Switch LLM provider to DeepSeek v4 Pro

- Create shared openai client (src/lib/openai.ts) pointing to api.deepseek.com
- Replace all gpt-4o-mini model references with deepseek-v4-pro
- Refactor 3 API routes to use shared client instead of inline OpenAI() calls
- Add OPENAI_BASE_URL env var for endpoint configuration

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/api/cron/weekly-summaries/route.ts

@@ -1,5 +1,5 @@
 import { NextResponse } from "next/server";
-import OpenAI from "openai";
+import { openai } from "@/lib/openai";
 import { generateAllWeeklySummaries } from "@/lib/engines/summary-generator";
 
 export async function POST(req: Request) {
@@ -18,8 +18,6 @@ export async function POST(req: Request) {
     return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
   }
 
-  const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
-
   try {
     const results = await generateAllWeeklySummaries(openai);
     const succeeded = results.filter((r) => r.success).length;

src/app/api/session/complete/route.ts

@@ -1,6 +1,6 @@
 import { auth } from "@clerk/nextjs/server";
 import { NextResponse } from "next/server";
-import OpenAI from "openai";
+import { openai } from "@/lib/openai";
 import { prisma } from "@/lib/prisma";
 import { processReflection } from "@/lib/engines/reflection-analyzer";
 import { computeStateUpdate } from "@/lib/engines/progress-tracker";
@@ -49,7 +49,6 @@ export async function POST(req: Request) {
     );
   }
 
-  const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
 
   // Process reflection through LLM #2
   const reflection = await processReflection(

src/app/api/task/generate/route.ts

@@ -1,14 +1,12 @@
 import { auth } from "@clerk/nextjs/server";
 import { NextResponse } from "next/server";
-import OpenAI from "openai";
+import { openai } from "@/lib/openai";
 import { generateDailyTask } from "@/lib/engines/task-selector";
 
 export async function POST() {
   const { userId } = await auth();
   if (!userId) return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
 
-  const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
-
   try {
     const result = await generateDailyTask(userId, openai);
 

src/lib/engines/reflection-analyzer.ts

@@ -98,7 +98,7 @@ export async function analyzeReflection(
 
   try {
     const response = await openai.chat.completions.create({
-      model: "gpt-4o-mini",
+      model: "deepseek-v4-pro",
       messages: [
         { role: "system", content: REFLECTION_PROMPT },
         {

src/lib/engines/summary-generator.ts

@@ -106,7 +106,7 @@ export async function generateWeeklySummary(
 
   try {
     const response = await openai.chat.completions.create({
-      model: "gpt-4o-mini",
+      model: "deepseek-v4-pro",
       messages: [
         { role: "system", content: SUMMARY_PROMPT },
         {

src/lib/engines/task-selector.ts

@@ -123,7 +123,7 @@ export async function generateTask(
 
   try {
     const response = await openai.chat.completions.create({
-      model: "gpt-4o-mini",
+      model: "deepseek-v4-pro",
       messages: [
         { role: "system", content: TASK_PROMPT },
         {

src/lib/openai.ts

@@ -0,0 +1,8 @@
+import OpenAI from "openai";
+
+const baseURL = process.env.OPENAI_BASE_URL || "https://api.deepseek.com";
+
+export const openai = new OpenAI({
+  apiKey: process.env.OPENAI_API_KEY,
+  baseURL,
+});

src/lib/safety.ts

@@ -43,7 +43,7 @@ export async function llmSafetyCheck(
 ): Promise<SafetyResult> {
   try {
     const response = await openai.chat.completions.create({
-      model: "gpt-4o-mini",
+      model: "deepseek-v4-pro",
       messages: [
         { role: "system", content: SELF_REVIEW_PROMPT },
         { role: "user", content: text },