OpenRouter lists a free 1M-context model that keeps your prompts

OpenRouter added stealth/ox-alpha on August 20. It's free, it carries a 1 million token context window, and it's built for reasoning work: coding, sustained agent tasks, and mixed text-and-visual output. It picked up 249 points on Hacker News, which tells you builders noticed the pricing and the context size together.

The catch is who's behind it. OpenRouter says plainly that it isn't the developer of Ox Alpha, and that a single anonymous third-party provider runs the model. Prompts and completions get retained by that provider. OpenRouter's listing says the data isn't used for training, but retention alone rules out anything you can't afford to have sitting on someone else's servers indefinitely.

That combination, free and 1M context, is rare enough to be worth testing. A context window that size handles a full codebase or a long agent trace without chunking, and paying nothing to run it against synthetic benchmarks costs you nothing but time. Anonymous authorship on an inference provider isn't new on OpenRouter's stealth listings, but the retention disclosure here is more direct than most.

What it doesn't do is say who the provider is, how long retention lasts, or what happens to the listing if the free tier disappears. Stealth models come and go on OpenRouter, and there's no guarantee this one stays free or stays up. Run it on throwaway prompts, benchmark the 1M context claim against your own workloads, and keep anything with a client name or real credentials off it until someone puts a name on the provider.