Performs the action given by the action query parameter on the expense reports listed in the request body. Every action is all or nothing: the whole batch is validated before anything happens, so a 4xx always means nothing was sent, paid or reminded. The reverse does not hold, a 200 does not mean every requested report was processed - setPaid answers 200 with missingBankAccountNumber when nothing was paid, and sendApproverReminders answers 200 after skipping the reports that are not waiting for an approver. In both cases the response body says what actually happened, so compare it against what you requested.

send sends the batch to its recipient. Reports that are not in a status the recipient accepts come back in invalidReports with a 400. On success the batch is handed to a send job and its id is returned in jobIds.

setPaid marks the reports as paid and optionally sends a payment basis mail with a combined payment basis PDF and a payment file. Reports in a status that can not be paid come back in invalidReports with a 400. Report owners without a bank account number are returned in missingBankAccountNumber with a 200, so that the caller can show the affected owners.

sendApproverReminders reminds the approvers that still have these reports on their todo list. Reports that are not in APPROVAL or APPROVAL_CANDIDATE are skipped, and the ids a reminder was actually sent for come back in expenseReportIds.