Define and develop your API in Postman

Use Postman's API-first tools to develop your API definition and build out your API with tests, documentation, and server-side code. Create or import common API definition types, including OpenAPI, GraphQL, Protobuf, RAML, and WSDL. Postman automatically validates requests and checks for errors as you work on your API.

Edit your API definition

Your API definition is the blueprint for your API's structure. To get started, create a new API definition or import an existing definition into the API Builder. Then use Postman's built-in tools to edit your API and preview API documentation as you work. Postman supports API definitions with multiple files, so you can add new files to a definition or import them from a connected Git repository.

Learn more about working with API definitions in Postman.

Add collections to your API

Postman Collections enable you to add API documentation and write API tests that you can automate. You can add a new collection or copy an existing collection to an API. You can also generate a collection from your API definition. Postman alerts you when there are differences between the generated collection and your definition, so you can keep them in sync.

Learn more about adding elements to an API in Postman.

Generate code from your API definition

You can use Postman to generate server code from your OpenAPI 3.0 definition. Supported languages and frameworks include Go, NodeJS, Java, and Python. Use the generated code to run a server based on your API specification and jump-start development of your business logic.

Learn more about generating server-side code from an OpenAPI 3.0 definition.

Validate your API

With request validation, Postman can detect inconsistencies between the requests in a collection and your API definition. This helps you make sure your API implementation is consistent with the API definition. Postman also automatically detects any syntax errors and governance rule violations as you work on your API definition.

Learn more about ensuring consistency between a collection and an API definition.