feat(app): cmd+F to search session with highlighting

packages/app/e2e/performance/README.md

@@ -43,6 +43,7 @@ The suite contains:
 - home-session click timing split between content and titlebar-tab paint
 - single-session tab close timing through stable home restoration
 - cached session repaint and mutation tracing
+- large-session search scan, first-result reveal, and highlight stabilization
 - streaming timeline throughput, RAF-gap, long-task, geometry, and remount diagnostics
 - retained renderer heap with a large model catalog across repeated session navigation
 

packages/app/e2e/performance/timeline/session-timeline-search-benchmark.spec.ts

@@ -0,0 +1,69 @@
+import { benchmark, expect } from "../benchmark"
+import { buildInitialStreamEvent, setupTimelineBenchmark, textPartID } from "./session-timeline-benchmark.fixture"
+import {
+  collectTimelineSearchMetrics,
+  installTimelineSearchProbe,
+  waitForStableTimelineSearch,
+} from "./session-timeline-search-probe"
+
+benchmark("searches a large virtualized session and reveals the first result", async ({ page, report }) => {
+  benchmark.setTimeout(180_000)
+  const historyTurns = Number(process.env.TIMELINE_SEARCH_HISTORY_TURNS ?? 320)
+  const completionTimeout = Number(process.env.TIMELINE_SEARCH_COMPLETION_TIMEOUT_MS ?? 60_000)
+  const query = "Historical prompt"
+  const targetPartID = "msg_0000_0000_a_user:text:0"
+  const expectedCounter = `1/${historyTurns}`
+  const fixture = await setupTimelineBenchmark(page, {
+    historyTurns,
+    eventBatch: 1,
+  })
+
+  fixture.transport.enqueue(buildInitialStreamEvent(1))
+  await expect(fixture.text).toContainText("Implementation plan")
+  await fixture.scrollToBottom()
+  await fixture.waitForStableGeometry()
+  // Chromium reserves the physical shortcut for its native find overlay, so request the same controller path directly.
+  await page.evaluate(() => document.dispatchEvent(new Event("opencode:timeline-search-open")))
+
+  const search = page.locator('[data-component="timeline-search-bar"]')
+  const field = search.getByRole("searchbox", { name: "Find..." })
+  const count = search.locator('[data-slot="timeline-search-count"]')
+  const target = page.locator(`[data-timeline-part-id="${targetPartID}"]`)
+  await expect(field).toBeVisible()
+  await expect(field).toBeFocused()
+  await installTimelineSearchProbe(page, { targetPartID })
+
+  await field.fill(query)
+  await expect(count).toHaveText(expectedCounter)
+  await expect(target).toBeVisible({ timeout: completionTimeout })
+  await waitForStableTimelineSearch(page, { counter: expectedCounter, targetPartID, timeout: completionTimeout })
+  const metrics = await collectTimelineSearchMetrics(page, { counter: expectedCounter, targetPartID })
+
+  expect(metrics.summary.handlerDurationMs).toBeDefined()
+  expect(metrics.summary.firstCountObservedMs).toBeDefined()
+  expect(metrics.summary.firstTargetVisibleMs).toBeDefined()
+  expect(metrics.summary.firstActiveHighlightObservedMs).toBeDefined()
+  expect(metrics.summary.stableResultObservedMs).toBeDefined()
+  expect(metrics.summary.activeHighlightRanges).toBe(1)
+  report(metrics, { historyTurns, query, expectedMatches: historyTurns })
+
+  // Check navigation and the V2 assistant content IDs outside the measured interval.
+  await field.press("Enter")
+  await expect(count).toHaveText(`2/${historyTurns}`)
+  await field.press("Shift+Enter")
+  await expect(count).toHaveText(expectedCounter)
+  await field.fill("Implementation plan")
+  await expect(count).toHaveText("1/1")
+  await expect(fixture.text).toBeInViewport()
+  await expect
+    .poll(() =>
+      page.evaluate(() => {
+        const range = [...(CSS.highlights.get("timeline-search-hit-active") ?? [])][0]
+        return range?.startContainer.parentElement?.closest<HTMLElement>("[data-timeline-part-id]")?.dataset
+          .timelinePartId
+      }),
+    )
+    .toBe(textPartID)
+  await field.press("Escape")
+  await expect(search).toBeHidden()
+})

