Azure ADF boolean parameter changes from true to True and false to False

You are seeing lowercase JSON Boolean literals displayed as True and False after creating an ADF trigger. If the pipeline parameter is Boolean, that capitalization is normally a UI or string representation; the runtime value remains Boolean. Verify the parameter type in both pipeline and trigger, publish, run, and inspect the run’s Input pane. A JSON Boolean is unquoted; “true” or “False” inside quotes is a string. In expressions, consume the typed value directly, or use bool() when the source might be text, instead of comparing spellings. If a downstream API or filename requires lowercase text, use toLower(string(pipeline().parameters.yourFlag)). Inspect the exported trigger JSON to ensure the value is not quoted. If the Input pane shows a type change rather than casing, reproduce it with a minimal Boolean parameter and trigger, retain the exported JSON, and open an ADF support case because that would be a serialization defect.