Mapping: Ekwo, EN 16931 and the FEC

Each Ekwo column that has a counterpart in a standard, lined up against it. It lets an integrator write a connector in a day instead of reading the schema and the standards in parallel for a week.

• EN 16931 references are business term identifiers (BT-) and business groups (BG-) of the European semantic standard for electronic invoicing, as used by Peppol BIS Billing 3.0 and Factur-X.
• FEC refers to the eighteen columns of the French fichier des écritures comptables, arrêté du 29 juillet 2013 (art. A. 47 A-1 du LPF). The column is produced by fec_lines().

An empty cell means there is no counterpart, which is itself information.

Company and period

Chart of accounts

Journals

Contacts

Taxes

Entries and ledger lines

Documents

Products

Ekwo has one table for a product and no variant of it, because variants are a commerce feature and a variant with no distinct price, account or tax is a row that carries nothing. Nothing here is stock: there is no qty_available, no valuation and no move, and there is deliberately no counterpart to them.

Document lines

To the Peppol invoice

@ekwo-ai/peppol-ubl reads one row of document_header, the rows of document_line_items and the rows of document_tax_summary, under the column names above, and nothing else: no join to a table and no option is needed for a posted sale to come out with no rule broken. Dates are selected ::text. What the views do not say yet, and the brick therefore reports rather than writes: the net price of a line keyed with its tax in it (BT-146, BR-26), document and line allowances and charges, and a reason for a supply outside the scope of the tax where the pack gives it no code (BR-O-10).

To the Factur-X invoice object

@ekwo-ai/factur-x takes a plain invoice object and emits EN 16931 CII XML. It lives in this repository under packages/formats/, but @ekwo-ai/core does not depend on it: a format is something you add on top of the ledger, not something the ledger needs. The mapping is therefore written here and asserted in tests/mcp/products.test.ts without the library.

Read document_line_items and build one line per row:

The header comes from documents and companies as the Documents table above says: number → number (BT-1), document_date → issueDate (BT-2), due_date → dueDate (BT-9), buyer_reference → buyerReference (BT-10), order_reference → orderReference (BT-13), payee_iban → payment.iban (BT-84).

Payments, matching, bank

Analytics and attachments

Deliberately absent

Producing a FEC

fec_lines(company_id, from, to) returns the eighteen columns: the opening balances of the financial year first, then its movements in chronological order. generateFec() in @ekwo-ai/fec turns them into the file, and checkFec() applies the file-level rules — mandatory fields, one side per line, each entry balancing — before you hand it over.

The opening lines are computed from the ledger and never posted, one per balance-sheet account, plus one for the result of a year that has not been closed yet. They appear only when the period is exactly a financial year. The sources below are those of a movement line; an opening line takes its journal from country_defaults.opening_journal_code, its account and amount from the cumulative balance of the day before the year opens, and its label from country_defaults.opening_entry_label.