# Getting Context in Your Canvas App

When you authenticate your canvas app using signed request, you get the [CanvasRequest](/docs/platform/canvas-framework/guide/canvas-request-object.md) object (which contains the Context object) as part of the POST to the canvas app URL. If you’re authenticating using OAuth, or you want to make a call to get context information, you can do so by making a JavaScript call.

:::note
Getting context data from the Canvas SDK is the most reliable way to identify users. Browsers may not send your canvas app cookies or other identifying data. See [Alternatives to Cookies for User Tracking](/docs/platform/canvas-framework/guide/canvas-app-iframe-considerations.md).
:::

The following code sample is an example of a JavaScript call to get context. This code creates a link with the text “Get Context” which then calls the `Sfdc.canvas.client.ctx` function.

```java
<script>
    function callback(msg) {
       if (msg.status !== 200) {
          alert("Error: " + msg.status);
          return;
       }
       alert("Payload: ", msg.payload);
    }
                
    var ctxlink = Sfdc.canvas.byId("ctxlink");
    var client = Sfdc.canvas.oauth.client();
    ctxlink.onclick=function() {
       Sfdc.canvas.client.ctx(callback, client)};
    }
</script>

<a id="ctxlink" href="#">Get Context</a>

```

**See Also**

- [Canvas SDK](/docs/platform/canvas-framework/guide/canvas-framework-using-sdk.md)
- [Context](/docs/platform/canvas-framework/guide/context-object.md)
- [Filtering CanvasRequest Context Data](/docs/platform/canvas-framework/guide/canvas-filtering-context-data.md)