feat(tui): add turn summary flash experiment

packages/tui/AGENTS.md

@@ -0,0 +1,9 @@
+# TUI UI Experiments
+
+- Before implementing a visual behavior as an experiment, add a fixture-driven story under `src/feature-plugins/system/storybook` that renders the real production component.
+- Put the current treatment and meaningfully different variants in the story. Expose replay and tuning controls in `StoryFooter`, including reset when values are adjustable.
+- Let the user choose or tune a variant in the story before selecting production defaults.
+- After selection, register the behavior in `src/component/dialog-experiments.tsx` and gate it with `config.data.experimental?.<id> === true`; experiments must not change default behavior.
+- Treat tuning-only stories as local scaffolding and remove them and their registration before committing. Commit a story only when the user explicitly wants it retained as a reusable regression fixture.
+- Use OpenCode Drive with a simulated LLM for deterministic turn/session behavior. Do not invoke a real model only to verify TUI behavior.
+- Run the story with `OPENCODE_STORY=<story-id> bun run dev:live` and exercise relevant wide and narrow terminal sizes.

packages/tui/src/component/assistant-summary.tsx

@@ -0,0 +1,55 @@
+import { RGBA } from "@opentui/core"
+import { useTerminalDimensions } from "@opentui/solid"
+import { createEffect, on, onMount, Show } from "solid-js"
+import { tint } from "../theme/color"
+import { createAnimatable, tween } from "../ui/animation"
+
+export type AssistantSummaryFlash = {
+  trigger: number
+  duration: number
+  intensity: number
+}
+
+export function AssistantSummary(props: {
+  agent: string
+  model: string
+  duration?: string
+  interrupted?: boolean
+  agentColor: RGBA
+  subduedColor: RGBA
+  flashColor: RGBA
+  animations: boolean
+  flash?: AssistantSummaryFlash
+}) {
+  const dimensions = useTerminalDimensions()
+  const flash = createAnimatable(
+    { level: 0 },
+    {
+      enabled: () => props.animations,
+      transition: tween({ duration: props.flash?.duration ?? 0.32 }),
+    },
+  )
+  const run = () => {
+    if (!props.flash || !props.animations || props.flash.trigger === 0) return
+    flash.jump({ level: props.flash.intensity })
+    flash.animate({ level: 0 })
+  }
+  onMount(run)
+  createEffect(on(() => props.flash?.trigger, run, { defer: true }))
+  const color = (resting: RGBA) => tint(resting, props.flashColor, flash.value().level)
+
+  return (
+    <text>
+      <span style={{ fg: color(props.agentColor) }}>{props.agent}</span>
+      <Show when={dimensions().width >= 28}>
+        <span style={{ fg: color(props.subduedColor) }}> · {props.model}</span>
+      </Show>
+      <Show when={props.duration && (dimensions().width < 28 || dimensions().width >= 36)}>
+        <span style={{ fg: color(props.subduedColor) }}> · {props.duration}</span>
+      </Show>
+      <Show when={props.interrupted}>
+        <span style={{ fg: color(props.subduedColor) }}> · interrupted</span>
+      </Show>
+    </text>
+  )
+}

packages/tui/src/component/dialog-experiments.tsx

@@ -19,6 +19,11 @@ export const experiments: Experiment[] = [
     title: "Remember tab scroll",
     description: "Keep each open tab's reading position and show a shortcut back to the bottom.",
   },
+  {
+    id: "turn_summary_flash",
+    title: "Turn summary flash",
+    description: "Brighten the agent, model, and duration when a turn completes, then fade to their resting colors.",
+  },
 ]
 
 export function DialogExperiments() {

packages/tui/src/routes/session/index.tsx

@@ -98,6 +98,7 @@ import {
   type SessionRow,
 } from "./rows"
 import { switchLabel } from "../../util/model"
+import { AssistantSummary } from "../../component/assistant-summary"
 import { findMessageBoundary, messageNavigationSlack } from "./message-navigation"
 import { stringWidth } from "../../util/string-width"
 import { useArgs } from "../../context/args"
@@ -1334,7 +1335,7 @@ function SessionRowView(props: SessionRowViewProps) {
             <Show when={props.message(row().messageID)}>
               {(message) => (
                 <Show when={message().type === "assistant"}>
-                  <AssistantFooter message={message() as SessionMessageAssistant} />
+                  <AssistantFooter message={message() as SessionMessageAssistant} flash={row().flash} />
                 </Show>
               )}
             </Show>
@@ -1794,11 +1795,10 @@ function SessionGroupView(props: {
   )
 }
 
