🤖 perf: bulk launch workflow agent tasks

docs/hooks/tools.mdx

@@ -641,17 +641,17 @@ If a value is too large for the environment, it may be omitted (not set). Mux al
 | `MUX_TOOL_INPUT_MIN_COMPLETED`    | `min_completed`     | number  | Number of awaited tasks that must complete before this call returns. Defaults to 1, so by default task_await returns as soon as the FIRST awaited task completes, letting you act on it while the rest keep running. The result still includes every task complete at that moment plus current status (running/queued) for the rest. Tasks that have not yet completed keep running and remain re-awaitable on a later task_await call. Raise this (e.g. set it to the total number of awaited tasks) when you genuinely need more before proceeding — for example best-of-N synthesis that must compare every candidate. Clamped to the number of awaited tasks; values above that behave like 'wait for all'. |
 | `MUX_TOOL_INPUT_TASK_IDS_<INDEX>` | `task_ids[<INDEX>]` | string  | List of task IDs or workflow run IDs to await — use only real IDs returned by prior task, bash, or workflow_run results; never fabricate an ID. task_list can rediscover sub-agent/background bash IDs, but workflow run rediscovery is done by omitting task_ids. When omitted, waits for active descendant tasks and workflow runs of the current workspace, excluding workflow-owned sub-agents and their background bash tasks because those results are consumed through workflow runs.                                                                                                                                                                                                                    |
 | `MUX_TOOL_INPUT_TASK_IDS_COUNT`   | `task_ids.length`   | number  | Number of elements in task_ids (List of task IDs or workflow run IDs to await — use only real IDs returned by prior task, bash, or workflow_run results; never fabricate an ID. task_list can rediscover sub-agent/background bash IDs, but workflow run rediscovery is done by omitting task_ids. When omitted, waits for active descendant tasks and workflow runs of the current workspace, excluding workflow-owned sub-agents and their background bash tasks because those results are consumed through workflow runs.)                                                                                                                                                                                   |
-| `MUX_TOOL_INPUT_TIMEOUT_SECS`     | `timeout_secs`      | number  | Maximum time to wait in seconds for each task. For bash tasks, this waits for NEW output (or process exit). If exceeded, the result returns status=queued\|running\|awaiting_report (task is still active). Defaults to 600 seconds (10 minutes) if not specified. Set to 0 for a non-blocking status check.                                                                                                                                                                                                                                                                                                                                                                                                    |
+| `MUX_TOOL_INPUT_TIMEOUT_SECS`     | `timeout_secs`      | number  | Maximum time to wait in seconds for each task. For bash tasks, this waits for NEW output (or process exit). If exceeded, the result returns status=queued\|starting\|running\|awaiting_report (task is still active). Defaults to 600 seconds (10 minutes) if not specified. Set to 0 for a non-blocking status check.                                                                                                                                                                                                                                                                                                                                                                                          |
 
 </details>
 
 <details>
 <summary>task_list (2)</summary>
 
-| Env var                           | JSON path           | Type   | Description                                                                                                            |
-| --------------------------------- | ------------------- | ------ | ---------------------------------------------------------------------------------------------------------------------- |
-| `MUX_TOOL_INPUT_STATUSES_<INDEX>` | `statuses[<INDEX>]` | enum   | Task statuses to include. Defaults to active tasks: queued, running, awaiting_report.                                  |
-| `MUX_TOOL_INPUT_STATUSES_COUNT`   | `statuses.length`   | number | Number of elements in statuses (Task statuses to include. Defaults to active tasks: queued, running, awaiting_report.) |
+| Env var                           | JSON path           | Type   | Description                                                                                                                      |
+| --------------------------------- | ------------------- | ------ | -------------------------------------------------------------------------------------------------------------------------------- |
+| `MUX_TOOL_INPUT_STATUSES_<INDEX>` | `statuses[<INDEX>]` | enum   | Task statuses to include. Defaults to active tasks: queued, starting, running, awaiting_report.                                  |
+| `MUX_TOOL_INPUT_STATUSES_COUNT`   | `statuses.length`   | number | Number of elements in statuses (Task statuses to include. Defaults to active tasks: queued, starting, running, awaiting_report.) |
 
