Y Combinator
Y Combinator is a technology startup accelerator launched in 2005. It has helped launch over 4,000 companies including Airbnb, Stripe, Coinbase, Reddit, and Supabase.
Backed Startups (47)
In directoryAgentOps
Observability, testing, and compliance framework for autonomous AI agents
Blacksmith
Bare-metal CI cloud and autonomous AI validation engine for engineering teams
Bland AI
Infrastructure platform for automating hyper-realistic outbound and inbound enterprise AI phone calls
Bretton AI
Trusted AI agents for financial crime
BuildForever
Building Extra
Fern
Open-source platform that generates SDKs and API docs from OpenAPI specs
Deepgram
Lightning-fast voice AI platform offering speech-to-text and text-to-speech APIs
Depot
The fastest place to build Docker images
Discovered Materials
Autonomous AI agent swarms for accelerated discovery of semiconductor and thermal materials
Driver
Create high-quality technical documentation
Edra
Building agents that reverse engineer process
Firecrawl
API platform that turns any website into clean, LLM-ready Markdown data for AI agents and web scrapers
Flagright
AI-powered operating system for real-time financial crime compliance and AML
Fly.io
Deploy full-stack applications and databases directly on servers close to users worldwide
Glow
Autonomous AI agent platform for prevention-first endpoint cybersecurity
HappyRobot
Autonomous voice AI agents automating freight logistics, dispatch, and carrier coordination
Helicone
Open-source LLM observability, caching, and rate limiting infrastructure
Infisical
Open-source secrets management platform for syncing environment variables and enterprise credentials securely
Instant
A modern Firebase
Langfuse
Open-source LLM engineering platform for tracing, analytics, and evaluations
Latent Health
The intelligence infrastructure for American healthcare
Loops
Modern email platform engineered specifically for software companies and SaaS product growth teams
Mem0
Open-source long-term memory layer for AI agents and LLM applications giving bots adaptive personal context
Mintlify
Automated developer documentation platform that converts code into beautiful docs
Nango
Unified integration platform for building, syncing, and maintaining product integrations with 250+ APIs
Novu
Open-source notification infrastructure for engineering teams
Ollama
Get up and running with open-weight local LLMs like Llama 3, Mistral & Gemma
Onyx AI
Open-source AI enterprise search platform connecting to Notion, Slack, GitHub, and Jira with strict access controls
Paradigm
Agentic spreadsheets
Peerlist
Professional network for tech proof-of-work, projects, and hiring
Plazza
AI-powered 15-30 minute medicine delivery platform stocking 40,000+ SKUs
PostHog
Open-source product analytics, session replay, feature flags, and A/B testing suite
Raycast
Extensible Mac productivity launcher that replaces Spotlight with AI extensions, window management, and developer tools
Render
The zero-friction cloud platform for hosting web apps, static sites, databases, and cron jobs
Replit
Software creation platform & AI agent enabling anyone to build and deploy software instantly
Resend
Modern email infrastructure and API built for developers
Scale AI
Data infrastructure for AI, supplying training data for frontier models
Supabase
The open source Firebase alternative with Postgres and instant APIs
Svix
Enterprise webhooks-as-a-service platform for developers
Tavus
Generative AI video voice and avatar replica platform for personalizing customer conversations at scale
TigerEye
Modern BI for go-to-market
Trigger.dev
Open-source background jobs platform designed for Next.js and TypeScript
Vapi AI
Voice AI developer platform for building low-latency, real-time conversational phone agents and voice apps
Vellum AI
The enterprise platform for testing, evaluating, and monitoring LLM applications in production
Webflow
The visual web development platform for building custom, production-ready websites
Zapier
The global leader in no-code workflow automation connecting over 7,000 web apps
Zepto
India's fastest-growing 10-minute quick commerce delivery unicorn