tRPC overview (in our stack)

tRPC is our internal API layer between the browser UI and server-side logic. It provides:

• end-to-end typing (client ↔ server)
• a single place to enforce validation (Zod) + auth (middleware)
• a clean boundary for calling internal microservices (server-side)

Mental model

Key concepts to learn (with docs)

• What is tRPC: https://trpc.io/docs 
• Routers / procedures: https://trpc.io/docs/server/routers 
• Input validation (Zod): https://trpc.io/docs/server/validators 
• Middleware: https://trpc.io/docs/server/middlewares 
• Error handling: https://trpc.io/docs/server/error-handling 

Standard approach (what we’ll converge on)

• Every procedure has:
  • input schema (Zod)
  • clear auth requirements (public vs protected)
  • consistent error mapping (developer logs vs user message)
• Microservice calls happen inside procedures (or server-only helper modules called by procedures).

Exercises

• content/exercises/04-trpc/01-protected-procedure.mdx