Generate an API specification from your collection

You can generate an OpenAPI 2.0, 3.0, and 3.1 specification from a collection in Spec Hub. Generated specifications enable you to complete the API lifecycle by integrating your API with downstream systems, such as API gateways or security scanners. You can also keep the specification in sync with its collection.

Add types to parameters and headers and body data that describe your APIs. This way Postman can generate a complete OpenAPI specification in Spec Hub. Learn more about types in collections.

To learn more about generating and syncing specifications, see Sync collections and specifications reference.

Generate OpenAPI specifications from a collection

You can generate an OpenAPI specification from your collection. Postman automatically creates a specification with paths, components, and more based on your collection. The specification will also have types associated with parameters, headers, and body data if types are defined in the collection.

To generate a specification from a collection, do the following:

1. Expand Collections in the sidebar.
2. Click View more actions next to a collection, then select More > Generate specification.
3. Enter a name for the specification.
4. Select YAML or JSON as the file format in the generated specification.
5. Click Generate Specification.

To view the generated specification, open the collection’s overview, and then click the specification’s name under Specification. You can also expand Specs in the sidebar and select the specification.

Keep OpenAPI specifications in sync with a collection

When you generate an OpenAPI specification from a collection, Postman creates a specification that matches the requests in the collection. If you update the collection or specification, such as by adding a new request, Postman alerts you that the generated specification isn’t in sync with the collection.

Sync changes to a specification

To sync changes made in a generated collection to your OpenAPI specification, do the following:

1. Expand Collections in the sidebar, then select the collection you want to sync.
2. In the collection’s Overview tab, click Sync specification.

Sync changes to a collection

To sync changes made in an OpenAPI specification to a generated collection, do the following:

1. Expand Specs in the sidebar and select an OpenAPI specification.
2. Click Update Collection.
3. Click Update next to the generated collection.

Configure sync settings

You can configure settings that enable you to customize the syncing behavior between collections and OpenAPI specifications.

To configure sync settings from a collection, do the following:

1. Expand Collections in the sidebar, then select the collection you want to sync.
2. In the collection’s Overview tab, click Configure update settings.
3. Configure sync settings between the collection and specification.
4. Click Save.

Sync settings

You can configure the following sync settings between collections and OpenAPI specifications:

• Sync example values between Spec and Collection — Turn this on to keep examples in the specification and values in the collection in sync.