 </details>
 

src/browser/components/AgentListItem/AgentListItem.tsx

@@ -11,9 +11,10 @@ import { useWorkspaceUnread } from "@/browser/hooks/useWorkspaceUnread";
 import { useRuntimeStatus } from "@/browser/stores/RuntimeStatusStore";
 import { useWorkspaceSidebarState } from "@/browser/stores/WorkspaceStore";
 import { stopKeyboardPropagation } from "@/browser/utils/events";
-import type {
-  AgentRowRenderMeta,
-  WorkspaceDelegatedActivity,
+import {
+  isRunningOrStartingTaskStatus,
+  type AgentRowRenderMeta,
+  type WorkspaceDelegatedActivity,
 } from "@/browser/utils/ui/workspaceFiltering";
 import { cn } from "@/common/lib/utils";
 import {
@@ -1192,7 +1193,7 @@ function AgentListItemInner(props: UnifiedAgentListItemProps) {
   if (rowMeta?.rowKind === "subagent") {
     // Connector geometry is driven by render metadata so visible siblings keep
     // consistent single/middle/last shapes as parents expand/collapse children.
-    const isElbowActive = props.metadata.taskStatus === "running";
+    const isElbowActive = isRunningOrStartingTaskStatus(props.metadata.taskStatus);
     const connectorLayout = props.subAgentConnectorLayout ?? "default";
     const connectorDepth = props.depth ?? rowMeta.depth;
     const connectorRailX = getSubAgentParentRailX(connectorDepth, connectorLayout);

src/browser/components/ChatPane/ChatPane.tsx

@@ -106,6 +106,7 @@ import {
   computeOperationalBundleInfos,
   computeWorkBundleInfos,
 } from "@/browser/utils/messages/transcriptRenderProjection";
+import { isBlockedPreStreamTaskStatus } from "@/browser/utils/ui/workspaceFiltering";
 import { recordSyntheticReactRenderSample } from "@/browser/utils/perf/reactProfileCollector";
 
 // Perf e2e runs load the production bundle where React's onRender profiler callbacks may not
@@ -321,9 +322,13 @@ const ChatPaneContent: React.FC<ChatPaneContentProps> = (props) => {
   // so the transcript stays readable while new sends remain disabled.
   const meta = workspaceMetadata.get(workspaceId);
   const transcriptOnly = meta?.transcriptOnly ?? false;
-  const isQueuedAgentTask = Boolean(meta?.parentWorkspaceId) && meta?.taskStatus === "queued";
+  const isPreStreamAgentTask =
+    Boolean(meta?.parentWorkspaceId) && isBlockedPreStreamTaskStatus(meta?.taskStatus);
+  const preStreamAgentTaskLabel = meta?.taskStatus === "starting" ? "Starting" : "Queued";
   const queuedAgentTaskPrompt =
-    isQueuedAgentTask && typeof meta?.taskPrompt === "string" && meta.taskPrompt.trim().length > 0
+    isPreStreamAgentTask &&
+    typeof meta?.taskPrompt === "string" &&
+    meta.taskPrompt.trim().length > 0
       ? meta.taskPrompt
       : null;
   const shouldShowQueuedAgentTaskPrompt =
@@ -1048,7 +1053,9 @@ const ChatPaneContent: React.FC<ChatPaneContentProps> = (props) => {
         node: (
           <div className="mt-4 mb-1 ml-auto w-fit max-w-full">
             <div className="rounded-lg border border-[var(--color-user-border)] bg-[var(--color-user-surface)] px-3 py-2 text-sm">
-              <div className="text-muted mb-1 text-[11px] font-medium">Queued</div>
+              <div className="text-muted mb-1 text-[11px] font-medium">
+                {preStreamAgentTaskLabel}
+              </div>
               <MarkdownRenderer
                 content={queuedAgentTaskPrompt ?? ""}
                 className="user-message-markdown text-foreground"
@@ -1528,7 +1535,8 @@ const ChatPaneContent: React.FC<ChatPaneContentProps> = (props) => {
               isTranscriptCaughtUp={isTranscriptCaughtUp}
               isHydratingTranscript={isHydratingTranscript}
               runtimeConfig={runtimeConfig}
-              isQueuedAgentTask={isQueuedAgentTask}
+              isPreStreamAgentTask={isPreStreamAgentTask}
+              preStreamAgentTaskStatus={meta?.taskStatus === "starting" ? "starting" : "queued"}
               isCompacting={isCompacting}
               shouldShowPinnedTodoList={shouldShowPinnedTodoList}
               shouldShowReviewsBanner={shouldShowReviewsBanner}
@@ -1580,7 +1588,8 @@ interface ChatInputPaneProps {
   projectName: string;
   workspaceName: string;
   runtimeConfig?: RuntimeConfig;
-  isQueuedAgentTask: boolean;
+  isPreStreamAgentTask: boolean;
+  preStreamAgentTaskStatus: "queued" | "starting";
   isCompacting: boolean;
   isStreamStarting: boolean;
   isTranscriptCaughtUp: boolean;
@@ -1695,12 +1704,14 @@ const ChatInputPane: React.FC<ChatInputPaneProps> = (props) => {
       ),
     });
   }
-  if (props.isQueuedAgentTask) {
+  if (props.isPreStreamAgentTask) {
     addDecorationEntry({
-      key: "queued-agent-task",
+      key: "pre-stream-agent-task",
       node: (
         <div className="border-border-medium bg-background-secondary text-muted rounded-md border px-3 py-2 text-xs">
-          This agent task is queued and will start automatically when a parallel slot is available.
+          {props.preStreamAgentTaskStatus === "starting"
+            ? "This agent task is starting and will become editable after launch accepts the initial prompt."
+            : "This agent task is queued and will start automatically when a parallel slot is available."}
         </div>
       ),
     });
@@ -1726,10 +1737,12 @@ const ChatInputPane: React.FC<ChatInputPaneProps> = (props) => {
         onResetContext={props.onResetContext}
         onTruncateHistory={props.onTruncateHistory}
         onModelChange={props.onModelChange}
-        disabled={!props.projectName || !props.workspaceName || props.isQueuedAgentTask}
+        disabled={!props.projectName || !props.workspaceName || props.isPreStreamAgentTask}
         disabledReason={
-          props.isQueuedAgentTask
-            ? "Queued - waiting for an available parallel task slot. This will start automatically."
+          props.isPreStreamAgentTask
+            ? props.preStreamAgentTaskStatus === "starting"
+              ? "Starting - waiting for launch to accept the initial prompt."
+              : "Queued - waiting for an available parallel task slot. This will start automatically."
             : undefined
         }
         isTranscriptCaughtUp={props.isTranscriptCaughtUp}

