How do I pass parameters to Fabric Notebook via REST API?

Hi arpost , Thank you for reaching out to the Microsoft Community Forum.

The generic Run On Demand Item Job API shows a top-level parameters property, but it also notes that parameter support is not broadly supported and can vary by item and job type. Based on your confirmation that passing the notebook parameters through executionData.parameters works, along with Srisakthi 's similar working example, this appears to be the approach that currently works for passing parameters when invoking a notebook through the REST API.

It seems RunNotebook does not honor the generic parameters payload in this case, so the documentation could be clearer about the expected request format for notebook jobs. If you believe the documentation should explicitly call this out, you could consider submitting an idea in the  Microsoft Fabric Ideas or create a post in the Fabric Community Blog to raise awareness among users, which will in turn gets the notice of Microsoft to help improve the documentation and guidance for this scenario.

Also, please refer:

Job Scheduler - Run On Demand Item Job - REST API (Core) | Microsoft Learn
Manage and execute Fabric notebooks with public APIs - Microsoft Fabric | Microsoft Learn

Thanks Srisakthi  for sharing your working example.