# Session Context in Amazon WorkSpaces Applications
<a name="managing-stacks-fleets-session-context"></a>

You can pass parameters to your streaming application by using either of the following methods:
+ Specify session content in the CreateStreamingURL WorkSpaces Applications API operation. For more information, see [CreateStreamingURL](https://docs.aws.amazon.com/appstream2/latest/APIReference/API_CreateStreamingURL.html).
+ Add the sts:TagSession permission to your IAM role's trust policy and specify the session context as a SAML assertion in your SAML 2.0 identity provider's authentication response. For more information, see [Step 5: Create Assertions for the SAML Authentication Response](external-identity-providers-setting-up-saml.md#external-identity-providers-create-assertions) and [Step 5: Create Assertions for the SAML Authentication Response](external-identity-providers-setting-up-saml.md#external-identity-providers-create-assertions).

If your image uses a version of the WorkSpaces Applications agent that was released on or after October 30, 2018, the session context is stored within the image as a Windows or Linux environment variable. For information about specific environment variables, see "User and Instance Metadata for WorkSpaces Applications Fleets" in [Customize an Amazon WorkSpaces Applications Fleet to Optimize Your Users' Application Streaming Experience](customize-fleets.md). 

**Note**  
The session context parameter is visible to the user in the WorkSpaces Applications streaming URL. We strongly recommend that you never put confidential or sensitive information in the session context parameter. Because it is possible for users to modify the streaming URL, we recommend performing additional validation to determine that the session context is valid for the end user. For example, you can compare the session context with other session information, such as user and instance metadata for WorkSpaces Applications fleets.   
WorkSpaces Applications does not perform validation on the session context parameter. 

## Using Session Context to Pass Parameters to a Streaming Application
<a name="managing-stacks-fleets-parameters"></a>

In the following steps, you'll use session context to start a web browser and automatically open a specific website. For instances running Windows, you'll use Firefox. For instances running Linux, you'll use Chromium.

**To use session context to launch a website**

1. In the left navigation pane, choose **Images**, **Image Builder**.

1. Choose the image builder to use, verify that it is in the **Running** state, and choose **Connect**. 

1. Log in to the image builder by choosing **Administrator** on the **Local User** tab.

1. Create a child folder of `C:\`. For this example, use `C:\Scripts`.

1. Create a Windows batch file in the new folder. For this example, create `C:\Scripts\session-context-test.bat` and add a script that launches Firefox with the URL from the session context.

   Use the following script:

   ```
   CD "C:\Program Files (x86)\Mozilla Firefox"
   Start firefox.exe %APPSTREAM_SESSION_CONTEXT%
   ```

1. In Image Assistant, add `session-context-test.bat` and change the name to **Firefox**.

   You do not need to add Firefox. This step requires that you add only the batch file.

1. Create an image, fleet, and stack. For this example, use a fleet name of **session-context-test-fleet** and a stack name of **session-context-test-stack**.

1. After the fleet is running, you can call [create-streaming-url](https://docs.aws.amazon.com/cli/latest/reference/appstream/create-streaming-url.html) with the `session-context` parameter, as shown in this example.

   ```
   aws appstream create-streaming-url --stack-name session-context-test-stack \ 
   --fleet-name session-context-test-fleet \
   --user-id username –-validity 10000 \
   --application-id firefox --session-context "www.amazon.com"
   ```

1. Open the streaming URL in a browser. The script file launches Firefox and loads `http://www.amazon.com`.

Similarly, you can perform the following steps to pass parameters to your Linux streaming application.

**To pass parameters to your Linux streaming application**

1. In the left navigation pane, choose **Images**, **Image Builder**.

1. Choose the image builder to use, verify that it is in the **Running** state, and choose **Connect**. 

1. Log in to the image builder by default as **ImageBuilderAdmin**.

1. Create a script file (for example, launch-chromium.sh) by running the following command:

   **sudo vim /usr/bin/launch-chromium.sh**

1. Write the script and set executable permissions, such as the following:
**Note**  
\$1\$1/bin/bash and source /etc/profile are always required in the script.

   ```
   #!/bin/bash
   source /etc/profile
   /usr/bin/chromium-browser $APPSTREAM_SESSION_CONTEXT
   ```

1. Use the Image Assistant CLI to add launch-chromium.sh:

   ```
   sudo AppStreamImageAssistant add-application \ 
   --name chromium \
   --absolute-app-path /usr/bin/launch-chromium.sh
   ```

1. Create an image, fleet, and stack. For this example, use a fleet name of **session-context-test-fleet** and a stack name of **session-context-test-stack**.

1. After the fleet is running, you can call [create-streaming-url](https://docs.aws.amazon.com/cli/latest/reference/appstream/create-streaming-url.html) with the `session-context` parameter, as shown in this example.

   ```
   aws appstream create-streaming-url --stack-name session-context-test-stack \ 
   --fleet-name session-context-test-fleet \
   --user-id username \
   --application-id chromium --session-context "www.amazon.com"
   ```

1. Open the streaming URL in a browser. The batch file launches Chromium and loads `http://www.amazon.com`.