diff --git a/packages/server/src/server/agent/providers/pi/agent.test.ts b/packages/server/src/server/agent/providers/pi/agent.test.ts
index c3fad836d..d6b0f9377 100644
--- a/packages/server/src/server/agent/providers/pi/agent.test.ts
+++ b/packages/server/src/server/agent/providers/pi/agent.test.ts
@@ -553,6 +553,61 @@ describe("PiRpcAgentSession", () => {
     ]);
   });
 
+  test("streams Pi task calls as sub-agent cards with lifecycle status", async () => {
+    const { pi, session, events } = await createSession();
+    const fakeSession = pi.latestSession();
+
+    await session.startTurn("delegate this");
+    fakeSession.emit({
+      type: "tool_execution_start",
+      toolCallId: "task-1",
+      toolName: "task",
+      args: {
+        agent: "explore",
+        task: "Trace the Pi provider tool mapper",
+      },
+    });
+    fakeSession.emit({
+      type: "tool_execution_end",
+      toolCallId: "task-1",
+      toolName: "task",
+      result: { content: [{ type: "text", text: "Found the mapper." }] },
+      isError: false,
+    });
+    fakeSession.finishTurn();
+
+    await events.nextTurnCompletion();
+
+    expect(events.timelineItems()).toEqual([
+      {
+        type: "tool_call",
+        callId: "task-1",
+        name: "task",
+        status: "running",
+        detail: {
+          type: "sub_agent",
+          subAgentType: "explore",
+          description: "Trace the Pi provider tool mapper",
+          log: "",
+        },
+        error: null,
+      },
+      {
+        type: "tool_call",
+        callId: "task-1",
+        name: "task",
+        status: "completed",
+        detail: {
+          type: "sub_agent",
+          subAgentType: "explore",
+          description: "Trace the Pi provider tool mapper",
+          log: "Found the mapper.",
+        },
+        error: null,
+      },
+    ]);
+  });
+
   test("keeps one generated message id when Pi omits message start and response id", async () => {
     const { pi, session, events } = await createSession();
     const fakeSession = pi.latestSession();
diff --git a/packages/server/src/server/agent/providers/pi/tool-call-mapper.test.ts b/packages/server/src/server/agent/providers/pi/tool-call-mapper.test.ts
index dd2213ed1..224e86176 100644
--- a/packages/server/src/server/agent/providers/pi/tool-call-mapper.test.ts
+++ b/packages/server/src/server/agent/providers/pi/tool-call-mapper.test.ts
@@ -136,6 +136,37 @@ describe("Pi tool call mapper", () => {
     });
   });
 
+  test("maps task calls to sub-agent detail while running", () => {
+    const toolCall = parseToolArgs("task", {
+      agent: "explore",
+      task: "Trace the Pi provider tool mapper",
+    });
+
+    expect(mapToolDetail(toolCall, null)).toEqual({
+      type: "sub_agent",
+      subAgentType: "explore",
+      description: "Trace the Pi provider tool mapper",
+      log: "",
+    });
+  });
+
+  test("maps completed subagent calls with task input to sub-agent detail", () => {
+    const toolCall = parseToolArgs("subagent", {
+      agent: "reviewer",
+      task: "Review the Pi mapper change",
+    });
+    const result = parseToolResult({
+      content: [{ type: "text", text: "The mapper change preserves provider status." }],
+    });
+
+    expect(mapToolDetail(toolCall, result)).toEqual({
+      type: "sub_agent",
+      subAgentType: "reviewer",
+      description: "Review the Pi mapper change",
+      log: "The mapper change preserves provider status.",
+    });
+  });
+
   test("normalizes Pi MCP proxy calls from requested tool args while running", () => {
     const toolCall = parseToolArgs("mcp", {
       tool: "paseo_list_models",
diff --git a/packages/server/src/server/agent/providers/pi/tool-call-mapper.ts b/packages/server/src/server/agent/providers/pi/tool-call-mapper.ts
index b53ed3993..499627377 100644
--- a/packages/server/src/server/agent/providers/pi/tool-call-mapper.ts
+++ b/packages/server/src/server/agent/providers/pi/tool-call-mapper.ts
@@ -340,6 +340,10 @@ export function resolveToolCallName(toolCall: PiTrackedToolCall, result?: PiTool
 export function mapToolDetail(toolCall: PiTrackedToolCall, result?: PiToolResult): ToolCallDetail {
   const parsedResult = result ?? null;
 
+  if (isTaskToolCall(toolCall)) {
+    return mapTaskToolDetail(toolCall.args, parsedResult);
+  }
+
   switch (toolCall.kind) {
     case "bash": {
       const summary = resolveToolCallOutput(parsedResult);
@@ -388,6 +392,30 @@ export function mapToolDetail(toolCall: PiTrackedToolCall, result?: PiToolResult
   }
 }
 
+function isTaskToolCall(toolCall: PiTrackedToolCall): boolean {
+  if (toolCall.toolName === "task") {
+    return true;
+  }
+  if (toolCall.toolName !== "subagent" || !isRecord(toolCall.args)) {
+    return false;
+  }
+  return (
+    toolCall.args.action === undefined &&
+    (readNonEmptyString(toolCall.args.agent) !== undefined ||
+      readNonEmptyString(toolCall.args.task) !== undefined)
+  );
+}
+
+function mapTaskToolDetail(args: unknown, result: PiToolResult): ToolCallDetail {
+  const argRecord = isRecord(args) ? args : {};
+  return {
+    type: "sub_agent",
+    subAgentType: readNonEmptyString(argRecord.agent),
+    description: readNonEmptyString(argRecord.task),
+    log: extractTextFromToolResult(result)?.trim() ?? "",
+  };
+}
+
 function mapWriteToolDetail(args: WriteToolInput, result: PiToolResult): ToolCallDetail {
   if (result && typeof result !== "string" && result.details && "xdev" in result.details) {
     const xdev = XdevExecuteDetailsSchema.safeParse(result.details.xdev);