YC Open Source
174 Y Combinator companies tagged Open Source, most in W23 (21).
Companies per batch
Companies
174 of 174 companies
Graphify LabsS26 · AIOn-device Knowledge Graph engine for Enterprise Software
OneCLIS26 · AIThe open source AI teammates for your company.
OneTriangleS26 · AIThe cheapest, fastest inference cloud
OrchestraS26 · AISelf-optimizing neocloud that cuts LLM costs by 100x
RiftenS26 · AIEarned intelligence for every company
RobocurveS26 · AIEvals for robots
TracerS26 · AICombining open-source AI models for better answers at lower cost
VendoS26 · AILet your users build their own features on top of your product
SuperlogX26 · AIMake software self-healing
ZenbuX26 · AIThe extensible IDE for coding agents
RunAnywhereW26 · AIFastest inference anywhere: open models on-prem, hosted or on-device
Expected ParrotF25 · AISimulate your customers with AI agents
s2.devF25 · AIAPI for unlimited, durable, real-time streams
SourcebotF25 · AIHelping humans and AI agents understand massive codebases
Cactus ComputeS25 · AIAutomation Foundation Models For Tiny Devices
CharS25 · AIThe AI notepad that knows and works for you
EpicenterS25 · AIChatGPT's memory feature in an open, portable format
MagnitudeS25 · AIOpen source inference server for local models
ManufactS25 · AICloud infrastructure for MCP servers and Claude / ChatGPT plugins.
ModelenceS25 · Developer toolsProduction infrastructure on autopilot
PangolinS25 · AIOpen networking and security for your workforce, AI agents, and infra
stagewiseS25 · AIThe Open Source Agentic IDE
Better AuthX25 · Developer toolsThe authentication framework for TypeScript
CuaX25 · AIGive every agent a cloud desktop
HelixDBX25 · AIThe fastest & most scalable graph-vector database on the market
KaelioX25 · AIThe open-source context layer for data agents
nao LabsX25 · AIOpen Source Analytics Agent
Browser UseW25 · AIAgents that use the browser.
CodevisorW25 · AIThe fastest native app for agentic engineering.
Confident AIW25 · AIThe LLM Eval and Observability Platform for AI Quality
CorsairW25 · AIOpenRouter for Integrations
MastraW25 · AIThe Javascript framework for building AI agents, from the Gatsby devs
MentraW25 · AIBuilding the open source smart glasses operating system.
SublingualW25 · InactiveDaily productivity tracker
superglueW25 · AIconnect, migrate and implement enterprise systems
cmuxS24 · AIOpen source applied AI lab building next-gen devtools
Dench.comS24 · AIWorkspace for your AI Agents, Build any Workflow.
Mem0S24 · AIThe Memory layer for AI Agents
OpslaneS24 · AIVerify AI-generated code before you ship it
Random LabsS24 · AIRandom labs is building long running autonomous coding agents.
Rowboat LabsS24 · AIOpen-source AI coworker with memory
Unsloth AIS24 · AIOpen-Source Reinforcement Learning (RL) & Fine-tuning for LLMs.
HatchetW24 · AIThe orchestration platform for teams who ship.
LanternW24 · InactivePostgres vector database extension to build AI applications
nCompass TechnologiesW24 · AIOptimize performance on GPUs - 10x faster
OnyxW24 · AcquiredOpen Source AI Chat
OpenFoundryW24 · AIThe fastest developer experience for building on open source AI.
Pretzel AIW24 · AIAI tooling
SuperagentW24 · AISecurity for AI-native developers
TesseralW24 · InactiveThe open source platform for managing identity in business software
TracecatW24 · AIOpen-source agentic security automation platform
TrieveW24 · AcquiredAll-in-one API for search, RAG, & recommendations
TuskW24 · InactiveAI agent that generates unit and integration tests
Vibrant LabsW24 · AIAutonomously scaling environments
FlowiseAIS23 · AcquiredOpen source GenAI development platform
KhojS23 · AIAI for humans
OpenPipeS23 · AcquiredTurn expensive prompts into cheap fine-tuned models
ParadeDBS23 · DataUnify application data, vectors, and full-text search in one Postgres
PeerDBS23 · AcquiredFast, native ETL for Postgres 🐘 🚀
RecipeUIS23 · Developer toolsThe open source Postman alternative.
refineS23 · Developer toolsOpen-source Retool for enterprise
ReworkdS23 · AIThe simplest way to extract web data at scale
SkyvernS23 · AIOpen Source AI Agent to automate browser workflows via an API
TiptapS23 · AIThe open-source document editor for humans and AI agents.
