# Quick Start Guide
source: https://developer.mastercard.com/mastercard-developers-api/documentation/quick-start-guide/index.md

###### Time to complete: *30 minutes*

## Overview {#overview}

Follow this guide to:

* Generate the credentials required to access the Mastercard Developers API
* Use the Postman collection to call the API

1. Log in to [Mastercard Developers](https://developer.mastercard.com/dashboard) and navigate to your **Account** page.
2. In your Account page, go to the Developers API Keys section and click **Add key**.
3. **Choose Key Creation Method:**
   * **Option 1: Browser Keystore**
     1. Select **Generate key**.
     2. Enter a **Key name** and **Key password**.
     3. If prompted, review and accept the **Mastercard Developers API Terms \& Conditions** to proceed.
     4. Click **Create key**.
     5. Click **Download key** to download the [signing key](https://developer.mastercard.com/platform/documentation/security-and-authentication/using-oauth-1a-to-access-mastercard-apis/#the-signing-key) as a PKCS#12 keystore. Download and save your key file in a secure location. Once you exit this screen, you won't be able to download it.
     6. Get your [consumer key](https://developer.mastercard.com/platform/documentation/security-and-authentication/using-oauth-1a-to-access-mastercard-apis/#the-consumer-key) from the Developers API Keys section of your Account page.
   * **Option 2: Certificate Signing Request (CSR)**
     1. Select **Upload a CSR**.
     2. Enter a **Key name** and click **Add an attachment** to upload your CSR file.
     3. If prompted, review and accept the **Mastercard Developers API Terms \& Conditions** to proceed.
     4. Click **Create Key**.
     5. Get your [consumer key](https://developer.mastercard.com/platform/documentation/security-and-authentication/using-oauth-1a-to-access-mastercard-apis/#the-consumer-key) from the Developers API Keys section of your Account page.

**Key Limits and Status:**

* After adding a key, its status will appear as **Pending**. You will receive an email notification once the key is approved, after which you can start sending requests to Developers API.
* You can add a maximum of **2 keys**.
* If a key request is declined, you must revoke the declined key before adding a new one.

*** ** * ** ***

Start using the Developers API without the need to write any code. Run the Developers API Postman Collection to explore and test all the endpoints.
> To get started using the Postman collection, you will need a [Postman account](https://identity.getpostman.com/signup?addAccount=1), and you can optionally download the [Postman desktop application](https://www.postman.com/downloads/).

1. Extract the signing key (private key) from your PKCS#12 keystore using the following command (use the passphrase protecting your PKCS#12 file):
   * OpenSSL

   ```OpenSSL
   openssl pkcs12 -in 'mykey.p12' -nocerts -nodes -passin pass:{password} | openssl rsa -out mykey.pem
   ```

   Expected result:  

   ```java
   -----BEGIN RSA PRIVATE KEY-----
   MIIEpQIBAAKCAQEAzSdC+wm6Dv4ynlhU5tuMLMsX7AeMWoysQKAaCDCStEWUHyj4
   K84X+ZQH0kIJkpWS0M1+vWHTSAu0QvHNDPRIJKMNE2cCRVKApVZ8jQ9DhFkVYE0j
   AhggCNQTJ0kXDBvc1mZPOJDmXusvHIG3BbRSE6ohZHoUXAuAg4bbwZwmvgDgMrmN
   9A9upgMrVZMfrCWeKiBUKoGnwGwUf0iMiHXJhD1Wjdtf0+VAsZNI7r05n9FTHmiC
   ...
   YlR8szTbz1WEx//hU5Ea2sfcKmPDTNWQnx0IgSmPu5I9qf7KJxSYhOk=
   -----END RSA PRIVATE KEY-----
   ```

2. Click the following links to open the files in a new tab:   
   [mastercard_developers_api_postman.json](https://static.developer.mastercard.com/content/mastercard-developers-api/swagger/mastercard_developers_api_postman.json) (23KB)   
   [mastercard_developers_api_postman_environment.json](https://static.developer.mastercard.com/content/mastercard-developers-api/swagger/mastercard_developers_api_postman_environment.json) (562B)
3. Copy the content from each tab, paste it into a text editor (e.g., Notepad), and save as:
   * `mastercard_developers_api_postman.json` for the collection.
   * `mastercard_developers_api_postman_environment.json` for the environment.
4. In Postman, click **Import** and import **mastercard_developers_postman.json** and **mastercard_developers_postman_environment.json** :

   ![Import Postman Collection](https://static.developer.mastercard.com/content/mastercard-developers-api/uploads/postman-import-button.png)
5. Click **Environments** , then select **Mastercard Developers** . Copy the Consumer Key from the Developers API keys section of your Account page and update the `consumerKey` variable. Use the private key extracted in step 1 and update the `privateKey` variable.

   ![Postman Environment](https://static.developer.mastercard.com/content/mastercard-developers-api/uploads/postman-environment-keys_3.png)
6. You can then test the other endpoints by clicking **Send** on individual requests, or **Run collection** .

   For instance:
   Call [POST /projects/{project_id}/credentials](https://developer.mastercard.com/mastercard-developers-api/documentation/api-reference/index.md) to add additional credentials to your project
   To request production access for your project, call [POST /projects/{project_id}/environments](https://developer.mastercard.com/mastercard-developers-api/documentation/api-reference/index.md).

   Did you know? You can generate code snippets in different languages or frameworks from the Postman Collection by using the [code snippets generator](https://learning.postman.com/docs/sending-requests/generate-code-snippets/).

*** ** * ** ***

## Next Steps {#next-steps}

Review [Use Cases](https://developer.mastercard.com/mastercard-developers-api/documentation/use-cases/index.md) to understand the different user scenarios and API calls you need to make in order to use the Developers API.