From a paid service only to the free list
The AI coding tool OpenCode on Nov. 6 (Nov. 7 Japan time) added "Iceman Free," a "stealth" model whose developer is not disclosed, to its public model list and documentation. Prices for input, output and reading reusable content (cache) are all $0, and the free offer is for a limited time.
It extends to the free model list "Iceman Contributor Free," which was released on Oct. 24 (Oct. 25 Japan time) for "OpenCode Go," a paid service starting at $10 a month. Its context window is 262,144 tokens (units of text), the maximum output per response is 131,072 tokens, it handles text only and it supports reasoning and tool calling. All of these specifications are the same as the Go model.
@aitrackerbot, an X account that tracks the appearance of models, reported the same day that it was "now free for everyone."
Iceman is back, now free for everyone on OpenCode Zen as iceman-free. Looks like the same Microsoft MAI model we flagged last month: its token counts match MAI-Thinking-1, and none of 15 other models match its tool-schema pattern. Same 262K context, 131K output.
Data stored and used for improvement while free
OpenCode's documentation says of Iceman Free that during the free period, collected data will be stored and used to improve the model. It does not say which provider stores the data or for how long.
The documentation says that, as a rule, providers do not store data or use it for training, and lists exceptions model by model. Conditions differ even among free models. The descriptions for Big Pickle and Pulse Alpha Free say data "may be used" for improvement, while Iceman Free states flatly that it "will be used."
The data handling points in the same direction as the Go version. The Go version is free in exchange for permission to use prompts and responses to improve the model, and is shown as an exception to the policy of not using data for training and not storing it.
OpenCode's privacy policy says prompts sent to AI are passed to upstream providers and not stored. Its terms of service say the content of free accounts may be used to develop and improve the service, and that for external models the providers' retention policies apply.
Caution is needed when sending confidential code or personal information while the developer remains unknown.
| Model | Use for improvement or training | Data retention |
|---|---|---|
| Iceman Free | Used | Stored (no period stated) |
| Pulse Alpha Free (ended Nov. 6) | May be used | May be stored |
| Big Pickle | May be used | Not stated |
| Flint 40B Free | May be used | 30 days |
| Crouton Alpha Free | Not used | 30 days |
| Beam Free | Not used | 30 days |
| GLM-5.3-Flash Free | Not used | Not stored |
Free tier only in OpenCode's apps, no end date given
OpenCode says its free chat models require the company's apps, and directs users of other apps to paid models or Go. Its website says free models require "no account." The documentation specific to Iceman Free does not say whether an account is required.
The end date of the free offer and any usage limits could not be confirmed in public documentation. OpenCode provides a setting to hide free models from the list. The models run in the United States and Europe, it says.
Microsoft origin unconfirmed
@aitrackerbot again estimated that Iceman Free is a model from Microsoft's "MAI." In its October analysis, it said token counts for 20 tool definitions and eight texts matched MAI-Thinking-1, and that the model itself identified as MAI. This time it added that the tool definition format did not match for 15 other models.
On the other hand, stealthmodels.com, a site that investigates stealth models, reported as of Oct. 25 that while the Go version's token counting matches MAI-Thinking-1, it matches OpenAI's GPT-6 models equally well. The site says this test cannot determine which lab the model comes from.
OpenCode's statistics show the developer as "Unknown." Microsoft has not announced it, and ORIENS has not independently verified it.
According to Microsoft's announcement page, MAI-Thinking-1 is a reasoning model with about 1 trillion total parameters, of which 35 billion are used at a time, and a context window of 256k. It is offered as a public preview on "Microsoft Foundry" for businesses.
According to DataStudios, the company's July-September quarter results announced on Oct. 28 showed revenue of $92.3 billion and capital expenditure including leases of $45.2 billion. If confirmed as a Microsoft model, it would offer a measure of how widely outside developers use the in-house models of a company that continues to invest huge sums.
Usage recorded in statistics before release
OpenCode's statistics have recorded usage under the name "iceman" since before Iceman Free was listed. Usage peaked at 594 billion tokens a day on Oct. 28 and had fallen to 15 billion tokens by Nov. 6. The two-month total is 2.7 trillion tokens, with about 83,000 users. OpenCode has not explained the relationship between this "iceman" and Iceman Free.
Over the past seven days, "iceman-contributor" for Go ranked 16th with 527 billion tokens and "iceman" 20th with 285 billion tokens. Anthropic's "Claude Haiku 5.5" ranked 18th with 402 billion tokens. The impact of the free listing has not yet shown up in the statistics.
Two weeks from discovery to free listing
Around the same time, OpenCode also made available the free "Pulse Alpha" and "Crouton Alpha," whose developers are not disclosed. Pulse Alpha ended on Nov. 6. Iceman joined the free list less than two weeks after appearing on the paid service.
- Microsoft announces MAI-Thinking-1Official
- Iceman Contributor Free added to OpenCode GoOfficial
- @aitrackerbot analyzes it as an MAI modelRumor
- OpenCode adds Iceman Free to its listOfficial
- @aitrackerbot estimates it is the same MAI modelRumor