packages/app/e2e/performance/timeline/session-timeline-search-probe.ts

@@ -0,0 +1,176 @@
+import type { Page } from "@playwright/test"
+
+export type TimelineSearchSample = {
+  observedAtMs: number
+  counter: string
+  targetMounted: boolean
+  targetVisible: boolean
+  targetTopPx?: number
+  activeRanges: number
+  activePartID?: string
+  activeVisible: boolean
+  scrollTopPx: number
+}
+
+type TimelineSearchProbe = {
+  samples: TimelineSearchSample[]
+  handlerDurationMs?: number
+  initialScrollTopPx: number
+  stop: () => void
+}
+
+export async function installTimelineSearchProbe(page: Page, input: { targetPartID: string }) {
+  await page.evaluate(({ targetPartID }) => {
+    const search = document.querySelector<HTMLElement>('[data-component="timeline-search-bar"]')
+    const field = search?.querySelector<HTMLInputElement>('[data-slot="text-input-v2-input"]')
+    const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+      element.querySelector("[data-timeline-row]"),
+    )
+    if (!search || !field || !root) throw new Error("missing timeline search benchmark nodes")
+
+    const samples: TimelineSearchSample[] = []
+    const initialScrollTopPx = root.scrollTop
+    let startedAt: number | undefined
+    let handlerDurationMs: number | undefined
+    let frame: number | undefined
+    let running = true
+
+    const visibleInRoot = (rect: DOMRect) => {
+      const viewport = root.getBoundingClientRect()
+      return rect.width > 0 && rect.height > 0 && rect.bottom > viewport.top && rect.top < viewport.bottom
+    }
+    const sample = () => {
+      if (!running || startedAt === undefined) return
+      frame = requestAnimationFrame(() => {
+        frame = undefined
+        setTimeout(() => {
+          if (!running || startedAt === undefined) return
+          const target = root.querySelector<HTMLElement>(`[data-timeline-part-id="${targetPartID}"]`)
+          const targetRect = target?.getBoundingClientRect()
+          const highlight = CSS.highlights.get("timeline-search-hit-active")
+          const ranges = highlight ? [...highlight] : []
+          const active = ranges.find((range): range is Range => range instanceof Range)
+          const activeRect = active?.getBoundingClientRect()
+          const activeElement =
+            active?.startContainer instanceof Element ? active.startContainer : active?.startContainer.parentElement
+
+          samples.push({
+            observedAtMs: performance.now() - startedAt,
+            counter:
+              search.querySelector<HTMLElement>('[data-slot="timeline-search-count"]')?.textContent?.trim() ?? "",
+            targetMounted: !!target,
+            targetVisible: !!targetRect && visibleInRoot(targetRect),
+            targetTopPx: targetRect?.top,
+            activeRanges: ranges.length,
+            activePartID: activeElement?.closest<HTMLElement>("[data-timeline-part-id]")?.dataset.timelinePartId,
+            activeVisible: !!activeRect && visibleInRoot(activeRect),
+            scrollTopPx: root.scrollTop,
+          })
+          sample()
+        }, 0)
+      })
+    }
+    const onInputCapture = (event: Event) => {
+      if (event.target !== field || startedAt !== undefined) return
+      startedAt = performance.now()
+      sample()
+    }
+    const onInput = (event: Event) => {
+      if (event.target !== field || startedAt === undefined || handlerDurationMs !== undefined) return
+      handlerDurationMs = performance.now() - startedAt
+    }
+    document.addEventListener("input", onInputCapture, { capture: true })
+    document.addEventListener("input", onInput)
+    ;(window as Window & { __timelineSearchBenchmark?: TimelineSearchProbe }).__timelineSearchBenchmark = {
+      samples,
+      initialScrollTopPx,
+      get handlerDurationMs() {