src/browser/components/ProjectSidebar/ProjectSidebar.tsx

@@ -60,6 +60,7 @@ import {
   getSectionExpandedKey,
   getSectionTierKey,
   resolveEffectiveSectionId,
+  isRunningOrStartingTaskStatus,
   type AgentRowRenderMeta,
 } from "@/browser/utils/ui/workspaceFiltering";
 import { Tooltip, TooltipTrigger, TooltipContent } from "../Tooltip/Tooltip";
@@ -2587,7 +2588,9 @@ const ProjectSidebarInner: React.FC<ProjectSidebarProps> = ({
 
                                   let lastRunningSiblingIndex = -1;
                                   for (let index = siblings.length - 1; index >= 0; index -= 1) {
-                                    if (siblings[index]?.taskStatus === "running") {
+                                    if (
+                                      isRunningOrStartingTaskStatus(siblings[index]?.taskStatus)
+                                    ) {
                                       lastRunningSiblingIndex = index;
                                       break;
                                     }

src/browser/utils/messages/modelMessageTransform.ts

@@ -711,7 +711,12 @@ function coalesceConsecutiveNoProgressTaskAwaitPairs(messages: ModelMessage[]):
       }
 
       const status = (entry as { status?: unknown }).status;
-      if (status !== "queued" && status !== "running" && status !== "awaiting_report") {
+      if (
+        status !== "queued" &&
+        status !== "starting" &&
+        status !== "running" &&
+        status !== "awaiting_report"
+      ) {
         return false;
       }
 

src/browser/utils/ui/workspaceFiltering.ts

@@ -148,8 +148,22 @@ function hasDelegatedActivity(activity: WorkspaceDelegatedActivity): boolean {
   return activity.activeCount > 0 || activity.queuedCount > 0;
 }
 
