feat(sidecars): add proxied sidecar tabs (#279)

## Summary
- add SideCar support across the server and UI, including proxied tabs,
picker/settings flows, and websocket-aware proxying
- unify top-level tab handling so workspace instances and SideCars share
the same tab model and navigation flows
- limit SideCars to port-based services only, removing server-managed
process control from the final API and UI

---------

Co-authored-by: Shantur <shantur@Mac.home>
Co-authored-by: Shantur <shantur@Shanturs-MacBook-Pro-M5.local>

packages/ui/src/components/folder-selection-view.tsx

@@ -27,6 +27,7 @@ type HomeTab = "local" | "servers"
 
 interface FolderSelectionViewProps {
   onSelectFolder: (folder: string, binaryPath?: string) => void
+  onOpenSidecar?: () => void
   isLoading?: boolean
   onClose?: () => void
 }
@@ -845,32 +846,43 @@ const FolderSelectionView: Component<FolderSelectionViewProps> = (props) => {
                 </div>
 
                 <div class="panel-body flex flex-col gap-3">
-                    <button
-                      onClick={() => void handleBrowse()}
-                      disabled={props.isLoading}
-                      class="button-primary w-full flex items-center justify-center text-sm disabled:cursor-not-allowed"
-                      onMouseEnter={() => setFocusMode("new")}
-                    >
-                      <div class="flex items-center gap-2">
-                        <FolderPlus class="w-4 h-4" />
-                        <span>
-                          {props.isLoading
-                            ? t("folderSelection.browse.buttonOpening")
-                            : t("folderSelection.browse.button")}
-                        </span>
-                      </div>
-                      <Kbd shortcut="cmd+n" class="ml-2 kbd-hint" />
-                    </button>
+                  <button
+                    onClick={() => void handleBrowse()}
+                    disabled={props.isLoading}
+                    class="button-primary w-full flex items-center justify-center text-sm disabled:cursor-not-allowed"
+                    onMouseEnter={() => setFocusMode("new")}
+                  >
+                    <div class="flex items-center gap-2">
+                      <FolderPlus class="w-4 h-4" />
+                      <span>
+                        {props.isLoading
+                          ? t("folderSelection.browse.buttonOpening")
+                          : t("folderSelection.browse.button")}
+                      </span>
+                    </div>
+                    <Kbd shortcut="cmd+n" class="ml-2 kbd-hint" />
+                  </button>
 
-                    <button
-                      onClick={openServerDialog}
-                      class="button-primary w-full flex items-center justify-center text-sm"
-                    >
-                      <div class="flex items-center gap-2">
-                        <Globe class="w-4 h-4" />
-                        <span>{t("folderSelection.actions.connectButton")}</span>
-                      </div>
-                    </button>
+                  <button
+                    type="button"
+                    onClick={() => props.onOpenSidecar?.()}
+                    class="button-primary mt-3 w-full flex items-center justify-center text-sm"
+                  >
+                    <div class="flex items-center gap-2">
+                      <MonitorUp class="w-4 h-4" />
+                      <span>{t("folderSelection.sidecars.button")}</span>
+                    </div>
+                  </button>
+
+                  <button
+                    onClick={openServerDialog}
+                    class="button-primary w-full flex items-center justify-center text-sm"
+                  >
+                    <div class="flex items-center gap-2">
+                      <Globe class="w-4 h-4" />
+                      <span>{t("folderSelection.actions.connectButton")}</span>
+                    </div>
+                  </button>
                 </div>
 
