> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. ## 0.41.1 **`(feat):`** Adds a V2 configuration for the `api` block that is more flexible and allows OpenAPI users to consume Fern Definition features. For example, now you can override environments directly in the api configuration: ```yml api: environments: Production: https://prod.com Staging: https://staging.com specs: - openapi: path/to/openapi overrides: path/to/overrides ``` If you want to define, multi-url environments, those can be done by configuring the following generators.yml: ```yml api: environments: Production: urls: api: https://api.com auth: https://auth.com Staging: api: https://stagingapi.com auth: https://stagingauth.com specs: - openapi: path/to/openapi overrides: path/to/overrides ``` Note that you will need to use the `x-fern-server-name` annotation on each endpoint to assign it to a relevant server. For example, ```yml paths: /api/users/: get: x-fern-server-name: api /token: post: x-fern-server-name: auth ``` ## 0.41.0 **`(feat):`** Adds generic object declarations to the fern definition. Now we can define generics and use them in alias declarations to minimize code duplication: ```yml types: `GenericTest`: properties: value: T other-value: string GenericApplication: type: `GenericTest` ``` More information can be found here: [https://buildwithfern.com/learn/api-definition/fern/types#generics](https://buildwithfern.com/learn/api-definition/fern/types#generics).