Using API Keys

This topic describes how to create an API key for the Maps SDK for Android, add it to your app, and secure the app by restricting the key. You must add an API key to any app that uses the SDK.

Before you begin

Before you start using the Maps SDK for Android, you need a project with a billing account and the Maps SDK for Android enabled. To learn more, see Set up in Cloud Console.

Creating API keys

The API key is a unique identifier that authenticates requests associated with your project for usage and billing purposes. You must have at least one API key associated with your project.

To create an API key:

Go to the APIs & Services > Credentials page.

Go to the Credentials page
On the Credentials page, click Create credentials > API key.
The API key created dialog displays your newly created API key.
Click Close.
The new API key is listed on the Credentials page under API keys.
(Remember to restrict the API key before using it in production.)

Adding the API key to your app

This section describes how to store your API key so that it can be more securely referenced by your app. You should not check your API key into your version control system, so we recommend storing it in the local.properties file, which is located in the root directory of your project. For more information about the local.properties file, see Gradle properties files.

To streamline this task, you can use the Secrets Gradle Plugin for Android.

To install the plugin and store your API key:

In Android Studio, open your app-level build.gradle file and add the following code to the plugins element.
```
id 'com.google.secrets_gradle_plugin' version '0.5'
    
```
Save the file and sync your project with Gradle.
Open the local.properties in your project level directory, and then add the following code. Replace YOUR_API_KEY with your API key.
```
MAPS_API_KEY=YOUR_API_KEY
    
```
Save the file and sync your project with Gradle.
In your AndroidManifest.xml file, go to com.google.android.geo.API_KEY and update the android:value attribute as follows:
```
<meta-data
    android:name="com.google.android.geo.API_KEY"
    android:value="${MAPS_API_KEY}" />
    
```

Note: As shown above, com.google.android.geo.API_KEY is the recommended metadata name for the API key. A key with this name can be used to authenticate to multiple Google Maps-based APIs on the Android platform, including the Maps SDK for Android. For backwards compatibility, the API also supports the name com.google.android.maps.v2.API_KEY. This legacy name allows authentication to the Android Maps API v2 only. An application can specify only one of the API key metadata names. If both are specified, the API throws an exception.

Restricting API keys

Restricting API Keys adds security to your application by ensuring only authorized requests are made with your API Key. We strongly recommend that you follow the instructions to set restrictions for your API Keys. For more information, see API Key best practices.

To restrict an API key:

Go to the APIs & Services > Credentials page.

Go to the Credentials page
Select the API key that you want to set a restriction on. The API key property page appears.
Under Key restrictions, set the following restrictions:

Application restrictions:

Select Android apps.
Click + Add package name and fingerprint.
Enter your package name and SHA-1 certificate fingerprint. For example:
```
com.example.android.mapexample
```
```
BB:0D:AC:74:D3:21:E1:43:67:71:9B:62:91:AF:A1:66:6E:44:5D:75
```
For more information, see Getting a SHA-1 fingerprint.

API restrictions:

Click Restrict key.
Select Maps SDK for Android from Select APIs dropdown.
If the Maps SDK for Android is not listed, you need to enable it.

To finalize your changes, click Save.

Getting a SHA-1 fingerprint

When you restrict your API key, you must provide the SHA-1 certificate fingerprint of the signing key that was used to sign the application. The fingerprint is a sequence of 20 two-digit hexadecimal numbers separated by colons. There are two certificate types:

Debug certificate: The Android SDK tools generate this certificate automatically when you do a debug build. Only use this certificate with apps that you're testing. Do not attempt to publish an app that's signed with a debug certificate.

Release certificate: The Android SDK tools generate this certificate when you run a release build. You can also generate this certificate using the keytool program. Use this certificate when you are ready to release your app to an app store.

Follow the steps below to display a SHA-1 fingerprint using the Keytool command line app.

Debug certificate

Displaying the debug certificate fingerprint

Locate your debug keystore file. The file name is debug.keystore, and is created the first time you build your project. By default, it is stored in the same directory as your Android Virtual Device (AVD) files:
- macOS and Linux: ~/.android/
- Windows Vista and Windows 7: C:\Users\your_user_name\.android\

List the SHA-1 fingerprint:

For Linux or macOS, open a terminal window and enter the following:

keytool -list -v -keystore ~/.android/debug.keystore
 -alias androiddebugkey -storepass android -keypass android

For Windows Vista and Windows 7, run:

keytool -list -v -keystore
 "%USERPROFILE%\.android\debug.keystore" -alias androiddebugkey
 -storepass android -keypass android

The output should be similar to the following. The line that begins with SHA1 contains the certificate's SHA-1 fingerprint.

Alias name: androiddebugkey
Creation date: Jan 01, 2013
Entry type: PrivateKeyEntry
Certificate chain length: 1
Certificate[1]:
Owner: CN=Android Debug, O=Android, C=US
Issuer: CN=Android Debug, O=Android, C=US
Serial number: 4aa9b300
Valid from: Mon Jan 01 08:04:04 UTC 2013 until: Mon Jan 01 18:04:04 PST 2033
Certificate fingerprints:
     MD5:  AE:9F:95:D0:A6:86:89:BC:A8:70:BA:34:FF:6A:AC:F9
     SHA1: BB:0D:AC:74:D3:21:E1:43:07:71:9B:62:90:AF:A1:66:6E:44:5D:75
     Signature algorithm name: SHA1withRSA
     Version: 3

Release certificate

Displaying the release certificate fingerprint

Locate your release certificate keystore file. There is no default location or name for the release keystore. If you don't specify one when you build your app for release, the build will leave your .apk unsigned, and you'll have to sign it before you can publish it. For the release certificate, you also need the certificate's alias and the passwords for the keystore and the certificate. You can list the aliases for all the keys in a keystore by entering:
```
keytool -list -keystore your_keystore_name
```
Replace your_keystore_name with the fully-qualified path and name of the keystore, including the .keystore extension. You'll be prompted for the keystore's password. Then keytool displays all the aliases in the keystore.
Enter the following at a terminal or command prompt:
```
keytool -list -v -keystore your_keystore_name -alias your_alias_name
```
Replace your_keystore_name with the fully-qualified path and name of the keystore, including the .keystore extension. Replace your_alias_name with the alias that you assigned to the certificate when you created it.

The output should be similar to the following. The line that begins with SHA1 contains the certificate's SHA-1 fingerprint.

Alias name: <alias_name>
Creation date: Feb 02, 2013
Entry type: PrivateKeyEntry
Certificate chain length: 1
Certificate[1]:
Owner: CN=Android Debug, O=Android, C=US
Issuer: CN=Android Debug, O=Android, C=US
Serial number: 4cc9b300
Valid from: Mon Feb 02 08:01:04 UTC 2013 until: Mon Feb 02 18:05:04 PST 2033
Certificate fingerprints:
    MD5:  AE:9F:95:D0:A6:86:89:BC:A8:70:BA:34:FF:6B:AC:F9
    SHA1: BB:0D:AC:74:D3:21:E1:43:67:71:9B:62:90:AF:A1:66:6E:44:5D:75
    Signature algorithm name: SHA1withRSA
    Version: 3

For more information about digital certificates, see the Sign your app guide.