OpenRouter route
Gone
stealth/union-alpha was delisted on 2026-09-18; the same model is listed as unbiased/pareto, billed.
Stealth line · Union Alpha · access
Union Alpha on OpenCode
Union Alpha was reported to have two front doors: the OpenRouter listing we could verify directly, and an OpenCode free-tier route that third parties described. Both closed on 2026-09-18, when the model was revealed as Unbiased Pareto. This page keeps the verified route and the reported one apart — and says which of the two we never managed to confirm.
The short version
OpenCode route
Reported, and now moot
Third-party write-ups said the same anonymous model was on OpenCode's free tier. We never confirmed it independently, and the anonymous model no longer exists to serve.
API key needed
Key needed now
Using unbiased/pareto means billing it, which means an OpenRouter key. No key from the maker was ever published.
Was it worth setting up
For two days
The free window lasted 2026-09-16 to 2026-09-18. Anything built to depend on it had to change on day three.
Two front doors, one anonymous release — both shut
OpenRouter was the route we track, and the source of every verified number on our tracker: its catalogue listed stealth/union-alpha under the stealth namespace with a provider tag of “Stealth” from 2026-09-16 until it was delisted on the
18th.
OpenCode is the route we cannot see. The claim is that the free tier of the OpenCode coding tool serves the same anonymous model, which would let you use it inside an agentic workflow without an API key of your own. It is plausible — stealth releases are often seeded through several tools at once to gather usage — but “plausible” is not “verified”, and we are not going to report it as fact.
How the route worked, while it was open
- 1. Install and sign in to OpenCode. The free tier is the part to look for — it is the route that does not ask for your own provider key.
- 2. Look for the anonymous model in the picker. Free stealth releases often appear without a vendor name attached. If you see an unexplained model alongside the named providers, that is the thing to test.
- 3. Run one prompt you already know the answer to. The identity of the model behind an anonymous endpoint is not something it can tell you reliably, so judge it on output, not on what it says about itself.
- 4. Assume it can vanish. Keep the workflow disposable: no credentials in prompts, no customer data, no dependency your product needs tomorrow.
We deliberately do not print a screenshot-accurate click path: the free tier's menu wording changes between OpenCode releases, and a stale step-by-step would be worse than none. These four steps are kept as the record of what a stealth seeding looked like, because the next codename will repeat the pattern.
How to check for yourself
| What you want to know | Where it can be checked |
|---|---|
| Is it still on OpenRouter, and still free? | No. The status endpoint answers “no longer listed”, and the stealth page ↗ still carries the reveal notice. |
| Is the OpenCode free tier still serving it? | Unknown, and no longer worth checking: the anonymous model was delisted from OpenRouter, which is the route both write-ups pointed at. |
| What it costs now | $2.50 in / $7.50 out per million, read from the catalogue. See the free-window page. |
FAQ
Is Union Alpha really available on OpenCode?
It was reported, never verified by us — and it is now moot. OpenCode's free tier was described by third parties as serving the same anonymous model; our own verification was always limited to OpenRouter, where we read the catalogue directly. That catalogue entry was removed on 2026-09-18 when the model was revealed as Unbiased Pareto, so there is no anonymous Union Alpha left to route anywhere.
Do I need an OpenRouter API key to use Union Alpha through OpenCode?
That was the appeal of the OpenCode route: no key of your own. It is gone with the free window. The revealed model, unbiased/pareto, is a normal billed OpenRouter listing, so using it now does need an OpenRouter key.
Was it the same model on both routes?
Reportedly yes: same anonymous release, two front doors. We could never prove it from outside, and the model's own answers about its identity were unreliable — testers reported inconsistent behaviour between sessions, which is one of the reasons people suspected more than one model behind the name.
What should I not use Union Alpha for?
Anything with secrets or other people's data — the advice has not changed now that the vendor has a name. Free stealth previews on this line have ended without warning three times, and the anonymous era of this model lasted two days. Evaluation and side projects, yes; production credentials or customer data, no.
Get notified about the next codename
This reveal is over. One email when the next stealth model is listed, and one when its identity comes out.
Union Alpha tracker → What it costs now How the Alpha line works