You asked about API
33 people built something like it. 33 are gone.
That is 100% of the ones whose fate we could settle, against 23% across the whole register.
| Launched | What it was | Today |
|---|---|---|
| 2018-01-01 | Engineering next-generation, brain-penetrant cancer therapies. · reverielabs.com | gone |
| 2019-01-01 | Precision-first therapies · endpointhealth.com | gone |
| 2022-01-01 | YCWingback Wingback provides tools and APIs for SaaS pricing and packaging. · wingback.com | gone |
| 2016-01-01 | YCElucify Elucify is an API that plugs into your CRM which automatically cleans… · getelucify.com | gone |
| 2022-06-01 | The Unified API for Business Financial Data · integrationlabs.co | gone |
| 2021-01-01 | YCNoya Radically reducing capital costs and build time for direct air capture · noya.co | gone |
| 2019-01-01 | YCFuse Unified API for financial data aggregators. · letsfuse.com | gone |
| 2017-06-01 | Rapid, scalable diagnostic for SARS-CoV-2 and beyond · predxionbio.com | gone |
| 2018-06-01 | YCXkit Universal CRM integration for B2B SaaS apps · xkit.co | gone |
| 2020-01-01 | We’re creating programmable therapies · felixbt.com | gone |
| 2022-01-01 | YCPelm Plaid for utilities · pelm.com | gone |
| 2022-01-01 | YCVessel Developer-first, native integration platform for GTM tools · vessel.dev | gone |
| 2024-01-01 | YCTesseral The open source platform for managing identity in business software · tesseral.com | gone |
| 2022-06-01 | Card issuer for Africa · bridgecard.cards | gone |
| 2018-01-01 | Point stores things you send over and over again and helps you re-use… · pointapi.com | gone |
| 2020-01-01 | YCEnveloop Design and send messages from your app with a simple API. · enveloop.com | gone |
| 2022-06-01 | API for Retrieval Augmented Generation · superpowered.ai | gone |
| 2021-01-01 | YCPensil New-Age White Label Community Platform SDKs and APIs for Games,… · pensil.in | gone |
| 2024-01-01 | API For PDF Document Workflows · fileforge.com | gone |
| 2021-06-01 | Zapier for billing · hyperseed.com | gone |
| 2022-01-01 | YCValari Embedded finance platform for LatAm. · valari.co | gone |
| 2019-06-01 | Turn any website into an API · dashblock.com | gone |
| 2016-06-01 | API for Invoice Financing · joinfellow.com | gone |
| 2025-09-01 | YCDome A unified API for prediction markets, like Kalshi and Polymarket · domeapi.io | gone |
| 2023-01-01 | YCMogara Automatic software R&D capitalization · mogara.com | gone |
| 2023-01-01 | YCCakework API that adds cloud hosting to any developer platform · cakework.com | gone |
| 2012-06-01 | API for video. · framebase.io | gone |
| 2019-01-01 | YCBasilica Basilica is an API that embeds high-dimensional data like images and… · basilica.ai | gone |
| 2022-01-01 | YCSendo The best SMS/RCS API for startups · sendo.dev | gone |
| 2020-01-01 | A Global Payouts API for Startups · carbon.money | gone |
| 2021-06-01 | YCCanopi API to measure and eliminate carbon emissions · canopi.cash | gone |
| 2019-06-01 | Api that let you connect all the restaurant tech services in Latam · mipos.dev | gone |
| 2022-01-01 | YCKable Usage-based billing for API companies · kable.io | 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.