                 {/* OpenCode settings section */}

packages/ui/src/components/instance-tabs.tsx

@@ -1,6 +1,5 @@
 import { Component, For, Show, createMemo } from "solid-js"
 import { Dynamic } from "solid-js/web"
-import type { Instance } from "../types/instance"
 import InstanceTab from "./instance-tab"
 import KeyboardHint from "./keyboard-hint"
 import { Plus, MonitorUp, Bell, BellOff, Settings } from "lucide-solid"
@@ -9,12 +8,13 @@ import { useI18n } from "../lib/i18n"
 import { isOsNotificationSupportedSync } from "../lib/os-notifications"
 import { useConfig } from "../stores/preferences"
 import { openSettings } from "../stores/settings-screen"
+import type { AppTabRecord } from "../stores/app-tabs"
 
 interface InstanceTabsProps {
-  instances: Map<string, Instance>
-  activeInstanceId: string | null
-  onSelect: (instanceId: string) => void
-  onClose: (instanceId: string) => void
+  tabs: AppTabRecord[]
+  activeTabId: string | null
+  onSelect: (tabId: string) => void
+  onClose: (tabId: string) => void
   onNew: () => void
 }
 
@@ -42,15 +42,25 @@ const InstanceTabs: Component<InstanceTabsProps> = (props) => {
         <div class="tab-scroll">
           <div class="tab-strip">
             <div class="tab-strip-tabs">
-              <For each={Array.from(props.instances.entries())}>
-                {([id, instance]) => (
-                  <InstanceTab
-                    instance={instance}
-                    active={id === props.activeInstanceId}
-                    onSelect={() => props.onSelect(id)}
-                    onClose={() => props.onClose(id)}
-                  />
-                )}
+              <For each={props.tabs}>
+                {(tab) =>
+                  tab.kind === "instance" ? (
+                    <InstanceTab
+                      instance={tab.instance}
+                      active={tab.id === props.activeTabId}
+                      onSelect={() => props.onSelect(tab.id)}
+                      onClose={() => props.onClose(tab.id)}
+                    />
+                  ) : (
+                    <div class={`tab-pill ${tab.id === props.activeTabId ? "tab-pill-active" : ""}`}>
+                      <button class="tab-pill-button" onClick={() => props.onSelect(tab.id)}>
+                        <span class="truncate max-w-[180px]">{tab.sidecarTab.name}</span>
+                      </button>
+                      <button class="tab-pill-close" onClick={() => props.onClose(tab.id)} aria-label={tab.sidecarTab.name}>
+                        ×
+                      </button>
+                    </div>
+                  )}
               </For>
               <button
                 class="new-tab-button"
@@ -62,7 +72,7 @@ const InstanceTabs: Component<InstanceTabsProps> = (props) => {
               </button>
             </div>
             <div class="tab-strip-spacer" />
-            <Show when={Array.from(props.instances.entries()).length > 1}>
+            <Show when={props.tabs.length > 1}>
               <div class="tab-shortcuts">
                 <KeyboardHint
                   shortcuts={[keyboardRegistry.get("instance-prev")!, keyboardRegistry.get("instance-next")!].filter(

packages/ui/src/components/message-block.tsx

@@ -9,7 +9,7 @@ import type { MessageRecord } from "../stores/message-v2/types"
 import { messageStoreBus } from "../stores/message-v2/bus"
 import { formatTokenTotal } from "../lib/formatters"
 import { sessions, setActiveParentSession, setActiveSession } from "../stores/sessions"
-import { setActiveInstanceId } from "../stores/instances"
+import { selectInstanceTab } from "../stores/app-tabs"
 import { showAlertDialog } from "../stores/alerts"
 import { deleteMessage } from "../stores/session-actions"
 import { useI18n } from "../lib/i18n"
@@ -130,7 +130,7 @@ function findTaskSessionLocation(sessionId: string, preferredInstanceId?: string
 }
 
 function navigateToTaskSession(location: TaskSessionLocation) {
-  setActiveInstanceId(location.instanceId)
+  selectInstanceTab(location.instanceId)
   const parentToActivate = location.parentId ?? location.sessionId
   setActiveParentSession(location.instanceId, parentToActivate)
   if (location.parentId) {

