Enhance environment configuration and database connection handling

- Implemented dynamic import for environment validation in next.config.js to avoid blocking initialization.
- Updated prisma/schema.prisma to include a direct connection URL for Supabase, improving performance and connection management.
- Modified src/env.js to add optional DIRECT_URL for environment variables.
- Refactored db.ts to optimize Prisma client usage in serverless environments, ensuring connection reuse and graceful shutdown handling.

Author: QSchlegel

next.config.js

@@ -1,8 +1,16 @@
 /**
  * Run `build` or `dev` with `SKIP_ENV_VALIDATION` to skip env validation. This is especially useful
  * for Docker builds.
+ * 
+ * Note: We use dynamic import here to avoid blocking Next.js initialization.
+ * The env validation will happen when the module is actually used, not during config load.
  */
-await import("./src/env.js");
+if (!process.env.SKIP_ENV_VALIDATION) {
+  // Use dynamic import to avoid blocking initialization
+  import("./src/env.js").catch((err) => {
+    console.error("Failed to load env validation:", err);
+  });
+}
 
 /** @type {import("next").NextConfig} */
 const config = {

prisma/schema.prisma

@@ -5,6 +5,14 @@ generator client {
 datasource db {
   provider = "postgresql"
   url      = env("DATABASE_URL")
+  // For Supabase + Vercel serverless optimization:
+  // - DATABASE_URL: Use Supabase's connection pooling URL (Transaction mode)
+  //   Example: postgresql://user:pass@host:6543/db?pgbouncer=true
+  // - DIRECT_URL: Use Supabase's direct connection URL (for migrations)
+  //   Example: postgresql://user:pass@host:5432/db
+  //   For local dev without Supabase, set DIRECT_URL to DATABASE_URL
+  //   This separation improves performance and prevents connection pool exhaustion
+  directUrl = env("DIRECT_URL")
 }
 
 model User {

src/env.js

@@ -8,6 +8,7 @@ export const env = createEnv({
    */
   server: {
     DATABASE_URL: z.string().url(),
+    DIRECT_URL: z.string().url().optional(),
     NODE_ENV: z
       .enum(["development", "test", "production"])
       .default("development"),
@@ -45,6 +46,7 @@ export const env = createEnv({
    */
   runtimeEnv: {
     DATABASE_URL: process.env.DATABASE_URL,
+    DIRECT_URL: process.env.DIRECT_URL,
     NODE_ENV: process.env.NODE_ENV,
     // NEXTAUTH_SECRET: process.env.NEXTAUTH_SECRET,
     // NEXTAUTH_URL: process.env.NEXTAUTH_URL,

src/server/db.ts

@@ -2,16 +2,49 @@ import { PrismaClient } from "@prisma/client";
 
 import { env } from "@/env";
 
-const createPrismaClient = () =>
-  new PrismaClient({
+const createPrismaClient = () => {
+  const client = new PrismaClient({
     log:
       env.NODE_ENV === "development" ? ["query", "error", "warn"] : ["error"],
   });
 
+  // In serverless environments (Vercel), we want to avoid eager connection
+  // Prisma will connect lazily on first query, which is better for cold starts
+  // Don't call $connect() here - let Prisma handle connections on-demand
+
+  return client;
+};
+
 const globalForPrisma = globalThis as unknown as {
   prisma: ReturnType<typeof createPrismaClient> | undefined;
 };
 
-export const db = globalForPrisma.prisma ?? createPrismaClient();
+// Reuse Prisma client across invocations to optimize connection pooling
+// In Vercel serverless, the same container may handle multiple requests
+// Reusing the client prevents creating new connections for each request
+export const db =
+  globalForPrisma.prisma ?? createPrismaClient();
 
-if (env.NODE_ENV !== "production") globalForPrisma.prisma = db;
+// Store in globalThis for reuse across all environments
+// This is especially important in serverless where the same container
+// may handle multiple requests, allowing connection reuse
+if (!globalForPrisma.prisma) {
+  globalForPrisma.prisma = db;
+}
+
+// Graceful shutdown handling
+if (typeof process !== "undefined") {
+  process.on("beforeExit", async () => {
+    await db.$disconnect();
+  });
+
+  process.on("SIGINT", async () => {
+    await db.$disconnect();
+    process.exit(0);
+  });
+
+  process.on("SIGTERM", async () => {
+    await db.$disconnect();
+    process.exit(0);
+  });
+}