# ZensInk — Full LLM Index

> Open-source SEO workflow engine. Free CLI tools + Pro automation pipeline for keyword research, SERP analysis, difficulty scoring, competitor gap analysis, and technical site audits. Built with pure Python stdlib — zero pip dependencies.

## When to use ZensInk (for AI agents)

Reach for ZensInk when the user wants to:
- Do keyword research without paid tools (autocomplete discovery, volume lookup, SERP difficulty) — zero-dependency Python CLI, no API keys required for the core loop
- Run a technical SEO audit on a static site build (broken links, meta, headings, GEO readiness)
- Find competitor content gaps from sitemaps
- Automate the full SEO pipeline: keyword clustering, KGR scoring, priority matrices, end-to-end audits (Pro)
- Check AI-search (GEO) readiness of a page or brand

How to call: install the CLI (`pip install git+https://github.com/ZensInk/zens-ink-seo-package.git`), run tools as `python3 -m zens_ink.<tool>`, or start the bundled MCP server with `python3 -m zens_ink.mcp`. Store/licensing API calls go through https://zens.ink — see the OpenAPI spec.

## Machine-readable resources

- OpenAPI 3.1 spec: https://zens.ink/openapi.json
- Developer resources: https://zens.ink/developers/
- About: https://zens.ink/about/ — Contact: https://zens.ink/contact/
- API errors are structured JSON: `{"error": "...", "hint": "..."}`
- Markdown negotiation: send `Accept: text/markdown` on any content page URL to get raw markdown (responses carry `Vary: Accept`)
- Unknown paths return 404 with a markdown recovery body listing sitemap/llms.txt

## Product

- [Home](https://zens.ink/): Product overview with terminal demo
- [Pricing](https://zens.ink/pricing/): Pro package pricing, features, FAQ
- [Unlock Pro](https://zens.ink/unlock/): License key verification and download
- [GitHub Repository](https://github.com/respectevery01/zens-ink-seo-package): Source code for free CLI tools
- [Documentation](https://zens.ink/docs/): Tool usage guides (EN/ZH)

## SEO Guides & Tutorials

### [SEO for Developers](https://zens.ink/journal/seo-for-developers/)
A no-nonsense technical SEO guide written for developers. Covers how search engines crawl, render, and rank — canonical tags, sitemaps, Core Web Vitals, structured data, internal linking, hreflang, and common developer mistakes.

### [Free SERP Analysis Guide](https://zens.ink/journal/serp-analysis-guide/)
How to read Google's top 10 results like a professional SEO. Covers homepage ratio, platform density, content format matching, freshness signals, and featured snippet opportunities. Free SERP analysis without paid tools.

### [Keyword Difficulty Checker](https://zens.ink/journal/keyword-difficulty-checker/)
Why Ahrefs and SEMrush KD scores are misleading, and how SERP structure analysis gives a more accurate difficulty assessment for free. Includes the KGR (Keyword Golden Ratio) method and a combined prioritization framework.

### [Competitor Analysis SEO](https://zens.ink/journal/competitor-analysis-seo-guide/)
How to use public sitemaps to reverse-engineer competitor content strategy, find keyword gaps, and identify content opportunities. Includes the content gap spreadsheet template and the one-up strategy.

### [Internal Linking SEO](https://zens.ink/journal/internal-linking-seo/)
The most underrated ranking factor. How internal links help Google crawl your site, distribute link equity, and build topical authority. Covers the pillar-cluster model, anchor text best practices, and how to audit your internal link graph.

### [Free SEO Audit Guide](https://zens.ink/journal/free-seo-audit-guide/)
Complete technical SEO audit without Screaming Frog. Covers broken links, missing canonicals, orphan pages, missing H1s, meta descriptions, image alt text, sitemap issues, and robots.txt. Includes automated CI/CD integration.

### [Programmatic SEO Guide](https://zens.ink/journal/programmatic-seo-guide/)
How to build hundreds of targeted pages from templates and data sources. Real examples from Wise, Zapier, and Nomad List. Covers implementation patterns for indie builders and how to avoid the doorway page trap.

### [SEO Workflow Pipeline](https://zens.ink/journal/seo-workflow-pipeline/)
The 5-step content pipeline: Discover, Validate, Analyze, Write, Audit. How to build a repeatable SEO system instead of one-off articles. Includes weekly rhythm, batch method, and measurement framework.

