T3 Stack Builder

T3 Stack Builder scaffolds and extends apps built on the T3 stack — Next.js, tRPC, Prisma, NextAuth.js, and Tailwind CSS — wiring them together so types flow unbroken from your database schema to your React components. It's for developers who like create-t3-app's opinions but don't want to hand-write every new router, model, and auth provider afterward. You describe the feature; it generates the Prisma model, the tRPC procedures, and the typed client hooks that consume them.

When to use it

• Starting a new T3 project and you want App Router, a configured prisma/schema.prisma, and a working NextAuth setup on day one.
• Adding a new resource (say, Post or Organization) and you'd otherwise repeat the model → router → api.x.useQuery() ceremony by hand.
• Bolting a new OAuth provider (GitHub, Google, Discord) onto an existing authOptions.
• Splitting a growing appRouter into feature routers without breaking the inferred AppRouter type.

What it does

• Runs create-t3-app style scaffolding with sensible defaults: App Router or Pages Router, @trpc/server/@trpc/react-query, Prisma client singleton, and Tailwind preflight.
• Generates tRPC routers using createTRPCRouter, publicProcedure, and protectedProcedure, with Zod input validation on each procedure.
• Writes Prisma models into schema.prisma and reminds you to run prisma migrate dev / prisma generate.
• Configures NextAuth providers and the Prisma adapter in src/server/auth.ts, including session callbacks that attach user.id.
• Keeps the RouterInputs / RouterOutputs inference helpers intact so the frontend stays fully typed.

Usage example

curl -fsSL --create-dirs -o ~/.claude/skills/t3-stack-builder/SKILL.md https://claudeskil.com/skills/t3-stack-builder/SKILL.md

# then, in a chat:
"Scaffold a new T3 app called taskly with the GitHub provider and a Task model
(title, done boolean, owner relation to User). Add a task router with list,
create, and toggle procedures behind protectedProcedure."

Generated procedure shape:

toggle: protectedProcedure
  .input(z.object({ id: z.string() }))
  .mutation(({ ctx, input }) =>
    ctx.db.task.update({ where: { id: input.id }, data: { done: { /* flip */ } } })),

Tips & gotchas

• Generated procedures reference ctx.db and ctx.session; the skill assumes the standard createTRPCContext. If you renamed prisma to db (or vice versa), tell it.
• It edits schema.prisma but does not run migrations — review the diff, then run npx prisma migrate dev yourself.
• protectedProcedure relies on the session callback exposing session.user.id. If auth was scaffolded elsewhere, verify that callback exists.
• Adding a provider needs the matching AUTH_* env vars; the skill updates .env.example, not your real .env.

FAQ

Does it support the App Router? Yes — it targets the current create-t3-app layout with src/app and Server Components, and also handles legacy Pages Router projects.

Can I use it on an existing repo? Yes. Point it at a repo that already follows the T3 conventions; it appends routers and models rather than overwriting.

Postgres, MySQL, or SQLite? Whatever your datasource db provider is set to — it writes provider-agnostic Prisma models and leaves the connection to your config.