# Postman quickstart

> Generate a postman collection full of example requests and responses

A Postman collection contains ready-to-use HTTP requests with example payloads and responses that developers can immediately test and explore in Postman. Each API definition generates one complete collection with all endpoints organized into folders.

Generate a Postman collection by following the instructions on this page.

<Info>
  This page assumes that you have an initialized `fern` folder on your local
  machine. See [Set up the `fern` folder](/sdks/overview/quickstart).
</Info>

<Steps>
  ### Pass `fern check`

  Run `fern check` to ensure that your API definition is valid. If there are any errors,
  fix them before proceeding.

  <Note>
    If you're using an OpenAPI Specification, check out all of our
    [supported extensions](/learn/api-definition/openapi/extensions).
  </Note>

  ### Add the Postman generator

  Run the following command to add the Postman generator to `generators.yml`:

  ```sh
  fern add fern-postman --group postman
  ```

  <Note>
    `postman` is the name of the `generators.yml` group that configures your Postman collection's output location and other metadata. You can customize this group name to differentiate between multiple collections if you have multiple APIs in your organization.
  </Note>

  This command adds the following `group` to `generators.yml`:

  ```yaml title="generators.yml" {2-8}
  groups:
    postman:
      generators:
        - name: fernapi/fern-postman
          version: 0.0.45
          output:
            location: local-file-system
            path: ../postman
  ```

  ### Generate the collection

  Run the following command:

  ```sh
  fern generate --group postman
  ```

  <Note>
    If you have multiple APIs, use the [`--api` flag](/cli-api-reference/cli-reference/commands#api) to specify the API you want to generate:

    ```bash
    fern generate --group postman --api your-api-name
    ```
  </Note>

  This creates a Postman collection on Fern's cloud. Once complete, you'll see a `collection.json`:

  <Files>
    <Folder name="fern" defaultOpen>
      <File name="fern.config.json" />

      <File name="generators.yml" />
    </Folder>

    <Folder name="postman" defaultOpen>
      <File name="collection.json" highlighted />
    </Folder>
  </Files>
</Steps>