Request endpoints

This page explains the different request endpoints you can use to access Cloud Storage. Cloud Storage supports HTTP/1.1, HTTP/2, and HTTP/3 protocols. An endpoint is the location where Cloud Storage can be accessed, written as a URL.

Typical API requests

For connections through a proxy, see the Troubleshooting topic for recommended practices.

Encoding URL path parts

In addition to general considerations for bucket naming and object naming, to ensure compatibility across Cloud Storage tools, you should encode the following characters when they appear in either the object name or query string of a request URL:

!, #, $, &, ', (, ), *, +, ,, /, :, ;, =, ?, @, [, ], and space characters.

For example, if you send a JSON API GET request for the object named foo??bar in the bucket example-bucket, then your request URL should be:

GET https://storage.googleapis.com/storage/v1/b/example-bucket/o/foo%3f%3fbar

Note that not all of the listed characters must be encoded in every scenario. Additionally, encoding is typically handled for you by client libraries, such as the Cloud Storage Client Libraries, so you can pass the raw object name when using such tools.

For more information about using percent-encoding, see Section 3.3 Path in RFC 3986.

Google Cloud console endpoints

When using the Google Cloud console, you access different resources using the following URLs:

gcloud endpoints

gcloud storage commands use JSON API endpoints. Endpoint usage is managed on your behalf by the gcloud CLI.

Client library endpoints

Cloud Storage client libraries manage request endpoints automatically. Optionally, you can set the request endpoint manually. This can be useful when you want to use a specific endpoint, or for testing, such as when you want to use a local emulator:

namespace g = ::google::cloud;
namespace gcs = ::google::cloud::storage;
[](std::string const& bucket_name, std::string const& object_name) {
  // NOTE: the CLOUD_STORAGE_EMULATOR_HOST environment variable overrides any
  //     value provided here.
  auto client = gcs::Client(g::Options{}.set<gcs::RestEndpointOption>(
      "https://storage.googleapis.com"));
  PerformSomeOperations(client, bucket_name, object_name);
}

using Google.Cloud.Storage.V1;
using System;

public class SetClientEndpointSample
{
    public StorageClient SetClientEndpoint(string endpoint) => new StorageClientBuilder
    {
        BaseUri = endpoint
    }.Build();
}

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/storage"
	"google.golang.org/api/option"
)

// setClientEndpoint sets the request endpoint.
func setClientEndpoint(w io.Writer, customEndpoint string, opts ...option.ClientOption) error {
	// customEndpoint := "https://my-custom-endpoint.example.com/storage/v1/"
	// opts := []option.ClientOption{}
	ctx := context.Background()

	// Add the custom endpoint option to any other desired options passed to storage.NewClient.
	opts = append(opts, option.WithEndpoint(customEndpoint))
	client, err := storage.NewClient(ctx, opts...)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	// Use the client as per your custom endpoint, for example, attempt to get a bucket's metadata.
	client.Bucket("bucket-name").Attrs(ctx)
	return nil
}

import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class SetClientEndpoint {

  public static void setClientEndpoint(String projectId, String endpoint) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The endpoint you wish to target
    // String endpoint = "https://storage.googleapis.com"

    Storage storage =
        StorageOptions.newBuilder().setProjectId(projectId).setHost(endpoint).build().getService();

    System.out.println(
        "Storage Client initialized with endpoint " + storage.getOptions().getHost());
  }
}

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The custom endpoint to which requests should be made
// const apiEndpoint = 'https://yourcustomendpoint.com';

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage({
  apiEndpoint: apiEndpoint,
  useAuthWithCustomEndpoint: true,
});

console.log(`Client initiated with endpoint: ${storage.apiEndpoint}.`);

use Google\Cloud\Storage\StorageClient;

/**
 * Sets a custom endpoint for storage client.
 *
 * @param string $projectId The ID of your Google Cloud Platform project.
 *        (e.g. 'my-project-id')
 * @param string $endpoint The endpoint for storage client to target.
 *        (e.g. 'https://storage.googleapis.com')
 */
function set_client_endpoint(
    string $projectId,
    string $endpoint
): void {
    $storage = new StorageClient([
        'projectId' => $projectId,
        'apiEndpoint' => $endpoint,
    ]);

