新增会话标题管理功能，优化会话标题生成

src/chat/sessionBridge.ts

@@ -11,6 +11,7 @@ export type ChatRequestContext = SessionContext & {
 export class ChatSessionBridge {
   // 这里额外保存 session -> 用户上下文，供工具桥在服务端代发真实后端请求时复用。
   private readonly sessionContexts = new Map<string, ChatRequestContext>();
+  private readonly sessionTitles = new Map<string, string>();
 
   constructor(
     private readonly registry: SessionRegistry,
@@ -70,6 +71,18 @@ export class ChatSessionBridge {
     return this.sessionContexts.get(sessionId) ?? null;
   }
 
+  getSessionTitle(sessionId: string) {
+    return this.sessionTitles.get(sessionId);
+  }
+
+  setSessionTitle(sessionId: string, title: string) {
+    const normalized = title.trim();
+    if (!normalized) {
+      return;
+    }
+    this.sessionTitles.set(sessionId, normalized);
+  }
+
   async abort(context: {
     clientSessionId?: string;
     accessToken?: string;
@@ -167,6 +180,7 @@ export class ChatSessionBridge {
     const expiredSessionIds = this.registry.evictExpired();
     for (const sessionId of expiredSessionIds) {
       this.sessionContexts.delete(sessionId);
+      this.sessionTitles.delete(sessionId);
       // 这里用 abort 做轻量清理；即使失败，也不阻断本地过期回收。
       void this.runtime.abortSession(sessionId).catch((error) => {
         logger.debug({ sessionId, err: error }, "ignoring failed abort for expired session");

src/routes/chat.ts

@@ -174,6 +174,12 @@ export const buildChatRouter = (
       res.flushHeaders?.();
 
       const clientSessionId = requestContext.clientSessionId;
+      const existingSessionTitle = sessionBridge.getSessionTitle(binding.sessionId);
+      const sessionTitle = existingSessionTitle
+        ?? (await generateSessionTitle(runtime, parsed.data.message));
+      if (!existingSessionTitle) {
+        sessionBridge.setSessionTitle(binding.sessionId, sessionTitle);
+      }
       let streamClosed = false;
       const abortController = new AbortController();
       const handleClientClose = () => {
@@ -187,6 +193,12 @@ export const buildChatRouter = (
       res.on("close", handleClientClose);
 
       try {
+        res.write(
+          toSse("session_title", {
+            session_id: clientSessionId,
+            title: sessionTitle,
+          }),
+        );
         await streamPromptResponse({
           runtime,
           opencodeSessionId: binding.sessionId,
@@ -556,6 +568,74 @@ const getToolProgressTitle = (tool: string, status: string) => {
   return `正在调用 ${toolName}`;
 };
 
+const buildSessionTitle = (message: string) => {
+  const normalized = message.replace(/\s+/g, " ").trim();
+  if (!normalized) {
+    return "新对话";
+  }
+  return normalized.length > 24 ? `${normalized.slice(0, 24)}...` : normalized;
+};
+
+const TITLE_PROMPT_TIMEOUT_MS = 2500;
+
+const generateSessionTitle = async (
+  runtime: OpencodeRuntimeAdapter,
+  userMessage: string,
+) => {
+  const fallback = buildSessionTitle(userMessage);
+  const normalized = userMessage.replace(/\s+/g, " ").trim();
+  if (!normalized) {
+    return fallback;
+  }
+
+  const titleSession = await runtime.createSession(`title-${Date.now().toString(36)}`);
+  const request = runtime
+    .prompt(
+      titleSession.id,
+      [
+        "你是会话标题生成器。",
+        "请根据用户问题生成一个 8-16 字中文标题。",
+        "要求：简洁、可读、避免标点、不要引号、不要解释。",
+        "只输出标题本身。",
+        `用户问题：${normalized}`,
+      ].join("\n"),
+    )
+    .then(async () => {
+      const messages = await runtime.messages(titleSession.id, 20);
+      const assistantMessage = [...messages]
+        .reverse()
+        .find((message) => message.info.role === "assistant");
+      const title = collectTextContent(assistantMessage?.parts ?? []);
+      return normalizeGeneratedTitle(title, fallback);
+    });
+
+  const timeout = new Promise<string>((resolve) => {
+    setTimeout(() => resolve(fallback), TITLE_PROMPT_TIMEOUT_MS);
+  });
+
+  try {
+    return await Promise.race([request, timeout]);
+  } catch (error) {
+    logger.warn({ err: error }, "failed to generate session title, using fallback");
+    return fallback;
+  } finally {
+    await runtime.abortSession(titleSession.id).catch((error) => {
+      logger.debug({ sessionId: titleSession.id, err: error }, "failed to cleanup title session");
+    });
+  }
+};
+
+const normalizeGeneratedTitle = (rawTitle: string, fallback: string) => {
+  const normalized = rawTitle
+    .replace(/\s+/g, " ")
+    .replace(/["'“”‘’`]/g, "")
+    .trim();
+  if (!normalized) {
+    return fallback;
+  }
+  return normalized.length > 24 ? `${normalized.slice(0, 24)}...` : normalized;
+};
+
 const toolLabels: Record<string, string> = {
   dynamic_http_call: "后端数据查询",
   locate_features: "地图定位",