feat: add support for user message events from Codex

Add sendUserMessage() method to ApiSessionClient and CodexSession to handle
user_message events from Codex. Updates CodexConversionResult type and
convertCodexEvent() to process user_message payloads, with test coverage.

cli/src/api/apiSession.ts

@@ -6,7 +6,7 @@ import { backoff } from '@/utils/time'
 import { AsyncLock } from '@/utils/lock'
 import type { RawJSONLines } from '@/claude/types'
 import { configuration } from '@/configuration'
-import type { AgentState, ClientToServerEvents, MessageContent, Metadata, ServerToClientEvents, Session, Update, UserMessage } from './types'
+import type { AgentState, ClientToServerEvents, MessageContent, MessageMeta, Metadata, ServerToClientEvents, Session, Update, UserMessage } from './types'
 import { AgentStateSchema, MetadataSchema, UserMessageSchema } from './types'
 import { RpcHandlerManager } from './rpc/RpcHandlerManager'
 import { registerCommonHandlers } from '../modules/common/registerCommonHandlers'
@@ -184,6 +184,29 @@ export class ApiSessionClient extends EventEmitter {
         }
     }
 
+    sendUserMessage(text: string, meta?: MessageMeta): void {
+        if (!text) {
+            return
+        }
+
+        const content: MessageContent = {
+            role: 'user',
+            content: {
+                type: 'text',
+                text
+            },
+            meta: {
+                sentFrom: 'cli',
+                ...(meta ?? {})
+            }
+        }
+
+        this.socket.emit('message', {
+            sid: this.sessionId,
+            message: content
+        })
+    }
+
     sendCodexMessage(body: unknown): void {
         const content = {
             role: 'agent',

cli/src/codex/codexLocalLauncher.ts

@@ -17,6 +17,9 @@ export async function codexLocalLauncher(session: CodexSession): Promise<'switch
                 session.onSessionFound(converted.sessionId);
                 scanner.onNewSession(converted.sessionId);
             }
+            if (converted?.userMessage) {
+                session.sendUserMessage(converted.userMessage);
+            }
             if (converted?.message) {
                 session.sendCodexMessage(converted.message);
             }

cli/src/codex/session.ts

@@ -45,6 +45,10 @@ export class CodexSession extends AgentSessionBase<EnhancedMode> {
         this.client.sendCodexMessage(message);
     };
 
+    sendUserMessage = (text: string): void => {
+        this.client.sendUserMessage(text);
+    };
+
     sendSessionEvent = (event: Parameters<ApiSessionClient['sendSessionEvent']>[0]): void => {
         this.client.sendSessionEvent(event);
     };

cli/src/codex/utils/codexEventConverter.test.ts

@@ -23,6 +23,15 @@ describe('convertCodexEvent', () => {
         });
     });
 
+    it('converts user_message events', () => {
+        const result = convertCodexEvent({
+            type: 'event_msg',
+            payload: { type: 'user_message', message: 'hello user' }
+        });
+
+        expect(result?.userMessage).toBe('hello user');
+    });
+
     it('converts reasoning events', () => {
         const result = convertCodexEvent({
             type: 'event_msg',

cli/src/codex/utils/codexEventConverter.ts

@@ -41,6 +41,7 @@ export type CodexMessage = {
 export type CodexConversionResult = {
     sessionId?: string;
     message?: CodexMessage;
+    userMessage?: string;
 };
 
 function asRecord(value: unknown): Record<string, unknown> | null {
@@ -118,7 +119,15 @@ export function convertCodexEvent(rawEvent: unknown): CodexConversionResult | nu
         }
 
         if (eventType === 'user_message') {
-            return null;
+            const message = asString(payloadRecord.message)
+                ?? asString(payloadRecord.text)
+                ?? asString(payloadRecord.content);
+            if (!message) {
+                return null;
+            }
+            return {
+                userMessage: message
+            };
         }
 
         if (eventType === 'agent_message') {