You asked about B2B
73 people built something like it. 18 are gone.
That is 31% 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 |
| 2021-01-01 | YCMindee AI Document Understanding API · mindee.com | still up |
| 2020-06-01 | YCDecentro API Platform for Banking Integrations (Plaid for India and APAC) · decentro.tech | 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 | YCAtomic API that lets companies embed investment accounts into their services · atomicvest.com | still up |
| 2020-06-01 | YCSeam API for IoT Devices · seam.co | 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 |
| 2022-06-01 | YCInvofox Invofox is the document parsing and data extraction API for software… · invofox.com | still up |
| 2021-01-01 | YCMystic Low latency API to run and deploy ML models · mystic.ai | gone |
| 2010-01-01 | YCZencoder Video Encoding API,
Open source video player (video.js) · zencoder.com | acquired |
| 2016-01-01 | YCElucify Elucify is an API that plugs into your CRM which automatically cleans… · getelucify.com | gone |
| 2014-01-01 | YCRickshaw Same day local delivery, via API. Currently operating in SF. · gorickshaw.com | acquired |
| 2014-01-01 | YCWit.ai Natural Language for Developers --Wit is an API that makes it easy… · wit.ai | acquired |
| 2022-01-01 | YCSpeechly Natural Language Understanding API for Speech that runs on device · speechly.com | acquired |
| 2023-01-01 | YCLiteLLM Call every LLM API like it's OpenAI [100+ LLMs] · litellm.ai | still up |
| 2023-06-01 | YCSkyvern Open Source AI Agent to automate browser workflows via an API · skyvern.com | still up |
| 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 |
| 2024-01-01 | YCTrieve All-in-one API for search, RAG, & recommendations · trieve.ai | acquired |
| 2019-01-01 | YCFuse Unified API for financial data aggregators. · letsfuse.com | gone |
| 2023-01-01 | Usage Metering, AI & API Monetization · openmeter.io | acquired |
| 2024-06-01 | 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 |
| 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 |
| 2020-01-01 | YCEnveloop Design and send messages from your app with a simple API. · enveloop.com | gone |
| 2026-08-17 | orbitquote.com | still up |
| 2020-01-01 | YCQuill Fullstack API and management platform for dashboards and reporting · quill.co | still up |
| 2018-01-01 | Point stores things you send over and over again and helps you re-use… · pointapi.com | gone |
| 2025-09-01 | YCParse Build an API to interact with any website. · parse.bot | still up |
| 2022-06-01 | API for Retrieval Augmented Generation · superpowered.ai | 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 |
| 2019-06-01 | Turn any website into an API · dashblock.com | gone |
| 2024-01-01 | API For PDF Document Workflows · fileforge.com | gone |
| 2023-06-01 | The API for LLM tool use · opentools.com | still up |
| 2022-01-01 | API for shared embeddable web browsers · hyperbeam.com | still up |
| 2023-01-01 | YCSuperAPI Programmable API gateway that makes APIs cacheable · trysuperapi.com | still up |
| 2022-01-01 | Open-source API & UI test automation · karatelabs.io | still up |
| 2019-01-01 | YCBasilica Basilica is an API that embeds high-dimensional data like images and… · basilica.ai | gone |
| 2022-06-01 | YCTypeLess AI messaging API for smarter, faster communication. · apps.apple.com | still up |
| 2024-06-01 | YCPinnacle API & SDK for RCS (the next-generation of texting) · pinnacle.sh | still up |
| 2023-01-01 | YCCakework API that adds cloud hosting to any developer platform · cakework.com | gone |
| 2025-09-01 | YCThe Hog Real-time web intelligence API for AI agents and GTM teams · thehog.ai | still up |
| 2025-01-01 | YCReJot We turn complex API integrations into drop‑in full‑stack libraries · rejot.dev | still up |
| 2019-06-01 | YCBouncer SDK for scanning and verifying credit cards and photo IDs in mobile… · getbouncer.com | acquired |
| 2026-06-01 | YCArchal API sandboxes, built for AI agents · archal.ai | still up |
| 2018-01-01 | YCNewCraft Universal API for HR & Payroll · newcraft.io | acquired |
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.