You asked about Infrastructure
20 people built something like it. 2 are gone.
That is 13% of the ones whose fate we could settle, against 23% across the whole register. 4 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2017-06-01 | YCTruepill API-connected healthcare infrastructure. · truepill.com | acquired |
| 2019-01-01 | YCAlpaca API-first stock and crypto brokerage platform · alpaca.markets | still up |
| 2022-01-01 | Identity Verification API for Emerging Markets · prembly.com | still up |
| 2020-01-01 | The API to get recordings, transcripts, and metadata from meetings · recall.ai | still up |
| 2010-01-01 | YCZencoder Video Encoding API,
Open source video player (video.js) · zencoder.com | acquired |
| 2021-01-01 | YCMystic Low latency API to run and deploy ML models · mystic.ai | still up |
| 2023-06-01 | YCSkyvern Open Source AI Agent to automate browser workflows via an API · skyvern.com | still up |
| 2024-01-01 | YCTrieve All-in-one API for search, RAG, & recommendations · trieve.ai | acquired |
| 2023-01-01 | Usage Metering, AI & API Monetization · openmeter.io | acquired |
| 2026-06-01 | YCLuca IQ API-first tax engine for CPA firms and developers · lucaiq.com | still up |
| 2025-09-01 | YCs2.dev API for unlimited, durable, real-time streams · s2.dev | still up |
| 2026-06-01 | YCSpeko OpenRouter for Voice AI: one API, every call on the best speech model · speko.ai | still up |
| 2025-01-01 | YCReJot We turn complex API integrations into drop‑in full‑stack libraries · rejot.dev | still up |
| 2026-06-01 | YCArchal API sandboxes, built for AI agents · archal.ai | still up |
| 2023-01-01 | YCCakework API that adds cloud hosting to any developer platform · cakework.com | gone |
| 2025-09-01 | YCDome A unified API for prediction markets, like Kalshi and Polymarket · domeapi.io | gone |
| 2023-01-01 | YCSuperAPI Programmable API gateway that makes APIs cacheable · trysuperapi.com | 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 | We give AI agents realtime web context via API · context.dev | 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.