[dadofsambonzuki]

Summary

When no Bitcoin price provider responds (e.g. during a transient DNS/outbound-network outage), get_fiat_rate_satoshis() silently returns 0.0 instead of raising. Because api_charge_create computes data.amount = round(rate * data.currency_amount) without validating the rate, the charge amount becomes 0 and create_charge() fails with the generic:

Exception: Amount must be greater than 0

This generic failure propagates to checkout callers such as the events extension, which surface it as:

HTTP 400: Could not create payment for any enabled method.
Last error: SatsPay error: Unexpected error! ID: ...

That is misleading — the request was fine; the fiat→sats conversion was impossible at that moment.

Change

In views_api.py, after fetching the fiat rate, raise a clear HTTP 503 Service Unavailable when rate <= 0:

if rate <= 0:
    raise HTTPException(
        status_code=HTTPStatus.SERVICE_UNAVAILABLE,
        detail=(
            f"Could not fetch Bitcoin price for {data.currency}. "
            "Please try again later."
        ),
    )

Callers (and customers on the checkout page) now see an actionable, retryable message instead of the confusing "Amount must be greater than 0" / "Unexpected error!".

Note: get_fiat_rate_satoshis() already has a sibling helper (fiat_amount_as_satoshis()) that guards with if rate > 0 / raise ValueError(...) — this brings the API path in line with that behavior.

Testing

make checkruff / make checkblack for views_api.py report only pre-existing violations on main (existing E501/import-order, unchanged E501s elsewhere in the file); this diff adds no new lint findings.

[dadofsambonzuki]

Closing this PR — it accidentally carried the full fork-main history (all changes already in #87). The currency-check change is being added to #87 and re-raised as a separate PR scoped to just that change.