HTTP triggers

In Cloud Functions, an HTTP trigger enables a function to run in response to HTTP(S) requests. When you specify an HTTP trigger for a function, the function is assigned a URL at which it can receive requests. HTTP triggers support the GET, POST, PUT, DELETE, and OPTIONS request methods.

Note: In Cloud Functions (2nd gen), all functions are assigned an HTTPS endpoint at which they can be invoked, regardless of any other trigger specified.

In Cloud Functions (2nd gen), requests to a function URL always require HTTPS. In Cloud Functions (1st gen), you can choose whether HTTPS is required during deployment.

By default, requests to a function with an HTTP trigger require authentication. You can choose to allow unauthenticated calls during deployment. See Allowing unauthenticated HTTP function invocation for more information.

You use HTTP functions to implement Cloud Functions that can handle general HTTP(S) requests.

Deployment

You can specify an HTTP trigger when you deploy a function. See Deploy a Cloud Function for general instructions on how to deploy a function, and see below for additional information specific to configuring HTTP triggers during deployment.

gcloud

If you are deploying using the gcloud CLI, the flags shown below are used to configure HTTP triggers:

gcloud functions deploy YOUR_FUNCTION_NAME \
--trigger-http \
[--allow-unauthenticated] \
[--security-level=SECURITY_LEVEL] \
...

• The --trigger-http flag specifies that the function uses an HTTP trigger.
• The --allow-unauthenticated flag specifies that the function can be called without authentication. Omitting this flag means that calls to the function require authentication, which is the default. See Authenticating for invocation for more information.
• (1st gen) The --security-level flag controls whether the function endpoint requires HTTPS. The value secure-always means HTTPS is required and non-SSL HTTP requests are not supported. The value secure-optional means both HTTP and HTTPS are supported. The default is secure-always.

Console

If you are deploying using the Google Cloud console, you can configure an HTTP trigger in the Trigger section.

• For Cloud Functions (2nd gen):
  1. Under HTTPS, in the Authentication field, select an option depending on whether you want to allow unauthenticated invocations of your function. By default, authentication is required. See Authenticating for invocation for more information.
• For Cloud Functions (1st gen):
  1. In the Trigger type field, select HTTP.
  2. In the Authentication field, select an option depending on whether you want to allow unauthenticated invocations of your function. By default, authentication is required. See Authenticating for invocation for more information.
  3. Select or deselect the Require HTTPS checkbox to control whether the function endpoint requires HTTPS. If deselected, both HTTP and HTTPS are supported.

Function URL

After your function is deployed with an HTTP trigger, you can retrieve its assigned URL.

Note: Currently, function URLs in Cloud Functions (2nd gen) use a non-deterministic format, meaning you cannot predict your function URL before deployment, though the URL remains stable after deployment. In a future release, function URLs will be updated to be both stable and deterministic.

gcloud

• For Cloud Functions (2nd gen):

  gcloud functions describe YOUR_FUNCTION_NAME \
  --gen2 \
  --region=YOUR_FUNCTION_REGION \
  --format="value(serviceConfig.uri)"
  

• For Cloud Functions (1st gen):

  gcloud functions describe YOUR_FUNCTION_NAME \
  --format="value(httpsTrigger.url)"
  

Console

1. Go to the Cloud Functions overview page in the Google Cloud console:

   Go to Cloud Functions

2. Click the name of the function whose URL you want to retrieve.

3. Click the Trigger tab. The function's assigned URL is shown.

Next steps

• Learn how to write HTTP functions.
• Learn how to deploy a Cloud Function.
• See the HTTP function tutorial for an example of writing, deploying, and calling an HTTP function.