STUPID SEXY TIMELINE (#16420)

4 files changed, 686 insertions, 410 deletions

diff --git a/packages/app/src/pages/session.tsx b/packages/app/src/pages/session.tsx
index 82a581e68..578dadecf 100644
--- a/packages/app/src/pages/session.tsx
+++ b/packages/app/src/pages/session.tsx
@@ -121,13 +121,9 @@ function createSessionHistoryWindow(input: SessionHistoryWindowInput) {
       return
     }
     const beforeTop = el.scrollTop
-    const beforeHeight = el.scrollHeight
     fn()
-    requestAnimationFrame(() => {
-      const delta = el.scrollHeight - beforeHeight
-      if (!delta) return
-      el.scrollTop = beforeTop + delta
-    })
+    void el.scrollHeight
+    el.scrollTop = beforeTop
   }
 
   const backfillTurns = () => {
@@ -210,7 +206,7 @@ function createSessionHistoryWindow(input: SessionHistoryWindowInput) {
     if (!input.userScrolled()) return
     const el = input.scroller()
     if (!el) return
-    if (el.scrollTop >= turnScrollThreshold) return
+    if (el.scrollHeight - el.clientHeight + el.scrollTop >= turnScrollThreshold) return
 
     const start = turnStart()
     if (start > 0) {
@@ -1110,7 +1106,7 @@ export default function Page() {
   const updateScrollState = (el: HTMLDivElement) => {
     const max = el.scrollHeight - el.clientHeight
     const overflow = max > 1
-    const bottom = !overflow || el.scrollTop >= max - 2
+    const bottom = !overflow || Math.abs(el.scrollTop) <= 2 || !autoScroll.userScrolled()
 
     if (ui.scroll.overflow === overflow && ui.scroll.bottom === bottom) return
     setUi("scroll", { overflow, bottom })
@@ -1133,7 +1129,7 @@ export default function Page() {
 
   const resumeScroll = () => {
     setStore("messageId", undefined)
-    autoScroll.forceScrollToBottom()
+    autoScroll.smoothScrollToBottom()
     clearMessageHash()
 
     const el = scroller
@@ -1201,13 +1197,11 @@ export default function Page() {
 
       const el = scroller
       const delta = next - dockHeight
-      const stick = el
-        ? !autoScroll.userScrolled() || el.scrollHeight - el.clientHeight - el.scrollTop < 10 + Math.max(0, delta)
-        : false
+      const stick = el ? Math.abs(el.scrollTop) < 10 + Math.max(0, delta) : false
 
       dockHeight = next
 
-      if (stick) autoScroll.forceScrollToBottom()
+      if (stick) autoScroll.smoothScrollToBottom()
 
       if (el) scheduleScrollState(el)
       scrollSpy.markDirty()
@@ -1293,6 +1287,7 @@ export default function Page() {
                     onScrollSpyScroll={scrollSpy.onScroll}
                     onTurnBackfillScroll={historyWindow.onScrollerScroll}
                     onAutoScrollInteraction={autoScroll.handleInteraction}
+                    onPreserveScrollAnchor={autoScroll.preserve}
                     centered={centered()}
                     setContentRef={(el) => {
                       content = el
diff --git a/packages/app/src/pages/session/message-timeline.tsx b/packages/app/src/pages/session/message-timeline.tsx
index ce6a01378..938ff4fbd 100644
--- a/packages/app/src/pages/session/message-timeline.tsx
+++ b/packages/app/src/pages/session/message-timeline.tsx
@@ -1,27 +1,31 @@
-import { For, createEffect, createMemo, on, onCleanup, Show, Index, type JSX } from "solid-js"
-import { createStore, produce } from "solid-js/store"
-import { useNavigate, useParams } from "@solidjs/router"
+import {
+  For,
+  Index,
+  createEffect,
+  createMemo,
+  createSignal,
+  on,
+  onCleanup,
+  Show,
+  startTransition,
+  type JSX,
+} from "solid-js"
+import { createStore } from "solid-js/store"
+import { useParams } from "@solidjs/router"
 import { Button } from "@opencode-ai/ui/button"
 import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { Icon } from "@opencode-ai/ui/icon"
-import { IconButton } from "@opencode-ai/ui/icon-button"
-import { DropdownMenu } from "@opencode-ai/ui/dropdown-menu"
-import { Dialog } from "@opencode-ai/ui/dialog"
-import { InlineInput } from "@opencode-ai/ui/inline-input"
 import { SessionTurn } from "@opencode-ai/ui/session-turn"
 import { ScrollView } from "@opencode-ai/ui/scroll-view"
 import type { AssistantMessage, Message as MessageType, Part, TextPart, UserMessage } from "@opencode-ai/sdk/v2"
-import { showToast } from "@opencode-ai/ui/toast"
 import { Binary } from "@opencode-ai/util/binary"
 import { getFilename } from "@opencode-ai/util/path"
 import { shouldMarkBoundaryGesture, normalizeWheelDelta } from "@/pages/session/message-gesture"
-import { SessionContextUsage } from "@/components/session-context-usage"
-import { useDialog } from "@opencode-ai/ui/context/dialog"
 import { useLanguage } from "@/context/language"
 import { useSettings } from "@/context/settings"
-import { useSDK } from "@/context/sdk"
 import { useSync } from "@/context/sync"
 import { parseCommentNote, readCommentMetadata } from "@/utils/comment-note"
+import { SessionTimelineHeader } from "@/pages/session/session-timeline-header"
 
 type MessageComment = {
   path: string
@@ -33,7 +37,9 @@ type MessageComment = {
 }
 
 const emptyMessages: MessageType[] = []
-const idle = { type: "idle" as const }
+
+const isDefaultSessionTitle = (title?: string) =>
+  !!title && /^(New session - |Child session - )\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/.test(title)
 
 const messageComments = (parts: Part[]): MessageComment[] =>
   parts.flatMap((part) => {
@@ -110,6 +116,8 @@ function createTimelineStaging(input: TimelineStageInput) {
     completedSession: "",
     count: 0,
   })
+  const [readySession, setReadySession] = createSignal("")
+  let active = ""
 
