Better logic around what a User Initiated Message is

src/extension/agents/claude/node/claudeLanguageModelServer.ts

@@ -26,6 +26,11 @@ import { SSEParser } from '../../../../util/vs/base/common/sseParser';
 import { generateUuid } from '../../../../util/vs/base/common/uuid';
 import { IInstantiationService } from '../../../../util/vs/platform/instantiation/common/instantiation';
 
+/**
+ * Marker string to identify user-initiated messages from VS Code in the Messages API.
+ */
+export const VSCODE_USER_INITIATED_MESSAGE_MARKER = '__vscode_user_initiated_message__';
+
 export interface IClaudeLanguageModelServerConfig {
 	readonly port: number;
 	readonly nonce: string;
@@ -161,7 +166,35 @@ export class ClaudeLanguageModelServer extends Disposable {
 
 			// Determine if this is a user-initiated message
 			const lastMessage = requestBody.messages?.at(-1);
-			const isUserInitiatedMessage = lastMessage?.role === 'user';
+			const lastContentItems = !lastMessage || typeof lastMessage.content === 'string'
+				? []
+				: lastMessage.content;
+
+			// Find the index of the marker content item if it exists
+			const markerIndex = lastContentItems.findIndex(
+				c => c.type === 'text' &&
+					// Our marker
+					c.text.includes(VSCODE_USER_INITIATED_MESSAGE_MARKER) &&
+					// The name of the hook we are using
+					c.text.includes('UserPromptSubmit')
+			);
+
+			const isUserInitiatedMessage =
+				// A user initiated message would only be of role 'user'
+				lastMessage?.role === 'user' &&
+				// We expect our marker AND the user's actual message so there will be multiple content items
+				lastContentItems.length > 1 &&
+				// The marker must be in a preceding content item, not the last one (which is the actual user message)
+				markerIndex !== -1 &&
+				markerIndex !== lastContentItems.length - 1;
+
+			// Remove the marker content item and the one before it (which just provides the status of our hook)
+			// so they don't influence the request
+			if (isUserInitiatedMessage) {
+				// Remove marker and its preceding item (if it exists)
+				const indicesToRemove = markerIndex > 0 ? [markerIndex - 1, markerIndex] : [markerIndex];
+				lastMessage.content = lastContentItems.filter((_, i) => !indicesToRemove.includes(i));
+			}
 
 			const allEndpoints = await this.endpointProvider.getAllChatEndpoints();
 			// Filter to only endpoints that support the Messages API

src/extension/agents/claude/node/hooks/loggingHooks.ts

@@ -18,6 +18,7 @@ import { ILogService } from '../../../../../platform/log/common/logService';
 import { CapturingToken } from '../../../../../platform/requestLogger/common/capturingToken';
 import { IClaudeSessionStateService } from '../claudeSessionStateService';
 import { registerClaudeHook } from './claudeHookRegistry';
+import { VSCODE_USER_INITIATED_MESSAGE_MARKER } from '../claudeLanguageModelServer';
 
 /**
  * Logging hook for Notification events.
@@ -60,7 +61,15 @@ export class UserPromptSubmitLoggingHook implements HookCallbackMatcher {
 		// Create a capturing token for this request to group tool calls under the request
 		const capturingToken = new CapturingToken(hookInput.prompt, 'sparkle', false);
 		this.sessionStateService.setCapturingTokenForSession(hookInput.session_id, capturingToken);
-		return { continue: true };
+
+		return {
+			continue: true,
+			// Mark this message as user-initiated for downstream processing of PRUs
+			hookSpecificOutput: {
+				hookEventName: 'UserPromptSubmit',
+				additionalContext: VSCODE_USER_INITIATED_MESSAGE_MARKER
+			}
+		};
 	}
 }
 registerClaudeHook('UserPromptSubmit', UserPromptSubmitLoggingHook);