Use session tokens with Map Tiles API

European Economic Area (EEA) developers

A session token is a piece of data (a UUID) that is used in REST calls to identify a session—a series of related message exchanges. You must include a session token in all requests for 2D Tiles and Street View imagery. You include it as the value of a session parameter appended to all request URLs.

In the Map Tiles API, a session token represents a defined set of display options. It means you don't have to pass a set of display options with each tile request. You can use the same session token across multiple clients. A session token is currently valid for two weeks from its issue time, but this might change. You can always check the expiration time of a session token by looking at the expiry field in the response message.

Session token request

To request a session token, send an HTTPS POST request to the createSession endpoint, as shown in the following example. You must send the request with a Content-Type: application/json header.

curl -X POST -d '{
  "mapType": "streetview",
  "language": "en-US",
  "region": "US"
}' \
-H 'Content-Type: application/json' \
"https://tile.googleapis.com/v1/createSession?key=YOUR_API_KEY"

Required fields

mapType

The type of base map. This value can be one of the following:

roadmap: The standard Google Maps painted map tiles.
satellite: Satellite imagery.
terrain: Terrain imagery. When selecting terrain as the map type, you must also include the layerRoadmap layer type (described in the Optional fields section).
streetview: Street View panoramas. For more information, see Street View Tiles.

language

An IETF language tag that specifies the language used to display information on the tiles. For example, en-US specifies the English language as spoken in the United States.

region

A Common Locale Data Repository region identifier (two uppercase letters) that represents the physical location of the user. For example, US.

Optional fields

imageFormat

Specifies the file format to return. Valid values are either jpeg or png. JPEG files don't support transparency, therefore they aren't recommended for overlay tiles. If you don't specify an imageFormat, then the best format for the tile is chosen automatically.

scale

Scales-up the size of map elements (such as road labels), while retaining the tile size and coverage area of the default tile. Increasing the scale also reduces the number of labels on the map, which reduces clutter. The following values are valid scale values:

scaleFactor1x: The default.
scaleFactor2x: Doubles label size and removes minor feature labels.
scaleFactor4x: Quadruples label size and removes minor feature labels.

The following examples demonstrate the effect of scaling map elements.

Scale Factor 1x	Scale Factor 2x

highDpi: Specifies whether to return high-resolution tiles. If the scale-factor is increased, highDpi is used to increase the size of the tile. Normally, increasing the scale factor enlarges the resulting tile into an image of the same size, which lowers quality. With highDpi, the resulting size is also increased, preserving quality. DPI stands for Dots per Inch, and High DPI means the tile renders using more dots per inch than normal. If true, then the number of pixels in each of the x and y dimensions is multiplied by the scale factor (that is , 2x or 4x). The coverage area of the tile remains unchanged. This parameter works only with scale values of 2x or 4x. It has no effect on 1x scale tiles.

Scale Factor 1x	Scale Factor 2x High DPI

layerTypes

An array of values that specifies the layer types added to the map. Valid values are:

layerRoadmap: Required if you specify terrain as the map type. Can also be optionally overlaid on the satellite map type. Has no effect on roadmap tiles.
layerStreetview: Shows Street View-enabled streets and locations using blue outlines on the map.
layerTraffic: Displays current traffic conditions.

styles

An array of JSON style objects that specify the appearance and detail level of map features such as roads, parks, and built-up areas. Styling is used to customize the standard Google base map. The styles parameter is valid only if the map type is roadmap. For the complete style syntax, see the Style Reference.

overlay

A boolean value that specifies whether layerTypes should be rendered as a separate overlay, or combined with the base imagery. When true, the base map isn't displayed. If you haven't defined any layerTypes, then this value is ignored.

For example, requesting a satellite map type with a layerRoadmap layer, and overlay set to false results in tiles equivalent to the hybrid map type used in the Maps JavaScript API (left image). The same map and layer types with overlay set to true results in a transparent tile with a map overlay, styled appropriately for overlaying over satellite imagery (right image).

`overlay`: false	`overlay`: true

The following JSON is an example of a typical request body that contains both required and optional fields.

{
  "mapType": "satellite",
  "language": "en-US",
  "region": "us",
  "layerTypes": [ "layerRoadmap", "layerStreetview" ],
  "overlay":  true,
  "scale": "scaleFactor1x",
  "styles": [
    {
      "stylers": [
        { "hue": "#00ffe6" },
        { "saturation": -20 }
      ]
    },{
      "featureType": "road",
      "elementType": "geometry",
      "stylers": [
        { "lightness": 100 },
        { "visibility": "simplified" }
      ]
    }
  ]
}

This example provides an overlay that's suitable for combining with satellite imagery. The example contains both a roadmap and street view overlay. The resulting map is rendered with names and data in the English language, as it's spoken in the United States.

Session token response

The following JSON is an example response body.

{
  "session": "IgAAAHGU9jnAU4KOAfwY3Bcd6eH_WxQsyocSBAdUnAr9pnvTTNXtF9c_27RBo94ytEXTDg",
  "expiry": "1361828036",
  "tileWidth": 256,
  "tileHeight": 256,
  "imageFormat": "png"
}

The following list contains definitions of the fields in the response body.

session: A session token value that you must include in all of your Map Tiles API requests.
expiry: A string that contains the time (in seconds since the epoch) at which the token expires. A session token is valid for two weeks from its creation time, but this policy might change without notice.
tileWidth: The width of the tiles measured in pixels.
tileHeight: The height of the tiles measured in pixels.
imageFormat: The image format, which can be either png or jpeg.