fix: forward task configuration through stdin-prompt-stream (#11778)

fix: forward task configuration through stdin-prompt-stream protocol

The stdin-prompt-stream `start` command only accepted `prompt` — any
`configuration` passed via the cloud worker's StartNewTask was silently
dropped. This meant custom modes (e.g. `ask-artifacts`), disabled tools,
and other task-level settings never reached the extension when running
via the CLI harness.

Changes:
- Add optional `configuration` field to the `start` stdin command
- Parse and forward it in `runStdinStreamMode`
- Thread it through `ExtensionHost.runTask` → `newTask` webview message
  → `ClineProvider.createTask` (which already calls `setValues`)
- Add `taskConfiguration` field to `WebviewMessage` type

Backward-compatible: older CLIs ignore the extra field; older workers
that don't send `configuration` trigger no change in behavior.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: cte <cestreich@gmail.com>

apps/cli/src/agent/extension-host.ts

@@ -108,7 +108,7 @@ interface WebviewViewProvider {
 export interface ExtensionHostInterface extends IExtensionHost<ExtensionHostEventMap> {
 	client: ExtensionClient
 	activate(): Promise<void>
-	runTask(prompt: string, taskId?: string): Promise<void>
+	runTask(prompt: string, taskId?: string, configuration?: RooCodeSettings): Promise<void>
 	resumeTask(taskId: string): Promise<void>
 	sendToExtension(message: WebviewMessage): void
 	dispose(): Promise<void>
@@ -510,8 +510,8 @@ export class ExtensionHost extends EventEmitter implements ExtensionHostInterfac
 		})
 	}
 
-	public async runTask(prompt: string, taskId?: string): Promise<void> {
-		this.sendToExtension({ type: "newTask", text: prompt, taskId })
+	public async runTask(prompt: string, taskId?: string, configuration?: RooCodeSettings): Promise<void> {
+		this.sendToExtension({ type: "newTask", text: prompt, taskId, taskConfiguration: configuration })
 		return this.waitForTaskCompletion()
 	}
 

apps/cli/src/commands/cli/stdin-stream.ts

@@ -1,6 +1,8 @@
 import { createInterface } from "readline"
 import { randomUUID } from "crypto"
 
+import type { RooCodeSettings } from "@roo-code/types"
+
 import { isRecord } from "@/lib/utils/guards.js"
 
 import type { ExtensionHost } from "@/agent/index.js"
@@ -13,7 +15,7 @@ import type { JsonEventEmitter } from "@/agent/json-event-emitter.js"
 export type StdinStreamCommandName = "start" | "message" | "cancel" | "ping" | "shutdown"
 
 export type StdinStreamCommand =
-	| { command: "start"; requestId: string; prompt: string }
+	| { command: "start"; requestId: string; prompt: string; configuration?: RooCodeSettings }
 	| { command: "message"; requestId: string; prompt: string }
 	| { command: "cancel"; requestId: string }
 	| { command: "ping"; requestId: string }
@@ -64,6 +66,10 @@ export function parseStdinStreamCommand(line: string, lineNumber: number): Stdin
 			throw new Error(`stdin command line ${lineNumber}: "${command}" requires non-empty string "prompt"`)
 		}
 
+		if (command === "start" && isRecord(parsed.configuration)) {
+			return { command, requestId, prompt: promptRaw, configuration: parsed.configuration as RooCodeSettings }
+		}
+
 		return { command, requestId, prompt: promptRaw }
 	}
 
@@ -488,7 +494,7 @@ export async function runStdinStreamMode({ host, jsonEmitter, setStreamRequestId
 					})
 
 					activeTaskPromise = host
-						.runTask(stdinCommand.prompt, latestTaskId)
+						.runTask(stdinCommand.prompt, latestTaskId, stdinCommand.configuration)
 						.catch((error) => {
 							const message = error instanceof Error ? error.message : String(error)
 

packages/types/src/vscode-extension-host.ts

@@ -679,6 +679,8 @@ export interface WebviewMessage {
 		codebaseIndexOpenRouterApiKey?: string
 	}
 	updatedSettings?: RooCodeSettings
+	/** Task configuration applied via `createTask()` when starting a cloud task. */
+	taskConfiguration?: RooCodeSettings
 	// Worktree properties
 	worktreePath?: string
 	worktreeBranch?: string

src/core/webview/ClineProvider.ts

@@ -2922,6 +2922,16 @@ export class ClineProvider
 			if (configuration.currentApiConfigName) {
 				await this.setProviderProfile(configuration.currentApiConfigName)
 			}
+
+			// Register custom modes so the CustomModesManager knows about them.
+			// setValues writes to global state, but the manager overwrites that
+			// when it merges .roomodes + global settings on refresh.  Persisting
+			// via updateCustomMode ensures modes survive the merge cycle.
+			if (configuration.customModes?.length) {
+				for (const mode of configuration.customModes) {
+					await this.customModesManager.updateCustomMode(mode.slug, mode)
+				}
+			}
 		}
 
 		const { apiConfiguration, organizationAllowList, enableCheckpoints, checkpointTimeout, experiments } =

src/core/webview/webviewMessageHandler.ts

@@ -554,9 +554,13 @@ export const webviewMessageHandler = async (
 			// task. This essentially creates a fresh slate for the new task.
 			try {
 				const resolved = await resolveIncomingImages({ text: message.text, images: message.images })
-				await provider.createTask(resolved.text, resolved.images, undefined, {
-					taskId: message.taskId,
-				})
+				await provider.createTask(
+					resolved.text,
+					resolved.images,
+					undefined,
+					{ taskId: message.taskId },
+					message.taskConfiguration,
+				)
 				// Task created successfully - notify the UI to reset
 				await provider.postMessageToWebview({ type: "invoke", invoke: "newChat" })
 			} catch (error) {