-function AssistantFooter(props: { message: SessionMessageAssistant }) {
+function AssistantFooter(props: { message: SessionMessageAssistant; flash?: true }) {
   const ctx = use()
   const data = useData()
   const local = useLocal()
-  const dimensions = useTerminalDimensions()
   const theme = useTheme("elevated")
   const model = createMemo(
     () =>
@@ -1818,20 +1818,21 @@ function AssistantFooter(props: { message: SessionMessageAssistant }) {
       </Show>
       <AssistantRetry retry={props.message.retry} />
       <box paddingLeft={3} marginTop={props.message.retry || (props.message.error && !interrupted()) ? 1 : 0}>
-        <text>
-          <span style={{ fg: props.message.error ? theme.text.subdued : local.agent.color(props.message.agent) }}>
-            {Locale.titlecase(props.message.agent)}
-          </span>
-          <Show when={dimensions().width >= 28}>
-            <span style={{ fg: theme.text.subdued }}> · {model()}</span>
-          </Show>
-          <Show when={duration() && (dimensions().width < 28 || dimensions().width >= 36)}>
-            <span style={{ fg: theme.text.subdued }}> · {Locale.duration(duration())}</span>
-          </Show>
-          <Show when={interrupted()}>
-            <span style={{ fg: theme.text.subdued }}> · interrupted</span>
-          </Show>
-        </text>
+        <AssistantSummary
+          agent={Locale.titlecase(props.message.agent)}
+          model={model()}
+          duration={duration() ? Locale.duration(duration()) : undefined}
+          interrupted={interrupted()}
+          agentColor={props.message.error ? theme.text.subdued : local.agent.color(props.message.agent)}
+          subduedColor={theme.text.subdued}
+          flashColor={theme.text.default}
+          animations={ctx.config.animations ?? true}
+          flash={
+            props.flash && ctx.config.experimental?.turn_summary_flash === true
+              ? { trigger: 1, duration: 0.8, intensity: 0.7 }
+              : undefined
+          }
+        />
       </box>
     </>
   )

packages/tui/src/routes/session/rows.ts

@@ -32,7 +32,7 @@ export type SessionRow =
       pending: PartRef[]
       completed: boolean
     }
-  | { type: "assistant-footer"; messageID: string }
+  | { type: "assistant-footer"; messageID: string; flash?: true }
   | { type: "turn-usage"; messageIDs: string[]; previousCache?: CacheUsage }
 
 export function createSessionRows(sessionID: Accessor<string>, onSynced?: (sessionID: string) => void) {
@@ -176,13 +176,13 @@ export function createSessionRows(sessionID: Accessor<string>, onSynced?: (sessi
       }),
     )
 
-  const appendFooter = (messageID: string) =>
+  const appendFooter = (messageID: string, flash?: true) =>
     setRows(
       produce((draft) => {
         if (draft.some((row) => row.type === "assistant-footer" && row.messageID === messageID)) return
         const index = queuedStart(draft)
         completePrevious(draft, index)
-        draft.splice(index, 0, { type: "assistant-footer", messageID })
+        draft.splice(index, 0, { type: "assistant-footer", messageID, ...(flash ? { flash } : {}) })
       }),
     )
 
@@ -268,12 +268,12 @@ export function createSessionRows(sessionID: Accessor<string>, onSynced?: (sessi
     }),
     data.on("session.step.ended", (event) => {
       if (event.data.sessionID !== sessionID() || ["tool-calls", "unknown"].includes(event.data.finish)) return
-      appendFooter(event.data.assistantMessageID)
+      appendFooter(event.data.assistantMessageID, true)
       if (turnTokens()) setRows(reconcile(reduce()))
     }),
     data.on("session.step.failed", (event) => {
       if (event.data.sessionID !== sessionID()) return
-      appendFooter(event.data.assistantMessageID)
+      appendFooter(event.data.assistantMessageID, true)
       if (turnTokens()) setRows(reconcile(reduce()))
     }),
   ]