You asked about API
49 people built something like it. 1 is gone.
That is 2% of the ones whose fate we could settle, against 23% across the whole register. 3 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2016-01-01 | YCDeepgram Building foundational AI for speech transcription and understanding. · deepgram.com | still up |
| 2020-06-01 | Power commerce photography with generative AI · photoroom.com | still up |
| 2017-01-01 | Document AI. One API Call. · veryfi.com | still up |
| 2021-06-01 | YCAnakin One API to get clean data from any website for your AI agents at scale · anakin.io | still up |
| 2017-06-01 | The best way to build Voice AI apps · assemblyai.com | still up |
| 2021-01-01 | YCMindee AI Document Understanding API · mindee.com | still up |
| 2021-01-01 | YCVapi Voice AI for developers. · vapi.ai | still up |
| 2022-01-01 | Unleashing the potential of DNA and RNA based therapies using AI · whitelabgx.com | still up |
| 2019-01-01 | YCOverview Reshaping industrial quality with AI, hardware, and software · overview.ai | still up |
| 2023-01-01 | YCPlayAI Our mission is to make Voice AI accessible and useful to all. · play.ai | acquired |
| 2020-01-01 | The API to get recordings, transcripts, and metadata from meetings · recall.ai | still up |
| 2020-01-01 | YCHandoff AI estimator & agent for remodelers. · handoff.ai | still up |
| 2023-01-01 | YCMetal The AI context platform for private capital. Everything your firm… · metal.ai | still up |
| 2022-06-01 | YCIntuned Code-first scrapers and RPAs — built and maintained by AI · intunedhq.com | still up |
| 2025-01-01 | AI voice and texting agents · leapingai.com | still up |
| 2022-01-01 | Rapid medical data annotation · redbrickai.com | still up |
| 2022-06-01 | YCTypewise Customer service AI that resolves requests end-to-end. · typewise.app | still up |
| 2014-01-01 | YCWit.ai Natural Language for Developers --Wit is an API that makes it easy… · wit.ai | acquired |
| 2024-06-01 | Capitol: the sovereign operating system for intelligence. · capitol.ai | still up |
| 2023-01-01 | YCLiteLLM Call every LLM API like it's OpenAI [100+ LLMs] · litellm.ai | still up |
| 2025-06-01 | Email Inboxes for AI Agents · agentmail.to | still up |
| 2023-06-01 | YCSkyvern Open Source AI Agent to automate browser workflows via an API · skyvern.com | still up |
| 2024-01-01 | YCego AI applied research lab building synthetic sapience; human-like AI · egoai.com | still up |
| 2023-06-01 | AI-powered insurance verification to boost patient conversion. · soharhealth.com | still up |
| 2023-06-01 | YCFiber AI The freshest data APIs for AI sales, recruiting, & growth products · fiber.ai | still up |
| 2023-01-01 | Usage Metering, AI & API Monetization · openmeter.io | acquired |
| 2024-06-01 | YCVideoGen Create professional videos in minutes with AI, online or via API · videogen.io | still up |
| 2019-01-01 | YCCosmic Cosmic is an AI-powered headless CMS · cosmicjs.com | still up |
| 2025-06-01 | YCTesora Frontier AI for Actuaries · tesora.ai | still up |
| 2025-09-01 | YCLapis AI that creates and runs ads, end-end · trylapis.com | still up |
| 2022-06-01 | YCCapix AI-powered private equity intelligence. · capix.ai | still up |
| 2026-06-01 | YCSpeko OpenRouter for Voice AI: one API, every call on the best speech model · speko.ai | still up |
| 2022-06-01 | API for Retrieval Augmented Generation · superpowered.ai | gone |
| 2023-06-01 | The API for LLM tool use · opentools.com | still up |
| 2024-01-01 | YCPrecip High precision AI weather models · precip.ai | still up |
| 2022-06-01 | YCTypeLess AI messaging API for smarter, faster communication. · apps.apple.com | still up |
| 2023-01-01 | YCMercoa AI Agent for Billpay platforms to pay invoices with virtual cards · mercoa.com | still up |
| 2022-01-01 | YCAndi AI Search for the Next Generation · andiai.com | still up |
| 2023-06-01 | YCMinded Cursor for AI Agents · minded.com | still up |
| 2024-01-01 | AI media creation platform for creators and developers · magichour.ai | still up |
| 2025-01-01 | AI documentation engineer – test & autoimprove stale product docs · quantstruct.com | still up |
| 2026-01-01 | YCCaptain Self-tuning file search for AI agents · captain.dev | still up |
| 2025-09-01 | YCThe Hog Real-time web intelligence API for AI agents and GTM teams · thehog.ai | still up |
| 2025-09-01 | API for parsing multimodal unstructured data · unsiloed.ai | still up |
| 2024-06-01 | Turn any website into an API. · expand.ai | still up |
| 2026-06-01 | YCArchal API sandboxes, built for AI agents · archal.ai | still up |
| 2026-06-01 | We give AI agents realtime web context via API · context.dev | still up |
| 2019-06-01 | AI platform accelerating therapies for rare & inflammatory diseases. · gen1e.com | still up |
| 2026-06-01 | AI-native back-office for banks and fintechs · rapidfolio.com | 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.