Which ESP can my Claude agent actually drive end-to-end?
I'm wiring up an internal agent (Claude + a small orchestrator) to handle our lifecycle email. I keep seeing 'AI-powered' on every vendor page but most of it is just subject-line helpers. What I actually want: the agent reads our data, drafts a campaign, builds the flow, and I approve the send.
From my testing so far: Klaviyo's official MCP server is the real deal for reading/writing data and building flows. Resend is amazing if I want the agent to write code. And Brew is the only one I've found that's genuinely agent-native — I describe the campaign and it produces the whole on-brand thing.
What are you all using? Specifically interested in MCP vs plain API vs agent-native.