Account derivation is the process of resolving which GL code combination (account) each subledger journal line should post to. Rather than hard-coding accounts on every transaction, FSL uses a priority-based rule engine that searches a chain of sources until it finds a match.
The chart of accounts defines the account structure used to classify every financial transaction in the General Ledger. Rather than a flat list of account numbers, Raytio uses a multi-segment model where each segment draws its allowed values from a value set, and the segments are assembled into a structure that defines the full account string.
The FGL data model is built around five core areas — Chart of Accounts, Periods and Calendars, Ledgers, Journals, and Balances — with supporting entities for value sets, segments, code combinations, and period statuses. Understanding how these relate is the key to understanding how Raytio records and reports on financial activity.