Instruction file imported from AbdallaMon/Insta-flow (.github/instructions/backend.instructions.md). Copyright stays with the author.

Backend Instructions (Server)

Must

• Follow module pattern:
  • <module>.routes.ts, <module>.service.ts, <module>.validators.ts, <module>.types.ts
• Do not create new endpoints unless explicitly requested. If needed, propose first.
• Validate inputs (use existing validators pattern). Never trust client input.
• Keep business logic in service, keep routes thin.

Frontend awareness

• Every endpoint must have:
  • request shape (params/body)
  • response shape (success + error)
  • stable field names (do not rename/remove fields used by frontend without coordinating)
• If response shape changes, mention required frontend updates explicitly.

Quality gates

• Typecheck + lint must pass.
• Add/adjust tests if repo has them (only if relevant).