***

title: Design API specifications in Postman
updated: 2025-10-15T00:00:00.000Z
max-toc-depth: 2
----------------

Take an API-first approach to development with *Spec Hub* in Postman. You can create OpenAPI 2.0, 3.0, or 3.1 specifications or AsyncAPI 2.0 specifications, and you can import existing OpenAPI and AsyncAPI specifications into Spec Hub. Navigate using the outline view, and add new sections with snippets. Tools such as autocomplete, syntax checking, and live documentation preview help you as you work.

When you're ready to share your API, use Spec Hub to generate a Postman Collection from your API specification. You can keep the generated collection in sync with an OpenAPI 3.0 specification. Team members and consumers can use these collections to explore or test your API.

## Design your API in a specification

In Spec Hub, you can [create a specification](/docs/design-apis/specifications/create-a-specification/) in OpenAPI 2.0, 3.0, or 3.1 format or AsyncAPI 2.0 format. You can also [import a specification](/docs/design-apis/specifications/import-a-specification/) from your computer or a repository to continue building it out in Spec Hub.

[Edit your specification](/docs/design-apis/specifications/edit-a-specification/) by adding new sections with pre-formatted snippets, generating a schema from a JSON body, or autocomplete suggestions. You can also organize your OpenAPI specifications into [multiple files and folders](/docs/design-apis/specifications/add-files-to-a-specification/). As you build out your specification, Postman identifies [syntax errors and API governance issues](/docs/design-apis/specifications/validate-a-specification/) based on your team's configured rules.

Postman also displays a [live preview of your API's documentation](/docs/design-apis/specifications/view-live-documentation/) to help you visualize your changes.

If you're on a Postman Enterprise plan, you can [create reusable components](/docs/design-apis/specifications/component-library/) for OpenAPI specifications in your team's Component Library. This enables your team to maintain and standardize components in a single place. Your teammates can reuse published components in their specifications.

## Generate a collection from a specification

Once you've designed and tested your API's structure in a specification, automatically generate a collection to share with your team members and consumers. Generate a collection from your API specification to create a collection with folders, requests, and response examples based on the specification.

You can keep a collection and its specification [in sync](/docs/design-apis/specifications/generate-collections#keep-collections-in-sync-with-an-openapi-specification) if it was generated from an OpenAPI 3.0 specification. When you make changes to the OpenAPI 3.0 specification, update the generated collection with your latest changes. If you make changes to the generated collection, you can update the specification to include the collection's changes. This ensures team members and consumers can explore, test, and collaborate on the latest iteration of your API.

Learn how to [generate a collection from a specification and keep them in sync](/docs/design-apis/specifications/generate-collections/).