TRIP-62641 Document sorted=false fast path on /ledger/posting/openPost

FAQ.md

@@ -26,6 +26,18 @@ If you want the orderlines related to the order as well you can expand the API r
 
 ---
 
+### How can I make `/ledger/posting/openPost` faster on accounts with many postings?
+
+#### Answer:
+
+`GET /v2/ledger/posting/openPost` returns the open postings on an account as of a given date. By default the result is sorted by voucher (year and number), which becomes expensive on accounts that have a large number of postings.
+
+If you do not need the voucher ordering, add `sorted=false` to the request. You get the exact same set of open postings, only unordered, and the response is significantly faster on large accounts. For best performance, combine it with the `fields` parameter (see above) to limit the returned data, and with paging (`from` and `count`).
+
+Example: `GET /v2/ledger/posting/openPost?date=2026-12-31&accountId=123456&sorted=false&fields=id,date,amount,invoiceNumber&count=1000`
+
+---
+
 ### How can I correct the validation message “The unit price must be exclusive VAT since the unit price on the order is exclusive VAT.”
 
 #### Answer:

changelog.md

@@ -1,5 +1,10 @@
 # API changelog
 
+## 2.75.06 (2026-06-23)
+- Added new optional query parameter `sorted` to `GET /ledger/posting/openPost`.
+  - `true` (default) — open postings are returned ordered by voucher (year, then number). Existing callers see no change.
+  - `false` — returns the same set of open postings, unordered. Significantly faster on accounts with a large number of postings, since the sort is skipped. Recommended when reading large accounts where you do not depend on the voucher ordering.
+
 ## 2.75.05 (2026-05-15)
 - Added new optional query parameter `addToInvoiceMode` to `PUT /order/{id}/:attach`. Controls which invoices receive the uploaded attachment.
   - `NEXT` (default) — only the next invoice. Legacy behavior; existing callers see no change.