+        return handlerDurationMs
+      },
+      stop: () => {
+        running = false
+        document.removeEventListener("input", onInputCapture, { capture: true })
+        document.removeEventListener("input", onInput)
+        if (frame !== undefined) cancelAnimationFrame(frame)
+      },
+    }
+  }, input)
+}
+
+export async function waitForStableTimelineSearch(
+  page: Page,
+  input: { counter: string; targetPartID: string; timeout: number },
+) {
+  await page.waitForFunction(
+    ({ counter, targetPartID }) => {
+      const samples = (window as Window & { __timelineSearchBenchmark?: TimelineSearchProbe }).__timelineSearchBenchmark
+        ?.samples
+      if (!samples) return false
+      return samples.some((_, index) => {
+        const stable = samples.slice(index, index + 3)
+        if (stable.length !== 3) return false
+        return stable.every(
+          (sample, sampleIndex) =>
+            sample.counter === counter &&
+            sample.targetVisible &&
+            sample.activeRanges === 1 &&
+            sample.activePartID === targetPartID &&
+            sample.activeVisible &&
+            (sampleIndex === 0 ||
+              (Math.abs(sample.scrollTopPx - stable[sampleIndex - 1]!.scrollTopPx) <= 1 &&
+                Math.abs((sample.targetTopPx ?? Infinity) - (stable[sampleIndex - 1]!.targetTopPx ?? -Infinity)) <= 1)),
+        )
+      })
+    },
+    { counter: input.counter, targetPartID: input.targetPartID },
+    { timeout: input.timeout },
+  )
+}
+
+export async function collectTimelineSearchMetrics(page: Page, input: { counter: string; targetPartID: string }) {
+  const result = await page.evaluate(() => {
+    const probe = (window as Window & { __timelineSearchBenchmark?: TimelineSearchProbe }).__timelineSearchBenchmark
+    if (!probe) throw new Error("missing timeline search benchmark probe")
+    probe.stop()
+    return {
+      samples: probe.samples,
+      handlerDurationMs: probe.handlerDurationMs,
+      initialScrollTopPx: probe.initialScrollTopPx,
+    }
+  })
+  const first = (predicate: (sample: TimelineSearchSample) => boolean) => result.samples.find(predicate)?.observedAtMs
+  const stable = result.samples.findIndex((_, index) => {
+    const samples = result.samples.slice(index, index + 3)
+    if (samples.length !== 3) return false
+    return samples.every(
+      (sample, sampleIndex) =>
+        sample.counter === input.counter &&
+        sample.targetVisible &&
+        sample.activeRanges === 1 &&
+        sample.activePartID === input.targetPartID &&
+        sample.activeVisible &&
+        (sampleIndex === 0 ||
+          (Math.abs(sample.scrollTopPx - samples[sampleIndex - 1]!.scrollTopPx) <= 1 &&
+            Math.abs((sample.targetTopPx ?? Infinity) - (samples[sampleIndex - 1]!.targetTopPx ?? -Infinity)) <= 1)),
+    )
+  })
+  const final = result.samples.at(-1)
+
+  return {
+    summary: {
+      handlerDurationMs: result.handlerDurationMs,
+      firstCountObservedMs: first((sample) => sample.counter === input.counter),
+      firstTargetMountedMs: first((sample) => sample.targetMounted),
+      firstTargetVisibleMs: first((sample) => sample.targetVisible),
+      firstActiveHighlightObservedMs: first(
+        (sample) => sample.activeRanges === 1 && sample.activePartID === input.targetPartID && sample.activeVisible,
+      ),
+      stableResultObservedMs: stable >= 0 ? result.samples[stable + 2]?.observedAtMs : undefined,
+      initialScrollTopPx: result.initialScrollTopPx,
+      finalScrollTopPx: final?.scrollTopPx,
+      scrollDistancePx: final === undefined ? undefined : Math.abs(result.initialScrollTopPx - final.scrollTopPx),
+      activeHighlightRanges: final?.activeRanges,
+    },
+    samples: result.samples,
+  }
+}