packages/ui/src/components/settings-screen.tsx

@@ -1,5 +1,5 @@
 import { Dialog } from "@kobalte/core/dialog"
-import { Settings, Bell, MonitorUp, Paintbrush, Terminal, Volume2, X } from "lucide-solid"
+import { Settings, Bell, MonitorUp, Paintbrush, Terminal, Volume2, Globe, X } from "lucide-solid"
 import { createMemo, For, type Component } from "solid-js"
 import { useI18n } from "../lib/i18n"
 import {
@@ -14,6 +14,7 @@ import { NotificationsSettingsSection } from "./settings/notifications-settings-
 import { OpenCodeSettingsSection } from "./settings/opencode-settings-section"
 import { RemoteAccessSettingsSection } from "./settings/remote-access-settings-section"
 import { SpeechSettingsSection } from "./settings/speech-settings-section"
+import { SideCarsSettingsSection } from "./settings/sidecars-settings-section"
 
 export const SettingsScreen: Component = () => {
   const { t } = useI18n()
@@ -23,6 +24,7 @@ export const SettingsScreen: Component = () => {
     { id: "notifications" as SettingsSectionId, icon: Bell, label: t("settings.nav.notifications") },
     { id: "remote" as SettingsSectionId, icon: MonitorUp, label: t("settings.nav.remote") },
     { id: "speech" as SettingsSectionId, icon: Volume2, label: t("settings.nav.speech") },
+    { id: "sidecars" as SettingsSectionId, icon: Globe, label: t("settings.nav.sidecars") },
     { id: "opencode" as SettingsSectionId, icon: Terminal, label: t("settings.nav.opencode") },
   ])
 
@@ -34,6 +36,8 @@ export const SettingsScreen: Component = () => {
         return <RemoteAccessSettingsSection />
       case "speech":
         return <SpeechSettingsSection />
+      case "sidecars":
+        return <SideCarsSettingsSection />
       case "opencode":
         return <OpenCodeSettingsSection />
       case "appearance":

