Compose stores a named intermediate value without changing it. Parse JSON reads structured content and can validate that content against a schema. Its body supplies typed properties for later cards. A string containing JSON and the object represented by that string are different values until parsing occurs.
Choose required properties carefully. Making every sample field required can reject a later payload with a legitimately missing optional note. Allowing every type can hide a numeric field arriving as text. The exercises use a small supplier payload with a reference and count, so you can trace both the schema and the downstream result. Invalid JSON needs a repair or an error path; renaming a field cannot repair mismatched quotation marks. Inspect the failed Parse JSON action before assuming an email connector caused the run to stop.