API reference / Changelog / 2026

API changelog: 2026

Every change to the Kintsugi API in 2026, newest first. For the latest changes and every release, see the API changelog.

All changes Breaking only

Area: Transactions

All areas Addresses Connections Exemptions Filings Imports Nexus Organizations Products Registrations Reports Transactions

Clear filters

Jump to date

2026-09-22

Breaking changes

Returns the existing credit note when a credit note is created twiceTransactions

Breaking changeTransactions

Creating a credit note with an external_id already used for a credit note on the same original transaction used to fail with 409 Conflict. It now succeeds and returns the stored credit note unchanged. On v1 that response is 200, and creating a new credit note now answers 201 instead of 200. On the 2026-07-21 release the stored credit note comes back with 202, the same as a new one. The same external_id against a different original transaction still returns 409.

Endpoints

What to do

On v1, treat both 201 and 200 as success.
Stop relying on 409 to detect an existing credit note.
To change an existing credit note, update it: PUT /v1/transactions/{original_transaction_id}/credit_notes/{credit_note_id} on v1, or PATCH /transactions/{transaction_id} on the 2026-07-21 release.