# ESRI ArcGIS Online

ArcGIS Online is a geographic information system (GIS) delivered using the software-as-a-service (SaaS) model. ArcGIS Online services are managed by ESRI and accessed by a client running on a wide range of options.

## What you need

* OS Maps API added to an API project in the OS Data Hub with an API Key; see [getting-started-with-an-api-project](https://docs.os.uk/os-apis/core-concepts/getting-started-with-an-api-project "mention") for more information
* An ArcGIS Online account

## Instructions

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**Add a new layer**

Once you've signed into your ESRI ArcGIS Online account and opened the map viewer.

* Select *Layers* > *Add* > *Add layer from URL*.

<figure><img src="https://4043944746-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FoEzqrBzRGoJw7nQyLj1W%2Fuploads%2Fgit-blob-9acf4ee788e28064216dae71e85ebae0e5ad65e9%2Fimage.png?alt=media" alt="ArcGIS Online Layers dialog." width="316"><figcaption><p>ArcGIS Online Layers dialog.</p></figcaption></figure>
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{% step %}
**Add an API and set up custom parameters**

In the Add Layer dialog:

* **URL**: Enter the base URL for OS Maps API, excluding the API Key. For example, <https://api.os.uk/maps/raster/v1/wmts>
* **Type**: Select *WMTS (OGC)*.
* Select *Custom request parameters* and enter the following:
  * **Parameter**: key
  * **Value**: \[Insert your OS API Key here]
* Click *Next*.

<figure><img src="https://4043944746-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FoEzqrBzRGoJw7nQyLj1W%2Fuploads%2Fgit-blob-b64485dd5808f17ce97b28be08dde401ab1600e6%2FWMTS%20Add%20Layer.png?alt=media" alt="ESRI ArcGIS Pro Add WMTS (OGC) Server Connection dialog with URL and custom request parameters set."><figcaption><p>ESRI ArcGIS Pro Add WMTS (OGC) Server Connection dialog with URL and custom request parameters set.</p></figcaption></figure>
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{% step %}
**Adding layers to the map**

In the Add Layer dialog:

* Select a layer to add to the map
* Set the max feature limit
* Click *Add to map*.

<figure><img src="https://4043944746-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FoEzqrBzRGoJw7nQyLj1W%2Fuploads%2Fgit-blob-78786ac77c95d815eae17f9342866c488dbe8241%2FWMTS%20Add%20Layer%20style.png?alt=media" alt="ArcGIS Online Add Layers dialog: Select a layer to add to map."><figcaption><p>ArcGIS Online Add Layers dialog: Select a layer to add to map.</p></figcaption></figure>

\_The layer will then display in the Layers panel and the data will display on the map:

<figure><img src="https://4043944746-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FoEzqrBzRGoJw7nQyLj1W%2Fuploads%2Fgit-blob-bc782f42eefed7b9476c3e36bee8b9edbdf0238b%2FWMTS%20Map%20Added.png?alt=media" alt="ArcGIS Online UI showing OS Maps API in the map area."><figcaption><p>ArcGIS Online UI showing OS Maps API in the map area.</p></figcaption></figure>
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