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	13248
title	NL undo Slice-1 Sub A1: capture set_instance_properties reverses onto the undo stack
state	Closed
labels	aiarchitecture
assignees	neo-opus-vega
createdAt	Jun 14, 2026, 7:37 PM
updatedAt	Jun 14, 2026, 8:54 PM
githubUrl	https://github.com/neomjs/neo/issues/13248
author	neo-opus-vega
commentsCount	0
parentIssue	13221
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
blockedBy	[]
blocking	[]
closedAt	Jun 14, 2026, 8:54 PM

NL undo Slice-1 Sub A1: capture set_instance_properties reverses onto the undo stack

Closed v13.1.0/archive-v13-1-0-chunk-2 aiarchitecture

neo-opus-vega commented on Jun 14, 2026, 7:37 PM

Context

Sub A1 of #13221 (Neural Link mutation undo, Slice-1), built on the merged #13238 (agentId, sessionId) 2-tuple TransactionService core. The first wiring slice: capture the reverse of a set_instance_properties write so it becomes undoable. (The undo NL tool + two-agent e2e = Sub A2; create_component / remove_component capture = Sub B.)

The Fix

Neo.ai.Client owns a per-heap TransactionService (sibling to WriteGuard, same singleton shape).
Neo.ai.client.InstanceService.setInstanceProperties captures the reverse-op (set⁻¹ = set(oldValues)) post-enforcement-grant, keyed on the live {agentId, sessionId} context, via a begin/record/commit per write. buildSetReverse captures the pre-set values + the audit targetSubtreePath; recordUndo commits the single-op tx best-effort.

Acceptance Criteria

Client owns a per-heap TransactionService.
An enforcement-granted set_instance_properties agent write captures set⁻¹ (the pre-set values) onto the writer's (agentId, sessionId) stack; multiple writes accumulate as separate committed transactions.
A legacy write (no context) applies but is not captured (no writer identity ⇒ no per-writer stack).
The capture is best-effort + fail-closed: a malformed / unserializable reverse, or an absent stack authority, is dropped (abort), never thrown into the forward write path.
Unit-tested.

Out of Scope

The undo NL tool (6-site wiring) + the two-agent e2e — Sub A2.
create_component / remove_component capture (needs a node-side marker, since they arrive app-side as generic call_method add/destroy) — Sub B.

Parent: #13221 (NL undo Slice-1). Core: #13238 (2-tuple key) / #13230. Epic: #13012 (Agent Harness Pillar-2) / #9848.

Authored by @neo-opus-vega (Claude Opus 4.8, Claude Code). Origin Session ID: 4cc428e3-cf36-4324-8646-1b96cb23fa4a.