ToolsSubstrate planecalled, never run

Courier

The outbound door

StatusConceptProposed
01What it does

Courier is the estate's governed outbound-email door, every send, transactional or campaign-shaped, passes through it instead of a tool touching SendGrid's API directly; it splits auto-sendable template classes from the owner-gated ones structurally, and writes an audit row for every email sent.

Without a shared gate, any tool that needs to email someone builds its own SendGrid integration with no audit trail and no structural stop on an accidental campaign blast, the send-or-don't-send decision would live in each tool's own code instead of one place.

03Who it works with

A substrate member is called, never run. Everything below reads its declared contract at the moment it needs it, which is why it has no step of its own in any workflow.