fix: Convert initial_message from string to Message object format

- Update CreateConversationRequest interface to use Message type instead of string
- Convert string initialMessage to proper Message object in RemoteConversation.create
- Add Message import to conversation models
- Fixes 422 error when creating conversations with initial messages

Co-authored-by: openhands <openhands@all-hands.dev>

Author: openhands-agent

src/conversation/remote-conversation.ts

@@ -204,9 +204,18 @@ export class RemoteConversation {
       timeout: 60000,
     });
 
+    // Convert string initialMessage to Message object if provided
+    let initialMessage: Message | undefined;
+    if (options.initialMessage) {
+      initialMessage = {
+        role: 'user',
+        content: [{ type: 'text', text: options.initialMessage }],
+      };
+    }
+
     const request: CreateConversationRequest = {
       agent,
-      initial_message: options.initialMessage,
+      initial_message: initialMessage,
       max_iterations: options.maxIterations || 50,
       stuck_detection: options.stuckDetection ?? true,
       workspace: options.workspace || { type: 'local', working_dir: '/tmp' },

src/models/conversation.ts

@@ -9,6 +9,7 @@ import {
   ConfirmationPolicyBase,
   ConversationStats,
   AgentBase,
+  Message,
 } from '../types/base';
 
 export interface ConversationInfo {
@@ -40,7 +41,7 @@ export interface ConfirmationResponseRequest {
 
 export interface CreateConversationRequest {
   agent: AgentBase;
-  initial_message?: string;
+  initial_message?: Message;
   max_iterations: number;
   stuck_detection: boolean;
   workspace: any;