   const stagedCount = createMemo(() => {
     const total = input.messages().length
@@ -134,23 +142,46 @@ function createTimelineStaging(input: TimelineStageInput) {
     cancelAnimationFrame(frame)
     frame = undefined
   }
+  const scheduleReady = (sessionKey: string) => {
+    if (input.sessionKey() !== sessionKey) return
+    if (readySession() === sessionKey) return
+    setReadySession(sessionKey)
+  }
 
   createEffect(
     on(
       () => [input.sessionKey(), input.turnStart() > 0, input.messages().length] as const,
       ([sessionKey, isWindowed, total]) => {
+        const switched = active !== sessionKey
+        if (switched) {
+          active = sessionKey
+          setReadySession("")
+        }
+
+        const staging = state.activeSession === sessionKey && state.completedSession !== sessionKey
+        const shouldStage = isWindowed && total > input.config.init && state.completedSession !== sessionKey
+
+        if (staging && !switched && shouldStage && frame !== undefined) return
+
         cancel()
-        const shouldStage =
-          isWindowed &&
-          total > input.config.init &&
-          state.completedSession !== sessionKey &&
-          state.activeSession !== sessionKey
+
+        if (shouldStage) setReadySession("")
         if (!shouldStage) {
-          setState({ activeSession: "", count: total })
+          setState({
+            activeSession: "",
+            completedSession: isWindowed ? sessionKey : state.completedSession,
+            count: total,
+          })
+          if (total <= 0) {
+            setReadySession("")
+            return
+          }
+          if (readySession() !== sessionKey) scheduleReady(sessionKey)
           return
         }
 
         let count = Math.min(total, input.config.init)
+        if (staging) count = Math.min(total, Math.max(count, state.count))
         setState({ activeSession: sessionKey, count })
 
         const step = () => {
@@ -160,10 +191,11 @@ function createTimelineStaging(input: TimelineStageInput) {
           }
           const currentTotal = input.messages().length
           count = Math.min(currentTotal, count + input.config.batch)
-          setState("count", count)
+          startTransition(() => setState("count", count))
           if (count >= currentTotal) {
             setState({ completedSession: sessionKey, activeSession: "" })
             frame = undefined
+            scheduleReady(sessionKey)
             return
           }
           frame = requestAnimationFrame(step)
@@ -177,9 +209,12 @@ function createTimelineStaging(input: TimelineStageInput) {
     const key = input.sessionKey()
     return state.activeSession === key && state.completedSession !== key
   })
+  const ready = createMemo(() => readySession() === input.sessionKey())
 
-  onCleanup(cancel)
-  return { messages: stagedUserMessages, isStaging }
+  onCleanup(() => {
+    cancel()
+  })
+  return { messages: stagedUserMessages, isStaging, ready }
 }
 
 export function MessageTimeline(props: {
@@ -196,6 +231,7 @@ export function MessageTimeline(props: {
   onScrollSpyScroll: () => void
   onTurnBackfillScroll: () => void
   onAutoScrollInteraction: (event: MouseEvent) => void
+  onPreserveScrollAnchor: (target: HTMLElement) => void
   centered: boolean
   setContentRef: (el: HTMLDivElement) => void
   turnStart: number
@@ -210,14 +246,19 @@ export function MessageTimeline(props: {
   let touchGesture: number | undefined
 
   const params = useParams()
-  const navigate = useNavigate()
-  const sdk = useSDK()
   const sync = useSync()
   const settings = useSettings()
-  const dialog = useDialog()
   const language = useLanguage()
 
-  const rendered = createMemo(() => props.renderedUserMessages.map((message) => message.id))
+  const trigger = (target: EventTarget | null) => {
+    const next =
+      target instanceof Element
+        ? target.closest('[data-slot="collapsible-trigger"], [data-slot="accordion-trigger"], [data-scroll-preserve]')
+        : undefined
+    if (!(next instanceof HTMLElement)) return
+    return next
+  }
+
   const sessionKey = createMemo(() => `${params.dir}${params.id ? "/" + params.id : ""}`)
   const sessionID = createMemo(() => params.id)
   const sessionMessages = createMemo(() => {
@@ -230,28 +271,20 @@ export function MessageTimeline(props: {
       (item): item is AssistantMessage => item.role === "assistant" && typeof item.time.completed !== "number",
     ),
   )
-  const sessionStatus = createMemo(() => {
-    const id = sessionID()
-    if (!id) return idle
-    return sync.data.session_status[id] ?? idle
-  })
+  const sessionStatus = createMemo(() => sync.data.session_status[sessionID() ?? ""]?.type ?? "idle")
   const activeMessageID = createMemo(() => {
-    const parentID = pending()?.parentID
-    if (parentID) {
-      const messages = sessionMessages()
-      const result = Binary.search(messages, parentID, (message) => message.id)
-      const message = result.found ? messages[result.index] : messages.find((item) => item.id === parentID)
-      if (message && message.role === "user") return message.id
+    const messages = sessionMessages()
+    const message = pending()
+    if (message?.parentID) {
+      const result = Binary.search(messages, message.parentID, (item) => item.id)
+      const parent = result.found ? messages[result.index] : messages.find((item) => item.id === message.parentID)
+      if (parent?.role === "user") return parent.id
     }
 
