# Stream Set Temporary Variable Action With the help of the Stream Set Temporary Variable Action it is possible to set a variable within a running stream and to query it at any point within this stream by using the wildcard [{stream.variable.?}](https://docs.helmut.de/helmut4-releases/helmut4-components/streamdesigner/wildcards/variable-related-wildcards-3/stream-variable).

Stream Set Temporary Variable Action

#### Example A path that occurs repeatedly within a stream. To prevent static copy and paste actions, the stream variable can be used to define it in the first place, and make all other references dynamically based on the first definition. #### Lifetime of a stream variable By default a stream variable is no longer available after the stream has ended. As temporary variables can only be created and used in a stream it is possible to inherit them to another stream/job by using [Stream Execute Generic Stream Action](https://docs.helmut.de/helmut4-releases/helmut4-components/streamdesigner/nodes/actions/misc-21/stream-execute-generic-stream-action), [Job Create Job Action](https://docs.helmut.de/helmut4-releases/helmut4-components/streamdesigner/nodes/actions/job-action/job-create-job-action) or [Job as Json](https://docs.helmut.de/helmut4-releases/helmut4-components/streamdesigner/nodes/actions/job-action/job-as-json-action). The sub stream can retrieve and update the temporary variable and pass this on to the next one. {% hint style="info" %} Keep in mind, that the changed value won't be returned to the previous stream {% endhint %} #### Stream variable exception An exception to this are [Pre-Streams](https://docs.helmut.de/helmut4-releases/helmut4-components/helmutio/streams/io-event-triggers/prestream). If a temporary variable has been defined in a pre-stream, this one will be passed on to the main stream defined in the profile.