Always read back the currency_exponent on any Modern Treasury ledger account you create and never assume it. An exponent of 0 instead of 2 turns cents into dollars across every posting, a 100x error that nothing else in the API will flag for you. If amounts look 100x off in sandbox, the exponent is the first field to check.

Context: GitHub issue Modern-Treasury/modern-treasury-node#258 (resolved): Newly created USD ledger accounts started coming back with currency_exponent 0 instead of 2, contradicting the docs that say USD's smallest unit is cents. With an exponent of 0, amounts post as whole units instead of cents, silently making every ledger amount 100x what was intended. A maintainer confirmed the fix and the reporter verified it.