Most email tools tell you nothing about whether your design is good. You build it, preview it on one screen size, and find out it was broken when the replies start coming in.
kopi scores every generated email on 14 criteria — layout hierarchy, CTA contrast, mobile readability, whitespace balance, and 10 others — on a 0-100 scale before anything goes to Klaviyo. The gap between a 70 and a 93 is almost always contrast or hierarchy: either the CTA color fails at 4.5:1, or the offer is buried three sections down on a 375px viewport.
I built it after a campaign that cleared every manual check I ran and still broke on Android Gmail. The scorer was my attempt to systematize what I should have caught.
The public gallery at trykopi.ai/emails has 400+ emails that cleared 80. Worth looking at if you want to see what the scorer rewards in practice — the patterns are easier to see across a corpus than in documentation.
Generation side: give it a text brief, get a complete HTML email in under 5 minutes. It picks up your fonts, colors, and layout preferences and applies them consistently across campaigns.
For anyone working in an agentic setup, it runs as an MCP server inside Claude Code, Cursor, or ChatGPT. You can generate, score, and iterate without leaving the editor.
github.com/robertnowell/kopi
Top comments (0)