Get an API Key and Signature

Before you begin

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

Overview

To use the Maps Static API you must have an API key. The API key is a unique identifier that is used to authenticate requests associated with your project for usage and billing purposes.

Depending on your usage, a digital signature may also be required (see Other Usage Limits) The digital signature allows our servers to verify that any site generating requests using your API key is authorized to do so.

Get the API key

You must have at least one API key associated with your project.

To get an API key:

1. Go to the Google Cloud Console.
2. Click the project drop-down and select or create the project for which you want to add an API key.
3. Click the menu button and select APIs & Services > Credentials.
4. On the Credentials page, click + Create Credentials > API key.
   The API key created dialog displays the newly created API key.
5. 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.)

Add the API key to your request

You must include an API key with every Maps Static API request. In the following example, replace YOUR_API_KEY with your API key.

Restrict the API key

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:

1. Go to the APIs & Services > Credentials page.

   Go to the Credentials page

2. Select the API key that you want to set a restriction on. The API key property page appears.
3. Under Key restrictions, set the following restrictions:
• Application restrictions:
1. To accept requests from the list of website that you supply, select HTTP referrers (web sites) from the list of Application restrictions.
2. Specify one or more referrer web sites. For example, *.google.com accepts all sites ending in google.com, such as https://developers.google.com.
   

   Note: file:// referers need a special representation to be added to the key restriction. The "file://" part should be replaced with "__file_url__" before being added to the key restriction. For example, "file:///path/to/" should be formatted as "__file_url__//path/to/*". After enabling file:// referers, it is recommended you regularly check your usage, to make sure it matches your expectations.

• API restrictions:
1. Click Restrict key.
2. Select Maps Static API from Select APIs dropdown.
   If the Maps Static API is not listed, you need to enable it.
4. To finalize your changes, click Save.
   

Digitally sign your request

Depending on your usage, a digital signature - in addition to an API key - may be required to authenticate requests (see Other Usage Limits).

How digital signatures work

Digital signatures are generated using a cryptographic URL signing secret, which is available on the Google Cloud Console. The secret, also known as a private key, is encoded in a modified Base64 for URLs. This secret is shared between you and Google, and is unique to your API key.

The signing process uses an encryption algorithm to combine the URL and your shared secret. The resulting unique signature allows our servers to verify that any site generating requests using your API key is authorized to do so.

You can generate a digital signature automatically or manually.

Limit unsigned requests

To ensure that your API key only accepts signed requests:

1. Go to the Google Maps Platform Quotas page in the Cloud Console.
2. Click the project drop-down and select the same project you used when you created the API key for the Maps Static API.
3. Click the APIs drop-down and select Maps Static API.
4. Expand the Unsigned requests section.
5. In the Quota Name table, click the edit button next to the quota you want to edit. For example, Unsigned requests per day.
6. Update Quota limit in the Edit Quota Limit pane.
7. Click save.

Generate a digital signature automatically

To automatically generate a digital signature for use with an API key (using the Google Cloud Platform console):

• Step 1: Build an unsigned request URL.
• Step 2: Check the URL Signing Secret.
• Step 3: Get a digitally signed URL.

Step 1: Build an unsigned request URL

Construct the request URL according to the Maps Static API Developer Guide. Include your API key in the key parameter as instructed in Add the API key to your request above. For example:

https://maps.googleapis.com/maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&key=YOUR_API_KEY

Step 2: Check the URL Signing Secret

To check your URL signing secret:

1. Go to the Google Maps Platform Credentials page in the Cloud Console.
2. Click the project drop-down and select the same project you used when you created the API key for the Maps Static API.
3. Click the APIs drop-down and select Maps Static API.
4. Scroll down to the Secret Generator card.
   The Current secret field contains your current URL signing secret.

To get a new URL signing secret, click Regenerate Secret. The previous secret will expire 24 hours after you've generated a new secret. After the 24 hours have passed, requests containing the old secret no longer work. Please keep your URL signing secret secure. Do not pass it in any requests, store it on any websites, or post it to any public forum. Anyone obtaining your URL signing secret could spoof requests using your identity.

Step 3: Generate a digitally signed URL

To generate a digitally signed URL:

1. Return to the Credentials page.
2. Scroll down to the Sign a URL now card.
3. In the URL field, paste your unsigned request URL from Step 1.
   A digital signature is generated, based on your unsigned request URL (Step 1) and your current URL signing secret (Step 2), and appended to your original URL.
4. The Your Signed URL field that appears will contain your digitally signed URL. Be sure to make a copy.

Generate a digital signature manually

To manually generate a digital signature for use with an API key:

1. Construct the request URL without the signature, making sure to include your API key in the key parameter. Note that you must URL-encode any non-standard characters. For example:

   https://maps.googleapis.com/maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&key=YOUR_API_KEY

   Note: All Google services require UTF-8 character encoding (which implicitly includes ASCII). If your applications operate using other character sets, make sure they construct URLs using UTF-8 and properly URL-encode them.