packages/ui/src/components/settings/sidecars-settings-section.tsx

@@ -0,0 +1,201 @@
+import { createMemo, createSignal, For, Show, onMount, type Component } from "solid-js"
+import { Globe, Loader2, Plus, Trash2 } from "lucide-solid"
+import { useI18n } from "../../lib/i18n"
+import { serverApi } from "../../lib/api-client"
+import { ensureSidecarsLoaded, sidecars, sidecarsLoading } from "../../stores/sidecars"
+
+function deriveSidecarId(value: string): string {
+  return value
+    .trim()
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, "-")
+    .replace(/-{2,}/g, "-")
+    .replace(/^-|-$/g, "")
+}
+
+export const SideCarsSettingsSection: Component = () => {
+  const { t } = useI18n()
+  const [name, setName] = createSignal("")
+  const [port, setPort] = createSignal("3000")
+  const [insecure, setInsecure] = createSignal(false)
+  const [prefixMode, setPrefixMode] = createSignal<"strip" | "preserve">("strip")
+  const [busyId, setBusyId] = createSignal<string | null>(null)
+  const [creating, setCreating] = createSignal(false)
+  const [formError, setFormError] = createSignal<string | null>(null)
+  const [actionError, setActionError] = createSignal<string | null>(null)
+
+  onMount(() => {
+    void ensureSidecarsLoaded()
+  })
+
+  const orderedSidecars = createMemo(() => Array.from(sidecars().values()).sort((a, b) => a.name.localeCompare(b.name)))
+  const derivedId = createMemo(() => deriveSidecarId(name()) || "your-sidecar")
+
+  async function handleCreate() {
+    const trimmedName = name().trim()
+    const nextPort = Number(port())
+    if (!trimmedName || !Number.isInteger(nextPort) || nextPort <= 0 || nextPort > 65535) {
+      setFormError(t("sidecars.form.validation"))
+      return
+    }
+
+    setCreating(true)
+    setFormError(null)
+    try {
+      await serverApi.createSidecar({
+        kind: "port",
+        name: trimmedName,
+        port: nextPort,
+        insecure: insecure(),
+        prefixMode: prefixMode(),
+      })
+      setName("")
+      setPort("3000")
+      setInsecure(false)
+      setPrefixMode("strip")
+    } catch (error) {
+      setFormError(error instanceof Error ? error.message : String(error))
+    } finally {
+      setCreating(false)
+    }
+  }
+
+  async function handleDelete(id: string) {
+    setBusyId(id)
+    setActionError(null)
+    try {
+      await serverApi.deleteSidecar(id)
+    } catch (error) {
+      setActionError(error instanceof Error ? error.message : String(error))
+    } finally {
+      setBusyId(null)
+    }
+  }
+
+  return (
+    <div class="settings-section-stack">
+      <div class="settings-card">
+        <div class="settings-card-header">
+          <div class="settings-card-heading-with-icon">
+            <Globe class="settings-card-heading-icon" />
+            <div>
+              <h3 class="settings-card-title">{t("settings.section.sidecars.title")}</h3>
+              <p class="settings-card-subtitle">{t("settings.section.sidecars.subtitle")}</p>
+            </div>
+          </div>
+          <span class="settings-scope-badge settings-scope-badge-server">{t("settings.scope.server")}</span>
+        </div>
+
+        <div class="settings-card-content">
+          <div class="settings-toggle-row settings-toggle-row-compact">
+            <div>
+              <div class="settings-toggle-title">{t("sidecars.form.name")}</div>
+              <div class="settings-toggle-caption">{t("sidecars.basePath")}: <code>/sidecars/{derivedId()}</code></div>
+            </div>
+            <input
+              class="selector-input w-full max-w-xs"
+              value={name()}
+              onInput={(event) => {
+                setFormError(null)
+                setName(event.currentTarget.value)
+              }}
+            />
+          </div>
+
+          <div class="settings-toggle-row settings-toggle-row-compact">
+            <div>
+              <div class="settings-toggle-title">{t("sidecars.form.port")}</div>
+              <div class="settings-toggle-caption">127.0.0.1</div>
+            </div>
+            <input
+              class="selector-input w-full max-w-xs"
+              value={port()}
+              onInput={(event) => {
