chore: remove tokenlens and token usage tracking (#1357)

lib/ai/prompts.ts

@@ -117,8 +117,10 @@ export const updateDocumentPrompt = (
 ${currentContent}`;
 };
 
-export const titlePrompt = `\n
-    - you will generate a short title based on the first message a user begins a conversation with
-    - ensure it is not more than 80 characters long
-    - the title should be a summary of the user's message
-    - do not use quotes or colons`;
+export const titlePrompt = `Generate a very short chat title (2-5 words max) based on the user's message.
+Rules:
+- Maximum 30 characters
+- No quotes, colons, hashtags, or markdown
+- Just the topic/intent, not a full sentence
+- If the message is a greeting like "hi" or "hello", respond with just "New conversation"
+- Be concise: "Weather in NYC" not "User asking about the weather in New York City"`;

lib/db/queries.ts

@@ -17,7 +17,6 @@ import postgres from "postgres";
 import type { ArtifactKind } from "@/components/artifact";
 import type { VisibilityType } from "@/components/visibility-selector";
 import { ChatSDKError } from "../errors";
-import type { AppUsage } from "../usage";
 import { generateUUID } from "../utils";
 import {
   type Chat,
@@ -502,21 +501,17 @@ export async function updateChatVisibilityById({
   }
 }
 
-export async function updateChatLastContextById({
+export async function updateChatTitleById({
   chatId,
-  context,
+  title,
 }: {
   chatId: string;
-  // Store merged server-enriched usage object
-  context: AppUsage;
+  title: string;
 }) {
   try {
-    return await db
-      .update(chat)
-      .set({ lastContext: context })
-      .where(eq(chat.id, chatId));
+    return await db.update(chat).set({ title }).where(eq(chat.id, chatId));
   } catch (error) {
-    console.warn("Failed to update lastContext for chat", chatId, error);
+    console.warn("Failed to update title for chat", chatId, error);
     return;
   }
 }

lib/db/schema.ts

@@ -3,7 +3,6 @@ import {
   boolean,
   foreignKey,
   json,
-  jsonb,
   pgTable,
   primaryKey,
   text,
@@ -11,7 +10,6 @@ import {
   uuid,
   varchar,
 } from "drizzle-orm/pg-core";
-import type { AppUsage } from "../usage";
 
 export const user = pgTable("User", {
   id: uuid("id").primaryKey().notNull().defaultRandom(),
@@ -31,7 +29,6 @@ export const chat = pgTable("Chat", {
   visibility: varchar("visibility", { enum: ["public", "private"] })
     .notNull()
     .default("private"),
-  lastContext: jsonb("lastContext").$type<AppUsage | null>(),
 });
 
 export type Chat = InferSelectModel<typeof chat>;

lib/types.ts

@@ -6,7 +6,6 @@ import type { getWeather } from "./ai/tools/get-weather";
 import type { requestSuggestions } from "./ai/tools/request-suggestions";
 import type { updateDocument } from "./ai/tools/update-document";
 import type { Suggestion } from "./db/schema";
-import type { AppUsage } from "./usage";
 
 export type DataPart = { type: "append-message"; message: string };
 
@@ -42,7 +41,7 @@ export type CustomUIDataTypes = {
   kind: ArtifactKind;
   clear: null;
   finish: null;
-  usage: AppUsage;
+  "chat-title": string;
 };
 
 export type ChatMessage = UIMessage<

lib/usage.ts

@@ -1,5 +0,0 @@
-import type { LanguageModelUsage } from "ai";
-import type { UsageData } from "tokenlens/helpers";
-
-// Server-merged usage: base usage + TokenLens summary + optional modelId
-export type AppUsage = LanguageModelUsage & UsageData & { modelId?: string };