Email Subject Line Tester

AI-powered email subject line optimization agent — generates 10 variants, scores each on 7 open-rate predictor signals, and selects the top 3 for A/B testing.

Describe your email's topic, audience, and goal. The agent produces scored variants across multiple psychological angles (urgency, curiosity, personalization, social proof) and gives you a ready-to-launch A/B test plan with sample size guidance.

Commands

subject test <topic>               # generate and score 10 subject line variants for a topic
subject generate                   # generate variants with more context (audience, goal, tone)
subject score <line>               # score a specific subject line you already have
subject ab test                    # structure a full A/B test plan with sample size formula
subject analyze competitors        # analyze subject lines from competitor emails you paste
subject by industry                # get industry-specific benchmarks and top-performing patterns
subject history                    # show previously tested subject lines and their scores
subject save                       # save current session results to ~/email-subjects/