2. Strip off the domain portion of the request, leaving only the path and the query:

   /maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&key=YOUR_API_KEY

3. Retrieve your URL signing secret, which is encoded in a modified Base64 for URLs, from the Google Cloud Console and sign the above URL above using the HMAC-SHA1 algorithm (see URL signing secret).

   You may need to decode your secret into its original binary format. Note that in most cryptographic libraries, the resulting signature is in binary format.

   Note: Modified Base64 for URLs replaces the + and / characters of standard Base64 with - and _ respectively, so that these Base64 signatures no longer need to be URL-encoded.

4. Encode the resulting binary signature using the modified Base64 for URLs to convert this signature into something that can be passed within a URL.

5. Add the resulting signature to the request URL within a signature parameter. For example:

   https://maps.googleapis.com/maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&key=YOUR_API_KEY&signature=BASE64_SIGNATURE

For samples showing ways to implement URL signing using server-side code, see Sample code for URL signing.

To sign a URL now, enter your URL and your URL signing secret below. The URL must have the format described in step 1 above, and be URL-encoded.

Sample code for URL signing

The following sections show ways to implement URL signing using server-side code. URLs should always be signed server-side to avoid exposing your cryptographic key to users.

#!/usr/bin/python
# -*- coding: utf-8 -*-
""" Signs a URL using a URL signing secret """

import hashlib
import hmac
import base64
import urllib.parse as urlparse


def sign_url(input_url=None, secret=None):
    """ Sign a request URL with a URL signing secret.
      Usage:
      from urlsigner import sign_url
      signed_url = sign_url(input_url=my_url, secret=SECRET)
      Args:
      input_url - The URL to sign
      secret    - Your URL signing secret
      Returns:
      The signed request URL
  """

    if not input_url or not secret:
        raise Exception("Both input_url and secret are required")

    url = urlparse.urlparse(input_url)

    # We only need to sign the path+query part of the string
    url_to_sign = url.path + "?" + url.query

    # Decode the private key into its binary format
    # We need to decode the URL-encoded private key
    decoded_key = base64.urlsafe_b64decode(secret)

    # Create a signature using the private key and the URL-encoded
    # string using HMAC SHA1. This signature will be binary.
    signature = hmac.new(decoded_key, str.encode(url_to_sign), hashlib.sha1)

    # Encode the binary signature into base64 for use within a URL
    encoded_signature = base64.urlsafe_b64encode(signature.digest())

    original_url = url.scheme + "://" + url.netloc + url.path + "?" + url.query

    # Return signed URL
    return original_url + "&signature=" + encoded_signature.decode()


if __name__ == "__main__":
    input_url = input("URL to Sign: ")
    secret = input("URL signing secret: ")
    print("Signed URL: " + sign_url(input_url, secret))

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;  // JDK 1.8 only - older versions may need to use Apache Commons or similar.
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.net.URL;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class UrlSigner {

  // Note: Generally, you should store your private key someplace safe
  // and read them into your code

  private static String keyString = "YOUR_PRIVATE_KEY";
  
  // The URL shown in these examples is a static URL which should already
  // be URL-encoded. In practice, you will likely have code
  // which assembles your URL from user or web service input
  // and plugs those values into its parameters.
  private static String urlString = "YOUR_URL_TO_SIGN";

  // This variable stores the binary key, which is computed from the string (Base64) key
  private static byte[] key;
  
  public static void main(String[] args) throws IOException,
    InvalidKeyException, NoSuchAlgorithmException, URISyntaxException {
    
    BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
    
    String inputUrl, inputKey = null;

    // For testing purposes, allow user input for the URL.
    // If no input is entered, use the static URL defined above.    
    System.out.println("Enter the URL (must be URL-encoded) to sign: ");
    inputUrl = input.readLine();
    if (inputUrl.equals("")) {
      inputUrl = urlString;
    }
    
    // Convert the string to a URL so we can parse it
    URL url = new URL(inputUrl);
 
    // For testing purposes, allow user input for the private key.
    // If no input is entered, use the static key defined above.   
    System.out.println("Enter the Private key to sign the URL: ");
    inputKey = input.readLine();
    if (inputKey.equals("")) {
      inputKey = keyString;
    }
    
    UrlSigner signer = new UrlSigner(inputKey);
    String request = signer.signRequest(url.getPath(),url.getQuery());
    
    System.out.println("Signed URL :" + url.getProtocol() + "://" + url.getHost() + request);
  }
  
  public UrlSigner(String keyString) throws IOException {
    // Convert the key from 'web safe' base 64 to binary
    keyString = keyString.replace('-', '+');
    keyString = keyString.replace('_', '/');
    System.out.println("Key: " + keyString);
    // Base64 is JDK 1.8 only - older versions may need to use Apache Commons or similar.
    this.key = Base64.getDecoder().decode(keyString);
  }

  public String signRequest(String path, String query) throws NoSuchAlgorithmException,
    InvalidKeyException, UnsupportedEncodingException, URISyntaxException {
    
    // Retrieve the proper URL components to sign
    String resource = path + '?' + query;
    
