companies

Codebuff

YC-backed terminal coding agent that edits whole codebases from natural-language instructions, plus a free ad-supported variant, Freebuff.

Codebuff was founded in San Francisco in 2024 by James Grugett and Brandon Chen and went through Y Combinator's Fall 2024 batch. Grugett had previously co-founded the prediction-market platform Manifold Markets with his brother Stephen Grugett and Austin Chen, growing it to roughly 150,000 users, while Chen brought experience from several other YC-backed startups. Codebuff is a terminal-first coding agent, installed via npm, that indexes an entire codebase and edits multiple files based on natural-language instructions rather than working file-by-file inside an IDE. The company has stayed deliberately small, running with around three people and roughly $1.5 million in total funding, including a $500,000 seed round led by Y Combinator, while reporting revenue growth from a lean team. In 2025 Codebuff launched Freebuff, a fully free variant of the agent funded through text ads shown in the terminal rather than subscriptions or usage credits, aimed at developers and students who want a no-cost entry point into agentic coding rather than a free trial that expires.

Founded

2024

Headquarters

San Francisco, United States

Sector

applications