# StackIndex — Full LLM Reference

> SaaS comparison index. Provides structured pricing, feature, and compliance data for email/newsletter platforms and project management tools. All data is manually verified and timestamped. Affiliate relationships are disclosed on every page and API response.

## Site structure

- `/` — Homepage with category overview, quick-compare tool, and popular comparisons
- `/c/{category-slug}` — Category index with all products, filterable by free tier / price
- `/p/{product-slug}` — Full product page: pricing tiers, key features, compliance, affiliate link
- `/vs/{slug-a}-vs-{slug-b}` — Side-by-side comparison of two products

## Categories

### Email & Newsletter Platforms (`/c/email-newsletter`)

Products covered: beehiiv, Kit (formerly ConvertKit), Mailchimp, Mailerlite, GetResponse, ActiveCampaign, Brevo (formerly Sendinblue), Substack

Key comparison dimensions:
- Starting price and free tier limits (subscriber count, send volume)
- Pricing model: per-subscriber, per-send, or flat monthly
- Automation depth: visual builder, conditional logic, multi-step sequences
- Monetization features: paid newsletters, paid subscriptions, tip jars
- Deliverability infrastructure: dedicated IPs, warmup tools, inbox placement rates
- Integrations: CMS, ecommerce, CRM, Zapier/Make

### Project Management Tools (`/c/project-management`)

Products covered: Monday.com, ClickUp, Asana, Notion, Linear, Basecamp, Jira

Key comparison dimensions:
- Starting price (per seat/month) and free tier seat limits
- Core paradigm: task lists, kanban boards, Gantt charts, databases, or hybrid
- AI features: task generation, summarization, writing assistant
- Reporting and dashboards: built-in vs. add-on
- Integrations: GitHub, Slack, Figma, Google Workspace, Microsoft 365
- Time tracking: built-in vs. third-party

## Product pages

Each product page at `/p/{slug}` contains:
- Full pricing tiers with price, annual savings, limits, and included features per tier
- Key features list (5–10 items most relevant for purchase decisions)
- Compliance badges: SOC 2, GDPR, HIPAA, ISO 27001
- Affiliate link (if available) with disclosure
- Last verified date for pricing and features
- FAQ section with 3 common questions about the product
- Compare-with links to all alternative products in the same category

## Comparison pages

Each comparison page at `/vs/{slug-a}-vs-{slug-b}` contains:
- Verdict for each product (best use case)
- Side-by-side table: pricing, free tier, key features, compliance, integrations
- FAQ with 3 questions specific to the two products being compared

## REST API

Base URL: `https://stackindex.org/api/v1`

### GET /categories
Returns all categories with product counts.

### GET /products
Query params: `category` (slug), `max_price` (number), `has_free_tier` (true/false)
Returns: id, slug, name, vendor, one_liner, starting_price_usd_month, has_free_tier, affiliate_link, last_pricing_verified_at

### GET /products/{slug}
Full product record including pricing_tiers (JSON), key_features (JSON), compliance (JSON), category_slug.

### GET /compare?slug=a&slug=b
Side-by-side data for 2–4 products. Accepts up to 4 `slug` query params.

## Affiliate redirect

`GET /go/{product-slug}` — logs the click and redirects to the affiliate or direct link. Click logging is privacy-preserving: IP is SHA-256 hashed with a daily salt; no raw IPs are stored.

## Data freshness

Every product record has `last_pricing_verified_at` and `last_features_verified_at` timestamps. The "Last verified" date is displayed on every product and comparison page.

## Affiliate disclosure

StackIndex earns affiliate commission when users sign up through the `affiliate_link` field in product records. Not all products have affiliate programs — products without programs still appear in results. Sponsored placement (one per category, labelled "Sponsored") is distinct from organic ranking. Sponsored products never appear in MCP `search_products` results.

## MCP server

Available at `/mcp` (Streamable HTTP transport) with tools:
- `search_products` — filter by category, price, features, integrations, compliance
- `get_product` — full record by slug
- `compare_products` — side-by-side for 2–4 products
- `list_categories` — all categories with product counts

Discovery: `/.well-known/mcp/server-card.json`

## Contact / about

StackIndex was built to help buyers make faster, more confident decisions about SaaS tools. Data is maintained manually and reverified on a rolling basis.