    // Get an HMAC-SHA1 signing key from the raw key bytes
    SecretKeySpec sha1Key = new SecretKeySpec(key, "HmacSHA1");

    // Get an HMAC-SHA1 Mac instance and initialize it with the HMAC-SHA1 key
    Mac mac = Mac.getInstance("HmacSHA1");
    mac.init(sha1Key);

    // compute the binary signature for the request
    byte[] sigBytes = mac.doFinal(resource.getBytes());

    // base 64 encode the binary signature
    // Base64 is JDK 1.8 only - older versions may need to use Apache Commons or similar.
    String signature = Base64.getEncoder().encodeToString(sigBytes);
    
    // convert the signature to 'web safe' base 64
    signature = signature.replace('+', '-');
    signature = signature.replace('/', '_');
    
    return resource + "&signature=" + signature;
  }
}

'use strict'

const crypto = require('crypto');
const url = require('url');

/**
 * Convert from 'web safe' base64 to true base64.
 *
 * @param  {string} safeEncodedString The code you want to translate
 *                                    from a web safe form.
 * @return {string}
 */
function removeWebSafe(safeEncodedString) {
  return safeEncodedString.replace(/-/g, '+').replace(/_/g, '/');
}

/**
 * Convert from true base64 to 'web safe' base64
 *
 * @param  {string} encodedString The code you want to translate to a
 *                                web safe form.
 * @return {string}
 */
function makeWebSafe(encodedString) {
  return encodedString.replace(/\+/g, '-').replace(/\//g, '_');
}

/**
 * Takes a base64 code and decodes it.
 *
 * @param  {string} code The encoded data.
 * @return {string}
 */
function decodeBase64Hash(code) {
  // "new Buffer(...)" is deprecated. Use Buffer.from if it exists.
  return Buffer.from ? Buffer.from(code, 'base64') : new Buffer(code, 'base64');
}

/**
 * Takes a key and signs the data with it.
 *
 * @param  {string} key  Your unique secret key.
 * @param  {string} data The url to sign.
 * @return {string}
 */
function encodeBase64Hash(key, data) {
  return crypto.createHmac('sha1', key).update(data).digest('base64');
}

/**
 * Sign a URL using a secret key.
 *
 * @param  {string} path   The url you want to sign.
 * @param  {string} secret Your unique secret key.
 * @return {string}
 */
function sign(path, secret) {
  const uri = url.parse(path);
  const safeSecret = decodeBase64Hash(removeWebSafe(secret));
  const hashedSignature = makeWebSafe(encodeBase64Hash(safeSecret, uri.path));
  return url.format(uri) + '&signature=' + hashedSignature;
}

using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;

namespace SignUrl {

  public struct GoogleSignedUrl {

    public static string Sign(string url, string keyString) {
      ASCIIEncoding encoding = new ASCIIEncoding();

      // converting key to bytes will throw an exception, need to replace '-' and '_' characters first.
      string usablePrivateKey = keyString.Replace("-", "+").Replace("_", "/");
      byte[] privateKeyBytes = Convert.FromBase64String(usablePrivateKey);

      Uri uri = new Uri(url);
      byte[] encodedPathAndQueryBytes = encoding.GetBytes(uri.LocalPath + uri.Query);

      // compute the hash
      HMACSHA1 algorithm = new HMACSHA1(privateKeyBytes);
      byte[] hash = algorithm.ComputeHash(encodedPathAndQueryBytes);

      // convert the bytes to string and make url-safe by replacing '+' and '/' characters
      string signature = Convert.ToBase64String(hash).Replace("+", "-").Replace("/", "_");
            
      // Add the signature to the existing URI.
      return uri.Scheme+"://"+uri.Host+uri.LocalPath + uri.Query +"&signature=" + signature;
    }
  }

  class Program {

    static void Main() {
    
      // Note: Generally, you should store your private key someplace safe
      // and read them into your code

      const string keyString = "YOUR_PRIVATE_KEY";
  
      // The URL shown in these examples is a static URL which should already
      // be URL-encoded. In practice, you will likely have code
      // which assembles your URL from user or web service input
      // and plugs those values into its parameters.
      const  string urlString = "YOUR_URL_TO_SIGN";
      
      string inputUrl = null;
      string inputKey = null;
    
      Console.WriteLine("Enter the URL (must be URL-encoded) to sign: ");
      inputUrl = Console.ReadLine();
      if (inputUrl.Length == 0) {
        inputUrl = urlString;
      }     
    
      Console.WriteLine("Enter the Private key to sign the URL: ");
      inputKey = Console.ReadLine();
      if (inputKey.Length == 0) {
        inputKey = keyString;
      }
      
      Console.WriteLine(GoogleSignedUrl.Sign(inputUrl,inputKey));
    }
  }
}

Examples in additional languages

Examples that cover more languages are available in the url-signing project.

Troubleshooting authentication issues

If your request is malformed or supplies an invalid signature, the Maps Static API returns an HTTP 403 (Forbidden) error.

To troubleshoot individual URLs, you can use the URL Signing Debugger. It allows you to quickly validate a URL and signature generated by your application.