Authenticate using API keys

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This page describes how to use API keys to authenticate to Google Cloud APIs and services that support API keys.

Most Google Cloud APIs don't support API keys. Check that the API that you want to use supports API keys before using this authentication method.

For information about using API keys to authenticate to Google Maps Platform, see the Google Maps Platform documentation. For more information about the API Keys API, see the API Keys API documentation.

Introduction to API keys

An API key has the following components, which you use to manage and use the key:

String
The API key string is an encrypted string, for example, AIzaSyDaGmWKa4JsXZ-HjGw7ISLn_3namBGewQe. When you use an API key to authenticate, you always use the key's string. API keys do not have an associated JSON file.
ID
The API key ID is used by Google Cloud administrative tools to uniquely identify the key. The key ID cannot be used to authenticate. The key ID can be found in the URL of the key's edit page in the Google Cloud console. You can also get the key ID by using the Google Cloud CLI to list the keys in your project.
Display name
The display name is an optional, descriptive name for the key, which you can set when you create or update the key.

When you use an API key to authenticate to an API, the API key does not identify a principal, nor does it provide any authorization information. The API key associates the request with a Google Cloud project for billing and quota purposes. Because API keys do not identify the caller, they are often used for accessing public data or resources.

Many Google Cloud APIs do not accept API keys for authentication. Review the authentication documentation for the service or API that you want to use to determine whether it supports API keys.

To manage API keys, you must have the API Keys Admin role (roles/serviceusage.apiKeysAdmin) on the project.

Create an API key

To create an API key, use one of the following options:

Console

  1. In the Google Cloud console, go to the Credentials page:

    Go to Credentials

  2. Click Create credentials, then select API key from the menu.

    The API key created dialog displays the string for your newly created key.

gcloud

You use the gcloud alpha services api-keys create command to create an API key.

Replace DISPLAY_NAME with a descriptive name for your key.

gcloud alpha services api-keys create --display-name=DISPLAY_NAME

REST

You use the keys.create method to create an API key. This request returns a long-running operation; you must poll the operation to get the information for the new key.

Replace the following values:

  • DISPLAY_NAME: Optional. A descriptive name for your key.
  • PROJECT_ID: Your Google Cloud project ID or name.
curl -X POST \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "Content-Type: application/json; charset=utf-8" \
-d {'"displayName" : "DISPLAY_NAME"'} \
"https://apikeys.googleapis.com/v2/projects/PROJECT/locations/global/keys"

For more information about creating API keys using the REST API, see Creating an API key in the API Key API documentation.

Copy your key string and keep it secure. Unless you're using a testing key that you intend to delete later, add application and API key restrictions.

Use an API key

You can use API keys with REST requests and with client libraries that support them.

Using an API key with REST

You can pass the API key into a REST API call as a query parameter with the following format. Replace API_KEY with the key string of your API key.

For example, to pass an API key for a Cloud Natural Language API request for documents.analyzeEntities:

POST https://language.googleapis.com/v1/documents:analyzeEntities?key=API_KEY

Alternatively, you can use the x-goog-api-key header to pass in your key. This header must be used with gRPC requests.

curl -X POST \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "X-goog-api-key: API_KEY" \
    -H "Content-Type: application/json; charset=utf-8" \
    -d @request.json \
    "https://translation.googleapis.com/language/translate/v2"

Using an API key with client libraries

When a service's API supports API keys, the client library for that service usually supports API keys. Check the client library documentation to see if the client creation method accepts an API key.

Secure an API key

When you use API keys in your applications, ensure that they are kept secure during both storage and transmission. Publicly exposing your API keys can lead to unexpected charges on your account. To help keep your API keys secure, follow these best practices:

  • Add API key restrictions to your key.

    By adding restrictions, you can limit the ways an API key can be used, reducing the impact of a compromised API key.

  • Delete unneeded API keys to minimize exposure to attacks.

  • Recreate your API keys periodically.

    Periodically create new API keys, delete the old keys, and update your applications to use the new API keys.

Apply API key restrictions

API keys are unrestricted by default. Unrestricted keys are insecure because they can be used by anyone from anywhere. For production applications, you should set both application restrictions and API restrictions.

Add application restrictions

Application restrictions specify which websites, IP addresses, or apps can use an API key.

You can apply only one application restriction type at a time. Choose the restriction type based on your application type:

Option Application type Notes
HTTP referrers Web applications Specifies the websites that can use the key.
IP Addresses Applications called by specific servers Specifies the servers or cron jobs that can use the key.
Android apps Android applications Specifies the Android application that can use the key.
iOS apps iOS applications Specifies the iOS bundles that can use the key.

HTTP referrers

To restrict the websites that can use your API key, you add one or more HTTP referrer restrictions.

