GhostUser – open-source AI personas that test UX by simulating user flows through your app

Five predefined personas (Maya the Newbie, Dan the Buyer, Riley the Power User, Sam the Skeptic, Alex In-A-Hurry) walk through your product, reporting confusion and broken features like console errors and HTTP 5xx responses.

Available as a Figma plugin (for designers), CLI agent (for developers testing localhost servers), or MCP server (for Claude Desktop, Claude Code, Cursor, Windsurf). Same engine across all three; you provide your own Anthropic API key.

Typical per-test cost is ~$0.02 for a single screenshot or ~$0.10–$0.25 for a full agent run with Sonnet 4.6; Haiku costs ~5× less and Opus ~5× more. Open source under MIT license.