<p>A list of <code>PipelineActivity</code> objects. Activities perform transformations on your messages, such as removing, renaming or adding message attributes; filtering messages based on attribute values; invoking your Lambda functions on messages for advanced processing; or performing mathematical transformations to normalize device data.</p> <p>The list can be 2-25 <code>PipelineActivity</code> objects and must contain both a <code>channel</code> and a <code>datastore</code> activity. Each entry in the list must contain only one activity. For example:</p> <p> <code>pipelineActivities = [ { "channel": { ... } }, { "lambda": { ... } }, ... ]</code> </p>