Pre-check states before every invoice

This is the fastest way to reduce invalid requests in your first week.

Endpoint: GET /api/v1/supported-states

If you accept invoices across many states, you need this check before calculation logic runs.

Expected response

• states: array of two-letter state codes
• count: number of active supported states

Real-world impact

Without this check

• failed calls
• confusing user-facing errors
• missed opportunities to route work correctly

With this check

• immediate validation
• faster exception handling
• cleaner closeout data quality

Example use in a pilot

1. Load the supported list at startup.
2. Validate each invoice state against the list.
3. If unsupported, assign to manual review and note the reason.
4. If supported, continue to /api/v1/calculate-deadline.