+                setFormError(null)
+                setPort(event.currentTarget.value)
+              }}
+              inputMode="numeric"
+            />
+          </div>
+
+          <div class="settings-toggle-row settings-toggle-row-compact">
+            <div>
+              <div class="settings-toggle-title">{t("sidecars.form.protocol")}</div>
+              <div class="settings-toggle-caption">{t("sidecars.form.protocol.help")}</div>
+            </div>
+            <select class="selector-input w-full max-w-xs" value={insecure() ? "http" : "https"} onChange={(event) => setInsecure(event.currentTarget.value === "http") }>
+              <option value="https">{t("sidecars.form.protocol.https")}</option>
+              <option value="http">{t("sidecars.form.protocol.http")}</option>
+            </select>
+          </div>
+
+          <div class="settings-toggle-row settings-toggle-row-compact">
+            <div>
+              <div class="settings-toggle-title">{t("sidecars.form.prefixMode")}</div>
+              <div class="settings-toggle-caption">{t("sidecars.form.prefixMode.help")}</div>
+            </div>
+            <select class="selector-input w-full max-w-xs" value={prefixMode()} onChange={(event) => setPrefixMode(event.currentTarget.value as "strip" | "preserve") }>
+              <option value="strip">{t("sidecars.form.prefixMode.strip")}</option>
+              <option value="preserve">{t("sidecars.form.prefixMode.preserve")}</option>
+            </select>
+          </div>
+
+          <Show when={formError()}>
+            <div class="text-sm text-red-500">{formError()}</div>
+          </Show>
+
+          <div class="flex justify-end">
+            <button type="button" class="selector-button selector-button-primary" disabled={creating()} onClick={() => void handleCreate()}>
+              <Show when={creating()} fallback={<Plus class="w-4 h-4" />}>
+                <Loader2 class="w-4 h-4 animate-spin" />
+              </Show>
+              <span>{t("sidecars.form.add")}</span>
+            </button>
+          </div>
+        </div>
+      </div>
+
+      <div class="settings-card">
+        <div class="settings-card-header">
+          <div>
+            <h3 class="settings-card-title">{t("sidecars.settings.listTitle")}</h3>
+            <p class="settings-card-subtitle">{t("sidecars.settings.listSubtitle")}</p>
+          </div>
+        </div>
+
+        <div class="settings-card-content">
+          <Show when={actionError()}>
+            <div class="text-sm text-red-500">{actionError()}</div>
+          </Show>
+
+          <Show when={!sidecarsLoading()} fallback={<div class="settings-card-message">{t("sidecars.picker.loading")}</div>}>
+            <Show when={orderedSidecars().length > 0} fallback={<div class="settings-card-message">{t("sidecars.settings.empty")}</div>}>
+              <For each={orderedSidecars()}>
+                {(sidecar) => (
+                  <div class="settings-toggle-row settings-toggle-row-compact">
+                    <div>
+                      <div class="settings-toggle-title">{sidecar.name}</div>
+                      <div class="settings-toggle-caption">
+                        {t("sidecars.kind.port")} · {sidecar.insecure ? "http" : "https"}://127.0.0.1:{sidecar.port}
+                      </div>
+                      <div class="settings-toggle-caption">
+                        {t("sidecars.basePath")}: <code>/sidecars/{sidecar.id}</code> · {t(`sidecars.form.prefixMode.${sidecar.prefixMode}`)}
+                      </div>
+                    </div>
+
+                    <div class="flex items-center gap-2">
+                      <span class="text-xs text-secondary min-w-[4.5rem] text-right">{t(`sidecars.status.${sidecar.status}`)}</span>
+                      <button type="button" class="selector-button selector-button-secondary" disabled={busyId() === sidecar.id} onClick={() => void handleDelete(sidecar.id)}>
+                        <Trash2 class="w-4 h-4" />
+                      </button>
+                    </div>
+                  </div>
+                )}
+              </For>
+            </Show>
+          </Show>
+        </div>
+      </div>
+    </div>
+  )
+}