TwentyS23 · Developer toolsOpen Source CRM
ArroyoW23 · AcquiredCloud-native stream processing
Common PaperW23 · Developer toolsThe SAFE for commercial contracts
DAGWorks Inc.W23 · AcquiredOpen source tools & services for reliable AI Agents & AI Applications
FernW23 · AcquiredInstantly offer SDKs and API Docs
HeliconeW23 · AcquiredLLM Observability for Developers
highlight.ioW23 · AcquiredThe open source, fullstack monitoring platform: stop guessing why…
InfisicalW23 · Developer toolsUnified platform for secrets, certs, and privileged access management
KeepW23 · AcquiredThe open-source AIOps platform
LangfuseW23 · AcquiredOpen source LLM engineering platform
LiteLLMW23 · AICall every LLM API like it's OpenAI [100+ LLMs]
MatanoW23 · DataCloud Native SIEM (alternative to Splunk/Elastic)
moonrepoW23 · InactiveOpen source build tool for monorepos and large codebases
NangoW23 · Developer toolsA single API for all your integrations
OpenIntW23 · AcquiredOpen Source Embedded Product Integrations
ReflexW23 · AIThe operating system for building mission-critical enterprise apps.
RivetW23 · AIRivet Actors are the primitive for stateful workloads
TecladaW23 · Developer toolsRemote Shell Access in the Browser
TraceloopW23 · AcquiredKnow what your LLM is doing — and why it’s failing
Trigger.devW23 · AIBuild and deploy fully‑managed AI agents and workflows
UnifyW23 · AIModels that keep learning
VocodeW23 · AcquiredOpen source Voice AI
ActivepiecesS22 · AIOpen-source, AI-first and no-code business automation tool
AnythingLLMS22 · AIBuilding the definitive all-in-one on-device AI productivity tool
DittofeedS22 · Developer toolsOpen-source customer engagement & messaging automation
FirecrawlS22 · AIThe web data API for searching and scraping. 🔥
GraiS22 · InactiveOpen source version control for metadata
HyperDXS22 · AcquiredOpen-source, dev-friendly observability.
LaminS22 · AIOpen data platform for traceable, multimodal AI
LotusS22 · InactiveOpen-Core Pricing and Billing Engine
MedplumS22 · Developer toolsAPI first electronic health record (EHR) that is open source
MistleS22 · AIOpen source background agents
PayloadS22 · AcquiredDeveloper-First Headless CMS and Application Framework
StackupS22 · Developer toolsStackup helps businesses manage their crypto assets.
WindmillS22 · Developer toolsOpen-source platform to turn scripts into internal apps & workflows
BeamW22 · AIAI-Native Cloud Platform
BotCityW22 · AIObservability and Governance for AI-Generated Python scripts.
ConvoyW22 · Developer toolsWebhooks Gateway for outgoing and incoming webhooks.
ElementaryW22 · DataOpen-source data observability for data teams
FirezoneW22 · Developer toolsEasiest way to set up Zero Trust Access for your team
GrowthBookW22 · DataOpen source feature flagging and A/B testing
HydraW22 · AcquiredServerless Analytics on Postgres
LanceDBW22 · AIOpen-source, serverless vectordb for production-scale generative AI
NetmakerW22 · Developer toolsAutomated WireGuard networks for distributed systems and Kubernetes
RequestlyW22 · AcquiredOpen-Source Postman alternative
RowndW22 · AIFully autonomous defense solutions for the global edge.
ArtilleryS21 · AIThe complete production quality platform. AI-powered E2E testing,…
EnsoS21 · DataSelf-Service Data Prep and Blend Built for Data Teams.
Evidently AIS21 · AIOpen-source monitoring for machine learning models
FormanceS21 · Developer toolsOpen Source Infrastructure for the Financial Internet
LagoS21 · AIThe AI Native Billing Platform
PipekitS21 · DataPipekit scales data & CI pipelines for enterprises
Vibe KanbanS21 · AIPlan and review AI generated code
WarrantS21 · AcquiredAuthorization and access control as a service.
