Blacksmith has raised $45 million in Series B funding at a $550 million valuation as demand grows for infrastructure that can build, test, and validate increasing volumes of AI-generated code. Peak XV Partners led the round, with existing investors Y Combinator and GV also participating.
Blacksmith operates a cloud platform for validating software code. The company said the number of continuous integration jobs running on its infrastructure has grown between 5% and 10% per week since the beginning of 2026.
More than 6,000 companies now use Blacksmith, including Supabase, Clerk, Ashby, and Mercury. That compares with approximately 800 customers when Blacksmith announced its Series A in September 2025.
The company sees increasing adoption of AI coding agents such as Claude Code and Codex as a major driver of demand. As developers generate more code and pull requests, Blacksmith is focused on the infrastructure required to validate those changes before deployment.
Blacksmith initially built purpose-designed infrastructure for running GitHub Actions continuous integration workloads faster than general-purpose cloud infrastructure. It is now expanding toward a broader code validation platform.
The company recently launched codesmith, a cloud coding agent that developers can use to build features, fix bugs, diagnose CI failures, automatically make corrections, and keep pull requests functioning properly. Codesmith is also the foundation for codesmith QA, which is being developed to autonomously test changes before they are merged.
Most of the Series B capital will be allocated to compute infrastructure. Blacksmith currently manages hundreds of thousands of cores and plans to increase that footprint by approximately 10 times in the coming months.
KEY QUOTES:
“Writing code has gotten dramatically easier. Validating it hasn’t. We’re seeing teams adopt coding agents, generate several times more pull requests, and suddenly CI becomes a bottleneck. Every piece of code an agent writes still has to be built, tested, and reviewed before it can ship. That validation layer is going to become increasingly important as more software is written by agents.”
Aditya “JP” Jayaprakash, Co-Founder and CEO of Blacksmith
