feat: implement message examples usage from character cards

Add support for using mes_example field from character cards to teach the AI the character's voice and writing style. Examples are parsed, processed with template variable replacement, and injected into the context at a configurable position.

Backend changes:
- Extended RoleplaySettings with examples_enabled and examples_position fields
- Implemented parse_message_examples() to parse <START>-delimited example blocks
- Added example injection in build_api_messages() with position control
- Integrated examples into token counter with accurate counting
- Created update_examples_settings command for saving settings

Frontend changes:
- Added Message Examples UI controls in Author's Note tab
- Checkbox to enable/disable examples
- Dropdown to select injection position (after_system/before_history)
- Save button with success/error feedback
- Token breakdown now shows examples token count
- Settings load/save integrated with roleplay panel

Message examples help the AI understand character personality, speaking patterns, and response style by providing concrete examples of how the character should respond.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src-tauri/src/lib.rs

@@ -291,6 +291,10 @@ struct RoleplaySettings {
     recursion_depth: usize, // Max depth for recursive World Info activation (default 3)
     #[serde(default)]
     active_preset_id: Option<String>, // Selected prompt preset for this character
+    #[serde(default)]
+    examples_enabled: bool, // Whether to include message examples from character card
+    #[serde(default = "default_examples_position")]
+    examples_position: String, // Where to insert examples: "after_system" or "before_history"
 }
 
 fn default_authors_note_depth() -> usize {
@@ -301,6 +305,10 @@ fn default_scan_depth() -> usize {
     20
 }
 
+fn default_examples_position() -> String {
+    "after_system".to_string() // Insert examples after system prompt, before history
+}
+
 fn default_recursion_depth() -> usize {
     3
 }
@@ -318,6 +326,8 @@ impl Default for RoleplaySettings {
             scan_depth: default_scan_depth(),
             recursion_depth: default_recursion_depth(),
             active_preset_id: None, // No preset selected by default
+            examples_enabled: false, // Message examples disabled by default
+            examples_position: default_examples_position(), // After system prompt by default
         }
     }
 }
@@ -1310,6 +1320,74 @@ fn replace_template_variables(
     result
 }
 
+// Parse mes_example field from character card into Message objects
+fn parse_message_examples(
+    mes_example: &str,
+    character: &Character,
+    settings: &RoleplaySettings,
+) -> Vec<Message> {
+    let mut examples = Vec::new();
+
+    // Split by <START> tag to get individual example blocks
+    let blocks: Vec<&str> = mes_example
+        .split("<START>")
+        .map(|s| s.trim())
+        .filter(|s| !s.is_empty())
+        .collect();
+
+    for block in blocks {
+        // Process each line in the block
+        for line in block.lines() {
+            let line = line.trim();
+            if line.is_empty() {
+                continue;
+            }
+
+            // Replace template variables
+            let processed_line = replace_template_variables(line, character, settings);
+
+            // Determine role based on prefix ({{user}}: or {{char}}:)
+            // After replacement, it will be the actual names
+            let user_name = if settings.persona_enabled {
+                settings.persona_name.as_deref().unwrap_or("User")
+            } else {
+                "User"
+            };
+
+            if processed_line.starts_with(&format!("{}:", user_name)) {
+                // User message
+                let content = processed_line
+                    .trim_start_matches(&format!("{}:", user_name))
+                    .trim()
+                    .to_string();
+                examples.push(Message::new_user(content));
+            } else if processed_line.starts_with(&format!("{}:", character.name)) {
+                // Assistant message
+                let content = processed_line
+                    .trim_start_matches(&format!("{}:", character.name))
+                    .trim()
+                    .to_string();
+                examples.push(Message::new_assistant(content));
+            } else if processed_line.contains(':') {
+                // Fallback: split on first colon
+                let parts: Vec<&str> = processed_line.splitn(2, ':').collect();
+                if parts.len() == 2 {
+                    let speaker = parts[0].trim();
+                    let content = parts[1].trim().to_string();
+
+                    if speaker == user_name {
+                        examples.push(Message::new_user(content));
+                    } else {
+                        examples.push(Message::new_assistant(content));
+                    }
+                }
+            }
+        }
+    }
+
+    examples
+}
+
 // Build injected context from roleplay settings
 fn build_roleplay_context(
     character: &Character,
@@ -1398,6 +1476,29 @@ fn build_api_messages(
     let mut api_messages = vec![Message::new_user(enhanced_system_prompt)];
     api_messages[0].role = "system".to_string();
 