packages/app/src/index.css

@@ -165,6 +165,15 @@
     }
   }
 
+  ::highlight(timeline-search-hit) {
+    background-color: color-mix(in srgb, var(--v2-icon-icon-accent) 28%, transparent);
+  }
+
+  ::highlight(timeline-search-hit-active) {
+    background-color: var(--v2-icon-icon-accent);
+    color: var(--v2-background-bg-deep);
+  }
+
   [data-component="getting-started"] {
     container-type: inline-size;
     container-name: getting-started;

packages/app/src/runtime/i18n/en.ts

@@ -769,6 +769,8 @@ export const dict = {
 
   "session.header.search.placeholder": "Search {{project}}",
   "session.header.searchFiles": "Search files",
+  "session.search.placeholder": "Find...",
+  "session.search.noResults": "No matches",
   "session.header.openIn": "Open in",
   "session.header.open.action": "Open {{app}}",
   "session.header.open.ariaLabel": "Open in {{app}}",

packages/app/src/session/screen.tsx

@@ -27,6 +27,8 @@ import { createSessionReview } from "./review/model"
 import { SessionDesktopReview, SessionMobileReview, SessionMobileViewTabs } from "./review/view"
 import { SessionContextTab } from "./files/session-context-tab"
 import { createSessionTimelineInteraction } from "./timeline/interaction"
+import { createTimelineSearchController } from "./timeline/search-controller"
+import { TimelineSearchBar } from "./timeline/search-bar"
 import { ActiveSessionComposerRegion, createActiveSessionRegion } from "./composer/region"
 import { SessionIdentityHeader } from "./session-identity-header"
 import { SessionReviewToggle } from "./header/session-header-actions"
@@ -47,6 +49,12 @@ export function SessionScreen(props: { session: SessionModel }) {
   const isDesktop = session.isDesktop
   const screen = createSessionScreenLayout(session)
   const timeline = createSessionTimelineInteraction(session)
+  const timelineSearch = createTimelineSearchController({
+    sessionID: session.identity.sessionID,
+    scrollRef: timeline.scroller,
+    revealMessage: timeline.actions.revealMessage,
+    pauseAutoScroll: timeline.view.unpin,
+  })
   const messagesReady = timeline.ready
   const [store, setStore] = createStore({
     deferRender: false,
@@ -262,6 +270,7 @@ export function SessionScreen(props: { session: SessionModel }) {
                   anchor={timeline.view.anchor}
                   setRevealMessage={timeline.view.setRevealMessage}
                   setScrollToEnd={timeline.view.setScrollToEnd}
+                  search={<TimelineSearchBar controller={timelineSearch} />}
                 />
               )}
             </Show>

packages/app/src/session/timeline/interaction.ts

@@ -24,6 +24,7 @@ export function createSessionTimelineInteraction(session: SessionModel) {
       pinned: true,
     },
     refs: {
+      scroller: undefined as HTMLDivElement | undefined,
       content: undefined as HTMLDivElement | undefined,
       dock: undefined as HTMLDivElement | undefined,
     },
@@ -38,7 +39,7 @@ export function createSessionTimelineInteraction(session: SessionModel) {
   }
   let scroller: HTMLDivElement | undefined
   let dockHeight = 0
-  let revealMessage = (_id: string) => {}
+  let revealMessage = (_id: string, _partID?: string) => {}
   let scrollToEnd = () => {}
   let scrollMark = 0
   let messageMark = 0
@@ -157,6 +158,7 @@ export function createSessionTimelineInteraction(session: SessionModel) {
   }
   const setScrollRef = (element: HTMLDivElement | undefined) => {
     scroller = element
+    setState("refs", "scroller", element)
     if (!element) return
     scheduleScrollState(element)
     fill()
@@ -290,6 +292,7 @@ export function createSessionTimelineInteraction(session: SessionModel) {
   return {
     actions: {
       navigateMessage,
+      revealMessage: (id: string, partID?: string) => revealMessage(id, partID),
       resume,
       setActiveMessage,
     },
@@ -297,7 +300,7 @@ export function createSessionTimelineInteraction(session: SessionModel) {
     resource: timeline.resource,
     ready: timeline.ready,
     scroll: state.scroll,
-    scroller: () => scroller,
+    scroller: () => state.refs.scroller,
     view: {
       anchor,
       markUserScroll,
@@ -313,7 +316,7 @@ export function createSessionTimelineInteraction(session: SessionModel) {
       setDockRef: (element: HTMLDivElement | undefined) => {
         setState("refs", "dock", element)
       },
-      setRevealMessage: (reveal: (id: string) => void) => {
+      setRevealMessage: (reveal: (id: string, partID?: string) => void) => {
         revealMessage = reveal
       },
       setScrollRef,

