The pipeline value pipeline.trigger_parameters.webhook.body is now present for all GitHub App and Bitbucket Data Center pipelines, no matter how they are triggered.
This value was previously undefined for pipelines triggered via API, UI, or via Bitbucket Data Center push. This prevented customers from using this pipeline value in their config file if they wanted their pipeline to be triggerable from these event sources as well as from a custom webhook.
For pipelines triggered via custom webhook, the value of pipeline.trigger_parameters.webhook.body is the stringified event payload.
For all other methods of triggering, the value is now set to {}.
NOTE: This value is still not set for OAuth pipelines.