What is the Neural Link?

The Neural Link is a bi-directional bridge that connects AI agents directly to the Neo.mjs runtime. It lets agents inspect the Scene Graph, component state, event listeners, computed styles, and DOM rectangles, and mutate the running application in real time.

Why is Neo.mjs called an Application Engine instead of a framework?

Neo.mjs maintains persistent application objects in a worker-backed Scene Graph instead of compiling application state away into ephemeral DOM nodes. That architecture enables multi-window orchestration, runtime permutation, and deep AI introspection.

What is Context Engineering?

Context Engineering shapes the information and tool environment around AI agents. Neo.mjs implements it through Knowledge Base, Memory Core, GitHub Workflow, and Neural Link MCP servers for frontier harnesses, plus a File System MCP server for internal Neo.ai.Agent local loops.

What is the Neo.mjs Agent OS?

The Neo.mjs Agent OS is the repository Brain: source code and services for Memory Core, Knowledge Base, Active Hybrid GraphRAG, DreamService, Golden Path synthesis, A2A coordination, and Neural Link tooling.

Frontmatter

id	13439
title	Fix neuralLink connectToApp e2e fixture for childapp SharedWorker topology (target.toLowerCase TypeError)
state	Closed
labels	enhancementaitestingarchitecture
assignees	neo-opus-ada
createdAt	Jun 16, 2026, 4:03 PM
updatedAt	Jun 17, 2026, 8:35 AM
githubUrl	https://github.com/neomjs/neo/issues/13439
author	neo-opus-ada
commentsCount	1
parentIssue	null
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[x] 13355 Render first-widget transcript and blueprint evidence pane
closedAt	Jun 16, 2026, 5:23 PM
milestone	v13.1

Fix neuralLink connectToApp e2e fixture for childapp SharedWorker topology (target.toLowerCase TypeError)

Closed v13.1.0/archive-v13-1-0-chunk-3 enhancementaitestingarchitecture

neo-opus-ada commented on Jun 16, 2026, 4:03 PM

Context

The shared Playwright e2e fixture neuralLink.connectToApp(appName) (test/playwright/fixtures.mjs) fails for a CHILD app running under a shared SharedWorker, blocking whitebox e2es that drive create_component into a child app. This is the M2 critical-path dependency for the v13.1 cockpit (Discussion #13436) and the blocker behind the #13355 external-agent → evidence whitebox.

Observed

connectToApp('AgentOSWidget') (booting /apps/agentos/childapps/widget/index.html) throws TypeError: target.toLowerCase is not a function at fixtures.mjs:142 → ConnectionService.waitForSession(targetId, ...) (ai/services/neural-link/ConnectionService.mjs:621 calls target.toLowerCase()). Both I (building #13437) and @neo-gpt (reviewing it) hit the same worker-registration wall. The bridge shows ONE SharedWorker hosting multiple app windows (agentos + AgentOSWidget).

Root cause (diagnosed)

fixtures.mjs:137 resolves targetId = workerId || appName || inferredAppName. workerId comes from await window.Neo.worker.App.getWorkerId() (src/worker/App.mjs:370 returns this.id). For the childapp's SharedWorker topology, workerId resolves to a truthy non-string, so the || keeps it (the designed appName fallback never fires) and waitForSession's String#toLowerCase throws. The exact non-string shape getWorkerId returns for a multi-window SharedWorker childapp needs an empirical confirm.

The Fix

Fixture (fixtures.mjs): guard targetId to a usable STRING — if workerId is not a non-empty string, fall back to appName / inferredAppName (the designed fallback): targetId = (typeof workerId === 'string' && workerId) ? workerId : (appName || inferredAppName).
Defense (ConnectionService.waitForSession): coerce/guard target so a non-string degrades to a clear "no session" timeout, not a TypeError.
Empirical confirm: log typeof/value of await Neo.worker.App.getWorkerId() for the childapp — confirm the non-string shape rather than mask a deeper getWorkerId multi-window bug.

Acceptance Criteria

A childapp whitebox e2e (connectToApp('AgentOSWidget') → getComponent / createComponent into the app) connects WITHOUT the target.toLowerCase error and reads back a live component.
No regression to top-level-app neuralLink e2es (e.g. NeuralLinkCreateGrid.spec.mjs).
Root cause empirically confirmed (what getWorkerId returns for the childapp); if a deeper getWorkerId fix is out of scope, note the mask explicitly.

Unblocks

#13355 external-agent create_component → evidence whitebox (the residual after PR #13437).
The M2 first-widget agent-driven demo (Discussion #13436).

Duplicate sweep

Checked open testing + ai labels + the recent backlog — no existing connectToApp / neuralLink-fixture ticket. Tracked locally as a session task chip before this.