needs to be updated to reflect the new serial execution model, or if the VDomUpdate manager should support a merging strategy that accommodates this test case without re-introducing the race condition. Reference: Paradox between AsymmetricUpdates (forbids merging Depth 1) and RealWorldUpdates (expects merging/bundling).

tobiu added the bug label on Jan 20, 2026, 4:25 AM

tobiu added the ai label on Jan 20, 2026, 4:25 AM

tobiu added the testing label on Jan 20, 2026, 4:25 AM

tobiu assigned to @tobiu on Jan 20, 2026, 4:55 AM

tobiu referenced in commit fc1bd2d - "test: Fix RealWorldUpdates regression via test logic and add VdomMerging test (#8823)" on Jan 20, 2026, 12:07 PM

tobiu Jan 20, 2026, 12:08 PM

Input from Gemini 3 Pro:

✦ I have resolved the regression in RealWorldUpdates.spec.mjs.

Root Cause: The test relied on parent.setSilent to bundle parent and child updates. However, the child update (triggered by heading setter) ran synchronously before the parent was marked as dirty (needsVdomUpdate). This caused the child to fail the merge check (because the parent appeared clean) and run disjointly. This disjoint execution is valid for Scoped Updates (< collision logic), but the test expected a bundled result (aggregation).

Solution:

Refactored Test Logic: Updated RealWorldUpdates.spec.mjs to ensure the parent is explicitly dirty (e.g., via a style change) before the child update is triggered. This is achieved by ordering the properties in setSilent ({style: ..., heading: ...}).

Enabled Optimization: Implemented canMergeUpdate in VdomLifecycle (using <=) to allow safe merging of disjoint updates (e.g., Parent Depth 1 + Child Depth 1) when the parent is already updating.

Added Regression Test: Created test/playwright/unit/vdom/VdomMerging.spec.mjs to explicitly verify this merging behavior in a clean, isolated environment.

All tests are now passing (8/8 in RealWorldUpdates, 1/1 in VdomMerging). The architecture remains consistent with Scoped VDOM Updates while supporting optimization where possible.

tobiu closed this issue on Jan 20, 2026, 12:08 PM

tobiu cross-referenced by #8826 on Jan 20, 2026, 12:21 PM