Design and build your APIs in Postman

Postman offers a variety of ways to design and develop your APIs. Use Postman Collections to add types to your HTTP requests that define parameters, headers, and body data. You can define your API’s structure with Spec Hub in an API specification, and generate a collection from the specification to share with your consumers. You can also create a mock server that simulates your API’s requests and responses before it’s production ready.

Design APIs with collections

You can use types to design and test your APIs with the Postman Collection format. Types help your team and API consumers send valid API requests, so they get successful responses instead of errors. Define types, such as data type and possible values, for your request parameters, headers, and body data in an HTTP collection. Postman then validates your requests using the defined types and identifies possible issues. Types also display in the collection’s documentation.

You can generate an OpenAPI 3.0 specification from an HTTP collection. Postman automatically creates a specification with paths, components, and more based on the collection. You can keep the specification in sync with your latest changes to the collection.

Learn more at Design your APIs with Postman Collections.

Design APIs with specifications

With Spec Hub, you can design your API’s structure in an OpenAPI, AsyncAPI, protobuf 2, protobuf 3, GraphQL, or Smithy 2.0 specification. Postman identifies syntax errors and API governance issues as you edit your OpenAPI or AsyncAPI specification. You can also view a live preview of the documentation that’s generated from the API specification in the right sidebar for OpenAPI or AsyncAPI specifications.

You can generate an HTTP collection from an API specification. Postman automatically creates a collection with folders, requests, and response examples based on the specification. If the collection was generated from an OpenAPI 3.0 specification, you can keep the collection in sync with your latest changes to the specification.

Learn more at Design API specifications in Postman.