Aquarium-as-sessions for Agent Host new-chat

[osortega]

What

Turns the decorative aquarium in the Agents window's new-chat view into a live 1:1 visualization of running Agent Host sessions, gated behind a hidden developer-only setting so the experience never ships to users by default.

Draft. Implementation is type-check / eslint / layer-check clean, but I have not yet exercised it in a running workbench. Marking ready once the human owner runs through the smoke tests below.

Triple-gate

Behavior activates only when all three are true:

1. sessions.developerJoy.enabled (existing public experimental key) is true.
2. sessions.developerJoy.aquariumAsSessions (NEW, hidden, intentionally unregistered) is true.
3. The selected workspace or the active session matches ANY_AGENT_HOST_PROVIDER_RE (local-agent-host + agenthost-*).

To opt in, hand-edit settings.json:

{
  "sessions.developerJoy.enabled": true,
  "sessions.developerJoy.aquariumAsSessions": true
}

The aquariumAsSessions key is deliberately not in any registerConfiguration block, so it never appears in Settings UI, IntelliSense for settings.json, default-settings exports, or our docs. A schema-guard unit test (aquariumConfiguration.test.ts) asserts this invariant so we can't accidentally promote it to public.

If any of the three flips false, the original decorative aquarium and always-visible chat input behavior is restored — live, no reload.

Behavior when the gate is on

• Chat input hidden by default. A transparent click-catcher hotspot covers the empty area with aria-label and focus-visible outline. Click, tab into, or activate the hotspot to reveal the input + workspace picker.
• Hybrid dismiss:
  • Submit success auto-dismisses after 250 ms (0 ms when motion-reduced).
  • Outside-click dismisses, skipping .monaco-list, .monaco-action-bar, .context-view, .monaco-menu, .monaco-hover, .monaco-quick-input-widget so menus/popups don't false-dismiss.
  • Esc dismisses, but only when the input is empty — so the first press still gets Monaco's native clear behavior.
• 1:1 fish-per-session. The new SessionPopulationDriver mirrors ISessionsManagementService.getSessions() filtered by ANY_AGENT_HOST_PROVIDER_RE. Fish color tracks status (in-progress / needs-input / completed / error) via setStatusVariant. Soft cap of 20 evicts oldest-terminal first.
• Activity bubbles. Each fish occasionally emits a chat bubble from session.description activity text — truncated, dwell-gated, hover-locked, max 6 visible.
• Submit grows a fish. Pressing send records a submit-intent (5 s window). The first session-fish added during that window spawns small (~18 px) and ease-out-cubic tweens to full size (~56 px) over 18 s. Reduced-motion spawns at half-grown with no tween.

Architecture

aquariumOverlay.ts's engine is split into a host + swappable IAquariumPopulationDriver. The default RandomPopulationDriver preserves today's 50-fish crowd. The new SessionPopulationDriver is attached on demand via IMountedToggleHandle.setDriverFactory(...), called from NewChatWidget whenever the triple-gate evaluation flips.

NewChatWidget adds a small collapse-mode controller (_setupAquariumModeController, _recomputeAquariumMode, _setRevealed, _installHotspot, _installAquariumDismissHandlers, _scheduleAquariumAutoDismiss) that reacts to configurationService.onDidChangeConfiguration, _workspacePicker.onDidSelectWorkspace, and an autorun on activeSession.

AquariumSubmitIntentService is a tiny singleton with recordIntent() / consumeIntent() and a 5 s window. NewChatWidget._send records the intent before awaiting sendAndCreateChat; SessionPopulationDriver._addSession consumes it the moment the new agent-host session is registered.

Telemetry

Two events:

Event	Properties	Purpose
aquarium.populationMode	mode: 'random' | 'sessions'	Adoption signal for the hidden mode. Fires on driver swap.
aquarium.chatInput	action: 'reveal' | 'dismiss', trigger: 'click' | 'submit' | 'outside' | 'esc' | 'scopeChanged'	Which dismiss triggers are actually used.

Owner is provisionally osortega — please confirm this is your registered GitHub handle for telemetry classifications before moving out of draft.

Files

Added (4):

• aquariumSubmitIntentService.ts — intent bus singleton with 5 s window.
• bubble.ts — Bubble class (text truncation, dwell, hover-lock, fade-out, idempotent dispose).
• sessionPopulationDriver.ts — 1:1 driver, per-session status autoruns, soft cap.
• aquariumConfiguration.test.ts — schema-guard test asserting the hidden key is NOT in the registered schema.

Modified (7):

• aquariumOverlay.ts — engine/population split (IAquariumHost, IAquariumPopulationDriver, IFishHandle, IAddFishOptions, IMountToggleOptions), setDriverFactory swap, bubble layer + positioning, hidden-gate constant + reader.
• fish.ts — setTargetSize (easeOutCubic tween), setStatusVariant, _speciesColor; size no longer readonly.
• aquarium.contribution.ts — registers IAquariumSubmitIntentService singleton; inline note that the hidden key is intentionally not registered.
• newChatViewPane.ts — full collapse-mode controller, hotspot, hybrid dismiss, scope-reactive driver swap, telemetry.
• newChatInput.ts — small isInputEmpty() accessor for the Esc handler.
• aquarium.css + chatWidget.css — bubble layer, status variants, reduced-motion bubble transition, hotspot styling, focus-visible outline.

