Error Model

Failures in agentic-proteins should help a reviewer tell whether the problem is local, upstream, downstream, or a boundary mismatch. Error handling that hides ownership makes the package harder to trust.

Error Rules

• preserve caller-visible compatibility behavior where retirement is not complete
• translate failures toward the canonical runtime model instead of inventing a separate long-term error taxonomy
• make migration-specific failures obvious so stale compatibility promises can be retired safely

First Proof Check

• package error types and failure paths
• tests that assert the intended failure class
• neighboring packages when a failure crosses a handoff seam