Named Maps are essentially the same as Anonymous Maps except the MapConfig is stored on the server, and the map is given a unique name. You can create Named Maps from private data, and users without an API Key can view your Named Map (while keeping your data private).
The Named Map workflow consists of uploading a MapConfig file to CARTO servers, to select data from your CARTO user database by using SQL, and specifying the CartoCSS for your map.
The response back from the API provides the template_id of your Named Map as the `name` (the identifier of your Named Map), which is the name that you specified in the MapConfig. You can which you can then use to create your Named Map details, or [fetch XYZ tiles](#fetching-xyz-tiles-for-named-maps) directly for Named Maps.
**Tip:** You can also use a Named Map that you created (which is defined by its `name`), to create a map using CARTO.js. This is achieved by adding the [`namedmap` type](http://docs.carto.com/carto-engine/carto-js/layer-source-object/#named-maps-layer-source-object-type-namedmap) layer source object to draw the Named Map.
The template map is static and may contain placeholders, enabling you to modify your maps appearance by using variables. Templates maps are persistent with no preset expiration. They can only be created, or deleted, by a CARTO user with a valid API KEY (See [auth argument](#arguments)).
Uploading a MapConfig creates a Named Map. MapConfigs are uploaded to the server by sending the server a "template".json file, which contain the [MapConfig specifications](http://docs.carto.com/carto-engine/maps-api/mapconfig/).
**Note:** There is a limit of 4,096 Named Maps allowed per account. If you need to create more Named Maps, it is recommended to use a single Named Map and change the variables using [placeholders](#placeholder-format), instead of uploading multiple [Named Map MapConfigs](http://docs.carto.com/carto-engine/maps-api/mapconfig/#named-map-layer-options).
The `name` argument defines how to name this "template_name".json. Note that there are some requirements for how to name a Named Map template. See the [`name`](#arguments) argument description for details.
name | There can only be _one_ template with the same name for any user. Valid names start with a letter or a number, and only contain letters, numbers, dashes (-), or underscores (_). _This is specific to the name of your Named Map that is specified in the `name` property of the template file_.
|_ valid_tokens | when `"method"` is set to `"token"`, the values listed here allow you to instantiate the Named Map. See this [example](http://docs.carto.com/faqs/manipulating-your-data/#how-to-create-a-password-protected-named-map) for how to create a password-protected map.
layergroup | the layergroup configurations, as specified in the template. See [MapConfig File Format](http://docs.carto.com/carto-engine/maps-api/mapconfig/) for more information.
view (optional) | extra keys to specify the view area for the map. It can be used to have a static preview of a Named Map without having to instantiate it. It is possible to specify it with `center` + `zoom` or with a bounding box `bbox`. Center+zoom takes precedence over bounding box. Also it is possible to choose which layers are visible or not with `preview_layers` indicating its visibility by layer index or id (visible by default).
Placeholders are variables that can be placed in your template.json file. Placeholders need to be defined with a `type` and a default value for MapConfigs. See details about defining a MapConfig `type` for [Layergoup configurations](http://docs.carto.com/carto-engine/maps-api/mapconfig/#layergroup-configurations).
Valid placeholder names start with a letter and can only contain letters, numbers, or underscores. They have to be written between the `<%=` and `%>` strings in order to be replaced inside the Named Maps API.
Placeholder default values will be used whenever new values are not provided as options, at the time of creation on the client. They can also be used to test the template by creating a default version with new options provided.
The response back from the API provides the name of your MapConfig as a template, enabling you to edit the Named Map details by inserting your variables into the template where placeholders are defined, and create custom queries using SQL.
Instantiating a Named Map allows you to fetch the map tiles. You can use the Maps API to instantiate, or use the CARTO.js `createLayer()` function. The result is an Anonymous Map.
The fields you pass as `params.json` depend on the variables allowed by the Named Map. If there are variables missing, it will raise an error (HTTP 400).
**Note:** It is required that you include a `params.json` file to instantiate a Named Map that contains variables, even if you have no fields to pass and the JSON is empty. (This is specific to when a Named Map allows variables (if placeholders were defined in the template.json by the user).
You can then use the `layergroupid` for fetching tiles and grids as you would normally (see [Anonymous Maps](http://docs.carto.com/carto-engine/maps-api/anonymous-maps/)).
If using a [JSONP](https://en.wikipedia.org/wiki/JSONP) (for old browsers) request, there is a special endpoint used to initialize and create a Named Map.
This takes the `callback` function (required), `auth_token` if the template needs auth, and `config` which is the variable for the template (in cases where it has variables).
You can use a Named Map that you created (which is defined by its `name`), to create a map using CARTO.js. This is achieved by adding the [`namedmap` type](http://docs.carto.com/carto-engine/carto-js/layer-source-object/#named-maps-layer-source-object-type-namedmap) layer source object to draw the Named Map.
**Note:** Instantiating a Named Map over a `createLayer` does not require an API Key and by default, does not include auth tokens. _If_ you defined auth tokens for the Named Map configuration, then you will have to include them.
1. [layer.setParams()](http://docs.carto.com/carto-engine/carto-js/api-methods/#layersetparamskey-value) allows you to change the template variables (in the placeholders object) via JavaScript
**Note:** The CARTO.js `layer.setParams()` function is not supported when using Named Maps for Torque. Alternatively, you can create a [Torque layer in a Named Map](http://bl.ocks.org/iriberri/de37be6406f9cc7cfe5a)
2. [layer.setAuthToken()](http://docs.carto.com/carto-engine/carto-js/api-methods/#layersetauthtokenauthtoken) allows you to set the auth tokens to create the layer
If you are creating a Torque layer in a Named Map without using the Torque.js library, you can apply the Torque layer by applying the following code with CARTO.js:
Authenticated users, with an auth token, can use XYZ-based URLs to fetch tiles directly, and instantiate the Named Map as part of the request to your application. You do not have to do any other steps to initialize your map.
- To show just the basemap layer, enter the number value `0` in the layer placeholder "https://{username}.carto.com/api/v1/map/named/{template_id}/0/{z}/{x}/{y}.png"
- To show the first layer, enter the number value `1` in the layer placeholder "https://{username}.carto.com/api/v1/map/named/{template_id}/1/{z}/{x}/{y}.png"
- To show all layers, enter the value `all` for the layer placeholder "https://{username}.carto.com/api/v1/map/named/{template_id}/all/{z}/{x}/{y}.png"
- To show a [list of layers](http://docs.carto.com/carto-engine/maps-api/anonymous-maps/#blending-and-layer-selection), enter the comma separated layer value as 0,1,2 in the layer placeholder. For example, to show the basemap and the first layer, "https://{username}.carto.com/api/v1/map/named/{template_id}/0,1/{z}/{x}/{y}.png"
Mapnik Retina tiles are not directly supported for Named Maps, so you cannot use the Named Map template_id. To fetch Mapnik Retina tiles, get the [layergroupid](http://docs.carto.com/carto-engine/maps-api/named-maps/#response-1) to initialize the map.