You can substitute a wildcard character (*) for the subdomain or the path, but you cannot insert a wildcard character into the middle of the URL. For example, *.google.com is valid, and accepts all sites ending in .google.com. However, mysubdomain*.google.com is not a valid restriction.

Port numbers can be included in HTTP referrer restrictions. If you include a port number, then only requests using that port are matched. If you do not specify a port number, then requests from any port number are matched.

You can add up to 1200 HTTP referrers to an API key.

The following table shows some example scenarios and browser restrictions:

Scenario Restrictions
Allow a specific URL Add a URL with an exact path. For example:
www.example.com/path
www.example.com/path/path
Allow any URL in your site You must set two URLs in the `allowedReferers` list.
  1. URL for the domain, without a subdomain, and with a wildcard for the path. For example:
    example.com/*
  2. A second URL that includes a wildcard for the subdomain and a wildcard for the path. For example:
    *.example.com/*
Allow any URL in a single subdomain or naked domain

You must set two URLs in the `allowedReferers` list to allow an entire domain:

  1. URL for the domain, without a trailing slash. For example:
    www.example.com
    sub.example.com
    example.com
  2. A second URL for the domain that includes a wildcard for the path. For example:
    www.example.com/*
    sub.example.com/*
    example.com/*

To restrict your API key to specific websites, use one of the following options:

Console

  1. In the Google Cloud console, go to the Credentials page:

    Go to Credentials

  2. Click the name of the API key that you want to restrict.

  3. In the Application restrictions section, select HTTP referrers.

  4. For each restriction that you want to add, click Add an item, enter the restriction, and click Done.

  5. Click Save to save your changes and return to the API key list.

gcloud

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the gcloud services api-keys list command to list the keys in your project.

  2. Use the gcloud alpha services api-keys update command to add HTTP referrer restrictions to an API key.

    Replace the following values:

    • KEY_ID: The ID of the key that you want to restrict.
    • ALLOWED_REFERRER_1: Your HTTP referrer restriction.

      You can add as many restrictions as needed; use commas to separate the restrictions. You must provide all referrer restrictions with the update command; the referrer restrictions provided replace any existing referrer restrictions on the key.

    gcloud alpha services api-keys update KEY_ID \
     --allowed-referrers="ALLOWED_REFERRER_1"
    

REST

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the keys.list method. The ID is listed in the uid field of the response.

    Replace PROJECT_ID with your Google Cloud project ID or name.

    curl -X GET \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/"
    
  2. Use the keys.patch method to add HTTP referrer restrictions to the API key.

    This request returns a long-running operation; you must poll the operation to know when the operation completes and get the operation status.

    Replace the following values:

    • ALLOWED_REFERRER_1: Your HTTP referrer restriction.

      You can add as many restrictions as needed; use commas to separate the restrictions. You must provide all referrer restrictions with the request; the referrer restrictions provided replace any existing referrer restrictions on the key.

    • PROJECT_ID: Your Google Cloud project ID or name.

    • KEY_ID: The ID of the key that you want to restrict.

    curl -X PATCH \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    --data '{
    "restrictions" : {
    "browserKeyRestrictions": {
      "allowedReferrers": ["ALLOWED_REFERRER_1"]
    }
    }
    }' \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/KEY_ID?updateMask=restrictions"
    

For more information about adding HTTP referrer restrictions to a key using the REST API, see Adding browser restrictions in the API Key API documentation.

IP Addresses

You can specify one or more IP addresses of the callers, such as a web server or cron job, that are allowed to use your API key. You can specify the IP addresses in any of the following formats:

  • IPv4 (198.51.100.1)
  • IPv6 (2001:db8::1)
  • A subnet using CIDR notation (198.51.100.0/24, 2001:db8::/64)

Using localhost is not supported for server restrictions.

To restrict your API key to specific IP addresses, use one of the following options:

Console

  1. In the Google Cloud console, go to the Credentials page:

    Go to Credentials

  2. Click the name of the API key that you want to restrict.

  3. In the Application restrictions section, select IP addresses.

  4. For each IP address that you want to add, click Add an item, enter the address, and click Done.

  5. Click Save to save your changes and return to the API key list.

gcloud

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the gcloud services api-keys list command to list the keys in your project.

  2. Use the gcloud alpha services api-keys update command to add server (IP address) restrictions to an API key.

    Replace the following values:

    • KEY_ID: The ID of the key that you want to restrict.
    • ALLOWED_IP_ADDR_1: Your allowed IP address.

      You can add as many IP addresses as needed; use commas to separate the addresses.

    gcloud alpha services api-keys update KEY_ID \
    --allowed-ips="ALLOWED_IP_ADDR_1"
    

REST

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the keys.list method. The ID is listed in the uid field of the response.