-    const status = sessionStatus()
-    if (status.type !== "idle") {
-      const messages = sessionMessages()
-      for (let i = messages.length - 1; i >= 0; i--) {
-        if (messages[i].role === "user") return messages[i].id
-      }
+    if (sessionStatus() === "idle") return undefined
+    for (let i = messages.length - 1; i >= 0; i--) {
+      if (messages[i].role === "user") return messages[i].id
     }
-
     return undefined
   })
   const info = createMemo(() => {
@@ -259,9 +292,19 @@ export function MessageTimeline(props: {
     if (!id) return
     return sync.session.get(id)
   })
-  const titleValue = createMemo(() => info()?.title)
+  const titleValue = createMemo(() => {
+    const title = info()?.title
+    if (!title) return
+    if (isDefaultSessionTitle(title)) return language.t("command.session.new")
+    return title
+  })
+  const defaultTitle = createMemo(() => isDefaultSessionTitle(info()?.title))
+  const headerTitle = createMemo(
+    () => titleValue() ?? (props.renderedUserMessages.length ? language.t("command.session.new") : undefined),
+  )
+  const placeholderTitle = createMemo(() => defaultTitle() || (!info()?.title && props.renderedUserMessages.length > 0))
   const parentID = createMemo(() => info()?.parentID)
-  const showHeader = createMemo(() => !!(titleValue() || parentID()))
+  const showHeader = createMemo(() => !!(headerTitle() || parentID()))
   const stageCfg = { init: 1, batch: 3 }
   const staging = createTimelineStaging({
     sessionKey,
@@ -269,212 +312,7 @@ export function MessageTimeline(props: {
     messages: () => props.renderedUserMessages,
     config: stageCfg,
   })
-
-  const [title, setTitle] = createStore({
-    draft: "",
-    editing: false,
-    saving: false,
-    menuOpen: false,
-    pendingRename: false,
-  })
-  let titleRef: HTMLInputElement | undefined
-
-  const errorMessage = (err: unknown) => {
-    if (err && typeof err === "object" && "data" in err) {
-      const data = (err as { data?: { message?: string } }).data
-      if (data?.message) return data.message
-    }
-    if (err instanceof Error) return err.message
-    return language.t("common.requestFailed")
-  }
-
-  createEffect(
-    on(
-      sessionKey,
-      () => setTitle({ draft: "", editing: false, saving: false, menuOpen: false, pendingRename: false }),
-      { defer: true },
-    ),
-  )
-
-  const openTitleEditor = () => {
-    if (!sessionID()) return
-    setTitle({ editing: true, draft: titleValue() ?? "" })
-    requestAnimationFrame(() => {
-      titleRef?.focus()
-      titleRef?.select()
-    })
-  }
-
-  const closeTitleEditor = () => {
-    if (title.saving) return
-    setTitle({ editing: false, saving: false })
-  }
-
-  const saveTitleEditor = async () => {
-    const id = sessionID()
-    if (!id) return
-    if (title.saving) return
-
-    const next = title.draft.trim()
-    if (!next || next === (titleValue() ?? "")) {
-      setTitle({ editing: false, saving: false })
-      return
-    }
-
-    setTitle("saving", true)
-    await sdk.client.session
-      .update({ sessionID: id, title: next })
-      .then(() => {
-        sync.set(
-          produce((draft) => {
-            const index = draft.session.findIndex((s) => s.id === id)
-            if (index !== -1) draft.session[index].title = next
-          }),
-        )
-        setTitle({ editing: false, saving: false })
-      })
-      .catch((err) => {
-        setTitle("saving", false)
-        showToast({
-          title: language.t("common.requestFailed"),
-          description: errorMessage(err),
-        })
-      })
-  }
-
-  const navigateAfterSessionRemoval = (sessionID: string, parentID?: string, nextSessionID?: string) => {
-    if (params.id !== sessionID) return
-    if (parentID) {
-      navigate(`/${params.dir}/session/${parentID}`)
-      return
-    }
-    if (nextSessionID) {
-      navigate(`/${params.dir}/session/${nextSessionID}`)
-      return
-    }
-    navigate(`/${params.dir}/session`)
-  }
-
-  const archiveSession = async (sessionID: string) => {
-    const session = sync.session.get(sessionID)
-    if (!session) return
-
-    const sessions = sync.data.session ?? []
-    const index = sessions.findIndex((s) => s.id === sessionID)
-    const nextSession = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
-
-    await sdk.client.session
-      .update({ sessionID, time: { archived: Date.now() } })
-      .then(() => {
-        sync.set(
-          produce((draft) => {
-            const index = draft.session.findIndex((s) => s.id === sessionID)
-            if (index !== -1) draft.session.splice(index, 1)
-          }),
-        )
-        navigateAfterSessionRemoval(sessionID, session.parentID, nextSession?.id)
-      })
-      .catch((err) => {
-        showToast({
-          title: language.t("common.requestFailed"),
-          description: errorMessage(err),
-        })
-      })
-  }
-
-  const deleteSession = async (sessionID: string) => {
-    const session = sync.session.get(sessionID)
-    if (!session) return false
-
-    const sessions = (sync.data.session ?? []).filter((s) => !s.parentID && !s.time?.archived)
-    const index = sessions.findIndex((s) => s.id === sessionID)
-    const nextSession = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
-
-    const result = await sdk.client.session
-      .delete({ sessionID })
-      .then((x) => x.data)
-      .catch((err) => {
-        showToast({
-          title: language.t("session.delete.failed.title"),
-          description: errorMessage(err),
-        })
-        return false
-      })
-
-    if (!result) return false
-
-    sync.set(
-      produce((draft) => {
-        const removed = new Set<string>([sessionID])
-
-        const byParent = new Map<string, string[]>()
-        for (const item of draft.session) {
-          const parentID = item.parentID
-          if (!parentID) continue
-          const existing = byParent.get(parentID)
-          if (existing) {
-            existing.push(item.id)
-            continue
-          }
-          byParent.set(parentID, [item.id])
-        }
-
-        const stack = [sessionID]
-        while (stack.length) {
-          const parentID = stack.pop()
-          if (!parentID) continue
-
-          const children = byParent.get(parentID)
-          if (!children) continue
-
-          for (const child of children) {
-            if (removed.has(child)) continue
-            removed.add(child)
-            stack.push(child)
-          }
-        }
-
-        draft.session = draft.session.filter((s) => !removed.has(s.id))
-      }),
-    )
-
-    navigateAfterSessionRemoval(sessionID, session.parentID, nextSession?.id)
-    return true
-  }
-
-  const navigateParent = () => {
-    const id = parentID()
-    if (!id) return
-    navigate(`/${params.dir}/session/${id}`)
-  }
-
-  function DialogDeleteSession(props: { sessionID: string }) {
-    const name = createMemo(() => sync.session.get(props.sessionID)?.title ?? language.t("command.session.new"))
-    const handleDelete = async () => {
-      await deleteSession(props.sessionID)
-      dialog.close()
-    }
-
-    return (
-      <Dialog title={language.t("session.delete.title")} fit>
-        <div class="flex flex-col gap-4 pl-6 pr-2.5 pb-3">
-          <div class="flex flex-col gap-1">
-            <span class="text-14-regular text-text-strong">
-              {language.t("session.delete.confirm", { name: name() })}
-            </span>
-          </div>
-          <div class="flex justify-end gap-2">
-            <Button variant="ghost" size="large" onClick={() => dialog.close()}>
-              {language.t("common.cancel")}
-            </Button>
-            <Button variant="primary" size="large" onClick={handleDelete}>
-              {language.t("session.delete.button")}
-            </Button>
-          </div>
-        </div>
-      </Dialog>
-    )
-  }
+  const rendered = createMemo(() => staging.messages().map((message) => message.id))
 
