## Summary
Maps every code path in the API repo that creates an e-conomic draft
invoice or sends draft lines, and documents which paths pick a layout,
which one they pick, and how the planned **with-discounts /
without-discounts** two-layout selection applies.
**Key finding:** the two envelope creators already implement a
discount-aware selector. No code change is required for the TRU-197
rollout — only the two `invoice*LayoutNumber` config variables need to
be set in the `economic` module.
## Findings at a glance
- **22** code paths in `services/nginx/app/` create or send draft
invoices (2 envelope creators + 6 line-add paths + 14
caller/selector/helper paths)
- **2** paths currently pick a layout — both already discount-aware
- **0** paths need updating for the 2-layout rollout
- **2** config variables drive the selection: `invoiceLayoutNumber` and
`invoiceDiscountLayoutNumber` (already wired into `economic::$config`
and the OpenAPI schema)
## The two selectors
1. `economic_invoice_draft_mo::resolveLayoutNumber()` at
`services/nginx/app/modules/economic/invoices/draft/economic_invoice_draft_mo.php:115`
— used by `createInvoiceDraftExample()` for the single-order draft flow.
2. `collected_order_invoices_o::resolveInvoiceLayoutNumber()` at
`services/nginx/app/objects/collected_order_invoices_o.php:673` — used
by `createInvoiceDraft()` for the collected-invoice flow.
Both return `invoice_discount_layout` if any item has a non-zero
discount, otherwise `invoice_layout`. They throw if the discount layout
is required and `invoiceDiscountLayoutNumber` is unconfigured.
## Document
`documentation/economic/layout-selection-flow.md` — full inventory
table, current/desired state, and migration plan.
## Related
- TRU-197 — `documentation/economic/invoice-template-audit.md`
- TRU-193 — `documentation/economic/export-field-audit.md`
- PR #391 — `economic_export_sanitizer`
Refs: TRU-198
---------
Co-authored-by: openhands <openhands@all-hands.dev>
Co-authored-by: OpenClaw <openclaw@copenhagentruckwash.io>
Co-authored-by: TRU-198 Subagent <subagent@openhands.dev>
