HEPH-MONEY-409

Currency mismatch

What the caller sees

This is the default detail sent in the problem+json response, verbatim:

This operation mixes two different currencies; both amounts must use the same currency.

What to do as a developer

Guidance for the engineer who hit this code. It is non-normative: it is never sent on the wire and does not constrain an implementation. Wire behaviour is defined only by spec/heph-spec.md and the conformance vectors.

An operation combined two amounts in different currencies, such as adding USD to EUR. The core never converts. Make sure both operands carry the same currency, or convert one explicitly, at a rate and rounding you choose, before the operation. A malformed money object is HEPH-MONEY-422, not this code.

Defined in spec/heph-spec.md section 1. See all codes in the error index.