Production scope
Sendblue publishes an AI Agent plan at $100 per line per month. It is inbound-first; full outbound capability sits under a custom Enterprise quote. Decide whether your agent simply answers an incoming request or also starts reminders and follow-ups. That decision belongs in the quote before implementation starts.
Sandbox scope
The sandbox lists ten verified contacts and no webhooks. It can help explore sending within its allowed scope, but it does not reproduce a complete event-driven agent. Ask for a supported paid evaluation path where inbound delivery and production authentication can be exercised.
What to prove
Track the original inbound event, the generated answer and the provider’s message identifier. Test a delayed callback and a retry in your application. A successful API response should not become proof that a person read the reply. The public pricing and integration pages support this buying assessment; delivery latency has not been measured here.