A new anonymous model called Ox Alpha appeared on OpenRouter on August 20, 2026, listed under the platform’s “Stealth” provider at $0 per token with a 1,048,576-token context window. No developer is named, no benchmarks were published, and OpenRouter — which routes the model but did not build it — has said nothing about its origin. The free preview is expected to end around August 27, 2026.
What the listing says
The OpenRouter entry for stealth/ox-alpha describes a reasoning model built for coding, sustained agentic work, and production workloads. The verifiable specifications are:
- Context window: 1,048,576 tokens
- Maximum output: 131,072 tokens
- Input: text, image and video (audio is rejected); output: text
- Tool/function calling and structured JSON output supported
- Price: $0 input, $0 output during the preview
- No open weights; no official benchmarks
We re-verified the listing, context length and pricing against OpenRouter’s public model list on August 22, 2026 and will keep doing so automatically twice a day — the live tracker shows the current state.
Why it matters
Two things stand out. The first is the context window: a million tokens is enough to hold a large codebase or several books in one request, which puts Ox Alpha at the upper end of what any model family currently offers. The second is the price. Stealth previews are free because the lab behind them wants real-world traffic before launch; for a week or so, that makes a frontier-scale model available to anyone with a free OpenRouter account. Our guide explains how to use Ox Alpha for free, and you can chat with it in your browser using your own key.
Who built it? Nobody knows — officially
Independent testers have been running fingerprinting checks since the listing appeared. Several analyses shared by those testers report a strong match to the GLM family, with the testers themselves quoting confidence figures of roughly 90–99%. A minority view points to Xiaomi’s MiMo line instead. None of this is confirmed, no lab has commented, and we treat it as attributed speculation until there is an announcement. The evidence on both sides is laid out in Who made Ox Alpha?
Early results
There are no official benchmarks. The one concrete third-party number so far is a reported pass rate of roughly 80% on a 10-task subset of the DeepSWE coding benchmark, shared by developer Ben Davis — a small sample that has not been reproduced. Community reports on Hacker News are mixed. We keep a running, caveated summary on the benchmarks page.
What to expect next
OpenRouter has run stealth previews before, and each one ended the same way: the model was revealed under its official name and, typically, re-listed with normal pricing. The reveal history lists all six earlier codenames and their identities. For Ox Alpha, the things to watch are the free window (expected to close around August 27), any change to the listing’s pricing or name, and an announcement from the developer. We will update the tracker and the chat banner the same day any of those happens.
Data terms reminder: prompts sent to Ox Alpha may be retained by the anonymous provider under OpenRouter’s Stealth Program terms (the listing states they are not used for training). Don’t send anything personal or confidential.