> ## Documentation Index > Fetch the complete documentation index at: https://docs.junction.com/llms.txt > Use this file to discover all available pages before exploring further. # API Endpoints and Errors > Error handling and optional features for scheduling appointments at Patient Service Centers (PSCs). ## API Endpoints All endpoints require authentication and are prefixed with `/v3/order`: * [`POST /v3/order/psc/appointment/availability`](/api-reference/lab-testing/psc-scheduling/appointment-psc-availability) - Get available time slots * [`POST /v3/order/{order_id}/psc/appointment/book`](/api-reference/lab-testing/psc-scheduling/appointment-psc-booking) - Book an appointment * [`PATCH /v3/order/{order_id}/psc/appointment/reschedule`](/api-reference/lab-testing/psc-scheduling/appointment-psc-rescheduling) - Reschedule an appointment * [`PATCH /v3/order/{order_id}/psc/appointment/cancel`](/api-reference/lab-testing/psc-scheduling/appointment-psc-cancelling) - Cancel an appointment * [`GET /v3/order/{order_id}/psc/appointment`](/api-reference/lab-testing/psc-scheduling/get-psc-appointment) - Get appointment details * [`GET /v3/order/psc/appointment/cancellation-reasons`](/api-reference/lab-testing/psc-scheduling/appointment-psc-cancellation-reasons) - Get cancellation reasons *** ## Error Handling ### Environment Differences ⚠️ **Important**: Currently, error behavior differs between sandbox and production environments: | Environment | Quest Integration | Slot Conflict Behavior | | -------------- | ----------------- | --------------------------------------------- | | **Sandbox** | Mock client | Returns 400 (mock doesn't simulate conflicts) | | **Production** | Real Quest API | Returns 404 (actual Quest response) | **Recommendation**: For now, handle both 400 and 404 responses as potential slot-unavailability scenarios. ### Frequently Asked Questions #### Q: Do I need to parse error messages to distinguish between different 400 errors? **Yes.** Since multiple error types return 400 status codes, you must examine the error message content to determine the appropriate handling: * **Time in the past**: `"This appointment slot is no longer available. Please select a new time."` → Select new slot * **Invalid booking key**: `"Invalid booking key format"` → Fix request * **Missing parameters**: `"radius must be provided when using zip_code"` → Fix request * **Order state issues**: `"Order is not in a state that allows booking..."` → Contact support HTTP status codes alone are insufficient because our API uses 400 for multiple distinct error categories that require different user experiences. ### Error Categories #### Slot Unavailability Errors *The user should select a different time slot* | Status | Error Message | When It Occurs | User Action | | ---------- | --------------------------------------------------------------------------- | ---------------------------------------- | -------------------------------------- | | 400 | `"This appointment slot is no longer available. Please select a new time."` | Requested time is in the past | Select a future time slot | | 400 or 404 | Quest-specific error messages | Slot already taken or no longer exists | Select a different time slot | | 404 | `"No slots found for zip code"` | No locations/slots in the area | Try a different location or date range | | 404 | `"No slots found. Not all PSCs support scheduling..."` | All locations lack scheduling capability | Use different locations | #### Input Validation Errors *Fix the request parameters* | Status | Error Message | When It Occurs | User Action | | ------ | ------------------------------------------------------------- | ------------------------------------- | ----------------------------------------------- | | 400 | `"Invalid booking key format"` | Malformed or corrupted booking key | Refresh availability and get a new booking key | | 400 | `"Location with site code {code} not found"` | Invalid PSC location code | Use a valid site code from the availability API | | 400 | `"Location with site code {code} is no longer active"` | PSC location disabled | Select a different location | | 400 | `"start_date must be greater or equal than the current date"` | Past date in the availability request | Use current or future date | | 400 | `"site_codes or zip_code must be provided"` | Missing search parameters | Provide either site codes or zip code | | 400 | `"radius must be provided when using zip_code"` | Missing radius with zip code search | Include radius parameter | | 400 | `"site_codes must be less than or equal to 3"` | Too many site codes | Limit to 3 site codes maximum | | 404 | `"This order doesn't exist."` | Invalid order ID | Verify order ID is correct | | 404 | `"This order is not a walk-in phlebotomy order."` | Wrong order type | Use the correct order type | #### Order State Errors *Order workflow or business logic issues* | Status | Error Message | When It Occurs | User Action | | ------ | ------------------------------------------------------- | ------------------------------------ | --------------------------------------- | | 400 | `"Order is not a walkin phlebotomy order"` | Wrong order type for PSC booking | Contact support | | 400 | `"Order does not have a sample ID..."` | Order missing requisition | Wait for requisition or contact support | | 400 | `"Order is not in a state that allows booking..."` | Order workflow prevents booking | Contact support | | 400 | `"Order is not in a state that allows cancelling..."` | Order workflow prevents cancellation | Contact support | | 400 | `"Order is not in a state that allows rescheduling..."` | Order workflow prevents rescheduling | Contact support | | 400 | `"This order does not have a requisition..."` | Missing requisition for appointment | Wait or contact support | | 400 | `"This lab is not supported."` | Order not for Quest lab | Use a supported lab | #### Appointment Management Errors *Appointment-specific business rules* | Status | Error Message | When It Occurs | User Action | | ------ | ----------------------------------------------------- | ------------------------------------------- | --------------------------------- | | 400 | `"This order doesn't have an appointment yet."` | Trying to modify a non-existent appointment | Book an appointment first | | 400 | `"This appointment cannot be rescheduled."` | Appointment marked non-reschedulable | Cancel and book a new appointment | | 400 | `"This appointment has been cancelled or completed."` | Operating on finalized appointment | No further action is possible | | 400 | `"This appointment has already been cancelled."` | Cancelling already cancelled appointment | No action needed | | 404 | `"Appointment not found."` | Appointment doesn't exist | Verify appointment exists | #### Authorization Errors *Access control issues* | Status | Error Message | When It Occurs | User Action | | ------ | -------------------- | ----------------------------------- | --------------- | | 401 | Authentication error | Invalid or expired token | Re-authenticate | | 403 | `"Action forbidden"` | User lacks permission for the order | Contact support | #### Service Availability Errors *System configuration or availability* | Status | Error Message | When It Occurs | User Action | | ------ | ----------------------- | ----------------------- | ---------------------------- | | 503 | `"Feature not enabled"` | PSC scheduling disabled | Contact support or try later | ### Testing Error Scenarios #### Sandbox Testing * Most validation errors can be tested in sandbox * Slot conflicts cannot be reliably tested (mock client always succeeds) * Use invalid parameters to test input validation #### Production Testing * Test with caution using real appointments * Slot conflicts will return actual 404 errors from Quest * Time-based errors can be tested with past dates ### Quest API Limitations * **Timeout**: 15 seconds read timeout, 5 seconds connection timeout * **Slot availability**: Real-time, can change between availability check and booking * **Mock client**: Doesn't simulate all real-world scenarios * **Rate limiting**: Standard Quest API rate limits apply