Peak XV Partners leads the round as Blacksmith grows from 800 to more than 6,000 customers amid surging demand for faster code validation.
SAN FRANCISCO, Aug. 12, 2026 /PRNewswire/ — Blacksmith, a cloud for validating code, has raised a $45 million Series B led by Peak XV Partners, with existing investors Y Combinator and GV also participating. The round values the company at $550 million.
The financing comes as AI coding tools are changing how quickly engineering teams produce software. Since the beginning of the year, the number of CI jobs running on Blacksmith has grown between 5% and 10% week over week. More than 6,000 companies now use Blacksmith, including Supabase, Clerk, Ashby and Mercury, up from approximately 800 when the company announced its Series A last September.
As developers adopt tools such as Claude Code, Codex and other coding agents, teams are producing significantly more code and opening more pull requests. That has put increasing pressure on the infrastructure responsible for building, testing and validating every change before it ships.
“Writing code has gotten dramatically easier. Validating it hasn’t,” said Aditya “JP” Jayaprakash, co-founder and CEO of Blacksmith. “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.”
Beyond CI: the validation platform
Blacksmith started with purpose-built infrastructure that runs CI workloads dramatically faster than general-purpose cloud instances, with migration taking a one-line change to a workflow file. That remains the foundation. The broader goal is helping developers validate and merge code faster, with confidence in every change they ship.
The company recently launched codesmith, a cloud coding agent developers can delegate tasks to. Beyond building features and fixing bugs, codesmith works inside the validation loop: diagnosing CI failures, autofixing them, and keeping pull requests green. It is also the foundation for codesmith QA, which will autonomously test changes before they merge.
Where the money goes
Most of the new capital goes to compute. Blacksmith manages hundreds of thousands of cores today and plans to grow that footprint by an order of magnitude in the coming months to stay ahead of demand.
Blacksmith is hiring engineers in New York and San Francisco: https://www.blacksmith.sh/careers
About Blacksmith
Blacksmith builds infrastructure and software for validating code. Its purpose-built CI cloud runs GitHub Actions workloads on dedicated compute with caching and storage optimized for CI. More than 6,000 companies use Blacksmith, including Supabase, Clerk, Ashby and Mercury. Blacksmith also develops codesmith, its cloud coding agent for building and validating software. The company was founded by Aditya (JP) Jayaprakash, Aayush Shah and Aditya Maru and is backed by Peak XV Partners, Y Combinator and GV. For more information, visit blacksmith.sh.
About Peak XV Partners
Peak XV Partners (formerly Sequoia Capital India & SEA) is a leading venture capital firm investing across India, APAC and beyond. Over the last 20 years of operations in the region, Peak XV has grown to manage over USD 10 billion in capital across 16 funds and has invested in over 450 companies. The portfolio has seen over 37 IPOs and several successful M&As to date. To know more, please visit www.peakxv.com.
SOURCE Blacksmith