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	16708
title	Harness UI-mode transport: self-supply mechanics + ownership/observation split
state	Closed
labels	enhancementai
assignees	neo-fable-clio
createdAt	Aug 8, 2026, 4:38 PM
updatedAt	Aug 8, 2026, 4:55 PM
githubUrl	https://github.com/neomjs/neo/issues/16708
author	neo-fable-clio
commentsCount	0
parentIssue	16694
subIssues	[]
subIssuesCompleted	0
subIssuesTotal	0
contentTrust
projected
quarantined	0
signals	[]
blockedBy	[]
blocking	[]
closedAt	Aug 8, 2026, 4:55 PM

Harness UI-mode transport: self-supply mechanics + ownership/observation split

Closed Backlog/active-chunk-14 enhancementai

neo-fable-clio commented on Aug 8, 2026, 4:38 PM

Pre-merge leaf of #16694 — split during PR #16696 review cycle 2 per the reviewer's close-target rule (@neo-gpt-emmy): Resolves #16694 would auto-close the umbrella while its renderer-side live-roster AC is explicitly post-merge (interactive-operator class). This leaf carries exactly the pre-merge-provable scope PR #16696 delivers; #16694 stays open until its live receipt lands.

Context

Full provenance, receipts, and the day's three live-run causes: #16694 (umbrella), #16693 (sibling), PR #16696 (the delivering PR). Short form: plain cd harness && npm start must self-supply the app↔fleet transport with the bearer the shell already holds — zero coordination — and a UI-mode transport must never be a whole-Brain health claim.

Scope (what PR #16696 delivers, all pre-merge-provable)

resolveUiFleetTransport (brain.mjs): the witnessable three-outcome OWNER COMPOSITION — reuse (canonical same-bearer/viewer proof; never spawns), foreign-listener (named refusal, up:false, never throws, never adopts), spawn (composition itself registers observeBrain: false; real wire readiness gates up:true).
registerOwnedChild (brain.mjs): teardown ownership UNCONDITIONAL; Brain-health observation only for organism children; diagnostic-only sink for unobserved children.
bootUiFleetTransport (main.mjs): thin collaborator binding; its receipt feeds fleetCapability's gate (which UI-only mode previously starved with null — the structural defect that made ANY external coordination impossible).
Smoke stays spawn-free (isolation contract).

Contract Ledger Matrix

Target Surface	Source of Authority	Proposed Behavior	Fallback	Docs	Evidence
`resolveUiFleetTransport` export	`harness/brain.mjs`	Three-outcome routing per the composition invariants above	n/a (new)	JSDoc on the export	3 composition witnesses in `brain.spec.mjs`
`registerOwnedChild` export	`harness/brain.mjs`	Drain membership unconditional; watcher routed by `observeBrain`	n/a (new)	JSDoc	3 registry witnesses in `brain.spec.mjs`
UI boot receipt → `fleetCapability.getBrain`	`harness/main.mjs`	`{fleetPort, mode, up}` feeds the existing gate; gate semantics UNCHANGED	absent receipt ⇒ gate's named not-ready (fail-closed, as before)	PR body	live spawn receipt + gate unchanged in diff
`HARNESS_UI_FLEET*` log markers	`harness/main.mjs`	One line per outcome + `HARNESS_UI_FLEET_CHILD` sink lines	n/a	JSDoc	live run output
Smoke spawn-free invariant	`harness/package.json` smoke flow	`NEO_HARNESS_SMOKE=1` never runs the UI transport boot	n/a	README unchanged	smoke output: zero `HARNESS_UI_FLEET` lines

Acceptance Criteria

The three-outcome composition witnessed: reuse never spawns/registers; foreign never spawns/adopts/throws with the refusal named; spawn registers observeBrain: false inside the composition and gates up:true on readiness.
Owner coverage deterministic: observed AND unobserved children both join the drain list (registry witnesses).
Live spawn receipt on a real machine: marker line, transport serving with supplied bearer, auth enforced, owned child + port drained on quit intent.
npm run smoke green with zero HARNESS_UI_FLEET lines.

Out of Scope

The renderer-side live-roster receipt and the operator one-command run — #16694 (stays open).
Reconnect/banner UX — #16699. Brain-leg attach re-triage — #16693.

Parent umbrella: #16694 · Delivering PR: PR #16696 · Siblings: #16693, #16699 · Epic context: #14560 Lane B.

Creation-gate record: live latest-6 sweep 2026-08-08T14:38Z — no equivalent; this leaf is the review-directed close-target split, announced in the PR thread. Self-assigned (the PR is mine).

Origin Session ID: 32bcb092-f1c7-4856-9141-3e602ea88ed8 Retrieval Hint: "harness UI transport leaf composition witness ownership observation split close-target"