API changelog
Every change to the Kintsugi API and every release, newest first. Breaking changes carry the mark. Tenanted releases are dated, and you choose one with the Api-Version header.
Changes
2026-10-05
Returns already_connected when an activated store is already connectedConnections
When POST /connections/apideck/{conn_id}/activate finds that the shopId belongs to a connection your organization already has, it reactivates that existing connection, removes the one being activated, and answers 400 as before. The error code is now already_connected instead of invalid_request, with the message This store is already connected. The existing connection was reactivated. The store is connected and nothing more is needed. already_connected is a new value of the code field in error responses.
- Treat
400with codealready_connectedas success, and list your connections again to find the one that remains. - Stop relying on
invalid_requestto detect an already connected store. - If your client accepts only known
codevalues, addalready_connected.
Releases
2026-07-21
LatestTenanted APIIntroducing the Tenanted API
A fresh foundation for building on Kintsugi. The Tenanted API is versioned by date, and you choose the release you build against. It speaks one consistent dialect from end to end: clean paths, camelCase fields, exact decimal amounts, and a single error format. And it is built for scale, with one credential reaching every organization it owns.
Compared with v1
| Topic | v1 | 2026-07-21 |
|---|---|---|
| Versioning | The /v1 path prefix | The Api-Version header, dated YYYY-MM-DD. Optional; without it, a request runs against the launch release |
| Paths | /v1/transactions | /transactions |
| Authentication | x-api-key | Api-Key. Endpoints that manage people accept a signed-in session token instead |
| Choosing an organization | x-organization-id, required on almost every request | One credential reaches every organization it owns. Narrow a request with Organization-Id, Connection-Id, or Entity-Id |
| Field names | snake_case | camelCase |
| Money and rates | Decimal strings out, numbers or strings in | Decimal strings at a fixed scale: amounts to 2 places, rates to 9 |
| Timestamps | No single documented format | RFC 3339 in UTC, always ending in Z |
| Errors | Shapes vary by endpoint | One envelope everywhere: code, message, requestId, and errors |
| Portfolio | Not available | Portfolio and Portfolio Reseller endpoints, for partner accounts |
Moving an integration from v1
- Send
Api-Version: 2026-07-21with every request, so your integration stays on this release until you decide to move. - Drop
/v1from your paths. - Send your key as
Api-Key, and replacex-organization-idwithOrganization-Idwherever you target one organization. - Rename fields to camelCase, and read every amount as a decimal string, never a float.
- Branch on the error
code, not the message or the HTTP status, and quoterequestIdwhen you contact support.
Creating a transaction answers 202 Accepted straight away, and tax is calculated just after. Check processingStatus before you read the tax totals.
v1
LegacyThe original Kintsugi API, versioned in the path. It remains the default in these docs and is documented exactly as before, so existing integrations can keep running with confidence. New integrations should start on the Tenanted API.