packages/ui/src/components/sidecar-picker-dialog.tsx

@@ -0,0 +1,82 @@
+import { Dialog } from "@kobalte/core/dialog"
+import { For, Show, createEffect, createMemo, type Component } from "solid-js"
+import { Globe, Square } from "lucide-solid"
+import { useI18n } from "../lib/i18n"
+import { ensureSidecarsLoaded, sidecars, sidecarsLoading } from "../stores/sidecars"
+
+interface SideCarPickerDialogProps {
+  open: boolean
+  onClose: () => void
+  onOpenSidecar: (sidecarId: string) => void | Promise<void>
+}
+
+export const SideCarPickerDialog: Component<SideCarPickerDialogProps> = (props) => {
+  const { t } = useI18n()
+  const orderedSidecars = createMemo(() => Array.from(sidecars().values()).sort((a, b) => a.name.localeCompare(b.name)))
+
+  createEffect(() => {
+    if (props.open) {
+      void ensureSidecarsLoaded()
+    }
+  })
+
+  return (
+    <Dialog open={props.open} onOpenChange={(open) => !open && props.onClose()}>
+      <Dialog.Portal>
+        <Dialog.Overlay class="modal-overlay" />
+        <div class="fixed inset-0 z-50 flex items-center justify-center p-4">
+          <Dialog.Content class="modal-surface w-full max-w-2xl p-6 flex flex-col gap-4 max-h-[80vh] overflow-hidden">
+            <div>
+              <Dialog.Title class="text-xl font-semibold text-primary">{t("sidecars.picker.title")}</Dialog.Title>
+              <Dialog.Description class="text-sm text-secondary mt-2">
+                {t("sidecars.picker.subtitle")}
+              </Dialog.Description>
+            </div>
+
+            <div class="flex-1 overflow-auto flex flex-col gap-3">
+              <Show when={!sidecarsLoading()} fallback={<div class="panel panel-empty-state">{t("sidecars.picker.loading")}</div>}>
+                <Show when={orderedSidecars().length > 0} fallback={<div class="panel panel-empty-state">{t("sidecars.picker.empty")}</div>}>
+                  <For each={orderedSidecars()}>
+                    {(sidecar) => (
+                      <button
+                        type="button"
+                        class="panel-list-item panel-list-item-content text-left disabled:cursor-not-allowed disabled:opacity-60"
+                        disabled={sidecar.status !== "running"}
+                        onClick={() => void props.onOpenSidecar(sidecar.id)}
+                      >
+                        <div class="flex items-center justify-between gap-4 w-full">
+                          <div class="flex items-center gap-3 min-w-0">
+                            <span class="panel-empty-state-icon !w-10 !h-10">
+                              <Globe class="w-5 h-5" />
+                            </span>
+                            <div class="min-w-0">
+                              <div class="text-sm font-medium text-primary truncate">{sidecar.name}</div>
+                              <div class="text-xs text-muted">
+                                {t("sidecars.kind.port")} - {sidecar.insecure ? "http" : "https"}://127.0.0.1:{sidecar.port}
+                              </div>
+                              <div class="text-xs text-muted mt-1">{t("sidecars.basePath")}: <code>/sidecars/{sidecar.id}</code></div>
+                            </div>
+                          </div>
+                          <div class="text-xs text-secondary flex items-center gap-2">
+                            <Square class="w-4 h-4" />
+                            <span>{t(`sidecars.status.${sidecar.status}`)}</span>
+                          </div>
+                        </div>
+                      </button>
+                    )}
+                  </For>
+                </Show>
+              </Show>
+            </div>
+
+            <div class="flex justify-end">
+              <button type="button" class="selector-button selector-button-secondary" onClick={props.onClose}>
+                {t("sidecars.picker.close")}
+              </button>
+            </div>
+          </Dialog.Content>
+        </div>
+      </Dialog.Portal>
+    </Dialog>
+  )
+}

