Fundraising Fox

Butter

YC W25

San Francisco, US · Founded 2024 · 2 employees · 2 known investors

Butter builds bVisor, a lightweight sandbox runtime for AI agents that runs locally within application processes, providing a secure bash environment without virtual machines or remote infrastructure.

Also known as Pig

Founders & leadership· Y Combinator alumni (W25)

Butter was founded in 2024 by Erik Dunteman.

EDErik Dunteman
Erik Duntemanin𝕏FounderErik founded Banana.dev, a serverless GPU platform for machine learning inference, before joining Modal as a growth engineer. He now leads Butter.

Investors · 2

The YC application· Winter 2025 batch

Alumni Q&A

What's the history of your company from getting started until the present day? What were the big inflection points?
The company began coding on December 11. On January 21 it launched a serverless VM cloud platform and found that users wanted to self-host. On February 16 it released the Piglet computer driver for self-hosting and learned that building agent loops was difficult. On February 27 it launched an agent layer with chat, and an API planned, to help users reach working automations faster.
What is the core problem you are solving? Why is this a big problem? What made you decide to work on it?
The founders are addressing the brittleness of RPA and its reliance on consultants who profit from repeatedly rewriting automations. Developers building on legacy applications often resort to insecure workarounds, such as exposing backdoors on users' machines, and still face fragile hardcoded automations. The founders are drawn to the problem partly on the expectation that enterprises will continue using Windows.
What is your long-term vision? If you truly succeed, what will be different about the world?
The founders aim for the company's product to become the interface agents use to operate in the business world as agent-driven labor output grows substantially.

Summarized from the founders' answers on their Y Combinator profile.

In the news

Frequently asked questions

What does Butter do?
Butter builds bVisor, a lightweight sandbox runtime for AI agents that runs locally within application processes, providing a secure bash environment without virtual machines or remote infrastructure.
Who founded Butter?
Butter was founded by Erik Dunteman in 2024.
Who are Butter's investors?
Butter's investors include Y Combinator, Norwest Venture Partners.
Where is Butter headquartered?
Butter is headquartered in San Francisco, US.