Universal Hydrogen
Universal Hydrogen Co. was a Hawthorne, California hydrogen-aviation startup founded in 2020 by former Airbus CTO Paul Eremenko to decarbonize regional air travel. Rather than building a hydrogen pipeline network, it proposed a modular capsule model: lightweight hydrogen capsules loaded into aircraft with existing cargo handling equipment, paired with fuel-cell powertrain conversion kits for regional turboprops such as the ATR 72 and De Havilland Dash 8. In March 2023 it flew a converted Dash 8-300 testbed with one propeller driven by a hydrogen fuel cell. The company raised roughly $100 million from backers including GE Aviation, American Airlines, JetBlue Ventures, Airbus Ventures, Toyota Ventures and Mitsubishi. Unable to raise further equity or debt or to find a buyer, it ceased operations on 27 June 2024 and liquidated. It was a hardware and fuel-logistics business and never shipped a public API, SDK, developer portal or machine-readable specification; its domains no longer serve a site.
Index entry only — little beyond a description and a link, and nothing machine-readable enough for an agent to act on without a human reading the site first.
Universal Hydrogen is tracked in the API Evangelist network. This page is the human-readable profile that sits on top of the machine-readable index we maintain at apis.io.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Universal Hydrogen scores 2.4/100 (minimal), with a separate agent-readiness read of 0/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Why this profile is thin
Universal Hydrogen Co. ran out of cash and shut down on 27 June 2024, and both of its web hosts are gone: hydrogen.aero and www.hydrogen.aero answer a bare HTTP 404 "Unknown site" page on the root and on every /.well-known/ and specification path despite the A record still resolving, while universalhydrogen.com has been re-pointed to a Sedo parking lander whose wildcard catch-all returns the same parking HTML with a 200 on /llms.txt and /api-docs and CHEQ bot-filter 440/441 codes elsewhere. Its real GitHub organization is still live but holds zero public repositories, api./docs./developers.hydrogen.aero do not resolve, and the Wayback archive of the domain contains no developer or specification path — the company was a hydrogen fuel-capsule and powertrain hardware business that never published an API.
This is an honest zero, not a gap in our research. Universal Hydrogen does not appear to expose an API, so there is nothing here for us to index and nothing for them to fix.
What we probed
https://hydrogen.aero/→ HTTP 404https://www.hydrogen.aero/→ HTTP 404https://hydrogen.aero/openapi.json→ HTTP 404https://hydrogen.aero/llms.txt→ HTTP 404https://hydrogen.aero/.well-known/agent-card.json→ HTTP 404https://hydrogen.aero/.well-known/agent.json→ HTTP 404https://hydrogen.aero/.well-known/security.txt→ HTTP 404https://universalhydrogen.com/→ HTTP 200https://universalhydrogen.com/openapi.json→ HTTP 441https://api.github.com/orgs/universal-hydrogen→ HTTP 200https://registry.npmjs.org/universal-hydrogen→ HTTP 404
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-02 · rubric v0.18.0
Put this on your own site. The badge is drawn live from Universal Hydrogen's current Kin Score — paste it once and it updates itself every time the score is recomputed. It follows your visitor's light or dark setting, and it links back here so anyone who sees it can read the full breakdown.
<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/universal-hydrogen/"
title="Universal Hydrogen on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/universal-hydrogen.svg"
alt="Universal Hydrogen Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/universal-hydrogen/)<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/universal-hydrogen/"
title="Universal Hydrogen on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/universal-hydrogen/card.svg"
alt="Universal Hydrogen Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
Resources
Every other property we hold for Universal Hydrogen — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Build 1
SDKs, sample code, and the tooling you integrate with
Universal Hydrogen is in the network as a tracked entity. We haven't yet indexed a public API surface for it — when one is published, the artifacts, score, and agent-readiness read will appear here automatically. The source repository is where that profile is built.
← All providers · Data indexed from github.com/api-evangelist/universal-hydrogen · machine-readable index on apis.io
This is an independent, third-party profile of Universal Hydrogen, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.