packages/app/src/session/timeline/message-timeline.tsx

@@ -353,8 +353,9 @@ type MessageTimelineProps = {
   workspaceMoveEligible: boolean
   onSummaryOpenChange: (open: boolean) => void
   anchor: (id: string) => string
-  setRevealMessage?: (fn: (id: string) => void) => void
+  setRevealMessage?: (fn: (id: string, partID?: string) => void) => void
   setScrollToEnd?: (fn: () => void) => void
+  search?: JSX.Element
 }
 
 export function MessageTimeline(props: MessageTimelineProps) {
@@ -789,6 +790,7 @@ function MessageTimelineView(
               <Show when={sessionID()} keyed>
                 {(id) => (
                   <div class="shrink-0 flex items-center gap-2">
+                    {props.search}
                     <SessionContextUsage placement="bottom" />
                     <Show when={!parentID() && project()}>
                       {(project) => (

packages/app/src/session/timeline/search-bar.css

@@ -0,0 +1,14 @@
+[data-component="timeline-search-bar"] [data-component="text-input-v2"] {
+  background: var(--v2-background-bg-base);
+  box-shadow: inset 0 0 0 1px var(--v2-border-border-base);
+  outline: none;
+}
+
+[data-component="timeline-search-bar"] [data-component="text-input-v2"]:hover {
+  background: var(--v2-background-bg-base);
+}
+
+[data-component="timeline-search-bar"] [data-component="text-input-v2"]:focus-within {
+  box-shadow: inset 0 0 0 1px var(--v2-border-border-focus);
+  outline: none;
+}

packages/app/src/session/timeline/search-bar.tsx

@@ -0,0 +1,72 @@
+import { Icon } from "@opencode-ai/ui/icon"
+import "@opencode-ai/ui/text-input.css"
+import { Show } from "solid-js"
+import type { TimelineSearchController } from "./search-controller"
+import "./search-bar.css"
+
+export function TimelineSearchBar(props: { controller: TimelineSearchController }) {
+  const c = props.controller
+
+  return (
+    <Show when={c.visible()}>
+      <div data-component="timeline-search-bar" class="h-7 w-[200px] max-w-[50vw] shrink-0">
+        <div data-component="text-input-v2" data-appearance="base" data-leading-icon class="!h-7 !w-full max-w-full">
+          <div data-slot="text-input-v2-value">
+            <span data-slot="text-input-v2-leading-icon">
+              <Icon name="magnifying-glass" size="small" />
+            </span>
+            <input
+              ref={c.element.setInput}
+              data-slot="text-input-v2-input"
+              type="search"
+              value={c.query.value()}
+              placeholder={c.query.placeholder()}
+              aria-label={c.query.placeholder()}
+              onInput={(event) => c.query.setValue(event.currentTarget.value)}
+              onKeyDown={(event) => {
+                if (event.key === "Escape") {
+                  event.preventDefault()
+                  c.query.close()
+                  return
+                }
+                if (event.altKey || event.metaKey || event.ctrlKey) return
+                if (event.key === "Enter" && !event.isComposing) {
+                  event.preventDefault()
+                  c.result.move(event.shiftKey ? -1 : 1)
+                  return
+                }
+                if (event.key === "ArrowDown" && !event.isComposing) {
+                  event.preventDefault()
+                  c.result.move(1)
+                  return
+                }
+                if (event.key === "ArrowUp" && !event.isComposing) {
+                  event.preventDefault()
+                  c.result.move(-1)
+                  return
+                }
+              }}
+            />
+          </div>
+          <Show when={c.query.value()}>
+            <span
+              data-slot="timeline-search-count"
+              class="shrink-0 self-center text-[11px] text-v2-text-text-muted [font-weight:440] tabular-nums"
+            >
+              {c.result.count() > 0 ? c.result.activeIndex() + 1 : 0}/{c.result.count()}
+            </span>
+          </Show>
+          <button
+            type="button"
+            class="-me-1 flex size-5 shrink-0 self-center items-center justify-center rounded-[2px] border-0 bg-transparent p-0 text-v2-icon-icon-muted outline outline-1 outline-transparent hover:bg-v2-overlay-simple-overlay-hover active:bg-v2-overlay-simple-overlay-pressed focus-visible:outline-v2-border-border-focus"
+            aria-label={c.query.placeholder()}
+            onMouseDown={(event) => event.preventDefault()}
+            onClick={() => c.query.close()}
+          >
+            <Icon name="xmark-small" />
+          </button>
+        </div>
+      </div>
+    </Show>
+  )
+}

