Top accelerator startups

Startups14,448Programs29

14,448 startups · 29 programs

Butter

Active · Embedded Sandboxes for Agents

WebsiteYC profile

Why it ranks

How the rank works
7signal of 100 · rising 4
  • went through YCProgram · this site+4
  • team of 2Team size · YC's directory+2.5

A sum of public facts, not a judgement and not investment advice.

Competitors

AIArdentShared: sandboxes, agent, infrastructureYC X26San FranciscoStartup →AIArchalShared: sandboxes, agent, infrastructureYC S26San FranciscoStartup →AIThunder ComputeShared: sandboxes, agent, infrastructureYC S24San FranciscoStartup →AIBeamShared: sandboxes, agent, infrastructureYC W22New York CityStartup →OtherSail ResearchShared: sandboxes, agentStartup →
Companies closest to Butter
Company
ArdentShared: sandboxes, agent, infrastructureYC X26ActiveAI, Data, Devtools
ArchalShared: sandboxes, agent, infrastructureYC S26ActiveAI, Devtools
Thunder ComputeShared: sandboxes, agent, infrastructureYC S24ActiveAI, Data, Devtools
BeamShared: sandboxes, agent, infrastructureYC W22ActiveAI, Devtools
Sail Researchnot in a program hereShared: sandboxes, agentElsewhereOther

Adjacent

AIAgent 37Shared: sandboxes, agent, infrastructureYC F26New York CityStartup →AILimrunShared: sandboxes, agent, infrastructureYC X26San FranciscoStartup →Developer toolsAcquiredBunShared: incredibly, building, infrastructureYC S19San FranciscoStartup →OtherSemaphorShared: embeddedAntler 2024USStartup →OtherAcquiredColumn TaxShared: embeddedSPC 2021New YorkStartup →
Companies next to Butter
Company
Agent 37Shared: sandboxes, agent, infrastructureYC F26ActiveAI, Devtools
LimrunShared: sandboxes, agent, infrastructureYC X26ActiveAI, Devtools
BunShared: incredibly, building, infrastructureYC S19AcquiredDevtools
SemaphorShared: embeddedAntler 2024Not statedOther
Column TaxShared: embeddedSPC 2021AcquiredOther

Also from W25 in AI

All of W25
AI.WaveInference for real-time AIYC W25ParisStartup →AI10xAI Sales Teams for Dental PracticesYC W25San FranciscoStartup →AIa0.devWe make mobile apps using AI.YC W25San FranciscoStartup →AIA1Zap by A1BaseThe social network layer for AI appsYC W25San FranciscoStartup →AIAdamAI Powered CADYC W25San FranciscoStartup →AIAfterQueryApplied research lab curating data solutions for foundation model…YC W25San FranciscoStartup →
Company
.WaveInference for real-time AIteam of 2ActiveAI, Devtools
10xAI Sales Teams for Dental Practicesteam of 3hiringActiveAI, Data
a0.devWe make mobile apps using AI.team of 3hiringActiveAI, Devtools
A1Zap by A1BaseThe social network layer for AI appsteam of 2ActiveAI, Devtools
AdamAI Powered CADteam of 4hiringActiveAI, Devtools
AfterQueryApplied research lab curating data solutions for foundation model…team of 30hiringActiveAI, Data, Devtools

Founders

  • Erik DuntemanFounder/CEO

About Butter

Butter is building bVisor, an incredibly lightweight sandbox runtime for AI agents. It embeds directly into your local process, providing a safe bash environment without the overhead of VMs or remote infra.

YC batch
W25 · Winter 2025
Status, per YC
Active
Category
AI, Developer tools
Team size
2
Location
San Francisco, CA, USA
Founded
2024
Checked
6h ago

Butter in W25: 166 companies, 84% AI

GitHub LinkedIn

Butter: questions

Which YC batch was Butter in?

Butter was in Y Combinator's Winter 2025 batch (W25).

Is Butter still active?

Y Combinator lists Butter as active.

Who founded Butter?

Butter's founders, as listed on its YC page: Erik Dunteman (Founder/CEO).

Where is Butter based?

Butter lists San Francisco, CA, USA as its location on YC's directory.