A new AI coding model called Ox Alpha showed up on OpenRouter on August 20. No company has said it built the model.
The model is free to use right now. There is no listed price for input or output tokens.
OpenCode, a tool built for coding agents, launched the model on the same day. It said the model could handle up to 100 trillion tokens a day.
OpenRouter told users the free access will run through August 24. OpenCode said its version would stay free for about a week from August 20, which points closer to August 27.
What the Model Can Do
Ox Alpha can read text, images and video. It cannot handle audio requests.
Its context window holds just over one million tokens. Output is capped at 131,072 tokens.
OpenRouter describes the model as built for long software engineering tasks and extended agent work.
Developer Ben Davis tested the model on 10 tasks from the DeepSWE benchmark. It scored above 80 percent, ahead of Claude Fable 5 at 65 percent and GPT-5.6-sol at 52 percent.
Davis warned that 10 tasks was too small a sample to trust. He later ran the full DeepSWE test set.
The larger test put Ox Alpha about even with GPT-5.6-sol, not ahead of it. No public leaderboard has posted a score yet.
Clues to Who Built It
A developer named unclecode built a tool called modelprint. It sends nine technical checks to an API to compare it against known models.
Ox Alpha matched GLM-5.3 on six of the nine checks. That included all four token counting tests.
Unclecode said this only shows shared computer infrastructure. It does not prove the two models are the same.
GLM-5.3 comes from Chinese company Z.ai. The company has released unnamed preview models before, including one called Pony Alpha ahead of the original GLM-5 launch.
Other developers point to Xiaomi's MiMo team instead. That team has also released unbranded test models in the past.
One clue complicates the Z.ai theory. The way Ox Alpha counts tokens matches an OpenAI encoding method called cl100k_base, an odd fit for a Chinese-made model.
The rules around user data differ by source. OpenRouter's page for the model says prompts and answers are kept by the provider but not used for training. Wider terms for anonymous preview models on the site do allow that data to be used for training and evaluation. OpenCode says its unnamed provider keeps no data at all.
This gap matters because the U.S. Commerce Department added Zhipu AI, Z.ai's former name, to its Entity List in January 2025. The listing cited the company's role in China's military technology development.
Use of Ox Alpha has kept growing despite the mystery. Bloomberg reported Sunday that coding tools, including Claude Code, sent billions of tokens through the model since last Thursday.
OpenRouter says it does not build, own or run Ox Alpha. The company says it only routes requests to the provider.
