Domain Model¶

SWEN uses a precise vocabulary throughout the codebase, API, and UI. This page is the ubiquitous language reference.

Banking Domain¶

These concepts are concerned with the banking side of things.

BankAccount¶

A real-world bank account identified by an IBAN. Corresponds to a single account at a single bank. Each BankAccount in SWEN is linked to exactly one bookkeeping Account (of type Asset) that records its running balance.

Key fields: iban, bic, account_name, bank_name, linked_account_id

BankTransaction¶

A raw transaction record fetched from the bank represents a bank statement line. Our business logic includes a solid de-duplication logic which many other similar software products dont. A BankTransaction is not a double-entry record. It becomes one when SWEN creates a linked Transaction (Draft or Posted).

Key fields: bank_account_id, amount, value_date, booking_date, purpose, counterparty_name, counterparty_iban, transaction_hash

Counterparty¶

The other party in a bank transfer. Identified by name and optionally by iban. We have to note that iban is not necessarily unique because many banks use generic ibans for visa debit payments. Therefore, Counterparties are extracted from BankTransaction.purpose and BankTransaction.counterparty_name fields.

Purpose¶

The free-text reference field of a bank transaction (Verwendungszweck in German). This is what you type when you make a bank transfer. SWEN's ML classification reads this field heavily. For Visa debit card transactions, this is usually a simple placeholder (Visa Debitkarten Umsatz vom 14.03.2025).

Accounting Domain¶

These concepts come from double-entry bookkeeping.

Account¶

A bookkeeping ledger account. Not a bank account! Has a type (Asset, Liability, Equity, Income, Expense) and a name (e.g. "Groceries", "Salary").

Accounts form a tree (chart of accounts). Each leaf account accumulates a running balance.

Key fields: name, account_type, parent_id, is_system

Counter-Account¶

The bookkeeping account that "receives" the other side of a bank import. For a supermarket payment, the bank Asset account is debited and the Groceries Expense account (the counter-account) is credited. SWEN's ML pipeline predicts the counter-account automatically.

Transaction (bookkeeping)¶

A double-entry transaction consisting of two or more JournalEntry lines that sum to zero. Linked to a BankTransaction when created from a bank import. Can assume the state draft and posted.

JournalEntry¶

A single line in a Transaction. Specifies an Account, an amount, and a side (debit or credit). A valid Transaction always has at least two JournalEntries with equal debit and credit totals.

Integration Domain¶

These concepts describe how banking aggregates are integrated into our accounting domain.

AccountMapping¶

A persistent rule that maps a BankAccount to exactly one bookkeeping Account. Created during the bank account onboarding wizard. Required before any imports can run.

InternalTransfer¶

A bank transfer between two of your own accounts (e.g. moving savings). SWEN detects these heuristically by matching counterparty IBANs against your known BankAccount list and creates a single balanced Transaction spanning both accounts.

Import¶

A single execution of the bank sync process for one BankAccount. Fetches BankTransaction records, deduplicates them, runs ML classification, and creates Draft Transaction records.

Terms SWEN Intentionally Avoids¶