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	9838
title	E2E: Expose Full Neural Link MCP API in Playwright Fixtures & Update Guide
state	Closed
labels	enhancementQAaitesting
assignees	tobiu
createdAt	Apr 9, 2026, 10:34 PM
updatedAt	Apr 9, 2026, 10:59 PM
githubUrl	https://github.com/neomjs/neo/issues/9838
author	tobiu
commentsCount	2
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Apr 9, 2026, 10:47 PM

E2E: Expose Full Neural Link MCP API in Playwright Fixtures & Update Guide

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

ClosedenhancementQAaitesting

tobiu commented on Apr 9, 2026, 10:34 PM

This issue focuses on expanding the capability of the Playwright Neural Link bridge by exposing the full suite of asynchronous MCP tools via the fixtures.mjs wrapper. Our current testing workflow establishes that all Whitebox E2E tests leverage the Neural Link wrapper (nlApp), but many powerful MCP capabilities remain missing from this fixture definition.

Scope of Work

Fixture Completeness: Expand test/playwright/fixtures.mjs to include the remaining MCP Neural Link endpoints (e.g. get_component_tree, get_dom_event_summary, get_drag_state, inspect_class, patch_code, manage_neo_config, etc.).
Asynchronous Integrity: Ensure all exposed fixture methods remain asynchronous to properly align with the post-message bridge architecture.
Documentation Update: Enhance learn/guides/testing/WhiteboxE2E.md to reflect the expanded API surface and document how these tools can be used in E2E tests.
Anchor & Echo: Apply the Knowledge Base Enhancement Strategy to the newly added fixture bindings.

This ticket serves as the prerequisite step for Phase 2, which will formally introduce baseline E2E tests validating these new capabilities in the browser context.

tobiu added the enhancement label on Apr 9, 2026, 10:34 PM

tobiu added the QA label on Apr 9, 2026, 10:34 PM

tobiu added the ai label on Apr 9, 2026, 10:34 PM

tobiu added the testing label on Apr 9, 2026, 10:34 PM

tobiu assigned to @tobiu on Apr 9, 2026, 10:34 PM

tobiu referenced in commit f060688 - "test: Expand Neural Link Playwright fixtures and document RMA fallback (#9838) on Apr 9, 2026, 10:47 PM

tobiu Apr 9, 2026, 10:47 PM

Input from Antigravity (Gemini 3.1 Pro):

✦ Status: Completed

The Neural Link Playwright fixture has been successfully expanded to incorporate the remaining MCP endpoints.

Changelog:

Exposed checkNamespace, getNamespaceTree, getComponentTree, getWorkerTopology, getWindowTopology, getDomEventSummary, getDragState, inspectClass, getMethodSource, patchCode, and manageNeoConfig via the neuralLink context (nlApp).

Enhanced test/playwright/fixtures.mjs and src/worker/App.mjs with JSDoc and warning flags indicating that legacy RMA techniques (neo fixture, window.Neo app worker bindings) are relegated as fallback structures for non-native Neo instances (e.g., React wrappers).

Rewrote the learn/guides/testing/WhiteboxE2E.md section covering the "Expanded Fixture API," clearly defining the operational paradigm shift and explicitly documenting the new features, alongside comprehensive warnings for the advanced metaprogramming module.

Note: We encountered the nested object array parsing blocker in simulateEvent validation exactly as tracked in #9837; that structural OpenApiValidator ticket remains the active requirement for finalizing object payload interactions.

Changes have been successfully committed and pushed to dev.

tobiu closed this issue on Apr 9, 2026, 10:47 PM

tobiu referenced in commit 5c2626d - "test: Implement cross-thread Live DOM vs App Worker verification tests (#9838)" on Apr 9, 2026, 10:58 PM

tobiu Apr 9, 2026, 10:59 PM

Input from Antigravity (Gemini 3.1 Pro):

✦ ✦ Neural Link fixture expansion has been strictly mapped following the asynchronous bridge architectural paradigm. All available MCP routes are documented and accessible to the test suites. Legacy RMA testing functions (createNeoInstance, setConfigs, etc) within src/worker/App.mjs have been clearly tagged and demoted to fallback support, maintaining our "Whitebox SDK" roadmap.

Finally, I replaced the non-deterministic simulateEvent Playwright tests with deterministic geometry and structural checks via the newly accessible getDomRect, getComputedStyles, and queryVdom bridging, aligning the Neo physics layout directly against Playwright's boundingBox Live DOM results.