diff --git a/src/features/background-agent/manager.ts b/src/features/background-agent/manager.ts
index f64065491..545cb329a 100644
--- a/src/features/background-agent/manager.ts
+++ b/src/features/background-agent/manager.ts
@@ -44,6 +44,8 @@ import { tryFallbackRetry } from "./fallback-retry-handler"
 import { registerManagerForCleanup, unregisterManagerForCleanup } from "./process-cleanup"
 import { isCompactionAgent, findNearestMessageExcludingCompaction } from "./compaction-aware-message-resolver"
 import { handleSessionIdleBackgroundEvent } from "./session-idle-event-handler"
+import { sendPostCompactionContinuation } from "./post-compaction-continuation"
+import { COUNCIL_MEMBER_KEY_PREFIX } from "../../agents/builtin-agents/council-member-agents"
 import { MESSAGE_STORAGE } from "../hook-message-injector"
 import { join } from "node:path"
 import { pruneStaleTasksAndNotifications } from "./task-poller"
@@ -766,6 +768,11 @@ export class BackgroundManager {
         findBySession: (id) => this.findBySession(id),
         idleDeferralTimers: this.idleDeferralTimers,
         recentlyCompactedSessions: this.recentlyCompactedSessions,
+        onPostCompactionIdle: (t, sid) => {
+          if (t.agent?.startsWith(COUNCIL_MEMBER_KEY_PREFIX)) {
+            sendPostCompactionContinuation(this.client, t, sid)
+          }
+        },
         validateSessionHasOutput: (id) => this.validateSessionHasOutput(id),
         checkSessionTodos: (id) => this.checkSessionTodos(id),
         tryCompleteTask: (task, source) => this.tryCompleteTask(task, source),
@@ -1494,6 +1501,12 @@ Use \`background_output(task_id="${task.id}")\` to retrieve this result when rea
             continue
           }
 
+          // Refresh lastUpdate so the next poll's stale check doesn't kill
+          // the task while we're awaiting async validation
+          if (task.progress) {
+            task.progress.lastUpdate = new Date()
+          }
+
           // Edge guard: Validate session has actual output before completing
           const hasValidOutput = await this.validateSessionHasOutput(sessionID)
           if (!hasValidOutput) {
diff --git a/src/features/background-agent/post-compaction-continuation.ts b/src/features/background-agent/post-compaction-continuation.ts
new file mode 100644
index 000000000..934fd23a5
--- /dev/null
+++ b/src/features/background-agent/post-compaction-continuation.ts
@@ -0,0 +1,55 @@
+import type { PluginInput } from "@opencode-ai/plugin"
+import type { BackgroundTask } from "./types"
+import {
+  log,
+  getAgentToolRestrictions,
+  createInternalAgentTextPart,
+} from "../../shared"
+import { setSessionTools } from "../../shared/session-tools-store"
+
+type OpencodeClient = PluginInput["client"]
+
+const CONTINUATION_PROMPT =
+  "Your session was compacted (context summarized). Continue your analysis from where you left off. Report your findings when done."
+
+export function sendPostCompactionContinuation(
+  client: OpencodeClient,
+  task: BackgroundTask,
+  sessionID: string,
+): void {
+  if (task.status !== "running") return
+
+  const resumeModel = task.model
+    ? { providerID: task.model.providerID, modelID: task.model.modelID }
+    : undefined
+  const resumeVariant = task.model?.variant
+
+  client.session.promptAsync({
+    path: { id: sessionID },
+    body: {
+      agent: task.agent,
+      ...(resumeModel ? { model: resumeModel } : {}),
+      ...(resumeVariant ? { variant: resumeVariant } : {}),
+      tools: (() => {
+        const tools = {
+          task: false,
+          call_omo_agent: true,
+          question: false,
+          ...getAgentToolRestrictions(task.agent),
+        }
+        setSessionTools(sessionID, tools)
+        return tools
+      })(),
+      parts: [createInternalAgentTextPart(CONTINUATION_PROMPT)],
+    },
+  }).catch((error) => {
+    log("[background-agent] Post-compaction continuation error:", {
+      taskId: task.id,
+      error: String(error),
+    })
+  })
+
+  if (task.progress) {
+    task.progress.lastUpdate = new Date()
+  }
+}
diff --git a/src/features/background-agent/session-idle-event-handler.ts b/src/features/background-agent/session-idle-event-handler.ts
index a5b1c087a..70c0e6530 100644
--- a/src/features/background-agent/session-idle-event-handler.ts
+++ b/src/features/background-agent/session-idle-event-handler.ts
@@ -12,6 +12,7 @@ export function handleSessionIdleBackgroundEvent(args: {
   findBySession: (sessionID: string) => BackgroundTask | undefined
   idleDeferralTimers: Map<string, ReturnType<typeof setTimeout>>
   recentlyCompactedSessions?: Set<string>
+  onPostCompactionIdle?: (task: BackgroundTask, sessionID: string) => void
   validateSessionHasOutput: (sessionID: string) => Promise<boolean>
   checkSessionTodos: (sessionID: string) => Promise<boolean>
   tryCompleteTask: (task: BackgroundTask, source: string) => Promise<boolean>
@@ -22,6 +23,7 @@ export function handleSessionIdleBackgroundEvent(args: {
     findBySession,
     idleDeferralTimers,
     recentlyCompactedSessions,
+    onPostCompactionIdle,
     validateSessionHasOutput,
     checkSessionTodos,
     tryCompleteTask,
@@ -37,6 +39,7 @@ export function handleSessionIdleBackgroundEvent(args: {
   if (recentlyCompactedSessions?.has(sessionID)) {
     recentlyCompactedSessions.delete(sessionID)
     log("[background-agent] Skipping post-compaction session.idle:", { taskId: task.id, sessionID })
+    onPostCompactionIdle?.(task, sessionID)
     return
   }
 
@@ -63,6 +66,13 @@ export function handleSessionIdleBackgroundEvent(args: {
     return
   }
 
+  // Refresh lastUpdate to prevent stale timeout from racing with this async validation.
+  // Without this, checkAndInterruptStaleTasks can kill the task synchronously
+  // while validateSessionHasOutput is still awaiting an API response.
+  if (task.progress) {
+    task.progress.lastUpdate = new Date()
+  }
+
   validateSessionHasOutput(sessionID)
     .then(async (hasValidOutput) => {
       if (task.status !== "running") {