OpenAPI specs
You can now download the OpenAPI specs of the Maesn Unified API. Use them to generate a client in your language, import the API into tools like Postman, or give an AI agent a full description of the API. The specs always match the live API.
More details herePartial errors
Some requests make more than one call to the target system. If the main object is created but a later step fails, for example the file upload, the API now still returns a success response. The failed step is listed in meta.partialErrors, so you keep the created object and can retry only the step that failed. This is supported for POST /bookingProposals in Microsoft Business Central, Lexware Office, Procountor, Snelstart and Xero.
More details hereBooking proposal attachments
You can now add a file to an existing booking proposal with POST /bookingProposals/:id/attachments. This is available for Microsoft Business Central, Moneybird, Procountor, Snelstart and Xero.New endpoints:
AbaConnect
Holded
Lexware Office
Microsoft Business Central
Improvements:
- Idempotency keys are now supported for POST /journalEntries.
- Booking proposals for Lexware Office now support credit notes as well as invoices and bills.
- The async task status is now
SUCCESS, FAILED or PARTIAL_SUCCESS for AbaConnect tasks. PARTIAL_SUCCESS means the object was created but couldn’t be read back.
- Holded now uses Holded’s new API keys with scoped permissions. The integration page lists the scopes each endpoint needs.
Idempotency keys Beta
You can now send an idempotency-key header with POST requests, so that you can safely retry a request without creating duplicates in the target system. This is supported for POST /bookingProposals, POST /bookingProposals/async and POST /journalEntries/bulk.
More details hereCustom texts on authentication pages
You can now set your own title, free text and button labels on the authentication pages, in several languages. Pass a locale when you request the authentication URL to choose the language.
More details hereNew endpoints:
DATEV Rechnungswesen
Fortnox
Lexware Office
Snelstart
Tripletex
Improvements:
New integration:
- Tripletex is now available via the Maesn Unified API
New endpoints:
Abacus
Dinero
Fortnox
Lexware Office
Procountor
Tripletex
Visma e-conomic
Improvements:
- Draft (unbooked) journal entries are now supported for Dinero and Visma e-conomic via the
isProvisional flag when creating or updating journal entries.
New integration:
- Procountor is now available via the Maesn Unified API
New endpoints:
Buchhaltungsbulter
Lexware Office
Odoo
Procountor
sevdesk
Snelstart
weclapp
Xero
New integration:
- Dinero is now available via the Maesn Unified API
New endpoints:
Abacus
Dinero
Lexware Office
Microsoft Business Central
Sage active
sevdesk
New endpoints:
Buchhaltungsbutler
DATEV Unternehmen Online
Lexware Office
Microsoft Business Central
Sage active
sevdesk
New asynchronous endpoints
We released new asynchronous versions of two endpoints, so that you can post your data to DATEV without concerns about refresh token race conditions or rate-limitsSigned authentication callbacks
We implemented signed authentication callbacks, so that you can be certain that your callbacks originate from your platform and not a malicious actor.
More details hereNew endpoints:
Exact Online
Buchhaltungsbutler
sevdesk
Last modified on November 3, 2026