YC S25 founder raised $6.3M seed in 4 days, the only signal at application: a GitHub repo with 10k stars.
Luigi (Manufact) built mcp-use, an open-source MCP SDK, from a bedroom with no revenue, no customers. Full timeline with screenshots in the blog post. Three mechanics: real devs using it beats a polished application; launch again and again (most growth came from announcing each ship); apply when you would keep going regardless. The open-source repo doubled as the distribution channel.
The part most founders skip: sending YC growth updates even after submission.
https://manufact.com/blog/10000-github-stars
Luigi (Manufact) built mcp-use, an open-source MCP SDK, from a bedroom with no revenue, no customers. Full timeline with screenshots in the blog post. Three mechanics: real devs using it beats a polished application; launch again and again (most growth came from announcing each ship); apply when you would keep going regardless. The open-source repo doubled as the distribution channel.
The part most founders skip: sending YC growth updates even after submission.
https://manufact.com/blog/10000-github-stars