> ## Documentation Index
> Fetch the complete documentation index at: https://open-fi.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Supported Rails

> Fiat rail coverage and known constraints by currency.

OpenFi routes fiat-side requests through different providers depending on currency. Coverage and capability currently differ by rail. Check the constraints below before assuming feature parity across currencies.

<Tabs>
  <Tab title="USD">
    Full support for both one-time payments and the mandate / session-key / debit-pull flow.
  </Tab>

  <Tab title="CAD">
    <Warning>
      Confirmed **one-time payments only**. The underlying CAD rail has no recurring mandate capability today. `POST /v1/mandates` is not available for CAD payer accounts.
    </Warning>
  </Tab>

  <Tab title="GBP">
    <Warning>
      Structurally different from the other rails: UK Payment Initiation Services (PIS) are user-consented **push** payments, not pull. Variable Recurring Payments (VRP), the closest analogue to a mandate, are only partially supported across UK banks today. Design GBP flows around push confirmation, not silent pulls.
    </Warning>
  </Tab>
</Tabs>