Maintain consistent patterns across all API endpoints, including naming conventions, response structures, HTTP status codes, and interface design. This ensures a predictable and professional API surface that follows established conventions. Key consistency requirements: - Use kebab-case (dashes) for endpoint paths, not snake_case: `/end-users` not `/end_users`, `/context-variables` not `/context_variables` - Return appropriate HTTP status codes: 200 for updates that return data, 204 for updates without response body, 422 for semantic validation errors - Follow consistent response patterns: create dedicated response DTOs like `ReadEvaluationResponse` instead of returning internal DTOs directly - Use uniform naming across similar operations: avoid having multiple methods for identical functionality - Maintain consistent response model specifications: either specify `response_model` everywhere or nowhere within the same module Example of consistent endpoint design: ```python @router.patch("/{customer_id}", response_model=CustomerDTO) async def update_customer(params: CustomerUpdateParamsDTO) -> CustomerDTO: # Returns 200 OK with updated entity @router.get("/{evaluation_id}") async def get_evaluation(evaluation_id: EvaluationId) -> ReadEvaluationResponse: # Dedicated response DTO, not direct internal model ``` This prevents API fragmentation and reduces cognitive load for API consumers by establishing predictable patterns they can rely on across all endpoints.