-function isActiveDelegatedStatus(status: FrontendWorkspaceMetadata["taskStatus"]): boolean {
-  return status === "running" || status === "awaiting_report";
+export function isActiveOrStartingTaskStatus(
+  status: FrontendWorkspaceMetadata["taskStatus"]
+): boolean {
+  return status === "starting" || status === "running" || status === "awaiting_report";
+}
+
+export function isRunningOrStartingTaskStatus(
+  status: FrontendWorkspaceMetadata["taskStatus"]
+): boolean {
+  return status === "starting" || status === "running";
+}
+
+export function isBlockedPreStreamTaskStatus(
+  status: FrontendWorkspaceMetadata["taskStatus"]
+): boolean {
+  return status === "queued" || status === "starting";
 }
 
 function getIsWorkspaceLiveActive(workspaceId: string, options: DelegatedActivityOptions): boolean {
@@ -166,7 +180,7 @@ export function isWorkspaceDelegatedActivityActive(
   workspace: FrontendWorkspaceMetadata,
   options: DelegatedActivityOptions = {}
 ): boolean {
-  if (isActiveDelegatedStatus(workspace.taskStatus)) {
+  if (isActiveOrStartingTaskStatus(workspace.taskStatus)) {
     return true;
   }
   if (hasCompletedAgentReport(workspace)) {
@@ -410,7 +424,7 @@ export function computeAgentRowRenderMeta(
 
         let lastRunningSiblingIndex = -1;
         for (let index = siblings.length - 1; index >= 0; index -= 1) {
-          if (siblings[index]?.taskStatus === "running") {
+          if (isRunningOrStartingTaskStatus(siblings[index]?.taskStatus)) {
             lastRunningSiblingIndex = index;
             break;
           }

src/common/orpc/schemas/api.ts

@@ -1657,7 +1657,7 @@ export const tasks = {
       z.object({
         taskId: z.string(),
         kind: z.literal("agent"),
-        status: z.enum(["queued", "running"]),
+        status: z.enum(["queued", "starting", "running"]),
       }),
       z.string()
     ),

src/common/orpc/schemas/workspace.ts

@@ -159,12 +159,15 @@ export const WorkspaceMetadataSchema = z.object({
     description: "Grouping metadata for child tasks spawned from the same parent tool call.",
   }),
   taskStatus: z
-    .enum(["queued", "running", "awaiting_report", "interrupted", "reported"])
+    .enum(["queued", "starting", "running", "awaiting_report", "interrupted", "reported"])
     .optional()
     .meta({
       description:
-        "Agent task lifecycle status for child workspaces (queued|running|awaiting_report|interrupted|reported).",
+        "Agent task lifecycle status for child workspaces (queued|starting|running|awaiting_report|interrupted|reported).",
     }),
+  taskLaunchError: z.string().optional().meta({
+    description: "Startup failure recorded before an agent task could begin streaming.",
+  }),
   reportedAt: z.string().optional().meta({
     description: "ISO 8601 timestamp for when an agent task reported completion (optional).",
   }),

src/common/schemas/project.ts

@@ -122,12 +122,15 @@ export const WorkspaceConfigSchema = z.object({
     description: "Grouping metadata for child tasks spawned from the same parent tool call.",
   }),
   taskStatus: z
-    .enum(["queued", "running", "awaiting_report", "interrupted", "reported"])
+    .enum(["queued", "starting", "running", "awaiting_report", "interrupted", "reported"])
     .optional()
     .meta({
       description:
-        "Agent task lifecycle status for child workspaces (queued|running|awaiting_report|interrupted|reported).",
+        "Agent task lifecycle status for child workspaces (queued|starting|running|awaiting_report|interrupted|reported).",
     }),
+  taskLaunchError: z.string().optional().meta({
+    description: "Startup failure recorded before an agent task could begin streaming.",
+  }),
   reportedAt: z.string().optional().meta({
     description: "ISO 8601 timestamp for when an agent task reported completion (optional).",
   }),

src/common/utils/agentTaskCompletion.ts

@@ -1,5 +1,12 @@
 export interface AgentTaskCompletionCandidate {
-  taskStatus?: "queued" | "running" | "awaiting_report" | "interrupted" | "reported" | null;
+  taskStatus?:
+    | "queued"
+    | "starting"
+    | "running"
+    | "awaiting_report"
+    | "interrupted"
+    | "reported"
+    | null;
   reportedAt?: string | null;
 }