   return (
     <Show
@@ -498,6 +336,16 @@ export function MessageTimeline(props: {
             <Icon name="arrow-down-to-line" />
           </button>
         </div>
+        <SessionTimelineHeader
+          centered={props.centered}
+          showHeader={showHeader}
+          sessionKey={sessionKey}
+          sessionID={sessionID}
+          parentID={parentID}
+          titleValue={titleValue}
+          headerTitle={headerTitle}
+          placeholderTitle={placeholderTitle}
+        />
         <ScrollView
           viewportRef={props.setScrollRef}
           onWheel={(e) => {
@@ -532,9 +380,18 @@ export function MessageTimeline(props: {
             touchGesture = undefined
           }}
           onPointerDown={(e) => {
+            const next = trigger(e.target)
+            if (next) props.onPreserveScrollAnchor(next)
+
             if (e.target !== e.currentTarget) return
             props.onMarkScrollGesture(e.currentTarget)
           }}
+          onKeyDown={(e) => {
+            if (e.key !== "Enter" && e.key !== " ") return
+            const next = trigger(e.target)
+            if (!next) return
+            props.onPreserveScrollAnchor(next)
+          }}
           onScroll={(e) => {
             props.onScheduleScrollState(e.currentTarget)
             props.onTurnBackfillScroll()
@@ -543,131 +400,21 @@ export function MessageTimeline(props: {
             props.onMarkScrollGesture(e.currentTarget)
             if (props.isDesktop) props.onScrollSpyScroll()
           }}
-          onClick={props.onAutoScrollInteraction}
+          onClick={(e) => {
+            props.onAutoScrollInteraction(e)
+          }}
           class="relative min-w-0 w-full h-full"
           style={{
-            "--session-title-height": showHeader() ? "40px" : "0px",
+            "--session-title-height": showHeader() ? "72px" : "0px",
             "--sticky-accordion-top": showHeader() ? "48px" : "0px",
           }}
         >
-          <div ref={props.setContentRef} class="min-w-0 w-full">
-            <Show when={showHeader()}>
-              <div
-                data-session-title
-                classList={{
-                  "sticky top-0 z-30 bg-[linear-gradient(to_bottom,var(--background-stronger)_48px,transparent)]": true,
-                  "w-full": true,
-                  "pb-4": true,
-                  "pl-2 pr-3 md:pl-4 md:pr-3": true,
-                  "md:max-w-200 md:mx-auto 2xl:max-w-[1000px]": props.centered,
-                }}
-              >
-                <div class="h-12 w-full flex items-center justify-between gap-2">
-                  <div class="flex items-center gap-1 min-w-0 flex-1 pr-3">
-                    <Show when={parentID()}>
-                      <IconButton
-                        tabIndex={-1}
-                        icon="arrow-left"
-                        variant="ghost"
-                        onClick={navigateParent}
-                        aria-label={language.t("common.goBack")}
-                      />
-                    </Show>
-                    <Show when={titleValue() || title.editing}>
-                      <Show
-                        when={title.editing}
-                        fallback={
-                          <h1
-                            class="text-14-medium text-text-strong truncate grow-1 min-w-0 pl-2"
-                            onDblClick={openTitleEditor}
-                          >
-                            {titleValue()}
-                          </h1>
-                        }
-                      >
-                        <InlineInput
-                          ref={(el) => {
-                            titleRef = el
-                          }}
-                          value={title.draft}
-                          disabled={title.saving}
-                          class="text-14-medium text-text-strong grow-1 min-w-0 pl-2 rounded-[6px]"
-                          style={{ "--inline-input-shadow": "var(--shadow-xs-border-select)" }}
-                          onInput={(event) => setTitle("draft", event.currentTarget.value)}
-                          onKeyDown={(event) => {
-                            event.stopPropagation()
-                            if (event.key === "Enter") {
-                              event.preventDefault()
-                              void saveTitleEditor()
-                              return
-                            }
-                            if (event.key === "Escape") {
-                              event.preventDefault()
-                              closeTitleEditor()
-                            }
-                          }}
-                          onBlur={closeTitleEditor}
-                        />
-                      </Show>
-                    </Show>
-                  </div>
-                  <Show when={sessionID()}>
-                    {(id) => (
-                      <div class="shrink-0 flex items-center gap-3">
-                        <SessionContextUsage placement="bottom" />
-                        <DropdownMenu
-                          gutter={4}
-                          placement="bottom-end"
-                          open={title.menuOpen}
-                          onOpenChange={(open) => setTitle("menuOpen", open)}
-                        >
-                          <DropdownMenu.Trigger
-                            as={IconButton}
-                            icon="dot-grid"
-                            variant="ghost"
-                            class="size-6 rounded-md data-[expanded]:bg-surface-base-active"
-                            aria-label={language.t("common.moreOptions")}
-                          />
-                          <DropdownMenu.Portal>
-                            <DropdownMenu.Content
-                              style={{ "min-width": "104px" }}
-                              onCloseAutoFocus={(event) => {
-                                if (!title.pendingRename) return
-                                event.preventDefault()
-                                setTitle("pendingRename", false)
-                                openTitleEditor()
-                              }}
-                            >
-                              <DropdownMenu.Item
-                                onSelect={() => {
-                                  setTitle("pendingRename", true)
-                                  setTitle("menuOpen", false)
-                                }}
-                              >
-                                <DropdownMenu.ItemLabel>{language.t("common.rename")}</DropdownMenu.ItemLabel>
-                              </DropdownMenu.Item>
-                              <DropdownMenu.Item onSelect={() => void archiveSession(id())}>
-                                <DropdownMenu.ItemLabel>{language.t("common.archive")}</DropdownMenu.ItemLabel>
-                              </DropdownMenu.Item>
-                              <DropdownMenu.Separator />
-                              <DropdownMenu.Item
-                                onSelect={() => dialog.show(() => <DialogDeleteSession sessionID={id()} />)}
-                              >
-                                <DropdownMenu.ItemLabel>{language.t("common.delete")}</DropdownMenu.ItemLabel>
-                              </DropdownMenu.Item>
-                            </DropdownMenu.Content>
-                          </DropdownMenu.Portal>
-                        </DropdownMenu>
-                      </div>
-                    )}
-                  </Show>
-                </div>
-              </div>
-            </Show>
-
+          <div>
             <div
+              ref={props.setContentRef}
               role="log"
-              class="flex flex-col gap-12 items-start justify-start pb-16 transition-[margin]"
+              class="flex flex-col gap-0 items-start justify-start pb-16 transition-[margin]"
+              style={{ "padding-top": "var(--session-title-height)" }}
               classList={{
                 "w-full": true,
                 "md:max-w-200 md:mx-auto 2xl:max-w-[1000px]": props.centered,
@@ -692,6 +439,15 @@ export function MessageTimeline(props: {
               </Show>
               <For each={rendered()}>
                 {(messageID) => {
+                  // Capture at creation time: animate only messages added after the
+                  // timeline finishes its initial backfill staging, plus the first
+                  // turn while a brand new session is still using its default title.
+                  const isNew =
+                    staging.ready() ||
+                    (defaultTitle() &&
+                      sessionStatus() !== "idle" &&
+                      props.renderedUserMessages.length === 1 &&
+                      messageID === props.renderedUserMessages[0]?.id)
                   const active = createMemo(() => activeMessageID() === messageID)
                   const queued = createMemo(() => {
                     if (active()) return false
@@ -700,7 +456,10 @@ export function MessageTimeline(props: {
                     return false
                   })
                   const comments = createMemo(() => messageComments(sync.data.part[messageID] ?? []), [], {
-                    equals: (a, b) => JSON.stringify(a) === JSON.stringify(b),
+                    equals: (a, b) => {
+                      if (a.length !== b.length) return false
+                      return a.every((x, i) => x.path === b[i].path && x.comment === b[i].comment)
+                    },
                   })
