Ringmaster

Ringmaster is a lifecycle email API that integrates with AI agents through the Model Context Protocol (MCP). Users send events from their application via REST API calls, then ask their AI agent to design email flows, segments and campaigns in plain language. Ringmaster handles the sending with built-in rules: each email goes out only once per recipient, always during their local daytime hours (08:00 to 20:00), and never to unsubscribed addresses.

The service enforces consent and compliance automatically. It validates merge fields and sender domains before saving, includes one-click unsubscribe links on every email, checks consent before each send, and stops all mail immediately upon bounces or complaints. Ringmaster includes a circuit breaker to pause sending if bounce or complaint rates climb, and supports deleting user profiles with a single API call that erases all associated data.

Agents can manage the full email lifecycle: writing and testing flows, running campaigns with dry runs before sending, managing subscriber consent and topics, configuring sending domains with DNS setup, and reading detailed analytics on opens, clicks, unsubscribes and conversions.