Add usernames to chat messages

src/games/storywriter/components/chat-sidebar.tsx

@@ -167,6 +167,8 @@ export const ChatPanel = () => {
         }
 
         try {
+            const charName = currentWorld.title ?? 'Assistant';
+            const prefix = `${charName}: `;
             let accumulatedContent = '';
             let accumulatedReasoning = '';
             let tool_calls: LLM.ToolCall[] | undefined;
@@ -184,6 +186,9 @@ export const ChatPanel = () => {
                 const content = delta?.content;
                 if (content) {
                     accumulatedContent += content;
+                    if (currentWorld?.chatOnly && accumulatedContent.startsWith(prefix)) {
+                        accumulatedContent = accumulatedContent.slice(prefix.length);
+                    }
                 }
                 const reasoningContent = delta?.reasoning_content;
                 if (reasoningContent) {
@@ -496,6 +501,7 @@ export const ChatPanel = () => {
             )}
             {currentStory && (
                 <div class={styles.inputContainer}>
+                    {!currentWorld?.chatOnly && (
                         <div class={styles.optionsRow}>
                             <label class={styles.toggleContainer}>
                                 <input
@@ -520,6 +526,7 @@ export const ChatPanel = () => {
                                 </button>
                             </div>
                         </div>
+                    )}
                     <ContentEditable
                         autoLines
                         class={styles.input}

src/games/storywriter/contexts/state.tsx

@@ -330,7 +330,7 @@ function reducer(state: IState, action: Action): IState {
                 ...state,
                 currentWorldId: action.worldId,
                 currentStoryId: action.id,
-                currentTab: world?.chatOnly ? 'chat' : 'story',
+                currentTab: 'menu',
             };
         }
         case 'DUPLICATE_STORY': {

src/games/storywriter/utils/llm.ts

@@ -62,6 +62,7 @@ namespace LLM {
         frequency_penalty?: number;
         presence_penalty?: number;
         enable_thinking?: boolean;
+        add_generation_prompt?: boolean;
     }
 
     export interface ChatCompletionChoice {

src/games/storywriter/utils/prompt.ts

@@ -323,7 +323,7 @@ namespace Prompt {
         newMessages: Iterable<ChatMessage> = [],
         excludedMessageIds: Iterable<string> = [],
     ): LLM.ChatCompletionRequest | null {
-        const { currentStory, model, enableThinking } = state;
+        const { currentStory, model, enableThinking, currentWorld } = state;
 
         if (!currentStory || !model) {
             return null;
@@ -345,6 +345,33 @@ namespace Prompt {
             }
         }
 
+        // Chat-only world: format messages with name prefixes
+        if (currentWorld?.chatOnly) {
+            const charName = currentWorld.title ?? 'Assistant';
+            const formattedMessages: ChatMessage[] = messages.map(msg => {
+                const prefix = msg.role === 'user' ? 'User' : charName;
+                return {
+                    ...msg,
+                    content: `${prefix}: ${msg.content}`,
+                };
+            });
+
+            // Prepend system message
+            formattedMessages.unshift({
+                id: crypto.randomUUID(),
+                role: 'system',
+                content: formatSystemPrompt(state, 0),
+            });
+
+            return {
+                model: model.id,
+                messages: formattedMessages,
+                enable_thinking: false,
+                max_tokens: model.max_length ? model.max_length : 2048,
+                add_generation_prompt: true,
+                banned_tokens: state.bannedTokens,
+            };
+        }
 
         // Estimate token budget for story text
         let storyTokenBudget = 0;
@@ -365,7 +392,7 @@ namespace Prompt {
         return {
             model: model.id,
             messages,
-            tools: state.currentWorld?.chatOnly ? undefined : Tools.getTools(),
+            tools: Tools.getTools(),
             banned_tokens: state.bannedTokens,
             enable_thinking: enableThinking,
             max_tokens: model.max_length ? model.max_length : 2048,