#Security boundary

watasu's core promise is no payload custody.

#What that means

watasu should not:

• receive plaintext payloads
• decrypt payloads
• store plaintext payloads
• log payload values
• retain encrypted payload bodies after a delivery attempt
• keep a payload retry queue

watasu may keep metadata-only delivery evidence, such as request id, request version, idempotency key, timestamps, delivery status, and encrypted payload hash.

#Why metadata still matters

Metadata can still become personal-related information when combined with other records. For that reason, hosted metadata paths use tenant, role, audit, and retention boundaries.

#Agent Card safety

Agent Cards can expose:

• request fields
• purpose text
• schema hash
• consent text hash
• encryption public metadata
• submit endpoint
• payload limits
• trust profile

Agent Cards must not expose:

• webhook secrets
• receiver private URLs
• private keys
• plaintext sample payload values
• database URLs
• service identity secrets

#Failure behavior

If delivery fails, watasu returns sender-actionable failure information such as resubmit_later. It should not keep a payload retry queue. The sender remains responsible for resubmitting when appropriate.

#Human responsibility

watasu does not guarantee legal consent, identity verification, delegated authority, regulatory compliance, or DSAR workflows. Those remain service-side or product-side responsibilities.