fix(tui): allow navigation into grandchild sessions from subagent view

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -353,8 +353,9 @@ export function Session() {
   const local = useLocal()
 
   function moveFirstChild() {
-    if (children().length === 1) return
-    const next = children().find((x) => !!x.parentID)
+    const currentID = session()?.id
+    if (!currentID) return
+    const next = sync.data.session.find((s) => s.parentID === currentID)
     if (next) {
       navigate({
         type: "session",
@@ -364,9 +365,11 @@ export function Session() {
   }
 
   function moveChild(direction: number) {
-    if (children().length === 1) return
+    const currentParentID = session()?.parentID
+    if (!currentParentID) return
 
-    const sessions = children().filter((x) => !!x.parentID)
+    const sessions = children().filter((x) => x.parentID === currentParentID)
+    if (sessions.length <= 1) return
     let next = sessions.findIndex((x) => x.id === session()?.id) - direction
 
     if (next >= sessions.length) next = 0
@@ -959,11 +962,24 @@ export function Session() {
       keybind: "session_child_first",
       category: "Session",
       hidden: true,
+      enabled: !session()?.parentID,
       onSelect: (dialog) => {
         moveFirstChild()
         dialog.clear()
       },
     },
+    {
+      title: "Go to child session",
+      value: "session.child.first.subagent",
+      keybind: "session_child_first_subagent",
+      category: "Session",
+      hidden: true,
+      enabled: !!session()?.parentID,
+      onSelect: childSessionHandler((dialog) => {
+        moveFirstChild()
+        dialog.clear()
+      }),
+    },
     {
       title: "Go to parent session",
       value: "session.parent",

packages/opencode/src/cli/cmd/tui/routes/session/subagent-footer.tsx

@@ -17,18 +17,19 @@ export function SubagentFooter() {
 
   const subagentInfo = createMemo(() => {
     const s = session()
-    if (!s) return { label: "Subagent", index: 0, total: 0 }
+    if (!s) return { label: "Subagent", index: 0, total: 0, hasChildren: false }
     const agentMatch = s.title.match(/@(\w+) subagent/)
     const label = agentMatch ? Locale.titlecase(agentMatch[1]) : "Subagent"
 
-    if (!s.parentID) return { label, index: 0, total: 0 }
+    if (!s.parentID) return { label, index: 0, total: 0, hasChildren: false }
 
     const siblings = sync.data.session
       .filter((x) => x.parentID === s.parentID)
       .toSorted((a, b) => a.time.created - b.time.created)
     const index = siblings.findIndex((x) => x.id === s.id)
+    const hasChildren = sync.data.session.some((x) => x.parentID === s.id)
 
-    return { label, index: index + 1, total: siblings.length }
+    return { label, index: index + 1, total: siblings.length, hasChildren }
   })
 
   const usage = createMemo(() => {
@@ -58,8 +59,8 @@ export function SubagentFooter() {
   const { theme } = useTheme()
   const keybind = useKeybind()
   const command = useCommandDialog()
-  const [hover, setHover] = createSignal<"parent" | "prev" | "next" | null>(null)
-  useTerminalDimensions()
+  const [hover, setHover] = createSignal<"parent" | "prev" | "next" | "child" | null>(null)
+  const dimensions = useTerminalDimensions()
 
   return (
     <box flexShrink={0}>
@@ -123,6 +124,18 @@ export function SubagentFooter() {
                 Next <span style={{ fg: theme.textMuted }}>{keybind.print("session_child_cycle")}</span>
               </text>
             </box>
+            <Show when={subagentInfo().hasChildren}>
+              <box
+                onMouseOver={() => setHover("child")}
+                onMouseOut={() => setHover(null)}
+                onMouseUp={() => command.trigger("session.child.first.subagent")}
+                backgroundColor={hover() === "child" ? theme.backgroundElement : theme.backgroundPanel}
+              >
+                <text fg={theme.text}>
+                  Child <span style={{ fg: theme.textMuted }}>{keybind.print("session_child_first_subagent")}</span>
+                </text>
+              </box>
+            </Show>
           </box>
         </box>
       </box>

packages/opencode/src/config/keybinds.ts

@@ -104,6 +104,7 @@ const KeybindsSchema = Schema.Struct({
   history_previous: keybind("up", "Previous history item"),
   history_next: keybind("down", "Next history item"),
   session_child_first: keybind("<leader>down", "Go to first child session"),
+  session_child_first_subagent: keybind("down", "Go to first child session (from subagent)"),
   session_child_cycle: keybind("right", "Go to next child session"),
   session_child_cycle_reverse: keybind("left", "Go to previous child session"),
   session_parent: keybind("up", "Go to parent session"),