                   const commentCount = createMemo(() => comments().length)
                   return (
@@ -757,7 +516,7 @@ export function MessageTimeline(props: {
                         messageID={messageID}
                         active={active()}
                         queued={queued()}
-                        status={active() ? sessionStatus() : undefined}
+                        animate={isNew || active()}
                         showReasoningSummaries={settings.general.showReasoningSummaries()}
                         shellToolDefaultOpen={settings.general.shellToolPartsExpanded()}
                         editToolDefaultOpen={settings.general.editToolPartsExpanded()}
diff --git a/packages/app/src/pages/session/session-timeline-header.tsx b/packages/app/src/pages/session/session-timeline-header.tsx
new file mode 100644
index 000000000..fcddb38a4
--- /dev/null
+++ b/packages/app/src/pages/session/session-timeline-header.tsx
@@ -0,0 +1,522 @@
+import { createEffect, createMemo, on, onCleanup, Show } from "solid-js"
+import { createStore, produce } from "solid-js/store"
+import { useNavigate, useParams } from "@solidjs/router"
+import { Button } from "@opencode-ai/ui/button"
+import { IconButton } from "@opencode-ai/ui/icon-button"
+import { DropdownMenu } from "@opencode-ai/ui/dropdown-menu"
+import { Dialog } from "@opencode-ai/ui/dialog"
+import { prefersReducedMotion } from "@opencode-ai/ui/hooks"
+import { InlineInput } from "@opencode-ai/ui/inline-input"
+import { animate, type AnimationPlaybackControls, clearFadeStyles, FAST_SPRING } from "@opencode-ai/ui/motion"
+import { showToast } from "@opencode-ai/ui/toast"
+import { errorMessage } from "@/pages/layout/helpers"
+import { SessionContextUsage } from "@/components/session-context-usage"
+import { useDialog } from "@opencode-ai/ui/context/dialog"
+import { useLanguage } from "@/context/language"
+import { useSDK } from "@/context/sdk"
+import { useSync } from "@/context/sync"
+
+export function SessionTimelineHeader(props: {
+  centered: boolean
+  showHeader: () => boolean
+  sessionKey: () => string
+  sessionID: () => string | undefined
+  parentID: () => string | undefined
+  titleValue: () => string | undefined
+  headerTitle: () => string | undefined
+  placeholderTitle: () => boolean
+}) {
+  const navigate = useNavigate()
+  const params = useParams()
+  const sdk = useSDK()
+  const sync = useSync()
+  const dialog = useDialog()
+  const language = useLanguage()
+  const reduce = prefersReducedMotion
+
+  const [title, setTitle] = createStore({
+    draft: "",
+    editing: false,
+    saving: false,
+    menuOpen: false,
+    pendingRename: false,
+  })
+  const [headerText, setHeaderText] = createStore({
+    session: props.sessionKey(),
+    value: props.headerTitle(),
+    prev: undefined as string | undefined,
+    muted: props.placeholderTitle(),
+    prevMuted: false,
+  })
+  let headerAnim: AnimationPlaybackControls | undefined
+  let enterAnim: AnimationPlaybackControls | undefined
+  let leaveAnim: AnimationPlaybackControls | undefined
+  let titleRef: HTMLInputElement | undefined
+  let headerRef: HTMLDivElement | undefined
+  let enterRef: HTMLSpanElement | undefined
+  let leaveRef: HTMLSpanElement | undefined
+
+  const clearHeaderAnim = () => {
+    headerAnim?.stop()
+    headerAnim = undefined
+  }
+
+  const animateHeader = () => {
+    const el = headerRef
+    if (!el) return
+
+    clearHeaderAnim()
+    if (!headerText.muted || reduce()) {
+      el.style.opacity = "1"
+      return
+    }
+
+    headerAnim = animate(el, { opacity: [0, 1] }, { type: "spring", visualDuration: 1.0, bounce: 0 })
+    headerAnim.finished.then(() => {
+      if (headerRef !== el) return
+      clearFadeStyles(el)
+    })
+  }
+
+  const clearTitleAnims = () => {
+    enterAnim?.stop()
+    enterAnim = undefined
+    leaveAnim?.stop()
+    leaveAnim = undefined
+  }
+
+  const settleTitleEnter = () => {
+    if (enterRef) clearFadeStyles(enterRef)
+  }
+
+  const hideLeave = () => {
+    if (!leaveRef) return
+    leaveRef.style.opacity = "0"
+    leaveRef.style.filter = ""
+    leaveRef.style.transform = ""
+  }
+
+  const animateEnterSpan = () => {
+    if (!enterRef) return
+    if (reduce()) {
+      settleTitleEnter()
+      return
+    }
+    enterAnim = animate(
+      enterRef,
+      { opacity: [0, 1], filter: ["blur(2px)", "blur(0px)"], transform: ["translateY(-2px)", "translateY(0)"] },
+      FAST_SPRING,
+    )
+    enterAnim.finished.then(() => settleTitleEnter())
+  }
+
+  const crossfadeTitle = (nextTitle: string, nextMuted: boolean) => {
+    clearTitleAnims()
+    setHeaderText({ prev: headerText.value, prevMuted: headerText.muted })
+    setHeaderText({ value: nextTitle, muted: nextMuted })
+
+    if (reduce()) {
+      setHeaderText({ prev: undefined, prevMuted: false })
+      hideLeave()
+      settleTitleEnter()
+      return
+    }
+
+    if (leaveRef) {
+      leaveAnim = animate(
+        leaveRef,
+        { opacity: [1, 0], filter: ["blur(0px)", "blur(2px)"], transform: ["translateY(0)", "translateY(2px)"] },
+        FAST_SPRING,
+      )
+      leaveAnim.finished.then(() => {
+        setHeaderText({ prev: undefined, prevMuted: false })
+        hideLeave()
+      })
+    }
+
+    animateEnterSpan()
+  }
+
+  const fadeInTitle = (nextTitle: string, nextMuted: boolean) => {
+    clearTitleAnims()
+    setHeaderText({ value: nextTitle, muted: nextMuted, prev: undefined, prevMuted: false })
+    animateEnterSpan()
+  }
+
+  const snapTitle = (nextTitle: string | undefined, nextMuted: boolean) => {
+    clearTitleAnims()
+    setHeaderText({ value: nextTitle, muted: nextMuted, prev: undefined, prevMuted: false })
+    settleTitleEnter()
+  }
+
+  createEffect(
+    on(props.showHeader, (show, prev) => {
+      if (!show) {
+        clearHeaderAnim()
+        return
+      }
+      if (show === prev) return
+      animateHeader()
+    }),
+  )
+
+  createEffect(
+    on(
+      () => [props.sessionKey(), props.headerTitle(), props.placeholderTitle()] as const,
+      ([nextSession, nextTitle, nextMuted]) => {
+        if (nextSession !== headerText.session) {
+          setHeaderText("session", nextSession)
+          if (nextTitle && nextMuted) {
+            fadeInTitle(nextTitle, nextMuted)
+            return
+          }
+          snapTitle(nextTitle, nextMuted)
+          return
+        }
+        if (nextTitle === headerText.value && nextMuted === headerText.muted) return
+        if (!nextTitle) {
+          snapTitle(undefined, false)
+          return
+        }
+        if (!headerText.value) {
+          fadeInTitle(nextTitle, nextMuted)
+          return
+        }
+        if (title.saving || title.editing) {
+          snapTitle(nextTitle, nextMuted)
+          return
+        }
+        crossfadeTitle(nextTitle, nextMuted)
+      },
+    ),
+  )
+
+  onCleanup(() => {
+    clearHeaderAnim()
+    clearTitleAnims()
+  })
+
+  const toastError = (err: unknown) => errorMessage(err, language.t("common.requestFailed"))
+
+  createEffect(
+    on(
+      props.sessionKey,
+      () => setTitle({ draft: "", editing: false, saving: false, menuOpen: false, pendingRename: false }),
+      { defer: true },
+    ),
+  )
+
+  const openTitleEditor = () => {
+    if (!props.sessionID()) return
+    setTitle({ editing: true, draft: props.titleValue() ?? "" })
+    requestAnimationFrame(() => {
+      titleRef?.focus()
+      titleRef?.select()
+    })
+  }
+
+  const closeTitleEditor = () => {
+    if (title.saving) return
+    setTitle({ editing: false, saving: false })
+  }
+
+  const saveTitleEditor = async () => {
+    const id = props.sessionID()
+    if (!id) return
+    if (title.saving) return
+
+    const next = title.draft.trim()
+    if (!next || next === (props.titleValue() ?? "")) {
+      setTitle({ editing: false, saving: false })
+      return
+    }
+
+    setTitle("saving", true)
+    await sdk.client.session
+      .update({ sessionID: id, title: next })
+      .then(() => {
+        sync.set(
+          produce((draft) => {
+            const index = draft.session.findIndex((session) => session.id === id)
+            if (index !== -1) draft.session[index].title = next
+          }),
+        )
+        setTitle({ editing: false, saving: false })
+      })
+      .catch((err) => {
+        setTitle("saving", false)
+        showToast({
+          title: language.t("common.requestFailed"),
+          description: toastError(err),
+        })
+      })
+  }
+
+  const navigateAfterSessionRemoval = (sessionID: string, parentID?: string, nextSessionID?: string) => {
+    if (params.id !== sessionID) return
+    if (parentID) {
+      navigate(`/${params.dir}/session/${parentID}`)
+      return
+    }
+    if (nextSessionID) {
+      navigate(`/${params.dir}/session/${nextSessionID}`)
+      return
+    }
+    navigate(`/${params.dir}/session`)
+  }
+
+  const archiveSession = async (sessionID: string) => {
+    const session = sync.session.get(sessionID)
+    if (!session) return
+
+    const sessions = sync.data.session ?? []
+    const index = sessions.findIndex((item) => item.id === sessionID)
+    const nextSession = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
+
+    await sdk.client.session
+      .update({ sessionID, time: { archived: Date.now() } })
+      .then(() => {
+        sync.set(
+          produce((draft) => {
+            const index = draft.session.findIndex((item) => item.id === sessionID)
+            if (index !== -1) draft.session.splice(index, 1)
+          }),
+        )
+        navigateAfterSessionRemoval(sessionID, session.parentID, nextSession?.id)
