Folder Structure (App)

prisma

The prisma folder contains the schema.prisma file which is used to configure the database connection and the database schema. It is also the location to store migration files and/or seed scripts, if used. See Prisma usage for more information.

public

The public folder contains static assets that are served by the web server. The favicon.ico file is an example of a static asset.

src/env

Used for environment variable validation and type definitions - see Environment Variables.

src/app

The app folder contains all the routes of the Next.js application. The page.tsx file at the root directory of /app is the homepage of the application. The layout.tsx file is used to wrap the application with providers. See Next.js documentation↗ for more information.

src/app/_components/post.tsx

The post.tsx file is an example of a client component that calls a tRPC mutation.

src/app/api/auth/[...nextauth]/route.ts

The [...nextauth]/route.ts file is the NextAuth.js authentication slug route. It is used to handle authentication requests. See NextAuth.js usage for more information on NextAuth.js, and Next.js Dynamic Routes Docs↗ for info on catch-all/slug routes.

src/app/api/trpc/[trpc]/route.ts

The [trpc].ts file is the tRPC API entrypoint. It is used to handle tRPC requests. See tRPC usage for more information on this file, and Next.js Dynamic Routes Docs↗ for info on catch-all/slug routes.

src/server

The server folder is used to clearly separate code that is only used on the server.

src/server/auth.ts

The main entrypoint for server-side authentication logic. Here, we setup the NextAuth.js configuration options, perform module augmentation as well as provide some DX utilities for authentication such as retrieving the user’s session on the server-side. See NextAuth.js usage for more information.

src/server/db.ts

The db.ts file is used to instantiate the Prisma client at global scope. See Prisma usage and best practices for using Prisma with Next.js↗ for more information.

src/server/db

The db folder contains the Drizzle client and schema. Note that drizzle also requires the drizzle.config.ts file (see below).

src/server/db/index.ts

The index.ts file is used to instantiate the Drizzle client at global scope. See Drizzle usage for more information.

src/server/db/schema.ts

The schema.ts file is used to define the database schema. See Drizzle usage and Drizzle schema docs↗ for more information.

src/server/api

The api folder contains the tRPC server-side code.

src/server/api/routers

The routers folder contains all your tRPC sub-routers.

src/server/api/routers/example.ts

The example.ts file is an example tRPC router utilizing the publicProcedure helper to demonstrate how to create a public tRPC route.

Depending on your chosen packages this router contains more or less routes to best demonstrate the usage to your needs.

src/server/api/trpc.ts

The trpc.ts file is the main configuration file for your tRPC back-end. In here we:

1. Define context used in tRPC requests. See tRPC usage for more information.
2. Export procedure helpers. See tRPC usage for more information.

src/server/api/root.ts

The root.ts file is used to merge tRPC routers and export them as a single router, as well as the router’s type definition. See tRPC usage for more information.

src/trpc

The trpc folder contains the setup to let you call tRPC procedures from server components and client components.

src/trpc/query-client.ts

The query-client.ts file creates the Query Client that tRPC uses to cache and deduplicate data in client components.

src/trpc/react.tsx

The react.tsx file is the front-end entrypoint to tRPC. It also contains utility types for the router inputs and outputs. See tRPC usage for more information.

src/trpc/server.ts

The server.ts file is the entrypoint for using tRPC in Server Components.

.env

The .env file is used to store environment variables. See Environment Variables for more information. This file should not be committed to git history.

.env.example

The .env.example file shows example environment variables based on the chosen libraries. This file should be committed to git history.

.eslintrc.cjs

The .eslintrc.cjs file is used to configure ESLint. See ESLint Docs↗ for more information.

db.sqlite (sqlite only)

The db.sqlite file contains your development database. This file is only created after running the db:push parseCommandLine, and ignored by git.

drizzle.config.ts

The drizzle.config.ts file is used to configure drizzle kit. See the documentation↗ for more information.

next-env.d.ts

The next-env.d.ts file ensures Next.js types are picked up by the TypeScript compiler. You should not remove it or edit it as it can change at any time. See Next.js Docs↗ for more information.

next.config.mjs

The next.config.mjs file is used to configure Next.js. See Next.js Docs↗ for more information. Note: The .mjs extension is used to allow for ESM imports.

postcss.config.js

The postcss.config.js file is used for Tailwind PostCSS usage. See Tailwind PostCSS Docs↗ for more information.

prettier.config.mjs

The prettier.config.mjs file is used to configure Prettier to include the prettier-plugin-tailwindcss for formatting Tailwind CSS classes. See the Tailwind CSS blog post↗ for more information.

start-database.sh (mysql or postgres only)

The start-database.sh file is used to start the database. Please see the comments inside the file for information on how to start the database with your operating system.

tsconfig.json

The tsconfig.json file is used to configure TypeScript. Some non-defaults, such as strict mode, have been enabled to ensure the best usage of TypeScript for Create T3 App and its libraries. See TypeScript Docs↗ or TypeScript Usage for more information.