packages/app/src/session/timeline/search-controller.ts

@@ -0,0 +1,275 @@
+import { useCommand } from "@/shell/commands/command"
+import { useLanguage } from "@/runtime/i18n/language"
+import { useData } from "@/runtime/server/current"
+import { Timeline } from "@opencode-ai/session-ui/timeline/projection"
+import { createEffect, createMemo, createSignal, on, onCleanup } from "solid-js"
+import { createStore } from "solid-js/store"
+
+export type TimelineSearchMatch = {
+  messageID: string
+  role: "user" | "assistant"
+  revealID: string
+  partID: string
+  occurrence: number
+  text: string
+}
+
+const HIGHLIGHT_HIT = "timeline-search-hit"
+const HIGHLIGHT_ACTIVE = "timeline-search-hit-active"
+const TEXT_SELECTORS = '[data-slot="text-part-body"], [data-slot="user-message-text"]'
+
+function supportsHighlights() {
+  return typeof CSS !== "undefined" && typeof CSS.highlights === "object" && CSS.highlights !== null
+}
+
+function clearHighlights() {
+  if (!supportsHighlights()) return
+  CSS.highlights.delete(HIGHLIGHT_HIT)
+  CSS.highlights.delete(HIGHLIGHT_ACTIVE)
+}
+
+function collectRanges(
+  root: HTMLElement,
+  query: string,
+  activePartID: string | undefined,
+  activeOccurrence: number | undefined,
+) {
+  const hits: Range[] = []
+  const active: Range[] = []
+  const lower = query.toLowerCase()
+  const bodies = root.querySelectorAll<HTMLElement>(TEXT_SELECTORS)
+  for (const body of bodies) {
+    const part = body.closest("[data-timeline-part-id]")
+    const partID = part?.getAttribute("data-timeline-part-id")
+    const isActivePart = activePartID !== undefined && partID === activePartID
+    let occurrenceInPart = 0
+    const walker = document.createTreeWalker(body, NodeFilter.SHOW_TEXT)
+    let node = walker.nextNode() as Text | null
+    while (node) {
+      const value = node.nodeValue ?? ""
+      const lowerValue = value.toLowerCase()
+      let from = 0
+      let at = lowerValue.indexOf(lower, from)
+      while (at !== -1) {
+        const range = document.createRange()
+        range.setStart(node, at)
+        range.setEnd(node, at + query.length)
+        if (isActivePart && activeOccurrence === occurrenceInPart) active.push(range)
+        else hits.push(range)
+        occurrenceInPart += 1
+        from = at + query.length
+        at = lowerValue.indexOf(lower, from)
+      }
+      node = walker.nextNode() as Text | null
+    }
+  }
+  return { hits, active }
+}
+
+function applyHighlights(
+  root: HTMLElement,
+  query: string,
+  activePartID: string | undefined,
+  activeOccurrence: number | undefined,
+) {
+  if (!supportsHighlights()) return
+  const { hits, active } = collectRanges(root, query, activePartID, activeOccurrence)
+  CSS.highlights.set(HIGHLIGHT_HIT, new Highlight(...hits))
+  CSS.highlights.set(HIGHLIGHT_ACTIVE, new Highlight(...active))
+}
+
+export function createTimelineSearchController(input: {
+  sessionID: () => string | undefined
+  scrollRef: () => HTMLDivElement | undefined
+  revealMessage: (id: string, partID?: string) => void
+  pauseAutoScroll: () => void
+}) {
+  const command = useCommand()
+  const language = useLanguage()
+  const data = useData()
+  const [state, setState] = createStore({ value: "", active: 0, visible: false })
+  const [focusTick, setFocusTick] = createSignal(0)
+  let inputEl: HTMLInputElement | undefined
+
+  const query = createMemo(() => state.value.trim().toLowerCase())
