As an API user I'd like to avoid double posting of manual general ledger journal entries and get an error message if the same journal entry was already posted before, e.g. by matching a client-provided unique ID.
When a timeout for a manual journal entry call occurs, there are two possibilities, either it's booked properly or not. For regular savings or loan transactions there is an option to require a unique custom field value, though this option is not available for booking manual journal entries.
If a timeout occurred and an auto re-try mechanism is used, Mambu should return an error code "926 DUPLICATE_UNIQUE_VALUE" if the provided unique custom field value for the journal entry already exists. That way the API user knows after a re-try whether the manual journal entry was actually booked on the first attempt or successful on the 2nd re-try attempt.
There is currently no workaround since the only extra information that can be provided is a note for a journal entry, which is not search-able.
Allow custom numerical entryIDs on Journal Entries.
Example Use Case
When posting a withdrawal transaction, one can specify a unique ID, which prevents double posting of transactions. If afterwards a manual journal entry needs to be posted to move a portion of the transaction amount to a different general ledger account, there needs to be a way to avoid double-posting of that manual journal entry.