    // fetching apiEndpoint and baseUri from StorageClient is excluded for brevity
    # ...
    print('Storage Client initialized.' . PHP_EOL);
}

from google.cloud import storage


def set_client_endpoint(api_endpoint):
    """Initiates client with specified endpoint."""
    # api_endpoint = 'https://storage.googleapis.com'

    storage_client = storage.Client(client_options={'api_endpoint': api_endpoint})

    print(f"client initiated with endpoint: {storage_client._connection.API_BASE_URL}")

    return storage_client

# api_endpoint = "https://storage.googleapis.com"

require "google/cloud/storage"

storage = Google::Cloud::Storage.new(
  endpoint: api_endpoint
)

puts "Client initiated with endpoint #{storage.service.service.root_url}"

Custom domains

If you own your own domain, you can map its URIs to one or more Google Cloud services, including Cloud Storage buckets. The term bucket-bound hostname is sometimes used to describe this Cloud Storage request endpoint. To connect a custom domain to a Cloud Storage bucket, you create either an A or CNAME redirect in your DNS record.

A records

When connecting a custom domain to a Cloud Storage bucket, you generally should use an A record.

• A records support HTTPS requests.
• A records can be used to send traffic coming from a single hostname to multiple buckets as well as to other Google Cloud services.
• A records do not place any restrictions on your bucket name.

The drawback to using A records is that they require additional setup and use of additional Google Cloud resources. See Setting up your load balancer and SSL certificate for a guide to using custom domains with A records.

CNAME records

When connecting a custom domain to a Cloud Storage bucket, you can use a CNAME record, but note that doing so has certain limitations:

• CNAME records only support HTTP requests.
• CNAME records can only direct traffic from a given hostname to a single bucket.
• CNAME records require the hostname and the associated bucket name to match, and you must validate your bucket name.
• CNAME records can only be used for subdomains, such as www.mydomain.com, not top-level domains such as mydomain.com.

When using CNAME records, the hostname portion of your CNAME record must be set to the following:

c.storage.googleapis.com.

For example, say your domain is example.com, and you want to make travel maps available to your customers. You can create a bucket in Cloud Storage called travel-maps.example.com, and then create a CNAME record in DNS that redirects requests from travel-maps.example.com to the Cloud Storage URI. To do this, you publish the following CNAME record in DNS:

NAME                      TYPE     DATA
travel-maps               CNAME    c.storage.googleapis.com.

By doing this, your customers can use the following URL to access a map of Paris:

http://travel-maps.example.com/paris.jpg

Your domain registration service should have a way for you to administer your domain, including adding a CNAME resource record. For example, if you use Cloud DNS, instructions for adding resource records can be found on the Add, modify, and delete records page.

Authenticated browser downloads

Authenticated browser downloads use cookie-based authentication. Cookie-based authentication asks users to sign in to their user account to establish their identity. The specified account must have appropriate permission to download the object. For example, if you are using Identity and Access Management to control access to your objects, the user's account should have the storage.objects.viewer permission, which is granted in the Storage Object Viewer role.

To download an object using cookie-based authentication, use the following URL, replacing BUCKET_NAME and OBJECT_NAME with the appropriate values:

https://storage.cloud.google.com/BUCKET_NAME/OBJECT_NAME

For example, if you shared an image london.jpg from your bucket example-maps, the URL would be:

https://storage.cloud.google.com/example-maps/london.jpg

After successfully signing in, you are redirected to the requested content. The URL for this content begins with an alphanumeric sequence and contains the string /download/storage/v1/b/BUCKET_NAME/o/OBJECT_NAME

Using HTTPS is required when performing authenticated browser downloads; attempts to use HTTP redirect to HTTPS.

Access to public objects

All requests to the storage.cloud.google.com URI require authentication. This applies even when allUsers have permission to access an object. If you want users to download anonymously accessible objects without authenticating, use the XML API path-style endpoint:

https://storage.googleapis.com/BUCKET_NAME/OBJECT_NAME

For details and examples, see Accessing Public Data.

Mutual TLS support

• JSON API requests: storage.mtls.googleapis.com

• Authenticated browser downloads: storage.mtls.cloud.google.com

What's next

• Upload a file to Cloud Storage.
• Download a file from Cloud Storage.
• Host a static website.
• Learn about options to control access to your data.