+      })
+      .catch((err) => {
+        showToast({
+          title: language.t("common.requestFailed"),
+          description: toastError(err),
+        })
+      })
+  }
+
+  const deleteSession = async (sessionID: string) => {
+    const session = sync.session.get(sessionID)
+    if (!session) return false
+
+    const sessions = (sync.data.session ?? []).filter((item) => !item.parentID && !item.time?.archived)
+    const index = sessions.findIndex((item) => item.id === sessionID)
+    const nextSession = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
+
+    const result = await sdk.client.session
+      .delete({ sessionID })
+      .then((x) => x.data)
+      .catch((err) => {
+        showToast({
+          title: language.t("session.delete.failed.title"),
+          description: toastError(err),
+        })
+        return false
+      })
+
+    if (!result) return false
+
+    sync.set(
+      produce((draft) => {
+        const removed = new Set<string>([sessionID])
+        const byParent = new Map<string, string[]>()
+
+        for (const item of draft.session) {
+          const parentID = item.parentID
+          if (!parentID) continue
+
+          const existing = byParent.get(parentID)
+          if (existing) {
+            existing.push(item.id)
+            continue
+          }
+          byParent.set(parentID, [item.id])
+        }
+
+        const stack = [sessionID]
+        while (stack.length) {
+          const parentID = stack.pop()
+          if (!parentID) continue
+
+          const children = byParent.get(parentID)
+          if (!children) continue
+
+          for (const child of children) {
+            if (removed.has(child)) continue
+            removed.add(child)
+            stack.push(child)
+          }
+        }
+
+        draft.session = draft.session.filter((item) => !removed.has(item.id))
+      }),
+    )
+
+    navigateAfterSessionRemoval(sessionID, session.parentID, nextSession?.id)
+    return true
+  }
+
+  const navigateParent = () => {
+    const id = props.parentID()
+    if (!id) return
+    navigate(`/${params.dir}/session/${id}`)
+  }
+
+  function DialogDeleteSession(input: { sessionID: string }) {
+    const name = createMemo(() => sync.session.get(input.sessionID)?.title ?? language.t("command.session.new"))
+
+    const handleDelete = async () => {
+      await deleteSession(input.sessionID)
+      dialog.close()
+    }
+
+    return (
+      <Dialog title={language.t("session.delete.title")} fit>
+        <div class="flex flex-col gap-4 pl-6 pr-2.5 pb-3">
+          <div class="flex flex-col gap-1">
+            <span class="text-14-regular text-text-strong">
+              {language.t("session.delete.confirm", { name: name() })}
+            </span>
+          </div>
+          <div class="flex justify-end gap-2">
+            <Button variant="ghost" size="large" onClick={() => dialog.close()}>
+              {language.t("common.cancel")}
+            </Button>
+            <Button variant="primary" size="large" onClick={handleDelete}>
+              {language.t("session.delete.button")}
+            </Button>
+          </div>
+        </div>
+      </Dialog>
+    )
+  }
+
+  return (
+    <Show when={props.showHeader()}>
+      <div
+        data-session-title
+        ref={(el) => {
+          headerRef = el
+          el.style.opacity = "0"
+        }}
+        class="pointer-events-none absolute inset-x-0 top-0 z-30"
+      >
+        <div
+          classList={{
+            "bg-[linear-gradient(to_bottom,var(--background-stronger)_38px,transparent)]": true,
+            "w-full": true,
+            "pb-10": true,
+            "px-4 md:px-5": true,
+            "md:max-w-200 md:mx-auto 2xl:max-w-[1000px]": props.centered,
+          }}
+        >
+          <div class="pointer-events-auto h-12 w-full flex items-center justify-between gap-2">
+            <div class="flex items-center gap-1 min-w-0 flex-1">
+              <Show when={props.parentID()}>
+                <div>
+                  <IconButton
+                    tabIndex={-1}
+                    icon="arrow-left"
+                    variant="ghost"
+                    onClick={navigateParent}
+                    aria-label={language.t("common.goBack")}
+                  />
+                </div>
+              </Show>
+              <Show when={!!headerText.value || title.editing}>
+                <Show
+                  when={title.editing}
+                  fallback={
+                    <h1 class="text-14-medium text-text-strong grow-1 min-w-0" onDblClick={openTitleEditor}>
+                      <span class="grid min-w-0" style={{ overflow: "clip" }}>
+                        <span ref={enterRef} class="col-start-1 row-start-1 min-w-0 truncate">
+                          <span classList={{ "opacity-60": headerText.muted }}>{headerText.value}</span>
+                        </span>
+                        <span
+                          ref={leaveRef}
+                          class="col-start-1 row-start-1 min-w-0 truncate pointer-events-none"
+                          style={{ opacity: "0" }}
+                        >
+                          <span classList={{ "opacity-60": headerText.prevMuted }}>{headerText.prev}</span>
+                        </span>
+                      </span>
+                    </h1>
+                  }
+                >
+                  <InlineInput
+                    ref={(el) => {
+                      titleRef = el
+                    }}
+                    value={title.draft}
+                    disabled={title.saving}
+                    class="text-14-medium text-text-strong grow-1 min-w-0 rounded-[6px]"
+                    style={{ "--inline-input-shadow": "var(--shadow-xs-border-select)" }}
+                    onInput={(event) => setTitle("draft", event.currentTarget.value)}
+                    onKeyDown={(event) => {
+                      event.stopPropagation()
+                      if (event.key === "Enter") {
+                        event.preventDefault()
+                        void saveTitleEditor()
+                        return
+                      }
+                      if (event.key === "Escape") {
+                        event.preventDefault()
+                        closeTitleEditor()
+                      }
+                    }}
+                    onBlur={closeTitleEditor}
+                  />
+                </Show>
+              </Show>
+            </div>
+            <Show when={props.sessionID()}>
+              {(id) => (
+                <div class="shrink-0 flex items-center gap-3">
+                  <SessionContextUsage placement="bottom" />
+                  <DropdownMenu
+                    gutter={4}
+                    placement="bottom-end"
+                    open={title.menuOpen}
+                    onOpenChange={(open) => setTitle("menuOpen", open)}
+                  >
+                    <DropdownMenu.Trigger
+                      as={IconButton}
+                      icon="dot-grid"
+                      variant="ghost"
+                      class="size-6 rounded-md data-[expanded]:bg-surface-base-active"
+                      aria-label={language.t("common.moreOptions")}
+                    />
+                    <DropdownMenu.Portal>
+                      <DropdownMenu.Content
+                        style={{ "min-width": "104px" }}
+                        onCloseAutoFocus={(event) => {
+                          if (!title.pendingRename) return
+                          event.preventDefault()
+                          setTitle("pendingRename", false)
+                          openTitleEditor()
+                        }}
+                      >
+                        <DropdownMenu.Item
+                          onSelect={() => {
+                            setTitle("pendingRename", true)
+                            setTitle("menuOpen", false)
+                          }}
+                        >
+                          <DropdownMenu.ItemLabel>{language.t("common.rename")}</DropdownMenu.ItemLabel>
+                        </DropdownMenu.Item>
+                        <DropdownMenu.Item onSelect={() => void archiveSession(id())}>
+                          <DropdownMenu.ItemLabel>{language.t("common.archive")}</DropdownMenu.ItemLabel>
+                        </DropdownMenu.Item>
+                        <DropdownMenu.Separator />
+                        <DropdownMenu.Item onSelect={() => dialog.show(() => <DialogDeleteSession sessionID={id()} />)}>
+                          <DropdownMenu.ItemLabel>{language.t("common.delete")}</DropdownMenu.ItemLabel>
+                        </DropdownMenu.Item>
+                      </DropdownMenu.Content>
+                    </DropdownMenu.Portal>
+                  </DropdownMenu>
+                </div>
+              )}
+            </Show>
+          </div>
+        </div>
+      </div>
+    </Show>
+  )
+}
diff --git a/packages/app/src/pages/session/use-session-hash-scroll.ts b/packages/app/src/pages/session/use-session-hash-scroll.ts
index 20e88a3ea..278a1ba6e 100644
--- a/packages/app/src/pages/session/use-session-hash-scroll.ts
+++ b/packages/app/src/pages/session/use-session-hash-scroll.ts
@@ -1,6 +1,5 @@
 import type { UserMessage } from "@opencode-ai/sdk/v2"
-import { useLocation, useNavigate } from "@solidjs/router"
-import { createEffect, createMemo, onMount } from "solid-js"
+import { createEffect, createMemo, onCleanup, onMount } from "solid-js"
 import { messageIdFromHash } from "./message-id-from-hash"
 
