Get a newsletter growth loop with mechanism, when it wins, execution rules, and failure mode. Loops: lead_magnet, social_repurpose, cross_promo, referral, sponsorship_swap. Omit for all loops + selection logic.

The 6-email welcome sequence architecture: per-email job, timing, and subject shape (deliver → receipt → quick win → segment → soft offer → close), plus the one-job-per-email rules.

Audit an email subject line: mobile truncation length, all-caps, spam phrases, fake Re:/Fwd:, specificity. Returns PASS/NEEDS WORK.

Interpret a list metric against practitioner ranges: open_rate, click_rate, growth_rate, unsubscribe_rate, reply_rate. Returns healthy range, warning threshold, and the diagnostic.

Given subscriber count (and optionally open/click rates as percents), returns readiness verdicts for the three monetization paths: own product, per-click sponsorships, flat-rate placements, with sequencing. Engagement monetizes; size impresses.

The complete newsletter library in one payload: growth loops, welcome sequence, metric reads.