# compatsy

> What fits, with live prices.

compatsy answers "does this part fit my machine, and where is it cheapest right now" with structured specs, versioned compatibility rules and merchant prices that show when they were last verified. The default buy link is always the lowest in-stock total price; commission never changes the ranking.

## 3D printing

- [Home](https://compatsy.com/3d-printing): categories, fit hubs and top products
- [Printer comparison](https://compatsy.com/3d-printing/compare/printer)
- [Nozzle comparison](https://compatsy.com/3d-printing/compare/nozzle)
- [Hotend comparison](https://compatsy.com/3d-printing/compare/hotend)
- [Build plate comparison](https://compatsy.com/3d-printing/compare/build_plate)
- [Filament comparison](https://compatsy.com/3d-printing/compare/filament)
- [Enclosure comparison](https://compatsy.com/3d-printing/compare/enclosure)
- [Fit hubs by printer](https://compatsy.com/3d-printing/fit)
- [Methodology](https://compatsy.com/3d-printing/methodology)
- [Affiliate disclosure](https://compatsy.com/3d-printing/disclosure)

## Agent access

- [OpenAPI](https://compatsy.com/api/v1/openapi.json): HTTP API, same handlers as the MCP tools
- [MCP server](https://compatsy.com/mcp): Streamable HTTP, read-only tools (search_products, get_product, compare, check_fit, check_stock, report_issue)
- [MCP server card](https://compatsy.com/.well-known/mcp/server-card.json)
- [API keys and plans](https://compatsy.com/data)

Any page also renders as markdown with `Accept: text/markdown` or `?format=md`.