packages/ui/src/components/sidecar-view.tsx

@@ -0,0 +1,197 @@
+import { ArrowLeft, ArrowRight, RefreshCw } from "lucide-solid"
+import { createEffect, createMemo, createSignal, type Component } from "solid-js"
+import type { SideCarTabRecord } from "../stores/sidecars"
+import { useI18n } from "../lib/i18n"
+
+interface SideCarViewProps {
+  tab: SideCarTabRecord
+}
+
+export const SideCarView: Component<SideCarViewProps> = (props) => {
+  const { t } = useI18n()
+  const [frameSrc, setFrameSrc] = createSignal(props.tab.shellUrl)
+  const [pathInput, setPathInput] = createSignal("/")
+  let iframeRef: HTMLIFrameElement | undefined
+
+  const lockedBaseLabel = createMemo(() => {
+    const hostLabel = props.tab.port ? `${props.tab.name}:${props.tab.port}` : props.tab.name
+    if (props.tab.prefixMode === "preserve") {
+      return `${hostLabel}${props.tab.proxyBasePath}`
+    }
+    return hostLabel
+  })
+
+  const getEditablePathFromUrl = (url: string): string => {
+    try {
+      const parsed = new URL(url, window.location.origin)
+      const basePath = props.tab.proxyBasePath
+      let pathname = parsed.pathname
+
+      if (basePath && pathname.startsWith(basePath)) {
+        pathname = pathname.slice(basePath.length) || "/"
+      }
+
+      if (!pathname.startsWith("/")) {
+        pathname = `/${pathname}`
+      }
+
+      return `${pathname}${parsed.search}${parsed.hash}`
+    } catch {
+      return "/"
+    }
+  }
+
+  const buildNormalizedTargetUrl = (rawInput: string): string => {
+    const trimmed = rawInput.trim()
+    const withLeadingSlash = trimmed.startsWith("/") ? trimmed : `/${trimmed}`
+    const parsed = new URL(withLeadingSlash || "/", window.location.origin)
+
+    const safeSegments: string[] = []
+    for (const segment of parsed.pathname.split("/")) {
+      if (!segment || segment === ".") {
+        continue
+      }
+      if (segment === "..") {
+        if (safeSegments.length > 0) {
+          safeSegments.pop()
+        }
+        continue
+      }
+      safeSegments.push(segment)
+    }
+
+    const normalizedPath = `/${safeSegments.join("/")}` || "/"
+    const basePath = props.tab.proxyBasePath
+    return `${basePath}${normalizedPath}${parsed.search}${parsed.hash}`
+  }
+
+  const syncPathInputFromFrame = () => {
+    try {
+      const currentHref = iframeRef?.contentWindow?.location.href
+      if (!currentHref) {
+        return
+      }
+      setPathInput(getEditablePathFromUrl(currentHref))
+    } catch {
+      setPathInput(getEditablePathFromUrl(frameSrc()))
+    }
+  }
+
+  createEffect(() => {
+    setFrameSrc(props.tab.shellUrl)
+    setPathInput(getEditablePathFromUrl(props.tab.shellUrl))
+  })
+
+  const handleBack = (event: MouseEvent) => {
+    event.preventDefault()
+    event.stopPropagation()
+
+    try {
+      const frameWindow = iframeRef?.contentWindow
+      if (!frameWindow) {
+        return
+      }
+
+      if (frameWindow.history.length <= 1) {
+        return
+      }
+
+      frameWindow.focus()
+      frameWindow.history.go(-1)
+    } catch {
+      // Ignore navigation errors from pages that do not expose history access.
+    }
+  }
+
+  const handleRefresh = () => {
+    try {
+      iframeRef?.contentWindow?.location.reload()
+      return
+    } catch {
+      // Fall back to resetting the iframe source if the frame cannot be reloaded directly.
+    }
+
+    setFrameSrc("about:blank")
+    requestAnimationFrame(() => setFrameSrc(props.tab.shellUrl))
+  }
+
+  const handleGo = (event?: Event) => {
+    event?.preventDefault()
+
+    const nextUrl = buildNormalizedTargetUrl(pathInput())
+    setFrameSrc(nextUrl)
+    setPathInput(getEditablePathFromUrl(nextUrl))
+  }
+
+  return (
+    <div class="flex h-full min-h-0 w-full flex-col bg-surface">
+      <div
+        class="flex shrink-0 items-center gap-2 px-3 py-2"
+        style={{ "border-bottom": "1px solid var(--border-base)" }}
+      >
+        <button
+          type="button"
+          class="new-tab-button"
+          onClick={handleBack}
+          title={t("sidecars.back")}
+          aria-label={t("sidecars.back")}
+        >
+          <ArrowLeft class="h-4 w-4" />
+        </button>
+        <button
+          type="button"
+          class="new-tab-button"
+          onClick={handleRefresh}
+          title={t("sidecars.refresh")}
+          aria-label={t("sidecars.refresh")}
+        >
+          <RefreshCw class="h-4 w-4" />
+        </button>
+        <div
+          class="shrink-0 rounded-md px-3 py-1.5 text-sm"
+          style={{
+            background: "var(--surface-secondary)",
+            color: "var(--text-secondary)",
+            border: "1px solid var(--border-base)",
+          }}
+        >
+          {lockedBaseLabel()}
+        </div>
+        <form class="flex min-w-0 flex-1 items-center gap-2" onSubmit={(event) => handleGo(event)}>
+          <input
+            type="text"
+            class="min-w-0 flex-1 rounded-md px-3 py-1.5 text-sm outline-none"
+            style={{
+              background: "var(--surface-secondary)",
+              color: "var(--text-primary)",
+              border: "1px solid var(--border-base)",
+            }}
+            value={pathInput()}
+            onInput={(event) => setPathInput(event.currentTarget.value)}
+            spellcheck={false}
+            autocomplete="off"
+            autocorrect="off"
+            autocapitalize="off"
+            aria-label={t("sidecars.path")}
+          />
+          <button
+            type="submit"
+            class="new-tab-button"
+            title={t("sidecars.go")}
+            aria-label={t("sidecars.go")}
+          >
+            <ArrowRight class="h-4 w-4" />
+          </button>
+        </form>
+      </div>
+      <iframe
+        ref={iframeRef}
+        src={frameSrc()}
+        title={props.tab.name}
+        class="min-h-0 flex-1 w-full border-0 bg-surface"
+        referrerPolicy="same-origin"
+        onLoad={syncPathInputFromFrame}
+      />
+    </div>
+  )
+}