A concrete map of data, storage and control.

This matrix reflects the inspected Gmail Multi repository. Unknown retention and deletion behavior is treated as a launch blocker, not softened into marketing copy.

Verified storage and deletion behavior
Data	Verified handling	Current deletion behavior	Status
OAuth grants	AES-256-GCM encrypted vault; includes account identity, scopes and tokens.	Account removal deletes the grant from the active vault. Google-side revocation is separate.	VERIFIED
Message metadata	SQLite can store IDs, subject, participants, dates, snippets, labels, attachment names and counts, and body hash.	No account-specific purge or retention period was found.	UNKNOWN
Full bodies and attachments	Fetched only by explicit read and fetch tools and returned to the connected MCP client; not written to the metadata index.	No separate local body store was found. Downstream client retention is not defined here.	UNKNOWN
Action ledger	Stores action ID, authenticated subject and claim timestamp to prevent replay.	No automatic purge was found.	UNKNOWN
Cost telemetry	Off by default. When enabled, stores tool and method names, sizes, timing and status — not arguments, content, headers or tokens.	File or platform-log retention has not been defined.	UNKNOWN

Verified safeguards

Bounded, staged reads
Two-step Gmail writes
Subject-bound, single-use action claims
Origin and authorization checks on HTTP transport
Tokens excluded from MCP results and cost telemetry

Launch blockers

Define and implement retention periods
Purge indexed account data on deletion
Document backup and log deletion
Implement public MCP OAuth
Resolve publisher, controller and support identity

UNKNOWN Unresolved before public release

Retention policyBackup purgePublic MCP OAuthController identitySupport channel