 export { messageIdFromHash } from "./message-id-from-hash"
@@ -16,7 +15,7 @@ export const useSessionHashScroll = (input: {
   setPendingMessage: (value: string | undefined) => void
   setActiveMessage: (message: UserMessage | undefined) => void
   setTurnStart: (value: number) => void
-  autoScroll: { pause: () => void; forceScrollToBottom: () => void }
+  autoScroll: { pause: () => void; snapToBottom: () => void }
   scroller: () => HTMLDivElement | undefined
   anchor: (id: string) => string
   scheduleScrollState: (el: HTMLDivElement) => void
@@ -27,18 +26,13 @@ export const useSessionHashScroll = (input: {
   const messageIndex = createMemo(() => new Map(visibleUserMessages().map((m, i) => [m.id, i])))
   let pendingKey = ""
 
-  const location = useLocation()
-  const navigate = useNavigate()
-
   const clearMessageHash = () => {
-    if (!location.hash) return
-    navigate(location.pathname + location.search, { replace: true })
+    if (!window.location.hash) return
+    window.history.replaceState(null, "", window.location.pathname + window.location.search)
   }
 
   const updateHash = (id: string) => {
-    navigate(location.pathname + location.search + `#${input.anchor(id)}`, {
-      replace: true,
-    })
+    window.history.replaceState(null, "", `${window.location.pathname}${window.location.search}#${input.anchor(id)}`)
   }
 
