You asked about Open Source
84 people built something like it. 3 are gone.
That is 4% of the ones whose fate we could settle, against 23% across the whole register. 11 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2016-01-01 | YCDaily Conversational Voice and Multimodal AI built with Open Source · daily.co | still up |
| 2020-01-01 | YCAirbyte Context layer for production-grade AI agents · airbyte.com | still up |
| 2021-06-01 | YCLago The AI Native Billing Platform · getlago.com | still up |
| 2022-01-01 | YCBotCity Observability and Governance for AI-Generated Python scripts. · botcity.dev | still up |
| 2022-01-01 | YCLanceDB Open-source, serverless vectordb for production-scale generative AI · lancedb.com | still up |
| 2021-01-01 | YCauthzed Authorization Infrastructure securing AI at OpenAI, Zoom, & more · authzed.com | still up |
| 2025-01-01 | YCMastra The Javascript framework for building AI agents, from the Gatsby devs · mastra.ai | still up |
| 2021-01-01 | YCOpenCode The open source AI coding agent · opencode.ai | still up |
| 2025-06-01 | YCKERNEL Crazy fast, open source infra for AI agents to use the Internet · kernel.sh | still up |
| 2024-01-01 | YCOnyx Open Source AI Chat · onyx.app | acquired |
| 2023-01-01 | YCLangfuse Open source LLM engineering platform · langfuse.com | acquired |
| 2023-06-01 | YCTiptap The open-source document editor for humans and AI agents. · tiptap.dev | still up |
| 2018-06-01 | Database for AI · activeloop.ai | still up |
| 2021-01-01 | YCChatwoot The modern, open source, self-hosted AI customer support platform · chatwoot.com | still up |
| 2023-06-01 | YCSkyvern Open Source AI Agent to automate browser workflows via an API · skyvern.com | still up |
| 2022-06-01 | YCLamin Open data platform for traceable, multimodal AI · lamin.ai | still up |
| 2023-01-01 | YCLiteLLM Call every LLM API like it's OpenAI [100+ LLMs] · litellm.ai | still up |
| 2022-06-01 | Open-source, AI-first and no-code business automation tool · activepieces.com | still up |
| 2021-06-01 | Plan and review AI generated code · vibekanban.com | still up |
| 2024-06-01 | YCMem0 The Memory layer for AI Agents · mem0.ai | still up |
| 2023-01-01 | Build and deploy fully‑managed AI agents and workflows · trigger.dev | still up |
| 2023-01-01 | Know what your LLM is doing — and why it’s failing · traceloop.com | acquired |
| 2025-06-01 | Tiny Edge AI For Tiny Devices · cactuscompute.com | still up |
| 2024-06-01 | Open-Source Reinforcement Learning (RL) & Fine-tuning for LLMs. · unsloth.ai | still up |
| 2025-01-01 | The LLM Eval and Observability Platform for AI Quality · confident-ai.com | still up |
| 2024-06-01 | Workspace for your AI Agents, Build any Workflow. · dench.com | still up |
| 2023-01-01 | YCUnify AI teammates for everyone else 🤖 · unify.ai | still up |
| 2023-01-01 | YCHelicone LLM Observability for Developers · helicone.ai | acquired |
| 2021-06-01 | The complete production quality platform. AI-powered E2E testing,… · artillery.io | still up |
| 2023-06-01 | Open source GenAI development platform · flowiseai.com | acquired |
| 2022-01-01 | YCBeam AI-Native Cloud Platform · beam.cloud | still up |
| 2025-09-01 | Simulate your customers with AI agents · expectedparrot.com | still up |
| 2022-01-01 | We make Orca, MIT open source terminal-based agent orchestrator · onorca.dev | still up |
| 2022-06-01 | Building the definitive all-in-one on-device AI productivity tool · anythingllm.com | still up |
| 2024-01-01 | YCTusk AI agent that generates unit and integration tests · usetusk.ai | acquired |
| 2021-06-01 | YCBytebot Bytebot is the open source container for AI desktop agents. · bytebot.ai | acquired |
| 2025-06-01 | Open source self-improving layer for AI agents · traceroot.ai | still up |
| 2023-01-01 | YCVocode Open source Voice AI · vocode.dev | acquired |
| 2024-06-01 | Open-source AI coworker with memory · rowboatlabs.com | still up |
| 2025-01-01 | Open Source React.js Library for AI Chat · assistant-ui.com | still up |
| 2024-01-01 | YCLantern Postgres vector database extension to build AI applications · lantern.dev | gone |
| 2024-06-01 | YCcmux Open source applied AI lab building next-gen devtools · cmux.com | still up |
| 2025-06-01 | YCPangolin Open networking and security for your workforce, AI agents, and infra · pangolin.net | still up |
| 2025-09-01 | Helping humans and AI agents understand massive codebases · sourcebot.dev | still up |
| 2023-01-01 | Open source tools & services for reliable AI Agents & AI Applications · dagworks.io | acquired |
| 2024-01-01 | The fastest developer experience for building on open source AI. · openfoundry.ai | still up |
| 2024-01-01 | Security for AI-native developers · superagent.sh | still up |
| 2024-01-01 | YCAedilic Open-Source AI-generated image/deepfake detection · nonescape.com | gone |
| 2024-01-01 | AI tooling · withpretzel.com | still up |
| 2023-06-01 | YCKhoj AI for humans · khoj.dev | still up |
| 2023-06-01 | YCHegel AI Open source tools for developing generative AI applications · hegel-ai.com | still up |
| 2024-06-01 | Open source AI copilot that knows your company's code and its context · storia.ai | still up |
| 2021-06-01 | Open-source monitoring for machine learning models · evidentlyai.com | still up |
| 2026-06-01 | Open source AI gateway that turns your traffic into a better model · experientiallabs.ai | still up |
| 2025-06-01 | YCChar The AI notepad that knows and works for you · char.com | still up |
| 2026-06-01 | Self-optimizing neocloud that cuts LLM costs by 100x · understudylabs.com | still up |
| 2024-06-01 | YCOpslane Verify AI-generated code before you ship it · opslane.com | still up |
| 2026-06-01 | YCTracer Combining open-source AI models for better answers at lower cost · tracerml.ai | still up |
| 2024-01-01 | YCTracecat The open source AI-native security automation platform · tracecat.com | still up |
| 2026-06-01 | YCOneCLI The open source AI teammates for your company. · onecli.sh | still up |
How this compares
The register re-probes every domain it holds. Some that answered last month stop answering. We send that list — what went quiet, and what it was — once a month. Nothing else.
How this was made. Show HN entries are every post from 2021 to 2023 with at least five points that linked to its own domain; code hosts and free hosting are excluded, because a repository outlives the effort behind it. Product Hunt entries needed 100 votes — a far higher bar, so they are the promoted top slice rather than a like-for-like sample. Both are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it shut down. An HTTP error is not counted as gone — a server answering 404 is one somebody still pays for, and an audit of 25 gone-calls found two such sites alive with only a moved homepage. Y Combinator entries use the status YC publishes itself, which is why only those can say acquired. Squatted domains — a lapsed name now serving somebody else's site — are not detected, so these figures run slightly low.