What OpenCode’s Ox Alpha actually is

On August 20, 2026, OpenCode posted that Ox Alpha, a stealth model, would be free for a week. The pitch was a 1 million-token context window, multimodal input, zero data retention, “near unlimited” rate limits, and capacity for 100 trillion tokens a day.

That last number is OpenCode’s claimed serving capacity for the whole pool. It is not a per-user quota.

Ox Alpha is not the model’s real name. OpenCode’s data page still lists the maker as Unknown. Context, output limit, knowledge cutoff, and release date are also Unknown there. OpenRouter’s listing is explicit: a third-party provider chose to stay anonymous during the preview. OpenRouter only routes the requests.

What the catalogs actually list

OpenRouter’s model id is stealth/ox-alpha. Released August 20, 2026. Context is 1,048,576 tokens. Maximum output is 131,072. Input is text, image, and video. Output is text. Function calling and JSON response_format are supported; JSON-schema enforcement is not. Price on that page is free for prompt and completion tokens.

OpenCode Zen names the same offer Ox Alpha Free. The Zen model id is x-preview-f-free. In an OpenCode config that is opencode/x-preview-f-free. The Zen pricing table lists input, output, and cached read as Free.

How much it is being used

OpenCode Data, retrieved August 22, ranks ox-alpha third in last week’s observed mix, at 1.5% token share. The same page reports 5.1 trillion tokens, 106,000 unique users, and 1,765,783 completed sessions, with about 2.9 million tokens per session and a 94% input-cache ratio. Spend is listed as $0.00 because the SKU is free.

Those are OpenCode’s observed totals, not a public leaderboard of quality.

What is not confirmed

Community posts have guessed a next GLM-family model from Zhipu / Z.ai, based on tokenizer behavior and serving fingerprints. No lab has said that. Do not write “Ox Alpha = GLM-5.x” as a fact.

There is also no official coding-agent table. Informal DeepSWE-style runs of a handful of tasks are not a ranking against named frontier models.

OpenCode’s own follow-up on August 21 is more useful than those guesses. The team told people seeing network errors to upgrade to OpenCode 1.18.21, which retries unknown stops. The model is a preview. Long agent loops can still die mid-job.

How to try it while it is free

In OpenCode: /connect, pick OpenCode Zen, then /models and Ox Alpha Free. Or connect OpenRouter and select Ox Alpha.

The free window was “the next week” from the August 20 post. Treat that as a short preview, not a permanent SKU.

The thing to test is not a TODO app. It is a long tool loop on a real repo: multi-file edits, tests, and a screenshot if you want to exercise the vision path. The identity reveal, if it comes, will not be a better test than using it while the name is still hidden.

Source cutoff: OpenCode’s August 20 post and Zen docs, OpenRouter’s stealth/ox-alpha listing, and OpenCode Data, as retrieved August 22, 2026.