    Replace PROJECT_ID with your Google Cloud project ID or name.

    curl -X GET \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/"
    
  2. Use the keys.patch method to add server (IP address) restrictions to an API key.

    This request returns a long-running operation; you must poll the operation to know when the operation completes and get the operation status.

    Replace the following values:

    • ALLOWED_IP_ADDR_1: Your allowed IP address.

      You can add as many IP addresses as needed; use commas to separate the restrictions. You must provide all IP addresses with the request; the referrer restrictions provided replace any existing IP address restrictions on the key.

    • PROJECT_ID: Your Google Cloud project ID or name.

    • KEY_ID: The ID of the key that you want to restrict.

    curl -X PATCH \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    --data '{
    "restrictions" : {
      "serverKeyRestrictions": {
        "allowedIps": ["ALLOWED_IP_ADDR_1"]
      }
    }
    }' \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/KEY_ID?updateMask=restrictions"
    

For more information about adding IP address restrictions to a key using the REST API, see Adding server restrictions in the API Key API documentation.

Android apps

You can restrict usage of an API key to specific Android apps. You must provide the package name and the 20-byte SHA-1 certificate fingerprint for each app.

To restrict your API key to one or more Android apps, use one of the following options:

Console

  1. In the Google Cloud console, go to the Credentials page:

    Go to Credentials

  2. Click the name of the API key that you want to restrict.

  3. In the Application restrictions section, select Android apps.

  4. For each Android app that you want to add, click Add an item and enter the package name and SHA-1 certificate fingerprint, then click Done.

  5. Click Save to save your changes and return to the API key list.

gcloud

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the gcloud services api-keys list command to list the keys in your project.

  2. Use the gcloud alpha services api-keys update command to specify the Android apps that can use an API key.

    Replace the following values:

    • KEY_ID: The ID of the key that you want to restrict.
    • SHA1_FINGERPRINT and PACKAGE_NAME: The app information for an Android app that can use the key.

      You can add as many apps as needed; use additional --allowed-application flags.

    gcloud alpha services api-keys update KEY_ID \
    --allowed-application=sha1_fingerprint=SHA1_FINGERPRINT_1,package_name=PACKAGE_NAME_1 \
    --allowed-application=sha1_fingerprint=SHA1_FINGERPRINT_2,package_name=PACKAGE_NAME_2
    

REST

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the keys.list method. The ID is listed in the uid field of the response.

    Replace PROJECT_ID with your Google Cloud project ID or name.

    curl -X GET \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/"
    
  2. Use the keys.patch method to specify the Android apps that can use an API key.

    This request returns a long-running operation; you must poll the operation to know when the operation completes and get the operation status.

    Replace the following values:

    • SHA1_FINGERPRINT_1 and PACKAGE_NAME_1: The app information for an Android app that can use the key.

      You can add the information for as many apps as needed; use commas to separate the AndroidApplication objects. You must provide all applications with the request; the applications provided replace any existing allowed applications on the key.

    • PROJECT_ID: Your Google Cloud project ID or name.

    • KEY_ID: The ID of the key that you want to restrict.

    curl -X PATCH \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    --data '{
    "restrictions" : {
    "androidKeyRestrictions": {
      "allowedApplications": [
        {
          "sha1Fingerprint": "SHA1_FINGERPRINT_1",
          "packageName": "PACKAGE_NAME_1"
        },
     ]
    }
    }
    }' \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/KEY_ID?updateMask=restrictions"
    

For more information about adding Android app restrictions to a key using the REST API, see Adding Android restrictions in the API Key API documentation.

iOS apps

You can restrict usage of an API key to specific iOS apps by providing the bundle ID of each app.

To restrict your API key to one or more iOS apps, use one of the following options:

Console

  1. In the Google Cloud console, go to the Credentials page:

    Go to Credentials

  2. Click the name of the API key that you want to restrict.

  3. In the Application restrictions section, select iOS apps.

  4. For each iOS app that you want to add, click Add an item and enter the bundle ID, then click Done.

  5. Click Save to save your changes and return to the API key list.

gcloud

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the gcloud services api-keys list command to list the keys in your project.

  2. Use the gcloud alpha services api-keys update method to specify the iOS apps that can use the key.

    Replace the following values:

    • KEY_ID: The ID of the key that you want to restrict.
    • ALLOWED_BUNDLE_ID: The bundle ID of an iOS app that you want to be able to use this API key.

      You can add as many bundle IDs as needed; use commas to separate the IDs.

    gcloud alpha services api-keys update KEY_ID \
    --allowed-bundle-ids=ALLOWED_BUNDLE_ID_1,ALLOWED_BUNDLE_ID_2
    

REST

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the keys.list method. The ID is listed in the uid field of the response.

