> For the complete documentation index, see [llms.txt](https://docs.mocklets.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mocklets.com/open-api-3.0.md).

# Open API Specifications 3.x

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 This feature is still in Beta phase.
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Open API Specification is the most widely used description language for REST APIs. Mocklets supports the automatic generation of mock APIs from imported Open API Specifications. You just have to upload your specs on Mocklets dashboard.

![](/files/-LdtaPwoXRO4sWhhL775)

Go to the Collection page and click the **Open API Spec** button. Then paste your YAML definition into the text editor, pick your duplicate policy and hit **Upload Specification**.

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 Currently, we are only supporting version 3.x of Open API Specification. If you have any older version, please let us know. We will try to provide support for as many versions as possible.
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### Duplicate Policy

If you’re working with an Open API Specification which is changing on a regular basis, you’ll probably want to re-import it repeatedly.

This means you have to decide what to do when a stub is newly generated for a URL/content type combination for which a stub already exists from a previous import. Most of the time, for the sake of keeping the mock API correct you’ll want to overwrite the previous stub, so this is the default behavior set on the dashboard. However, you also have the option of skipping the already created mock APIs and keep the data for those APIs the same as a previous import.