+
+  const matches = createMemo<TimelineSearchMatch[]>(() => {
+    const value = query()
+    if (!value) return []
+    const sessionID = input.sessionID()
+    if (!sessionID) return []
+    const messages = data.session.message.list(sessionID)
+    const result: TimelineSearchMatch[] = []
+    let revealID = ""
+    for (const message of messages) {
+      if (message.type === "user" || message.type === "shell") revealID = message.id
+      if (message.type !== "user" && message.type !== "assistant") continue
+      const visibleParts =
+        message.type === "user"
+          ? [{ id: `${message.id}:text:0`, content: { type: "text" as const, text: message.text } }]
+          : Timeline.contentEntries(message)
+      for (const textPart of visibleParts) {
+        if (textPart.content.type !== "text") continue
+        const text = textPart.content.text
+        if (!text) continue
+        const lower = text.toLowerCase()
+        let from = 0
+        let occurrence = 0
+        let at = lower.indexOf(value, from)
+        while (at !== -1) {
+          result.push({
+            messageID: message.id,
+            role: message.type,
+            revealID,
+            partID: textPart.id,
+            occurrence,
+            text,
+          })
+          occurrence += 1
+          from = at + value.length
+          at = lower.indexOf(value, from)
+        }
+      }
+    }
+    return result
+  })
+
+  const activeIndex = createMemo(() => {
+    const list = matches()
+    if (list.length === 0) return 0
+    if (state.active >= list.length) return 0
+    if (state.active < 0) return 0
+    return state.active
+  })
+
+  const activePartID = createMemo(() => matches()[activeIndex()]?.partID)
+  const activeOccurrence = createMemo(() => matches()[activeIndex()]?.occurrence)
+
+  createEffect(() => {
+    const root = input.scrollRef()
+    const q = query()
+    if (!root || !state.visible || !q) {
+      clearHighlights()
+      return
+    }
+    applyHighlights(root, q, activePartID(), activeOccurrence())
+    let frame: number | undefined
+    const scheduleApply = () => {
+      if (frame !== undefined) return
+      frame = requestAnimationFrame(() => {
+        frame = undefined
+        if (!state.visible) return
+        applyHighlights(root, query(), activePartID(), activeOccurrence())
+      })
+    }
+    const observer = new MutationObserver(scheduleApply)
+    observer.observe(root, { childList: true, subtree: true, characterData: true })
+    onCleanup(() => {
+      observer.disconnect()
+      if (frame !== undefined) cancelAnimationFrame(frame)
+      clearHighlights()
+    })
+  })
+
+  createEffect(
+    on(focusTick, () => {
+      if (!state.visible) return
+      requestAnimationFrame(() => {
+        inputEl?.focus()
+        inputEl?.select()
+      })
+    }),
+  )
+
+  command.register("session.search", () => [
+    {
+      id: "session.search",
+      title: language.t("session.search.placeholder"),
+      keybind: "mod+f",
+      hidden: true,
+      onSelect: () => open(),
+    },
+  ])
+  const onOpenRequest = () => open()
+  document.addEventListener("opencode:timeline-search-open", onOpenRequest)
+  onCleanup(() => document.removeEventListener("opencode:timeline-search-open", onOpenRequest))
+
+  function open() {
+    setState("visible", true)
+    setFocusTick((t) => t + 1)
+  }
+
