Breaking (!) API changes for v1 API, September 11 to September 18

During the week of September 11 to September 18, 2026, the mittwald API introduced several significant changes, including the addition of new endpoints for managing GDPR contracts and authentication, the removal of deprecated paths, updates to response properties, and the requirement of certain request parameters.

Breaking changes

This document contains changes that can under certain circumstances be considered breaking. Please review the changes carefully.

While we generally strive to avoid breaking changes in accordance with our API stability guarantees, we occasionally might perform changes that would be considered breaking in the strictest sense of the term, but we do not consider as breaking in a practical sense. We will always provide ample notice and documentation for such changes.

Summary

• The domainIdentifier request parameter in the DELETE operation for deleting a certificate has become required, which is a breaking change. The endpoint is DELETE /accounts/{accountIdentifier}/domains/{domainIdentifier}/certificate.
• The response body for the GET operation to list application tokens has become nullable, and the property type for /items/crdate has changed from string/date-time to integer for status 200. The endpoint is GET /authentication/tokens.
• The crdate response property type has changed from string/date-time to integer for status 201 in the POST operation for creating an application token. The endpoint is POST /authentication/tokens.
• Several API paths related to GDPR contracts have been removed without deprecation:
  • POST /gdpr/contracts/{contractIdentifier}/actions/accept
  • POST /gdpr/contracts/{contractIdentifier}/actions/mail
  • POST /gdpr/contracts/{contractIdentifier}/actions/pdf
  • POST /gdpr/pdfs/{pdfIdentifier}/actions/download
• The response property contract/items/payload/statusFields/editLock has become nullable for status 200 in the GET operation for menu generation, along with similar changes for left, support, and top properties. The endpoint is GET /menu.
• A new POST operation for authenticating with a token has been added at the endpoint POST /authenticate/token.
• A non-success response with status 401 has been added for the GET operation to list application tokens, the POST operation to create an application token, and the DELETE operation to delete an application token. The endpoints are GET /authentication/tokens, POST /authentication/tokens, and DELETE /authentication/tokens/{uuid} respectively.
• Several optional properties have been added to the response with status 200 for the GET operation to retrieve GDPR contracts, including client/creationDate, client/type, recipient/creationDate, recipient/type, tom/content, and tom/creationDate. The endpoint is GET /gdpr/contracts.
• Required properties have been added to the response with status 200 for the GET operation to retrieve GDPR contracts, including client/city, client/houseNumber, client/mail, client/name, client/street, client/zipCode, recipient/city, recipient/houseNumber, recipient/mail, recipient/name, recipient/street, and recipient/zipCode. The endpoint is GET /gdpr/contracts.
• New endpoints have been added for various operations related to GDPR contracts:
  • POST /gdpr/contracts/{contractIdentifier}/actions/accept
  • POST /gdpr/contracts/{contractIdentifier}/actions/mail
  • POST /gdpr/contracts/{contractIdentifier}/actions/pdf
  • POST /gdpr/pdfs/{pdfIdentifier}/actions/download
• The GET operation for retrieving navigation meta has a new endpoint at GET /menu-meta.
• The oneOf list for the response properties contract/items/payload/statusFields/editLock, left/items/payload/statusFields/editLock, support/items/payload/statusFields/editLock, and top/items/payload/statusFields/editLock has had certain subschemas removed for the response status 200. The endpoint is GET /menu.

Disclaimer: This summary is AI-generated. If you find any discrepancies, please refer to the detailed changes below.

Detailed changes

Changes in "Let's Encrypt Zertifikat einer Domain löschen"

• ⚠️ Breaking: the 'path' request parameter 'domainIdentifier' became required

For details, refer to the DELETE/accounts/{accountIdentifier}/domains/{domainIdentifier}/certificate/ endpoint.

Changes in "Auslesen von erstellten application-Tokens"

• ⚠️ Breaking: the response's body became nullable

• ⚠️ Breaking: the '/items/crdate' response's property type/format changed from 'string'/'date-time' to 'integer'/'' for status '200'

• added the non-success response with the status '401'

For details, refer to the GET/authentication/tokens/ endpoint.

Changes in "Neues Access-Token erstellen"

• ⚠️ Breaking: the 'crdate' response's property type/format changed from 'string'/'date-time' to 'integer'/'' for status '201'

• added the new optional request property 'token'

• added the non-success response with the status '401'

For details, refer to the POST/authentication/tokens/ endpoint.

Changes in "Vertrag - Akzeptiert den Vertrag"

• ⚠️ Breaking: api path removed without deprecation

• endpoint added

For details, refer to the POST/gdpr/contracts/{contractIdentifier}/actions/accept/ endpoint.

Changes in "Vertrag - Verschickt eine E-Mail mit PDF an den Empfänger des Vertrags"

• ⚠️ Breaking: api path removed without deprecation

• endpoint added

For details, refer to the POST/gdpr/contracts/{contractIdentifier}/actions/mail/ endpoint.

Changes in "Vertrag - Liefert ein PDF zu einem bestimmten Vertrag"

• ⚠️ Breaking: api path removed without deprecation

• endpoint added

For details, refer to the POST/gdpr/contracts/{contractIdentifier}/actions/pdf/ endpoint.

Changes in "PDF - Stellt ein Vertrags-PDF zum Download bereit"

• ⚠️ Breaking: api path removed without deprecation

• endpoint added

For details, refer to the POST/gdpr/pdfs/{pdfIdentifier}/actions/download/ endpoint.

