Stackup: Fannie, Freddie and HUD multifamily loan sizing

Overview

Stackup is a Model Context Protocol server that sizes apartment loans under Fannie Mae, Freddie Mac, and HUD published limits, all in one view. Compare loan sizing across the three agencies side by side to find the best fit for your multifamily deal. AI assistants can call Stackup as a set of tools, eliminating copy-paste workflows between apps.

Stackup runs as a remote hosted server at https://multifamily.online/mcp with no local installation required. No authentication is needed. The current release is v1.2026.1101.0. Learn more and access developer documentation at https://multifamily.online/developers/.

Stackup lives in the Development category on mcp.site and works with any MCP client including Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, and Zed. If you maintain this server, claim your listing to earn the Verified badge and keep information up to date.

Installation

Settings → Connectors → Add custom connector
Name: Stackup: Fannie, Freddie and HUD multifamily loan sizing
URL:  https://multifamily.online/mcp