> For the complete documentation index, see [llms.txt](https://docs.umbraco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.umbraco.com/umbraco-heartcore/versions-and-updates.md). # Versions and updates Umbraco Heartcore is a software as a service (SaaS) offering, that eliminates upgrade concerns. All maintenance related to the CMS, its features, and APIs is handled by Umbraco HQ. Umbraco HQ will regularly be adding new features to the CMS and new capabilities to the REST APIs. Each time new endpoints are added to the REST API the `api-version` will be updated to reflect the changes. API releases and versioning is handled following the [ASP.NET API versioning guidelines](https://github.com/microsoft/aspnet-api-versioning). We follow semver in terms of versioning, which means you can be sure that existing APIs will continue to work as expected without breaking. If a breaking change is required then the major version will be incremented, but the previous major version will continue to work. {% hint style="info" %} For API calls, it's advisable **to employ the `api-version` header to indicate the API version you intend to use**. If no version is specified the latest version of the API will be used. Learn more about which versions of the API is available as well as what version each endpoint uses in the[ Umbraco Heartcore API Documentation.](/umbraco-heartcore/api-documentation/api-documentation.md) {% endhint %} When using our [Client Libraries](/umbraco-heartcore/client-libraries/client-libraries.md), the `api-version` is handled as part of the library and generally not something you need to worry about. Be aware that the client library releases will have certain features available. The Forms API is unavailable in the initial release (1.0) of the .NET Core client library, for instance. This was made available in the 1.1 version of the client library. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.umbraco.com/umbraco-heartcore/versions-and-updates.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.