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	13286
title	NL undo Slice-1: e2e proof — agent-created component reverts via undo (AC10)
state	Closed
labels	aitesting
assignees	neo-opus-vega
createdAt	Jun 15, 2026, 2:52 AM
updatedAt	Jun 16, 2026, 4:57 AM
githubUrl	https://github.com/neomjs/neo/issues/13286
author	neo-opus-vega
commentsCount	5
parentIssue	13221
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[x] 13167 Extended-NL: forward the sender agentId from Bridge to the app Client
blocking	[x] 13306 Neural Link redo Slice-2: e2e proof — undone component restored via redo
closedAt	Jun 16, 2026, 4:57 AM
milestone	v13.1

NL undo Slice-1: e2e proof — agent-created component reverts via undo (AC10)

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

neo-opus-vega commented on Jun 15, 2026, 2:52 AM

Context

Completes #13221's AC10 — the last open AC of NL undo Slice-1 (AC7 is in flight as #13282). Surfaced by the #13221 completeness audit: all four undo specs (InstanceServiceUndo* + the capture specs) are unit-level (mocked transport / re-dispatch). The slice AC requires a live-tree proof — "agent-created component → undo → reverts cleanly in the live tree" — which the sub-PRs each scoped as "broader than this sub's AC", so it was never landed.

The Architectural Reality

The repo already has an NL e2e harness — test/playwright/e2e/NeuralLinkCreateComponent.spec.mjs + the neuralLink fixture (test/playwright/fixtures.mjs), which boots the bridge (NeuralLink_ConnectionService.manageConnection) and connects to a live useAiClient app. The fixture's app handle exposes createComponent, getComponentTree, queryComponent, etc., but not undo — even though the server-side NeuralLink_InstanceService.undo({sessionId}) (ai/services/neural-link/InstanceService.mjs:89) is already present and NeuralLink_InstanceService is already imported into the fixture.

The Fix

test/playwright/fixtures.mjs — add async undo() to the app handle, mirroring the existing methods: return NeuralLink_InstanceService.undo({ sessionId }).
test/playwright/e2e/NeuralLinkUndo.spec.mjs (new) — mirror NeuralLinkCreateComponent.spec: goto a useAiClient app → connectToApp → createComponent into the resolved container → assert it is present in get_component_tree + the live DOM → app.undo() → assert it is gone from the tree + DOM (create⁻¹ = destroy(newId)).

Acceptance Criteria

An e2e spec drives a live app over the Neural Link: create_component → undo → the created component is gone from get_component_tree and the live DOM.
The neuralLink fixture app handle exposes undo().

Out of Scope

set_instance_properties / remove_component undo e2e (this proof covers the create round-trip — the canonical AC10 case; the others stay unit-covered).

Completes #13221 AC10 (NL undo Slice-1; AC7 is #13282). Tool: #13259 (undo). Harness sibling: NeuralLinkCreateComponent.spec (#9846 era).
Epic: #13012 (Agent Harness, Pillar-2). Decision Record impact: none (test + a one-line fixture helper).

Release classification: boardless (post-release Pillar-2 test coverage — not v13-blocking).

Origin Session ID: a0bc6b23-78c5-4bd7-b944-9db5e236f42d