Backend Writing (Metroscope)

Use this skill when implementing or editing backend code in this repo.

Essentials

• Use io-ts for runtime validation.
• Prefer null over undefined for intentional absence.
• When making API changes run yarn openapi:generate to keep the generated API doc up to date.
• Use logger for logging errors instead of console.error.
• Do NOT export any type or interface that is not used outside of the file it is defined in.

Baseline references

Use back/CONTRIBUTING.md for API and Prisma conventions. See also: back/AGENTS.override.md for operational context.

Workflow