refactor: update session title model to use configured summary model and remove deprecated constant

Author: neozhu

app/api/messages/sync/route.test.mts

@@ -3,7 +3,7 @@ import assert from "node:assert/strict";
 import { readFileSync } from "node:fs";
 import { fileURLToPath } from "node:url";
 
-test("message sync summarizes every first user title with the fast mini model", () => {
+test("message sync summarizes every first user title with the configured summary model", () => {
   const routeSource = readFileSync(
     fileURLToPath(new URL("./route.ts", import.meta.url)),
     "utf8"
@@ -17,7 +17,11 @@ test("message sync summarizes every first user title with the fast mini model",
     routeSource,
     /const\s+lastText\s*=\s*last\s*\?\s*messageText\(last\)/
   );
-  assert.match(routeSource, /model:\s*openai\(SESSION_TITLE_MODEL_ID\)/);
+  assert.match(
+    routeSource,
+    /import\s+\{\s*getConversationSummaryModelId\s*\}\s+from\s+"@\/lib\/ai\/openai"/
+  );
+  assert.match(routeSource, /model:\s*openai\(getConversationSummaryModelId\(\)\)/);
   assert.match(routeSource, /reasoningEffort:\s*"none"/);
   assert.match(routeSource, /session:\s*{\s*id:\s*sessionId,\s*\.\.\.update\s*}/);
 });

app/api/messages/sync/route.ts

@@ -1,9 +1,9 @@
 import { generateText, type UIMessage } from "ai";
 import { openai } from "@ai-sdk/openai";
+import { getConversationSummaryModelId } from "@/lib/ai/openai";
 import { persistRollingConversationSummary } from "@/lib/botchat/rolling-summary";
 import { createSupabaseServerClient } from "@/lib/supabase/server";
 import {
-  SESSION_TITLE_MODEL_ID,
   buildSessionTitlePrompt,
   normalizeGeneratedSessionTitle,
   shouldGenerateSessionTitle,
@@ -59,7 +59,7 @@ function messageTotalTokens(message: UIMessage) {
 async function buildSessionTitle(titleSource: string) {
   try {
     const { text } = await generateText({
-      model: openai(SESSION_TITLE_MODEL_ID),
+      model: openai(getConversationSummaryModelId()),
       providerOptions: {
         openai: {
           reasoningEffort: "none",

lib/botchat/session-title.test.mts

@@ -4,18 +4,13 @@ import assert from "node:assert/strict";
 import {
   SESSION_TITLE_MAX_CJK_CHARACTERS,
   SESSION_TITLE_MAX_ENGLISH_WORDS,
-  SESSION_TITLE_MODEL_ID,
   buildSessionTitlePrompt,
   getOptimisticSessionTitle,
   isSessionTitleTooLong,
   normalizeGeneratedSessionTitle,
   shouldGenerateSessionTitle,
 } from "./session-title.ts";
 
-test("session title model is the fast mini model", () => {
-  assert.equal(SESSION_TITLE_MODEL_ID, "gpt-5.4-mini");
-});
-
 test("session title over-limit detection uses twelve English words", () => {
   assert.equal(
     isSessionTitleTooLong(

lib/botchat/session-title.ts

@@ -1,4 +1,3 @@
-export const SESSION_TITLE_MODEL_ID = "gpt-5.4-mini";
 export const SESSION_TITLE_MAX_ENGLISH_WORDS = 12;
 export const SESSION_TITLE_MAX_CJK_CHARACTERS = 12;