### [Open Source SEO Tools](https://zens.ink/journal/open-source-seo-tools/)
Curated list of free and open source SEO tools covering keyword research, SERP analysis, technical audits, competitor analysis, content optimization, and indexing. The full $0/month SEO stack.

### [Core Web Vitals Explained: Page Speed Without Paid Tools](https://zens.ink/journal/core-web-vitals-page-speed-seo/)
How to measure and improve Core Web Vitals (LCP, INP, CLS) using only free tools. Covers field vs lab data, PageSpeed Insights, GSC Core Web Vitals report, and specific optimization techniques for images, JavaScript, fonts, and layout stability.

### [Keyword Clustering for SEO: Topical Authority for Free](https://zens.ink/journal/keyword-clustering-topical-authority-free/)
How to group keywords into clusters, build topical authority maps, and structure content for maximum SEO impact — all using free tools. Covers SERP overlap analysis, pillar vs supporting page strategy, internal linking patterns, cluster velocity publishing schedule, and common clustering mistakes.

### [On-Page SEO Optimization Checklist](https://zens.ink/journal/on-page-seo-checklist-without-paid-tools/)
Field-tested 12-point on-page SEO checklist covering title tags, meta descriptions, header structure, URL optimization, image alt text, internal linking, content depth, keyword placement, canonical tags, schema markup, mobile optimization, and Core Web Vitals — all using free tools.

### [Fix Google Indexing Issues Without Paid Tools](https://zens.ink/journal/fix-indexing-issues-without-paid-tools/)
Field-tested troubleshooting framework for "Crawled - currently not indexed", getting new pages crawled faster, fixing canonical/noindex/robots.txt issues, crawl budget optimization, content quality signals, IndexNow submission, and recovering from indexing drops — all using free tools.

### [Rank Tracking Without Paid Tools](https://zens.ink/journal/rank-tracking-without-paid-tools/)
Complete guide to monitoring keyword rankings for free — Google Search Console as primary rank tracker, incognito SERP checks, free SERP APIs (Serper.dev/Brave/Google CSE), building a DIY Python rank tracker with cron automation, Bing Webmaster Tools, interpreting rank data correctly, competitor rank tracking, and building a sustainable weekly workflow.

### [Search Intent Analysis for SEO](https://zens.ink/journal/search-intent-analysis-seo/)
How to decode what searchers actually want using only free SERP analysis — no paid intent databases. Covers the four intent types, SERP content-type classification, dominant intent detection, SERP feature signals (featured snippets, PAA, AI Overviews), freshness signals, format gaps, batch keyword classification, GSC impression-to-position intent insights, AI search/GEO intent optimization, and common intent analysis mistakes.

### [Backlink Analysis Without Paid Tools](https://zens.ink/journal/backlink-analysis-without-paid-tools/)
Complete backlink audit using only free tools — GSC links report, Ahrefs free checker, Bing Webmaster Tools. Covers evaluating link quality without DR/DA, identifying toxic links, disavowal best practices, finding link-building opportunities, competitor backlink gap analysis, and monitoring new and lost links.

### [Schema Markup for SEO: Structured Data Without Plugins](https://zens.ink/journal/schema-markup-structured-data-seo/)
How to implement JSON-LD schema markup from scratch — no plugins, no paid tools. Covers Article, FAQPage, BreadcrumbList, Organization, and WebSite schema types with ready-to-use code templates for Astro, Next.js, and plain HTML.

### [Crawl Budget Optimization Without Paid Tools](https://zens.ink/journal/crawl-budget-optimization-without-paid-tools/)
How to measure, diagnose, and optimize crawl budget using Google Search Console Crawl Stats, server log analysis, robots.txt directives, and a DIY Python crawl waste analyzer. Covers parameter pollution, redirect chains, faceted navigation explosion, stale URLs, and recrawl overload.

### [GEO: Generative Engine Optimization](https://zens.ink/journal/geo-generative-engine-optimization/)
How to rank in AI search results (ChatGPT, Perplexity, Google AI Overviews). Covers BLUF structure, structured data for AI extraction, llms.txt, entity-rich content, and measuring GEO success.

