typescript

name	typescript
description	TypeScript backend conventions for this user: Bun, Fastify, Zod, PostgreSQL, Drizzle ORM, Better Auth. Load before creating or editing TypeScript application code.

TypeScript conventions

• Runtime and package manager: Bun. Use bun for dependencies, scripts, tests, and execution; do not add npm, pnpm, or a second lockfile.

Default backend stack

Use this stack for new TypeScript backend work unless the repository already has an established alternative:

• HTTP: Fastify. Keep routes thin and register behavior through Fastify plugins.
• Validation: Zod with fastify-type-provider-zod. A route's request and response schemas are its executable contract.
• Database: PostgreSQL.
• Database access and migrations: Drizzle ORM and drizzle-kit. Keep the schema, migrations, and database access in the application rather than introducing a second ORM.
• Authentication: Better Auth with its Drizzle adapter. Use the admin, organization, and API-key plugins when those capabilities are needed.
• Server-to-browser events: Server-Sent Events for one-way updates. Use WebSocket only when clients must send application messages over the same connection.
• Tests: bun:test, unless an integration dependency requires another test runner.

Default frontend stack

• Use svelte and shadcn-svelte.

New projects

• Add node_modules/ to the project's .gitignore when creating a new TypeScript project. Do this even when a parent .gitignore already ignores it, so the project remains safe if it is moved or published independently.