diff --git a/packages/ui/src/stores/session-api.ts b/packages/ui/src/stores/session-api.ts
index 4d00cee8..556d625c 100644
--- a/packages/ui/src/stores/session-api.ts
+++ b/packages/ui/src/stores/session-api.ts
@@ -8,9 +8,11 @@ import {
   activeSessionId,
   agents,
   clearSessionDraftPrompt,
+  getChildSessions,
+  isBlankSession,
   messagesLoaded,
-  providers,
   pruneDraftPrompts,
+  providers,
   setActiveSessionId,
   setAgents,
   setMessagesLoaded,
@@ -228,6 +230,10 @@ async function createSession(instanceId: string, agent?: string): Promise<Sessio
       return next
     })
 
+    getSessionIndex(instanceId, session.id)
+
+    await cleanupBlankSessions(instanceId, session.id)
+
     return session
   } catch (error) {
     console.error("Failed to create session:", error)
@@ -401,6 +407,27 @@ async function deleteSession(instanceId: string, sessionId: string): Promise<voi
   }
 }
 
+async function cleanupBlankSessions(instanceId: string, excludeSessionId?: string): Promise<void> {
+  const instanceSessions = sessions().get(instanceId)
+  if (!instanceSessions) return
+
+  const deletionPromises: Promise<void>[] = []
+
+  for (const [sessionId, session] of instanceSessions) {
+    if (sessionId === excludeSessionId) continue
+    if (!isBlankSession(session, instanceId)) continue
+
+    deletionPromises.push(deleteSession(instanceId, sessionId).catch((error) => {
+      console.error(`Failed to delete blank session ${sessionId}:`, error)
+    }))
+  }
+
+  if (deletionPromises.length > 0) {
+    console.log(`Cleaning up ${deletionPromises.length} blank sessions`)
+    await Promise.all(deletionPromises)
+  }
+}
+
 async function fetchAgents(instanceId: string): Promise<void> {
   const instance = instances().get(instanceId)
   if (!instance || !instance.client) {
diff --git a/packages/ui/src/stores/session-state.ts b/packages/ui/src/stores/session-state.ts
index e646cd64..3fbb9d28 100644
--- a/packages/ui/src/stores/session-state.ts
+++ b/packages/ui/src/stores/session-state.ts
@@ -221,6 +221,49 @@ function getSessionInfo(instanceId: string, sessionId: string): SessionInfo | un
   return sessionInfoByInstance().get(instanceId)?.get(sessionId)
 }
 
+function isBlankSession(session: Session, instanceId: string): boolean {
+  if (session.parentId === null) {
+    // Parent session is only blank if actually blank AND has no children
+
+    const sessionInfo = getSessionInfo(instanceId, session.id)
+    const hasChildren = getChildSessions(instanceId, session.id).length > 0
+    
+    // Only consider blank if we have loaded info, it shows 0 tokens, and no children
+    return sessionInfo !== undefined && sessionInfo.tokens === 0 && !hasChildren
+  } else if (session.title?.includes("subagent")) {
+    // Subagent
+
+    const loadedSet = messagesLoaded().get(instanceId) || new Set()
+    if (!loadedSet.has(session.id)) return false
+
+    if (session.messages.length === 0) return true
+
+    const hasStreamingMessage = session.messages.some((msg) => msg.status === "streaming")
+    const isWaitingForPermission = session.pendingPermission === true
+
+    // If streaming or waiting for permission, not blank
+    if (hasStreamingMessage || isWaitingForPermission) return false
+
+    // Check if last message was a tool call
+    const lastMessage = session.messages[session.messages.length - 1]
+    const lastMessageWasToolCall = lastMessage.parts.some((part) => part.type === "tool")
+
+    // Subagent is blank if last message was NOT a tool call
+    return !lastMessageWasToolCall
+  } else if (session.revert?.messageID) {
+    // Fork
+    const loadedSet = messagesLoaded().get(instanceId) || new Set()
+    if (!loadedSet.has(session.id)) return false
+
+    if (session.messages.length === 0) return true
+
+    const lastMessage = session.messages[session.messages.length - 1]
+    return lastMessage.id === session.revert.messageID
+  }
+
+  return false // default to not saying it's blank, just to be safe
+}
+
 export {
   sessions,
   setSessions,
@@ -259,4 +302,5 @@ export {
   isSessionBusy,
   isSessionMessagesLoading,
   getSessionInfo,
+  isBlankSession,
 }