   const scrollToElement = (el: HTMLElement, behavior: ScrollBehavior) => {
@@ -47,15 +41,15 @@ export const useSessionHashScroll = (input: {
 
     const a = el.getBoundingClientRect()
     const b = root.getBoundingClientRect()
-    const sticky = root.querySelector("[data-session-title]")
-    const inset = sticky instanceof HTMLElement ? sticky.offsetHeight : 0
-    const top = Math.max(0, a.top - b.top + root.scrollTop - inset)
+    const title = parseFloat(getComputedStyle(root).getPropertyValue("--session-title-height"))
+    const inset = Number.isNaN(title) ? 0 : title
+    // With column-reverse, scrollTop is negative — don't clamp to 0
+    const top = a.top - b.top + root.scrollTop - inset
     root.scrollTo({ top, behavior })
     return true
   }
 
   const scrollToMessage = (message: UserMessage, behavior: ScrollBehavior = "smooth") => {
-    console.log({ message, behavior })
     if (input.currentMessageId() !== message.id) input.setActiveMessage(message)
 
     const index = messageIndex().get(message.id) ?? -1
@@ -103,9 +97,9 @@ export const useSessionHashScroll = (input: {
   }
 
   const applyHash = (behavior: ScrollBehavior) => {
-    const hash = location.hash.slice(1)
+    const hash = window.location.hash.slice(1)
     if (!hash) {
-      input.autoScroll.forceScrollToBottom()
+      input.autoScroll.snapToBottom()
       const el = input.scroller()
       if (el) input.scheduleScrollState(el)
       return
@@ -129,13 +123,26 @@ export const useSessionHashScroll = (input: {
       return
     }
 
-    input.autoScroll.forceScrollToBottom()
+    input.autoScroll.snapToBottom()
     const el = input.scroller()
     if (el) input.scheduleScrollState(el)
   }
 
+  onMount(() => {
+    if (typeof window !== "undefined" && "scrollRestoration" in window.history) {
+      window.history.scrollRestoration = "manual"
+    }
+
+    const handler = () => {
+      if (!input.sessionID() || !input.messagesReady()) return
+      requestAnimationFrame(() => applyHash("auto"))
+    }
+
+    window.addEventListener("hashchange", handler)
+    onCleanup(() => window.removeEventListener("hashchange", handler))
+  })
+
   createEffect(() => {
-    location.hash
     if (!input.sessionID() || !input.messagesReady()) return
     requestAnimationFrame(() => applyHash("auto"))
   })
@@ -159,7 +166,6 @@ export const useSessionHashScroll = (input: {
       }
     }
 
-    if (!targetId) targetId = messageIdFromHash(location.hash)
     if (!targetId) return
     if (input.currentMessageId() === targetId) return
 
@@ -171,12 +177,6 @@ export const useSessionHashScroll = (input: {
     requestAnimationFrame(() => scrollToMessage(msg, "auto"))
   })
 
-  onMount(() => {
-    if (typeof window !== "undefined" && "scrollRestoration" in window.history) {
-      window.history.scrollRestoration = "manual"
-    }
-  })
-
   return {
     clearMessageHash,
     scrollToMessage,