Changes in "Menu generation"

• ⚠️ Breaking: the response property 'contract/items/payload/statusFields/editLock' became nullable for the status '200'

• ⚠️ Breaking: the response property 'left/items/payload/statusFields/editLock' became nullable for the status '200'

• ⚠️ Breaking: the response property 'support/items/payload/statusFields/editLock' became nullable for the status '200'

• ⚠️ Breaking: the response property 'top/items/payload/statusFields/editLock' became nullable for the status '200'

• ⚠️ Breaking: the 'contract/items/payload/statusFields/editLock' response's property type/format changed from ''/'' to 'string'/'' for status '200'

• ⚠️ Breaking: the 'left/items/payload/statusFields/editLock' response's property type/format changed from ''/'' to 'string'/'' for status '200'

• ⚠️ Breaking: the 'support/items/payload/statusFields/editLock' response's property type/format changed from ''/'' to 'string'/'' for status '200'

• ⚠️ Breaking: the 'top/items/payload/statusFields/editLock' response's property type/format changed from ''/'' to 'string'/'' for status '200'

• removed 'subschema #1, subschema #2' from the 'contract/items/payload/statusFields/editLock' response property 'oneOf' list for the response status '200'

• removed 'subschema #1, subschema #2' from the 'left/items/payload/statusFields/editLock' response property 'oneOf' list for the response status '200'

• removed 'subschema #1, subschema #2' from the 'support/items/payload/statusFields/editLock' response property 'oneOf' list for the response status '200'

• removed 'subschema #1, subschema #2' from the 'top/items/payload/statusFields/editLock' response property 'oneOf' list for the response status '200'

For details, refer to the GET/menu/ endpoint.

Changes in "Get meta menu items"

• ⚠️ Breaking: api path removed without deprecation

• endpoint added

For details, refer to the GET/menu-meta/ endpoint.

Changes in "Anmeldung mit einem Transfer-Token"

• endpoint added

For details, refer to the POST/authenticate/token/ endpoint.

Changes in "Löschen von application-Tokens"

• added the non-success response with the status '401'

For details, refer to the DELETE/authentication/tokens/{uuid}/ endpoint.

Changes in "Vertrag - Liefert alle hinterlegten Verträge"

• added the optional property '/items/client/creationDate' to the response with the '200' status

• added the optional property '/items/client/type' to the response with the '200' status

• added the optional property '/items/recipient/creationDate' to the response with the '200' status

• added the optional property '/items/recipient/type' to the response with the '200' status

• added the optional property '/items/tom/content' to the response with the '200' status

• added the optional property '/items/tom/creationDate' to the response with the '200' status

• added the required property '/items/client/city' to the response with the '200' status

• added the required property '/items/client/houseNumber' to the response with the '200' status

• added the required property '/items/client/mail' to the response with the '200' status

• added the required property '/items/client/name' to the response with the '200' status

• added the required property '/items/client/street' to the response with the '200' status

• added the required property '/items/client/zipCode' to the response with the '200' status

• added the required property '/items/recipient/city' to the response with the '200' status

• added the required property '/items/recipient/houseNumber' to the response with the '200' status

• added the required property '/items/recipient/mail' to the response with the '200' status

• added the required property '/items/recipient/name' to the response with the '200' status

• added the required property '/items/recipient/street' to the response with the '200' status

• added the required property '/items/recipient/zipCode' to the response with the '200' status

For details, refer to the GET/gdpr/contracts/ endpoint.

Changes in "Vertrag - Vertrag anlegen"

• added the optional property 'client/creationDate' to the response with the '201' status

• added the optional property 'client/type' to the response with the '201' status

• added the optional property 'recipient/creationDate' to the response with the '201' status

• added the optional property 'recipient/type' to the response with the '201' status

• added the optional property 'tom/content' to the response with the '201' status

• added the optional property 'tom/creationDate' to the response with the '201' status

• added the required property 'client/city' to the response with the '201' status

• added the required property 'client/houseNumber' to the response with the '201' status

• added the required property 'client/mail' to the response with the '201' status

• added the required property 'client/name' to the response with the '201' status

• added the required property 'client/street' to the response with the '201' status

• added the required property 'client/zipCode' to the response with the '201' status

• added the required property 'recipient/city' to the response with the '201' status

• added the required property 'recipient/houseNumber' to the response with the '201' status

• added the required property 'recipient/mail' to the response with the '201' status

• added the required property 'recipient/name' to the response with the '201' status

• added the required property 'recipient/street' to the response with the '201' status

• added the required property 'recipient/zipCode' to the response with the '201' status

For details, refer to the POST/gdpr/contracts/ endpoint.

Changes in "Vertrag - Liefert einen bestimmten Vertrag"

• added the optional property 'client/creationDate' to the response with the '200' status

• added the optional property 'client/type' to the response with the '200' status

• added the optional property 'recipient/creationDate' to the response with the '200' status

• added the optional property 'recipient/type' to the response with the '200' status

• added the optional property 'tom/content' to the response with the '200' status

• added the optional property 'tom/creationDate' to the response with the '200' status

• added the required property 'client/city' to the response with the '200' status

• added the required property 'client/houseNumber' to the response with the '200' status

• added the required property 'client/mail' to the response with the '200' status

• added the required property 'client/name' to the response with the '200' status

• added the required property 'client/street' to the response with the '200' status

• added the required property 'client/zipCode' to the response with the '200' status

• added the required property 'recipient/city' to the response with the '200' status

• added the required property 'recipient/houseNumber' to the response with the '200' status

• added the required property 'recipient/mail' to the response with the '200' status

• added the required property 'recipient/name' to the response with the '200' status

• added the required property 'recipient/street' to the response with the '200' status

• added the required property 'recipient/zipCode' to the response with the '200' status

For details, refer to the GET/gdpr/contracts/{contractIdentifier}/ endpoint.