diff --git a/packages/server/src/server/agent/agent-prompt.ts b/packages/server/src/server/agent/agent-prompt.ts
index 41e2d52014..0bcd46636a 100644
--- a/packages/server/src/server/agent/agent-prompt.ts
+++ b/packages/server/src/server/agent/agent-prompt.ts
@@ -309,18 +309,30 @@ export async function sendPromptToAgent(
   const unarchive = params.unarchive ?? true;
 
   const record = await params.agentStorage.get(params.agentId);
+  let archivedAtToRestore: string | null = null;
   if (record?.archivedAt) {
     if (!unarchive) {
       return { disposition: "turn_started" };
     }
-    await unarchiveAgentState(params.agentStorage, params.agentManager, params.agentId);
+    if (await unarchiveAgentState(params.agentStorage, params.agentManager, params.agentId)) {
+      archivedAtToRestore = record.archivedAt;
+    }
   }
 
-  await ensureAgentLoaded(params.agentId, {
-    agentManager: params.agentManager,
-    agentStorage: params.agentStorage,
-    logger: params.logger,
-  });
+  try {
+    await ensureAgentLoaded(params.agentId, {
+      agentManager: params.agentManager,
+      agentStorage: params.agentStorage,
+      logger: params.logger,
+    });
+  } catch (error) {
+    // A send that could not load the agent leaves it where it was: still archived.
+    // Concurrent sends share this load, so none of them holds a live session.
+    if (archivedAtToRestore) {
+      await params.agentManager.archiveSnapshot(params.agentId, archivedAtToRestore);
+    }
+    throw error;
+  }
 
   if (params.sessionMode) {
     await params.agentManager.setAgentMode(params.agentId, params.sessionMode);
diff --git a/packages/server/src/server/daemon-client.e2e.test.ts b/packages/server/src/server/daemon-client.e2e.test.ts
index f429cb672c..0bc3310b41 100644
--- a/packages/server/src/server/daemon-client.e2e.test.ts
+++ b/packages/server/src/server/daemon-client.e2e.test.ts
@@ -831,6 +831,29 @@ test("send_agent_message auto-unarchives archived agents", async () => {
   }
 }, 180000);
 
+test("send_agent_message leaves an archived agent archived when its directory is gone", async () => {
+  const cwd = tmpCwd();
+  try {
+    const created = await ctx.client.createAgent({
+      config: {
+        ...getFullAccessConfig("codex"),
+        cwd,
+      },
+    });
+    const archived = await ctx.client.archiveAgent(created.id);
+    rmSync(cwd, { recursive: true, force: true });
+
+    await expect(ctx.client.sendMessage(created.id, "hello")).rejects.toThrow(
+      "Working directory does not exist",
+    );
+
+    const afterSend = await ctx.client.fetchAgent({ agentId: created.id });
+    expect(afterSend?.agent.archivedAt).toBe(archived.archivedAt);
+  } finally {
+    rmSync(cwd, { recursive: true, force: true });
+  }
+}, 30000);
+
 test("refresh_agent auto-unarchives archived agents", async () => {
   const cwd = tmpCwd();
   try {