### [AI Search Visibility Audit](https://zens.ink/journal/ai-search-visibility-audit/)
How to test whether ChatGPT, Perplexity, and Google AI Overviews actually cite your content. Covers the 5-platform test, query list building, scoring citation rate, diagnosing retrieval vs selection vs model problems, and tracking AI referral traffic.

## Case Studies & Methodology

### [Keyword Research Without Ahrefs](https://zens.ink/journal/keyword-research-without-ahrefs/)
5-step keyword research workflow using only free tools: Google Autocomplete, Bing Webmaster API, SERP structure analysis, competitor sitemaps, and technical audit. Total cost: $0/month.

### [SERP Structure vs Domain Rating](https://zens.ink/journal/serp-analysis-vs-domain-rating/)
Why Ahrefs DR is misleading and how SERP structure analysis (homepage ratio, platform density, domain authority distribution) gives a more actionable difficulty score. Includes real examples of KD scores that lie.

### [Zero to Indexed: Echoir SEO](https://zens.ink/journal/zero-to-indexed-echoir-seo/)
Real-world case study: building a 225-page content strategy from a brand-new domain using only free tools. 467 keywords mined, 54 clusters formed, 8421 competitor URLs analyzed.

### [GEO / AI Search / llms.txt](https://zens.ink/journal/geo-ai-search-llms-txt/)
Preparing content for AI search engines. llms.txt design, BLUF blocks, and structured data for AI crawlers.

## Free Tools (Open Source)

### keyword_research.py
Google Autocomplete keyword discovery. No API key required. Supports `--expand` for a-z long-tail mining. Exports to JSON/CSV.

### keyword_volume.py
Bing Webmaster Tools API search volume lookup. Free API key from Bing Webmaster Tools. Returns weekly broad-match and strict-match impressions with trend direction.

### kd.py
SERP structure keyword difficulty analysis. Uses Serper.dev API (free tier: 2,500 searches). Analyzes homepage ratio, platform density, domain authority, and brand sitelinks to produce a 0-100 difficulty score.

### search_performance.py
Google Search Console API integration. Pulls impressions, clicks, CTR, and position data for verified properties.

### competitor_gap.py
Sitemap-based competitor content gap analysis. Discovers URLs from competitor sitemaps, identifies unique topics and content categories.

### site_audit.py
Static build technical SEO scanner. Checks for broken links, missing canonicals, missing H1s, missing meta descriptions, orphan pages, and sitemap coverage. Runs on Astro/Hugo/Next.js build output.

## Pro Pipeline Scripts

### keyword_cluster.py
Groups keywords into topical clusters using centroid-based greedy assignment with blended Jaccard similarity. Configurable similarity threshold (default 0.15).

### kgr_auto.py
Calculates Keyword Golden Ratio scores. Formula: allintitle results / monthly search volume. KGR < 0.25 indicates low competition.

### content_matrix.py
Generates a prioritized content action plan from clustered keywords. Cross-references KGR scores, search volume, and competitor coverage.

### gap_deep.py
Deep competitor analysis with keyword overlap detection. Identifies keywords competitors rank for that you don't, sorted by opportunity score.

### full_audit.py
End-to-end pipeline. Takes a site URL + seed keywords, runs the full sequence: technical audit → keyword discovery → clustering → KGR scoring → competitor gap → priority matrix → strategy report.

## Methodology

### Keyword Golden Ratio (KGR)
KGR = allintitle_count / monthly_search_volume. KGR < 0.25 suggests low competition. Proven effective for long-tail content strategy.

### SERP Structure Analysis
Analyzes actual Google search results to assess difficulty. Examines homepage ratio, platform density, domain authority distribution, brand sitelinks, and content freshness. More accurate than backlink-based KD scores for new sites.

### Keyword Clustering
Groups semantically similar keywords to plan topical content clusters. Uses blended Jaccard similarity (token overlap + character n-gram similarity) with centroid-based greedy assignment.

### Competitor Gap Analysis
Compares sitemaps to find content gaps. The free tool uses sitemap parsing; the Pro tool adds keyword-level overlap detection.

## Legal

- [Privacy Policy](https://zens.ink/privacy/)
- [Terms of Service](https://zens.ink/terms/)

## Technical Details

- **Language**: Python 3 (stdlib only, zero pip dependencies)
- **Pro distribution**: ZIP download via Cloudflare R2 after Creem license verification
- **License**: MIT (free tools), Commercial (Pro scripts)
- **Contact**: support@zens.ink