AlokaiW21 · Developer toolsFrontend Platform for eCommerce
authzedW21 · AIAuthorization Infrastructure securing AI at OpenAI, Zoom, & more
ChatwootW21 · AIThe modern, open source, self-hosted AI customer support platform
InfracostW21 · Developer toolsShift FinOps Left: Proactively Find & Fix Cloud Cost Issues
LaudspeakerW21 · AcquiredOpen source mobile marketing platform. Alternative to appcues /…
LunaticW21 · InactiveOperating System for server-side apps
OllamaW21 · AIGet up and running with large language models.
OpenCodeW21 · AIThe open source AI coding agent
PyroscopeW21 · AcquiredOpen source continuous profiling software to debug performance issues
SigNozW21 · Developer toolsOpen source alternative to DataDog
SvixW21 · Developer toolsEnterprise ready webhooks service, open-source and in the cloud
WaspW21 · Developer toolsConfiguration language for building enterprise web apps 10x faster
WebinyW21 · Developer toolsOpen-source framework for building serverless applications
FigS20 · AcquiredFig adds visual apps, shortcuts, and autocomplete to your terminal.
JitsuS20 · AcquiredOpen-Source CDP (acquired by Helium Ventures)
KeyDBS20 · AcquiredThe only database you'll ever need
LightdashS20 · DataThe open source Looker alternative
MitoS20 · AICursor for data analysis
MonosiS20 · InactiveOpen Source Data ObservabilityOpenbaseS20 · InactiveOpen-source library discovery
QuestDBS20 · AIHigh-performance time series database
ShuttleS20 · InactiveBuild Backends. Fast.
SupabaseS20 · DataBuild in a weekend. Scale to millions.
SuperTokensS20 · Developer toolsOpen source alternative to Auth0 / AWS Cognito / Firebase Auth
UkamaS20 · Developer toolsEmpowering anyone to build cellular network
AirbyteW20 · AIContext layer for production-grade AI agents
Chaos GeniusW20 · AcquiredDataOps Observability Platform for Snowflake
MindsDBW20 · AIConnect, Unify, Respond to any data, anywhere with human-level…
PostHogW20 · AIThe single platform to analyze, test, observe, and deploy new features
ReplicateW20 · AcquiredRun machine learning models in the cloud
BunS19 · AcquiredBun is an incredibly fast all-in-one JavaScript toolkit
Data MechanicsS19 · AcquiredSpark-on-Kubernetes Data Engineering Platform
EmbraceS19 · AcquiredModern user-focused observability built on OpenTelemetry
LunaSecS19 · InactiveAn Open Source dependency security tool that is smarter than the rest
OpenReplayS19 · Developer toolsOpen-source, self-hosted, session replay tool for developers.
TensilS19 · InactiveWe turn machine learning models into custom hardware.
WasmerS19 · Developer toolsThe Operating System for Edge Computing
OktetoW19 · Developer toolsCloud Development Environments with one click
ActiveloopS18 · AIDatabase for AI
OpticS18 · AcquiredMaking APIs Developer-friendly
CodeStreamW18 · AcquiredCodeStream is a Developer Collaboration Platform designed to…
TipeW18 · InactiveOpen-source, customizable, headless CMS
DailyW16 · AIConversational Voice and Multimodal AI built with Open Source
Font AwesomeS15 · Developer toolsIcons and social logos for your website.
GitLabW15 · PublicA complete DevOps platform delivered as a single application.
Sails Co.W15 · Developer toolsFull-service web, mobile, & cloud studio providing professional…
Standard CyborgW15 · InactiveBuid, test and deploy perception applications
Protocol LabsS14 · Developer toolsProtocol Labs makes internet protocols: IPFS, Filecoin, and more.
PipelineDBW14 · AcquiredOpen-source time-series data analytics extension for PostgreSQL
CoreOSS13 · AcquiredOpen source tools of modern distributed systems.
InfluxDataW13 · DataThe platform for building and operating time series applications.
MattermostS12 · Developer toolsSecure Collaboration for Technical Teams
ApolloS11 · Developer toolsApollo helps engineering teams accelerate delivery
Citus DataS11 · AcquiredReal-time. Big data. PostgreSQL
DockerS10 · Developer toolsSoftware development platform.
RethinkDBS09 · AcquiredThe open source database for the realtime web.Not affiliated with Y Combinator. From YC's public directory. Logos via logo.dev; trademarks belong to their owners.