+    // Insert message examples if enabled
+    if roleplay_settings.examples_enabled {
+        if let Some(ref mes_example) = character.mes_example {
+            if !mes_example.is_empty() {
+                let examples = parse_message_examples(mes_example, character, roleplay_settings);
+
+                // Insert examples based on position setting
+                match roleplay_settings.examples_position.as_str() {
+                    "after_system" => {
+                        // Insert right after system message (position 1)
+                        for (i, example) in examples.into_iter().enumerate() {
+                            api_messages.insert(1 + i, example);
+                        }
+                    }
+                    "before_history" | _ => {
+                        // Insert at end (before history gets added)
+                        api_messages.extend(examples);
+                    }
+                }
+            }
+        }
+    }
+
     // Add history messages with current swipe content
     for msg in &history.messages {
         let mut api_msg = Message::new_user(msg.get_content().to_string());
@@ -2630,6 +2731,18 @@ fn update_persona(
     save_roleplay_settings(&character_id, &settings)
 }
 
+#[tauri::command]
+fn update_examples_settings(
+    character_id: String,
+    enabled: bool,
+    position: String,
+) -> Result<(), String> {
+    let mut settings = load_roleplay_settings(&character_id);
+    settings.examples_enabled = enabled;
+    settings.examples_position = position;
+    save_roleplay_settings(&character_id, &settings)
+}
+
 #[tauri::command]
 fn update_recursion_depth(
     character_id: String,
@@ -2797,6 +2910,7 @@ struct TokenBreakdown {
     persona: usize,
     world_info: usize,
     authors_note: usize,
+    message_examples: usize,
     message_history: usize,
     current_input: usize,
     estimated_max_tokens: usize,
@@ -2887,6 +3001,19 @@ fn get_token_count(character_id: Option<String>, current_input: String) -> Resul
         0
     };
 
+    // Count message examples
+    let mut examples_tokens = 0;
+    if roleplay_settings.examples_enabled {
+        if let Some(ref mes_example) = character.mes_example {
+            if !mes_example.is_empty() {
+                let examples = parse_message_examples(mes_example, &character, &roleplay_settings);
+                for example in examples {
+                    examples_tokens += count_tokens(example.get_content());
+                }
+            }
+        }
+    }
+
     // Count message history
     let mut history_tokens = 0;
     for msg in &history.messages {
@@ -2898,7 +3025,7 @@ fn get_token_count(character_id: Option<String>, current_input: String) -> Resul
 
     // Calculate total
     let total = system_prompt_tokens + preset_tokens + persona_tokens + world_info_tokens +
-                authors_note_tokens + history_tokens + input_tokens;
+                authors_note_tokens + examples_tokens + history_tokens + input_tokens;
 
     // Estimate remaining tokens for response (assuming 16k context with 4k max response)
     let estimated_max_tokens = if total < 12000 { 4096 } else { 16384 - total };
@@ -2910,6 +3037,7 @@ fn get_token_count(character_id: Option<String>, current_input: String) -> Resul
         persona: persona_tokens,
         world_info: world_info_tokens,
         authors_note: authors_note_tokens,
+        message_examples: examples_tokens,
         message_history: history_tokens,
         current_input: input_tokens,
         estimated_max_tokens,
@@ -3211,6 +3339,7 @@ pub fn run() {
             update_roleplay_depths,
             update_authors_note,
             update_persona,
+            update_examples_settings,
             update_recursion_depth,
             get_presets,
             get_preset,