    Replace PROJECT_ID with your Google Cloud project ID or name.

    curl -X GET \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/"
    
  2. Use the keys.patch method to specify the iOS apps that can use an API key.

    This request returns a long-running operation; you must poll the operation to know when the operation completes and get the operation status.

    Replace the following values:

    • ALLOWED_BUNDLE_ID: The bundle ID of an iOS app that can use the key.

      You can add the information for as many apps as needed; use commas to separate the bundle IDs. You must provide all bundle IDs with the request; the bundle IDs provided replace any existing allowed applications on the key.

    • PROJECT_ID: Your Google Cloud project ID or name.

    • KEY_ID: The ID of the key that you want to restrict.

    curl -X PATCH \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    --data '{
    "restrictions" : {
    "iosKeyRestrictions": {
      "allowedBundleIds": ["ALLOWED_BUNDLE_ID_1","ALLOWED_BUNDLE_ID_2"]
    }
    }
    }' \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/KEY_ID?updateMask=restrictions"
    

For more information about adding iOS app restrictions to a key using the REST API, see Adding iOS restrictions in the API Key API documentation.

Add API restrictions

API restrictions specify which APIs can be called using the API key.

To add API restrictions, use one of the following options:

Console

  1. In the Google Cloud console, go to the Credentials page:

    Go to Credentials

  2. Click the name of the API key that you want to restrict.

  3. In the API restrictions section, click Restrict key.

  4. Select all APIs that your API key will be used to access.

  5. Click Save to save your changes and return to the API key list.

gcloud

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the gcloud services api-keys list command to list the keys in your project.

  2. Use the gcloud alpha services api-keys update command to specify which services an API key can be used to authenticate to.

    Replace the following values:

    • KEY_ID: The ID of the key that you want to restrict.
    • SERVICE_1, SERVICE_2...: The service names of the APIs that the key can be used to access.

      You must provide all service names with the update command; the service names provided replace any existing services on the key.

    You can find the service name by searching for the API on the API dashboard. Service names are strings like bigquery.googleapis.com.

    gcloud alpha services api-keys update KEY_ID \
    --api-target=service=SERVICE_1 --api-target=service=SERVICE_2
    

REST

  1. Get the ID of the key that you want to restrict.

    The ID is not the same as the display name or the key string. You can get the ID by using the keys.list method. The ID is listed in the uid field of the response.

    Replace PROJECT_ID with your Google Cloud project ID or name.

    curl -X GET \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/"
    
  2. Use the keys.patch method to specify which services an API key can be used to authenticate to.

    This request returns a long-running operation; you must poll the operation to know when the operation completes and get the operation status.

    Replace the following values:

    • SERVICE_1, SERVICE_2...: The service names of the APIs that the key can be used to access.

      You must provide all service names with the request; the service names provided replace any existing services on the key.

      You can find the service name by searching for the API on the API dashboard. Service names are strings like bigquery.googleapis.com.

    • PROJECT_ID: Your Google Cloud project ID or name.

    • KEY_ID: The ID of the key that you want to restrict.

    curl -X PATCH \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    --data '{
    "restrictions" : {
    "apiTargets": [
      {
        "service": "SERVICE_1"
      },
      {
        "service" : "SERVICE_2"
      },
    ]
    }
    }' \
    "https://apikeys.googleapis.com/v2/projects/PROJECT_ID/locations/global/keys/KEY_ID?updateMask=restrictions"
    

For more information about adding API restrictions to a key using the REST API, see Adding API restrictions in the API Key API documentation.

Get project information from a key string

You can determine which Google Cloud project an API key is associated with from its string.

Replace KEY_STRING with the key string you need project information for.

gcloud

You use the gcloud alpha services api-keys lookup command to get the project ID from a key string.

gcloud alpha services api-keys lookup KEY_STRING

REST

You use the lookupKey method to get the project ID from a key string.

curl -X GET \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "Content-Type: application/json; charset=utf-8" \
"https://apikeys.googleapis.com/v2/keys:lookupKey?keyString=KEY_STRING"

Poll long-running operations

API Key API methods use long-running operations. If you use the REST API to create and manage API keys, an operation object is returned from the initial method request. You use the operation name to poll the long-running operation. When the long-running request completes, polling the operation returns the data from the long-running request.

To poll a long-running API Key API operation, you use the operations.get method.

Replace OPERATION_NAME with the operation name returned by the long-running operation. For example, operations/akmf.p7-358517206116-cd10a88a-7740-4403-a8fd-979f3bd7fe1c.

curl -X GET \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    "https://apikeys.googleapis.com/v2/OPERATION_NAME"

Limits on API keys

You can create up to 300 API keys per project. This limit is a system limit, and cannot be changed using a quota increase request.

If more API keys are needed, you must use more than one project.

What's next