Topic cluster plan from a seed keyword

Build a topic cluster plan around this seed keyword.

Seed keyword (the pillar topic): {{seed_keyword}}
My niche / audience: {{niche}}
What I want this cluster to do for me: {{cluster_goal}} (e.g. 'rank for the head term', 'build topical authority', 'convert to a free-resource download')
Existing content I have on this topic (URLs or titles): {{existing_content}}
Domain authority / starting position: {{authority}} (rough — new site / 6 months / established / strong)
Realistic timeframe: {{timeframe}}

Return the cluster plan:
1. PILLAR PAGE — title, ≤60-char SEO title option, target word count, what makes it the comprehensive resource (3 differentiators).
2. CLUSTER PAGES — 8–12 cluster pages. For each: working title, primary keyword, secondary keywords (2), 1-line angle, target word count, search intent.
3. INTERNAL LINKING MAP — for each cluster, which pillar section it links from + the anchor text.
4. PRODUCTION ORDER — which 4 cluster pages to publish FIRST (lowest competition + highest intent).
5. ASSETS REUSE PLAN — for each pillar/cluster, what blog → newsletter → social repurpose looks like.
6. SUCCESS METRICS — 3 specific metrics to track at 90 days, with realistic ranges given starting authority.

AU English. Don't pad with low-volume keywords just to hit 12 — fewer, better.