diff --git a/api/serverless/openapi.yaml b/api/serverless/openapi.yaml
index 4db8a51..69874e6 100644
--- a/api/serverless/openapi.yaml
+++ b/api/serverless/openapi.yaml
@@ -4854,10 +4854,9 @@ components:
         endpointPath:
           $ref: '#/components/schemas/EndpointPath'
         output:
-          type: object
-          additionalProperties: true
-          nullable: true
-          description: Inference result payload on success; null otherwise.
+          description: >
+            Inference result payload on success; null otherwise. May be any JSON
+            value, including an object, array, string, number, boolean, or null.
         error:
           type: string
           nullable: true
diff --git a/internal/api/serverless/gen/client.gen.go b/internal/api/serverless/gen/client.gen.go
index a47bab7..e644d30 100644
--- a/internal/api/serverless/gen/client.gen.go
+++ b/internal/api/serverless/gen/client.gen.go
@@ -1551,9 +1551,9 @@ type Task struct {
 	// Id Task identifier, supplied by the caller when the task was submitted.
 	Id string `json:"id"`
 
-	// Output Inference result payload on success; null otherwise.
-	Output *map[string]interface{} `json:"output,omitempty"`
-	Status TaskStatus              `json:"status"`
+	// Output Inference result payload on success; null otherwise. May be any JSON value, including an object, array, string, number, boolean, or null.
+	Output interface{} `json:"output,omitempty"`
+	Status TaskStatus  `json:"status"`
 }
 
 // TaskId Client-generated task identifier, canonical lowercase UUID. One id is one task: resubmitting it is answered with the task it already names rather than starting a second, so a request whose response was lost can be sent again without paying for the work twice. Reusing an id for a different request returns the first task, so the id is the caller's to keep unique.
diff --git a/internal/api/serverless/tasks_test.go b/internal/api/serverless/tasks_test.go
index dc016e6..93c34a3 100644
--- a/internal/api/serverless/tasks_test.go
+++ b/internal/api/serverless/tasks_test.go
@@ -132,11 +132,42 @@ func TestInvokeSync_Completed(t *testing.T) {
 	if err != nil {
 		t.Fatalf("InvokeSync: %v", err)
 	}
-	if task.Status != TaskStatusCompleted || task.Output == nil || (*task.Output)["ok"] != true {
+	output, ok := task.Output.(map[string]any)
+	if task.Status != TaskStatusCompleted || !ok || output["ok"] != true {
 		t.Fatalf("unexpected task: %+v", task)
 	}
 }
 
+func TestInvokeAsync_CompletedDuplicateTaskAcceptsAnyJSONOutput(t *testing.T) {
+	tests := []struct {
+		name   string
+		output string
+	}{
+		{name: "scalar", output: `"done"`},
+		{name: "list", output: `["done",1,false]`},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			body := `{"id":"` + testTaskID + `","status":"completed","appId":"my-app","endpointPath":"infer","createdAt":"2026-07-30T12:00:00Z","output":` + tc.output + `}`
+			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Set("Content-Type", "application/json")
+				w.WriteHeader(http.StatusAccepted)
+				_, _ = w.Write([]byte(body))
+			}))
+			defer srv.Close()
+
+			c := newClient("test-key", srv.URL, slog.Default(), srv.Client())
+			task, err := c.InvokeAsync(context.Background(), testAppID, testEndpoint, testTaskID, nil)
+			if err != nil {
+				t.Fatalf("InvokeAsync: %v", err)
+			}
+			if task.Output == nil {
+				t.Fatal("expected output to be decoded")
+			}
+		})
+	}
+}
+
 func TestInvokeAsync_GeneratesTaskID(t *testing.T) {
 	var gotID string
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -275,6 +306,23 @@ func TestListTasks_CursorAndStatus(t *testing.T) {
 	}
 }
 
+func TestListTasks_AcceptsScalarOutput(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"data":[{"id":"` + testTaskID + `","status":"completed","appId":"my-app","endpointPath":"infer","createdAt":"2026-07-30T12:00:00Z","output":"done"}]}`))
+	}))
+	defer srv.Close()
+
+	c := newClient("test-key", srv.URL, slog.Default(), srv.Client())
+	page, err := c.ListTasks(context.Background(), testAppID, nil)
+	if err != nil {
+		t.Fatalf("ListTasks: %v", err)
+	}
+	if len(page.Data) != 1 || page.Data[0].Output != "done" {
+		t.Fatalf("unexpected tasks: %+v", page.Data)
+	}
+}
+
 func TestListTasks_EmptyPageKeepsCursor(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
diff --git a/internal/cmd/serverless/apps_tasks_test.go b/internal/cmd/serverless/apps_tasks_test.go
index 881e67e..262daa0 100644
--- a/internal/cmd/serverless/apps_tasks_test.go
+++ b/internal/cmd/serverless/apps_tasks_test.go
@@ -37,7 +37,7 @@ func TestTaskResult_IncludesOutputAndError(t *testing.T) {
 		AppId:       testAppID,
 		Status:      serverlessapi.TaskStatusFailed,
 		Error:       &errMsg,
-		Output:      &output,
+		Output:      output,
 		CreatedAt:   created,
 		CompletedAt: &completed,
 	}
@@ -54,6 +54,17 @@ func TestTaskResult_IncludesOutputAndError(t *testing.T) {
 	}
 }
 
+func TestTaskResult_RendersScalarOutput(t *testing.T) {
+	r := taskResult{Output: "done"}
+	rows := r.Rows()
+	for _, row := range rows {
+		if row[0] == "Output" && row[1] == `"done"` {
+			return
+		}
+	}
+	t.Fatalf("scalar output missing from rows: %#v", rows)
+}
+
 func TestTasksResult_Headers(t *testing.T) {
 	r := tasksResult{
 		{Id: testTaskID, Status: serverlessapi.TaskStatusPending, CreatedAt: time.Date(2026, 7, 30, 12, 0, 0, 0, time.UTC)},
diff --git a/internal/cmd/serverless/display.go b/internal/cmd/serverless/display.go
index 838769b..e12cbf5 100644
--- a/internal/cmd/serverless/display.go
+++ b/internal/cmd/serverless/display.go
@@ -345,7 +345,7 @@ func (r taskResult) Rows() [][]any {
 		{colError, formatOptionalString(r.Error)},
 	}
 	if r.Output != nil {
-		rows = append(rows, []any{"Output", formatJSONValue(*r.Output)})
+		rows = append(rows, []any{"Output", formatJSONValue(r.Output)})
 	}
 	return rows
 }