Fundraising Fox
/Companies
Sign in

Baserun

YC S23

San Francisco, US · Founded 2023 · 2 employees · 3 known investors

Find your way into Baserun

Sign up to see every warm intro you have to Baserun

  • Paths you didn't know you had: your email and LinkedIn already hold routes to the Baserun team. We find them for you
  • 2nd- and 3rd-degree connections: the friend-of-a-friend routes that take hours to manually find through your inbox or LinkedIn
  • Answers now, not in days: momentum is everything in a raise. Skip asking around whether someone knows someone

Days of research, done the moment you sign in, with every route ranked by how warm it is.

Sign up with GoogleAlready have an account? Log in

Baserun provides testing and observability tools for LLM applications, helping teams monitor latency, costs, and output quality while debugging and evaluating model behavior.

Also known as Mochi Labs, Inc. · baserun.ai · Mochi Labs · Mochi Labs, baserun.ai

AI & Machine LearningDeveloper ToolsEnterprise SoftwareAIOpsArtificial IntelligenceB2BAIUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (S23)

Baserun was founded in 2023 by Effy Zhang.

EZEffy Zhang
Effy ZhangCEO & Founder2023–2024Effy Zhang is founder of Baserun, which provides testing and observability tools for LLM applications.
AG
Adam Ginzberg

Investors · 3

Greylock PartnersreportedSan Francisco · $100K – $10M

How we know: Y Combinator's founder network · Not right? Tell us

Kleiner PerkinsreportedMenlo Park · $500K – $15M

How we know: Y Combinator's founder network · Not right? Tell us

Funding

SEC filings, press & company announcements

Source: company announcements and press reports — follow each round's link for the claim.

Related companies · 4

Query VaryQuery Vary provides a no-code platform for building workflows that connect software inputs to large language models and output integrations, enabling tasks like data extraction from transcripts, documentation chatbots, and form-to-report automation.
AtlaAtla provides debugging and monitoring tools for AI agents, using LLM-based evaluation to identify error patterns in agent behavior and suggest targeted improvements. The platform integrates with popular agent frameworks like LangChain and CrewAI, offering developers real-time insights into agent failures and performance issues.
LaminarLaminar is an observability and debugging platform for AI agents that captures failures, surfaces root causes, and confirms fixes through trace visualization, automated anomaly detection, and eval-driven development. It serves AI teams building and iterating on agent applications.
MirrorsMirrors offers regression testing for AI agents by reconstructing the internal tools and APIs an agent uses from production traces, then replaying real sessions against each code change to flag differences in tool calls, arguments, and resulting state. It runs in CI on every pull request and targets teams whose agents perform irreversible actions such as issuing refunds, updating records, or sending outbound email.

Companies working in the same space as Baserun.

Legal entities · 1

corporate structure
Mochi Labs, Inc.

In the news

Baserun Funding | Complete Analysis | Extruct AIextruct.ai · Sep 2023baserun.ai: Ship LLM features with confidence 💪💪💪ycombinator.com · Aug 2023

Frequently asked questions

What does Baserun do?
Baserun provides testing and observability tools for LLM applications, helping teams monitor latency, costs, and output quality while debugging and evaluating model behavior.
Who founded Baserun?
Baserun was founded by Effy Zhang in 2023.
Who are Baserun's investors?
Baserun's investors include Y Combinator, Greylock Partners, Kleiner Perkins.
Where is Baserun headquartered?
Baserun is headquartered in San Francisco, US.