Backend Development Guidelines

Backend Development Guidelines

Use this skill for backend and API work across web/, worker/, and packages/shared/.

When to Apply

• Creating or modifying tRPC routers and procedures
• Creating or modifying public API endpoints
• Creating or modifying queue processors, producers, or queue-backed workflows
• Building or refactoring backend services and repositories
• Working on backend auth, middleware, validation, or observability
• Updating Prisma or ClickHouse access patterns
• Adding a field, option, flag, or enum member to shared backend code
• Adding or fixing backend tests

How to Read This Skill

• Use this SKILL.md when the task spans multiple backend areas or you need the end-to-end reference map.
• Read only the specific reference file that matches the work when the scope is narrower.
• If the task introduces a user-supplied URL, an outbound HTTP request, a new integration, or touches secrets, RBAC, or redirect handling, also load the shared security-review skill before designing or implementing the change.

Before Adding a New Concept

Before adding a field to a shared schema or payload, an option or flag on a shared signature, an enum member, an env toggle, or a branch that exists for one caller — or before concluding that no change is needed — read references/new-concepts.md.

Quick Start Checklists

UI: New tRPC Feature

• Define the router in features/[feature]/server/*Router.ts.
• Use the appropriate protected or public procedure.