You asked about B2B
74 people built something like it. 17 are gone.
That is 28% of the ones whose fate we could settle, against 23% across the whole register. 14 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2014-01-01 | YCAlgolia A developer-friendly and enterprise-grade search API. · algolia.com | still up |
| 2022-01-01 | Identity Verification API for Emerging Markets · prembly.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 |
| 2017-01-01 | Document AI. One API Call. · veryfi.com | still up |
| 2020-06-01 | YCDecentro API Platform for Banking Integrations (Plaid for India and APAC) · decentro.tech | still up |
| 2021-01-01 | YCMindee AI Document Understanding API · mindee.com | still up |
| 2011-01-01 | YCMailgun Email API service. · mailgun.net | acquired |
| 2019-06-01 | Financial connectivity API for consumer liabilities · methodfi.com | still up |
| 2021-06-01 | YCMalga Malga is an API to accept payments with multiple payment providers · malga.io | still up |
| 2021-06-01 | YCCoast Demo Platform for API-First Companies · trycoast.com | still up |
| 2020-01-01 | The API to get recordings, transcripts, and metadata from meetings · recall.ai | still up |
| 2023-01-01 | YCFern Instantly offer SDKs and API Docs · buildwithfern.com | acquired |
| 2022-01-01 | YCTheneo Stripe-like API Docs in just a few clicks · theneo.io | still up |
| 2021-01-01 | API for developers and AIs to access health data · tryterra.co | still up |
| 2020-06-01 | YCSeam API for IoT Devices · seam.co | still up |
| 2020-06-01 | YCAtomic API that lets companies embed investment accounts into their services · atomicvest.com | still up |
| 2019-06-01 | YCRutter The Unified API for Business Financial Data · rutter.com | still up |
| 2022-06-01 | YCKombo Unified API for HR, payroll and recruiting software · kombo.dev | still up |
| 2022-01-01 | YCVelt SDK for adding an agent and human governance layer to your product · velt.dev | still up |
| 2024-09-01 | The legal back-office for European founders - the incorporation API… · beglaubigt.de | still up |
| 2022-06-01 | YCInvofox Invofox is the document parsing and data extraction API for software… · invofox.com | still up |
| 2016-01-01 | YCElucify Elucify is an API that plugs into your CRM which automatically cleans… · getelucify.com | gone |
| 2014-01-01 | YCWit.ai Natural Language for Developers --Wit is an API that makes it easy… · wit.ai | acquired |
| 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 |
| 2014-01-01 | YCRickshaw Same day local delivery, via API. Currently operating in SF. · gorickshaw.com | acquired |
| 2023-06-01 | YCSkyvern Open Source AI Agent to automate browser workflows via an API · skyvern.com | still up |
| 2023-01-01 | YCLiteLLM Call every LLM API like it's OpenAI [100+ LLMs] · litellm.ai | still up |
| 2022-01-01 | YCSpeechly Natural Language Understanding API for Speech that runs on device · speechly.com | acquired |
| 2020-01-01 | YCWeav Weav is the universal API for commerce platforms · weav.co | acquired |
| 2022-06-01 | The Unified API for Business Financial Data · integrationlabs.co | gone |
| 2019-01-01 | YCFuse Unified API for financial data aggregators. · letsfuse.com | gone |
| 2023-01-01 | Usage Metering, AI & API Monetization · openmeter.io | acquired |
| 2024-01-01 | YCTrieve All-in-one API for search, RAG, & recommendations · trieve.ai | acquired |
| 2024-06-01 | YCVideoGen Create professional videos in minutes with AI, online or via API · videogen.io | still up |
| 2023-01-01 | YCNango A single API for all your integrations · nango.dev | still up |
| 2020-01-01 | YCEnveloop Design and send messages from your app with a simple API. · enveloop.com | gone |
| 2020-01-01 | YCQuill Fullstack API and management platform for dashboards and reporting · quill.co | still up |
| 2025-09-01 | YCs2.dev API for unlimited, durable, real-time streams · s2.dev | still up |
| 2026-06-01 | YCLuca IQ API-first tax engine for CPA firms and developers · lucaiq.com | still up |
| 2018-01-01 | Point stores things you send over and over again and helps you re-use… · pointapi.com | gone |
| 2023-01-01 | YCTrigo Rent verification API for landlords and lenders · trigodata.com | acquired |
| 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 |
| 2025-09-01 | YCParse Build an API to interact with any website. · parse.bot | still up |
| 2022-06-01 | The API to search, scrape, and interact with the web at scale. 🔥 · firecrawl.dev | still up |
| 2023-06-01 | The API for LLM tool use · opentools.com | still up |
| 2024-01-01 | API For PDF Document Workflows · fileforge.com | gone |
| 2022-01-01 | API for shared embeddable web browsers · hyperbeam.com | still up |
| 2019-06-01 | Turn any website into an API · dashblock.com | gone |
| 2024-06-01 | YCPinnacle API & SDK for RCS (the next-generation of texting) · pinnacle.sh | still up |
| 2018-06-01 | YCOneGraph GraphQL API to connect all of the internet's APIs. Join us at Netlify! · onegraph.com | acquired |
| 2019-01-01 | YCBasilica Basilica is an API that embeds high-dimensional data like images and… · basilica.ai | gone |
| 2025-09-01 | YCDome A unified API for prediction markets, like Kalshi and Polymarket · domeapi.io | gone |
| 2025-01-01 | YCReJot We turn complex API integrations into drop‑in full‑stack libraries · rejot.dev | still up |
| 2016-06-01 | API for Invoice Financing · joinfellow.com | gone |
| 2023-01-01 | YCSuperAPI Programmable API gateway that makes APIs cacheable · trysuperapi.com | still up |
| 2019-06-01 | YCBouncer SDK for scanning and verifying credit cards and photo IDs in mobile… · getbouncer.com | acquired |
| 2018-01-01 | YCNewCraft Universal API for HR & Payroll · newcraft.io | acquired |
| 2017-01-01 | The Universal API · scaphold.io | acquired |
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.