---
title: "Blacksmith Raises $45M Series B at $550M — Peak XV Bets on AI-Era CI"
description: "Peak XV led Blacksmith’s $45M Series B (closed March, announced Aug 12) with YC and GV tripling down — purpose-built CI compute as AI codegen floods test queues."
date: 2026-08-12T00:00:00.000Z
tags: ["2026-vc-news", "startup-funding", "venture-capital", "artificial-intelligence", "developer-tools", "y-combinator"]
source: https://venturecapitaltracker.com/2026-blacksmith-45m-series-b-peak-xv-ci-ai
---

# Blacksmith Raises $45M Series B at $550M — Peak XV Bets on AI-Era CI

> Peak XV led Blacksmith’s $45M Series B (closed March, announced Aug 12) with YC and GV tripling down — purpose-built CI compute as AI codegen floods test queues.

**Blacksmith** raised a **$45 million Series B** at a **$550 million** valuation. **Peak XV Partners** led; **[Y Combinator](/fund/y-combinator)** and **GV** tripled down. The round **closed March 2026** and was **announced August 12, 2026**. Total funding: **$58.5M**.

## Key facts

| Field | Detail |
| --- | --- |
| Company | Blacksmith — CI cloud + [code]smith agent |
| Round | $45M Series B @ $550M (closed Mar 2026; announced Aug 12) |
| Lead | Peak XV Partners |
| Returning | Y Combinator, GV |
| Prior | Seed $3.5M (May 2025, GV/YC); Series A $10M (Sep 2025, GV) |
| Traction (company) | 6,000+ companies; customers incl. Supabase, Clerk, Ashby, Mercury; CI jobs +5–10% WoW in 2026 |
| Use of proceeds | Expand compute footprint (hundreds of thousands of cores → ~10×) |
| HQ / hiring | NYC and SF |

## Who uses the product — and for what job

**Users:** platform/DevEx teams whose developers adopted Claude Code / Cursor-class tools and watched **PR volume and CI minutes** explode.

**Job:** run tests faster on purpose-built infra and autofix red builds so merge queues do not become the weekly incident.

Customer quote pattern in the announce: 4× PR volume → CI cannot keep up → merge-blocking incidents.

## Why now

- Codegen made **writing** cheap; **validating** is the new capacity constraint.
- Blacksmith’s valuation jumped ~9× from the ~$60M Series A print in under a year (press) — pricing CI as AI infra, not a cost-center tool.
- Peak XV’s developer-tools book (Supabase, PostHog) maps to Blacksmith’s ICP; Supabase is also a named customer.
- Compute is the bill — this raise is explicitly for cores, not brand ads.

## Why Peak XV / YC — portfolio fit

**Peak XV** (ex–Sequoia India/SEA) underwrites product-led developer platforms and already knows Supabase-scale usage curves. **[Y Combinator](/fund/y-combinator)** returning hard is the classic W24 follow-on when usage is compounding weekly.

**Likely founder rationale:** pick a lead that understands PLG developer GTM and will fund the infra CapEx race without forcing an enterprise-only pivot too early.

| Investor type | What they bring |
| --- | --- |
| Peak XV | Devtools pattern recognition; board for PLG scale |
| YC | Talent + company-building network |
| GV | Cloud/Google ecosystem adjacency from prior leads |

## Competitive map

| Player | Lane |
| --- | --- |
| GitHub-hosted runners / Buildkite / CircleCI | General CI; less AI-codegen-native autofix |
| [CodeRabbit](/2026-coderabbit-143m-series-c-agentic-change-management) | PR judgment & security; not CI compute |
| [Lovable](/2026-lovable-400m-series-c-menlo-13-3b) | App generation; upstream of CI |
| In-house runner fleets | CapEx and ops heavy |

## Market signal

Announcing a March close in August with **$550M** attached says the company preferred **shipping through the Claude Code wave** over a flashy fundraise day — then used the tape to brand the category.

## When not to use this as a template

- Wrong if CI spend is still tiny relative to headcount (no pain).
- Wrong if autofix agents merge without human policy.
- Wrong if you only optimize list price/minute without cache/hit-rate economics.

## Practical takeaway

- **Founders (infra):** When agents write code, sell **minutes and green builds**, not another chat UI.
- **Investors:** Model gross margin on compute carefully — this is closer to cloud than SaaS seats.
- **Operators:** Track CI queue time vs PR volume after codegen adoption; that ratio is the buying trigger.

### Sources

1. Blacksmith blog (Aug 12, 2026): https://www.blacksmith.sh/blog/announcing-blacksmiths-series-b-led-by-peak-xv-partners
2. TechCrunch: https://techcrunch.com/2026/08/12/blacksmiths-valuation-jumps-10x-to-550m-as-ai-coding-fuels-software-validation/
3. Related: [/fund/y-combinator](/fund/y-combinator) · [/2026-august-12-13-investment-news-energy-codegen-enterprise](/2026-august-12-13-investment-news-energy-codegen-enterprise)