Blacksmith raises $45M Series B at $550M valuation on CI demand from AI-written code

Blacksmith closed a $45 million Series B led by Peak XV Partners, with GV and Y Combinator participating, putting the two-year-old CI startup at a $550 million valuation, up from $60 million less than a year ago. Total funding now stands at $58.5 million.

The jump tracks a customer surge: Blacksmith grew from roughly 700 to more than 5,000 customers in under a year, including Supabase, Clerk, and Expensify, with some accounts now spending over $1 million annually. Revenue has moved from a $10 million annualized run rate on 10 employees to "tens of millions" with a team of about 30.

Founder and CEO Aditya Jayaprakash ties the growth directly to AI coding agents: as tools like Cursor and Claude Code make code generation faster, validating that code becomes the bottleneck, not writing it. Blacksmith's core CI cloud service now ships alongside Codesmith, an agent that automatically fixes failed checks rather than just flagging them.

For a team already running Claude Code or Cursor against a real codebase, the read here isn't the valuation number, it's the underlying claim: agent-generated code volume is outpacing manual review capacity, and CI vendors are positioning validation, not generation, as the next constraint worth paying for.