+  function close() {
+    setState({ value: "", active: 0, visible: false })
+    inputEl?.blur()
+  }
+
+  function setValue(value: string) {
+    setState("value", value)
+    const list = matches()
+    const match = list[0]
+    if (!value.trim() || !match) {
+      setState("active", 0)
+      return
+    }
+    setState("active", 0)
+    input.pauseAutoScroll()
+    input.revealMessage(match.revealID, match.partID)
+    scrollToMatch(match)
+  }
+
+  function scrollToMatch(match: TimelineSearchMatch) {
+    let attempts = 0
+    const seek = () => {
+      if (!state.visible) return
+      const root = input.scrollRef()
+      if (!root) return
+      const { active } = collectRanges(root, query(), match.partID, match.occurrence)
+      if (active.length === 0) {
+        if (attempts++ < 12) requestAnimationFrame(seek)
+        return
+      }
+      const rect = active[0].getBoundingClientRect()
+      const rootRect = root.getBoundingClientRect()
+      const sticky = root.querySelector("[data-session-title]")
+      const inset = sticky instanceof HTMLElement ? sticky.offsetHeight : 0
+      const top = rect.top - rootRect.top + root.scrollTop - inset - (rootRect.height - rect.height) / 2
+      root.scrollTo({ top: Math.max(0, top), behavior: "auto" })
+    }
+    requestAnimationFrame(seek)
+  }
+
+  function move(delta: number) {
+    const list = matches()
+    if (list.length === 0) return
+    const next = (activeIndex() + delta + list.length) % list.length
+    setState("active", next)
+    const match = list[next]
+    if (!match) return
+    input.pauseAutoScroll()
+    input.revealMessage(match.revealID, match.partID)
+    scrollToMatch(match)
+  }
+
+  return {
+    visible: () => state.visible,
+    query: {
+      value: () => state.value,
+      placeholder: () => language.t("session.search.placeholder"),
+      noResults: () => language.t("session.search.noResults"),
+      open,
+      close,
+      setValue,
+    },
+    result: {
+      activeIndex,
+      count: () => matches().length,
+      move,
+    },
+    element: {
+      setInput: (element: HTMLInputElement) => (inputEl = element),
+    },
+  }
+}
+
+export type TimelineSearchController = ReturnType<typeof createTimelineSearchController>

packages/app/src/session/timeline/virtualizer.tsx

@@ -69,7 +69,7 @@ type Input = {
     row: TimelineRow.TimelineRow,
     disclosure: Readonly<Record<string, boolean | undefined>>,
   ) => boolean
-  setRevealMessage?: (fn: (id: string) => void) => void
+  setRevealMessage?: (fn: (id: string, partID?: string) => void) => void
   setScrollToEnd?: (fn: () => void) => void
 }
 
@@ -271,8 +271,13 @@ export function createTimelineVirtualizer(input: Input) {
   const virtualRowKeys = createMemo(() => virtualizer.getVirtualItems().map((item) => String(item.key)))
 
   createEffect(() => {
-    input.setRevealMessage?.((id) => {
-      const index = input.projection.messageRowIndex().get(id)
+    input.setRevealMessage?.((id, partID) => {
+      const partIndex = partID
+        ? rows().findIndex(
+            (row) => row._tag === "AssistantPart" && row.group.type === "part" && row.group.ref.partID === partID,
+          )
+        : -1
+      const index = partIndex >= 0 ? partIndex : input.projection.messageRowIndex().get(id)
       if (index === undefined) return
       virtualizer.scrollToIndex(index, { align: "center" })
     })