You asked about API
30 people built something like it. 4 are gone.
That is 15% of the ones whose fate we could settle, against 23% across the whole register. 3 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2021-01-01 | YCGigs The OS for Embedded Telecom · gigs.com | still up |
| 2021-01-01 | Tools & infra to build and scale high-quality blockchain applications. · quicknode.com | still up |
| 2021-06-01 | YCExa Web search rebuilt for LLMs · exa.ai | 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 |
| 2021-01-01 | YCEnode Energy Orchestration Platform · enode.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 |
| 2021-06-01 | YCMalga Malga is an API to accept payments with multiple payment providers · malga.io | still up |
| 2021-01-01 | YCHapi Stocks and cryptos trading app with zero commissions and no minimums… · hapi.trade | still up |
| 2021-01-01 | YCDyte Real-time audio & video SDKs, ready to launch 🚀 · dyte.io | acquired |
| 2021-06-01 | YCCoast Demo Platform for API-First Companies · trycoast.com | still up |
| 2021-01-01 | YCFinley Streamline your debt capital raise and management · finleycms.com | acquired |
| 2021-06-01 | YCPluggy Plaid for Brazil: we allow developers to access users' financial data · pluggy.ai | still up |
| 2021-01-01 | API for developers and AIs to access health data · tryterra.co | still up |
| 2021-06-01 | The Work Number for LatAm · burodeingresos.com | still up |
| 2021-01-01 | YCTerapify Online therapy platform for the Spanish-speaking market · terapify.com | still up |
| 2021-01-01 | YCSvix Enterprise ready webhooks service, open-source and in the cloud · svix.com | still up |
| 2021-01-01 | YCMystic Low latency API to run and deploy ML models · mystic.ai | still up |
| 2021-01-01 | YCHUBUC Global Card Issuing and Payment Processing Engine · hubuc.com | still up |
| 2021-06-01 | YCDots 💸 Developer friendly drop in payouts infrastructure · usedots.com | still up |
| 2021-01-01 | YCFlowEQ No-code workflow tool · floweq.com | still up |
| 2021-06-01 | Using protein coupling to build new therapies · catenabiosciences.com | still up |
| 2021-01-01 | YCNoya Radically reducing capital costs and build time for direct air capture · noya.co | gone |
| 2021-01-01 | World's fastest and most optimal route optimization engine · logisticsos.com | still up |
| 2021-06-01 | YCCumbuca Bare-metal access to Brazil's Open Finance and Pix systems · cumbuca.com | still up |
| 2021-01-01 | YCPensil New-Age White Label Community Platform SDKs and APIs for Games,… · pensil.in | gone |
| 2021-06-01 | YCWarrant Authorization and access control as a service. · warrant.dev | acquired |
| 2021-06-01 | Zapier for billing · hyperseed.com | gone |
| 2021-01-01 | YCWaypoint The email API built for product teams · usewaypoint.com | still up |
| 2021-06-01 | YCCanopi API to measure and eliminate carbon emissions · canopi.cash | gone |
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.