| Client | Submit inputs, read own engagement status, respond to clarifications | Change lifecycle state or authorize release |
| Partner system | Read agreed state and record shapes, submit mapped inputs | Approve, review, or release |
| Agent runtime | Read permitted context, prepare drafts and findings, request clarification | Conclude, approve, or release |
| Operator | Coordinate workflow, move an engagement through operational steps | Provide professional approval |
| Reviewer | Exercise review authority, approve, authorize release | Delegate professional judgment to an agent |
| Soteris backend | Validate transitions, record events, store references | Substitute for reviewer judgment |