You asked about AR
66 people built something like it. 11 are gone.
That is 18% of the ones whose fate we could settle, against 23% across the whole register. 6 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2017-06-01 | YCTruepill API-connected healthcare infrastructure. · truepill.com | acquired |
| 2014-01-01 | YCAlgolia A developer-friendly and enterprise-grade search API. · algolia.com | still up |
| 2022-01-10 | databar.ai | still up |
| 2021-09-22 | motion.dev | still up |
| 2022-05-19 | apitracker.io | still up |
| 2022-05-27 | ramper.xyz | still up |
| 2022-02-02 | climatiq.io | still up |
| 2022-06-16 | console.connect.earth | still up |
| 2022-03-13 | filedoge.com | unverified |
| 2022-01-10 | speechly.com | moved |
| 2022-02-09 | nyckel.com | still up |
| 2022-03-25 | flagright.com | still up |
| 2022-05-17 | rarify.tech | unverified |
| 2017-06-01 | Health enterprise API for data on doctors, insurance, costs, & quality · ribbonhealth.com | acquired |
| 2022-01-01 | Identity Verification API for Emerging Markets · prembly.com | still up |
| 2021-06-01 | auxl.io | still up |
| 2021-01-01 | YCMindee AI Document Understanding API · mindee.com | still up |
| 2022-07-15 | eesel.app | still up |
| 2023-09-25 | crystaldoc.info | still up |
| 2023-03-08 | searq.org | gone |
| 2014-06-01 | API platform for partners to issue branded debit and credit cards to… · aptopayments.com | acquired |
| 2023-03-01 | summarize.tech | unverified |
| 2022-09-12 | libninja.com | still up |
| 2021-09-20 | oikolab.com | still up |
| 2021-05-23 | glitterly.app | unverified |
| 2022-06-01 | YCKombo Unified API for HR, payroll and recruiting software · kombo.dev | still up |
| 2022-06-01 | YCMedplum API first electronic health record (EHR) that is open source · medplum.com | still up |
| 2020-01-01 | YCJunction API for at-home health data · junction.com | still up |
| 2022-02-09 | goperigon.com | moved |
| 2026-10-01 | helohq.com | unverified |
| 2021-10-20 | swell.is | still up |
| 2023-02-07 | oneapikey.com | gone |
| 2022-06-01 | YCInvofox Invofox is the document parsing and data extraction API for software… · invofox.com | still up |
| 2026-08-25 | keenable.ai | still up |
| 2020-06-01 | API for healthcare compliance · verifiable.com | still up |
| 2023-05-31 | brave.com | still up |
| 2023-08-30 | pyas.io | still up |
| 2022-07-01 | taddy.org | still up |
| 2021-01-01 | YCMystic Low latency API to run and deploy ML models · mystic.ai | gone |
| 2023-10-12 | markdowndb.com | still up |
| 2023-01-01 | YCScanbase The API for Diagnostic Test Analysis (COVID-19, FLU, RSV, STD,… · scanbase.com | still up |
| 2022-07-28 | sabil.io | still up |
| 2024-01-01 | YCTrieve All-in-one API for search, RAG, & recommendations · trieve.ai | acquired |
| 2022-03-16 | plaraphy.com | gone |
| 2024-06-01 | YCVideoGen Create professional videos in minutes with AI, online or via API · videogen.io | still up |
| 2023-09-13 | docs.switchboard.audio | still up |
| 2026-06-01 | Human as API for robots · aktoria.com | still up |
| 2022-01-23 | databar.ai | still up |
| 2023-11-14 | alignapi.com | still up |
| 2021-09-14 | mixpeek.com | still up |
| 2026-10-08 | uselayer.sh | unverified |
| 2021-01-25 | newscatcherapi.com | still up |
| 2023-08-08 | litellm.ai | still up |
| 2023-05-04 | llm.report | unverified |
| 2020-01-01 | YCQuill Fullstack API and management platform for dashboards and reporting · quill.co | still up |
| 2022-10-05 | mesh.martify.io | still up |
| 2026-08-19 | marginalhq.com | still up |
| 2025-09-01 | YCParse Build an API to interact with any website. · parse.bot | still up |
| 2019-06-01 | Turn any website into an API · dashblock.com | gone |
| 2022-01-01 | API for shared embeddable web browsers · hyperbeam.com | still up |
How this compares
Y Combinator reports its own outcomes, including acquisitions. The other two are judged by asking the domain, so they are not measured the same way and are never averaged together.
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.