src/index.html

@@ -153,9 +153,34 @@
                 Enable Author's Note
               </label>
             </div>
-            <button type="button" id="save-authors-note-btn" class="btn-primary" style="width: 100%;">
+            <button type="button" id="save-authors-note-btn" class="btn-primary" style="width: 100%; margin-bottom: 20px;">
               Save Author's Note
             </button>
+
+            <!-- Message Examples Section -->
+            <div class="form-group" style="border-top: 1px solid var(--border); padding-top: 16px;">
+              <label>Message Examples</label>
+              <p style="color: var(--text-secondary); font-size: 12px; margin-bottom: 8px;">
+                Use character card's message examples to teach the AI the character's voice and style.
+              </p>
+              <label>
+                <input type="checkbox" id="examples-enabled" />
+                Enable Message Examples
+              </label>
+            </div>
+            <div class="form-group">
+              <label for="examples-position">Examples Position</label>
+              <select id="examples-position" style="width: 100%;">
+                <option value="after_system">After System Prompt (Recommended)</option>
+                <option value="before_history">Before Message History</option>
+              </select>
+              <p style="color: var(--text-secondary); font-size: 11px; margin-top: 4px;">
+                Where to inject examples in the context. After system prompt works best for most models.
+              </p>
+            </div>
+            <button type="button" id="save-examples-btn" class="btn-primary" style="width: 100%;">
+              Save Examples Settings
+            </button>
           </div>
         </div>
 
@@ -671,6 +696,10 @@
               <span>Author's Note:</span>
               <span id="token-authorsnote">0</span>
             </div>
+            <div class="token-breakdown-item">
+              <span>Message Examples:</span>
+              <span id="token-examples">0</span>
+            </div>
             <div class="token-breakdown-item">
               <span>Message History:</span>
               <span id="token-history">0</span>

src/main.js

@@ -1561,6 +1561,7 @@ function setupAppControls() {
   document.getElementById('add-worldinfo-btn').addEventListener('click', handleAddWorldInfoEntry);
   document.getElementById('save-authors-note-btn').addEventListener('click', handleSaveAuthorsNote);
   document.getElementById('save-persona-btn').addEventListener('click', handleSavePersona);
+  document.getElementById('save-examples-btn').addEventListener('click', handleSaveExamples);
 
   // Setup recursion depth change handler
   document.getElementById('recursion-depth').addEventListener('change', handleRecursionDepthChange);
@@ -1622,6 +1623,7 @@ async function updateTokenCount() {
       document.getElementById('token-persona').textContent = tokenData.persona;
       document.getElementById('token-worldinfo').textContent = tokenData.world_info;
       document.getElementById('token-authorsnote').textContent = tokenData.authors_note;
+      document.getElementById('token-examples').textContent = tokenData.message_examples;
       document.getElementById('token-history').textContent = tokenData.message_history;
       document.getElementById('token-input').textContent = tokenData.current_input;
       document.getElementById('token-total-detail').textContent = tokenData.total;
@@ -2012,6 +2014,10 @@ async function loadRoleplaySettings() {
     document.getElementById('persona-description').value = settings.persona_description || '';
     document.getElementById('persona-enabled').checked = settings.persona_enabled || false;
 
+    // Load Message Examples
+    document.getElementById('examples-enabled').checked = settings.examples_enabled || false;
+    document.getElementById('examples-position').value = settings.examples_position || 'after_system';
+
     // Load Presets
     await loadPresets();
   } catch (error) {
@@ -2243,6 +2249,29 @@ async function handleSavePersona() {
   }
 }
 
+// Save Message Examples Settings
+async function handleSaveExamples() {
+  if (!currentCharacter) return;
+
+  const enabled = document.getElementById('examples-enabled').checked;
+  const position = document.getElementById('examples-position').value;
+
+  try {
+    await invoke('update_examples_settings', {
+      characterId: currentCharacter.id,
+      enabled,
+      position
+    });
+
+    // Show success message
+    setStatus('Message Examples settings saved', 'success');
+    setTimeout(() => setStatus('Ready'), 2000);
+  } catch (error) {
+    console.error('Failed to save Message Examples settings:', error);
+    setStatus('Failed to save Message Examples settings', 'error');
+  }
+}
+
 // Handle recursion depth change
 async function handleRecursionDepthChange() {
   if (!currentCharacter) return;