Accessibility

• Hotspot: <button> with aria-label, natively focusable, :focus-visible outline.
• Aquarium subtree (water, bubbleLayer, bubble, fish containers) all aria-hidden="true" (decorative).
• Reduced-motion users: no tween on the grow-fish animation; auto-dismiss timer collapses to 0 ms; existing aquarium swim-in/out fades respect the existing reduced-motion CSS already in aquarium.css.
• Focus restored to hotspot on dismiss-via-Esc, to input on reveal.

How to try this

1. Add the two keys above to your settings.json.
2. Open the Agents window's new-chat view.
3. Select a local-agent-host workspace (or connect to an agenthost-* remote tunnel). The chat input collapses; the aquarium reveals.
4. Click the empty area → input slides in. Tab from elsewhere → hotspot is reachable, Enter reveals.
5. Type a query, press send → submit-fish should appear and grow. Chat input slides away after 250 ms.
6. Wait for the session's _activity to update → its fish should occasionally pop a bubble of the text.
7. Press Esc on an empty input, or click outside → input slides away.
8. Flip sessions.developerJoy.aquariumAsSessions to false → behavior reverts immediately to the legacy decorative aquarium with the chat input always visible.

Validation

• npm run compile-check-ts-native — clean.
• npx eslint on all 11 changed/new files — clean.
• npm run valid-layers-check — clean.
• Schema-guard test runs in CI (needs the built out/ directory which the local worktree doesn't have).

Follow-ups before going non-draft

• Confirm telemetry owner: 'osortega' is the right value for the GDPR classifications.
• Manual smoke test using the steps above.

---

Co-authored-by: Copilot 223556219+Copilot@users.noreply.github.com

[Copilot]

Pull request overview

This PR adds a hidden developer-gated mode that turns the Agents window aquarium into a live visualization of Agent Host sessions, with collapsed new-chat input behavior and session activity bubbles.

Changes:

• Adds aquarium-as-sessions gating, input reveal/dismiss behavior, and telemetry in the new-chat view.
• Refactors aquarium population into swappable drivers and adds session-backed fish, growth, status colors, and bubbles.
• Adds a hidden-setting schema guard test plus CSS for collapsed hotspot, fish variants, and bubbles.

Show a summary per file

File	Description
src/vs/sessions/contrib/chat/browser/newChatViewPane.ts	Adds aquarium-mode controller, driver switching, dismiss/reveal handling, submit intent recording, and telemetry.
src/vs/sessions/contrib/chat/browser/newChatInput.ts	Adds an input-empty accessor for Esc dismiss logic.
src/vs/sessions/contrib/chat/browser/media/chatWidget.css	Styles the collapsed-mode hotspot.
src/vs/sessions/contrib/aquarium/test/browser/aquariumConfiguration.test.ts	Verifies the hidden aquarium setting is not registered.
src/vs/sessions/contrib/aquarium/browser/sessionPopulationDriver.ts	Adds session-to-fish population, status mapping, cap eviction, growth, and bubbles.
src/vs/sessions/contrib/aquarium/browser/media/aquarium.css	Adds bubble, status variant, and reduced-motion styling.
src/vs/sessions/contrib/aquarium/browser/fish.ts	Adds fish resizing and status-variant support.
src/vs/sessions/contrib/aquarium/browser/bubble.ts	Adds disposable activity bubble behavior.
src/vs/sessions/contrib/aquarium/browser/aquariumSubmitIntentService.ts	Adds submit-intent tracking service.
src/vs/sessions/contrib/aquarium/browser/aquariumOverlay.ts	Splits aquarium engine from population drivers and adds bubble hosting.
src/vs/sessions/contrib/aquarium/browser/aquarium.contribution.ts	Registers the submit-intent service and documents the hidden key.

Copilot's findings

Comments suppressed due to low confidence (2)

src/vs/sessions/contrib/chat/browser/newChatViewPane.ts:262

• The hotspot only handles click activation. Tabbing to the button focuses it but does not reveal the input, which breaks the intended keyboard/focus path for showing the composer.

		store.add(dom.addDisposableListener(button, dom.EventType.CLICK, () => {
			if (this._aquariumModeActive) {
				this._setRevealed(true, chatWidgetContainer, /*focus*/ true, 'click');
			}
		}));

src/vs/sessions/contrib/aquarium/browser/sessionPopulationDriver.ts:84

• Incremental additions use the raw onDidChangeSessions event, while getSessions() is deduplicated by ISessionsManagementService. When duplicate local/remote agent-host sessions arrive after attach, this adds fish that getSessions() would filter out, breaking the intended 1:1 mapping to visible sessions.

			for (const added of e.added) {
				if (this._isAgentHost(added)) {
					this._addSession(added);

• Files reviewed: 11/11 changed files
• Comments generated: 9