A mystery model appears. It is free for four days, its identity is undisclosed, and it shows up at a competitor’s product during the exact week a new flagship launches. Then it vanishes hours before the real thing goes live. If you searched for a free Qwen4 API this week, you probably landed on it: a stealth model called Qoduck, run inside Qoder, Alibaba’s agentic coding product.
The internet has mostly decided Qoduck was Qwen4. This post is the case for and against, laid out honestly, because the clues genuinely point in more than one direction and Alibaba has confirmed none of them. We will cover what Qoduck actually was, the free window and its rules, the Koduck claim that complicates the story, what each theory explains and what it does not, and why any of this matters when the model you can call is already live.
What Qoduck was, factually
Strip the speculation and here is what is confirmed by Qoder’s own promotion page.
Qoder ran a stealth model named Qoduck from November 7 to November 11, 2026 at 10:00 UTC+8 (07:30 IST). Within a daily free allowance, calls consumed no credits: the rate dropped from 0.5x to 0.0x, even at the highest thinking intensity. Paid subscribers got more free uses per day, and the allowance reset daily. Past the free window, Qoduck billed at its standard 0.5x rate.
The eligibility rules were narrow. Individual Qoder International accounts on Free, Pro Trial, Lite, Pro, Pro+ and Ultra qualified. Teams and Enterprise never saw Qoduck in the picker. It did not cover Qoder IDE, the JetBrains plugin or Qoder CLI. The docs say Qoduck is removed when the promotion ends, and it was: the window closed on the morning of November 11.
Crucially, Qoduck was never an API offer. There was no base URL, no key, no model id you could call from your own code. It was a free taste inside one product. That single fact rules out most of the “free Qwen4 API” tutorials you will find today, because whatever they point at, it is not the thing that just expired.
The Koduck wrinkle
Just when the Qoduck-equals-Qwen4 story felt settled, a Chinese tech site added a twist: it reported that Koduck, not Qoduck, was an early checkpoint of Qwen4 Max. Alibaba has not confirmed it.
The distinction sounds like a typo, and it might be one. But the naming logic is coherent. If Qwen4 Max was being tested in the wild before launch under a codename, an earlier checkpoint getting one name and a later one getting a near-identical name is exactly the kind of thing that happens inside a lab. It also matches the shape of this launch, where the flagship appeared quietly before its public debut.
We cannot resolve Qoduck versus Koduck from outside. What we can say is that the existence of two near-identical codenames, reported separately, is consistent with Qwen4 Max being trialed in Qoder before launch. It is also consistent with sloppy reporting. Hold it loosely.
The case that Qoduck was Qwen4
The case rests on three facts that line up almost too well.
Ownership. Qoder is Alibaba’s product. A stealth flagship being tested inside Alibaba’s own agentic coding tool, rather than a neutral playground, points at Alibaba’s next model rather than a third-party one.
Timing. Qoduck’s free window ended at 07:30 IST on November 11. Qwen4 Max Preview went live on the Token Plan that same day. A mystery model closing the morning the real one launches reads like a handoff, not a coincidence.
Launch tracker. Cellcog lists Qoder among the early-access platforms for Qwen4. That is not proof of identity, but it puts Qoder on the official early-access map at the same moment Qoduck was running.
Together these make a reasonable case. If you had to bet, this is the direction the evidence leans.
The case that we do not actually know
Now the honest counterweight, because the community has run ahead of the facts.
Qoder has not said. The official framing calls Qoduck “a stealth model whose identity has yet to be disclosed” and asks users to judge it on their own tasks. That is a deliberate non-answer. Launch-week timing is suggestive, not confirming.
No benchmark links them. Qwen4 Max Preview has no published model card and no benchmark row anywhere. Qoduck has no published scores either. There is no measurement that ties the two together, only timing and ownership.
The connection is unconfirmed by Alibaba. Neither the Qwen X account nor the Model Marketplace mentions Qoduck. A launch this closely choreographed, with an 80% off Token Plan banner and a coordinated announcement, has said nothing about the stealth model that preceded it.
Qoduck being free does not fit Qwen4’s launch. Qwen4 Max Preview launched behind a paid Token Plan, from $3. A model given away at 0.0x credits for four days is a strange way to introduce a flagship you are about to put behind a subscription. It fits better as a separate preview or an early checkpoint, which is exactly what the Koduck claim suggests.
So: plausible, leaning yes, but unproven. Anyone stating “Qoduck was Qwen4 Max” as settled fact is guessing.
Does it even matter now?
Honestly, less than the discussion implies. Qoduck’s window is closed and the model is removed. Whatever it was, you cannot call it today. The thing you can call is qwen4-max-preview on the Token Plan, live since November 11.
The question only matters for two practical decisions. First, if you were hoping Qoduck’s free tier would return or carry over to Qwen4, do not build on that: the promo is gone and Qwen4 is subscription-only. Second, if you are evaluating whether Qwen4 Max is worth testing, Qoduck’s free window was your one chance to try it at zero cost, and that chance has passed. The cheapest official access now is the $3 Lite plan.
For a free route that is actually live, the free models lane runs the Qwen3.8 generation: qwen3.8-max:free and qwen3.8-27b:free at $0 with 100 requests a day, no card. It is not Qwen4, but it is real and it works right now.
Free today, no mystery about what it is
Qoduck is gone. The free lane on One AI API Key runs Qwen3.8 ids you can verify in the live model list: 100 requests a day, $10 sign-up credit, no card. When Qwen4 lands here, your key already works.
Mistakes to avoid
- Building on a dead promo. Qoduck’s free window closed November 11 and the model is removed with it. Any “free Qoduck API” tutorial written after that date is pointing at nothing.
- Stating the identity as fact. Qoder has not disclosed it, Alibaba has not confirmed it, and no benchmark links Qoduck to Qwen4 Max. It is a well-supported guess, not a fact.
- Treating Qoduck as an API. It was an in-product free taste with no base URL, no key and no model id. It was never callable from your own code.
- Confusing Qoduck and Koduck. A Chinese tech site claims Koduck was an early Qwen4 Max checkpoint. Whether that is the same model as Qoduck, a typo, or a different checkpoint is unresolved. Do not build a theory on the difference.
- Assuming the free window returns. The 0.0x credit promo was a launch-week event with a hard end time and narrow eligibility. Do not plan capacity around its return.
FAQ
Is Qoduck Qwen4 Max Preview?
Unconfirmed, though the evidence leans that way. Qoder is Alibaba’s product, Qoduck’s free window closed the same morning Qwen4 Max Preview launched, and Cellcog lists Qoder among Qwen4’s early-access platforms. But Qoder has not disclosed the identity, Alibaba has not confirmed it, and no benchmark connects them. Treat “Qoduck was Qwen4” as a reasonable guess.
What was the Koduck claim?
A Chinese tech site reported that Koduck was an early checkpoint of Qwen4 Max. Alibaba has not confirmed it. Whether Koduck and Qoduck are the same model, a typo, or two different checkpoints is not resolved from outside.
Can I still use Qoduck for free?
No. The free window ran November 7 to 11, 2026 and closed at 07:30 IST on the 11th. Qoder removes the model when the promotion ends, so it is no longer in the picker. Treat any current “free Qoduck” guide as expired.
Was Qoduck ever available as an API?
No. There was no base URL, no API key and no model id. It was a free model inside the Qoder product only, for individual Qoder International accounts. It could not be called from your own application.
What is the free way to use Qwen4 Max Preview today?
There is no confirmed free API tier. The cheapest official access is the $3 Lite Token Plan during the launch event. For a free route that is live and verifiable, the free lane on One AI API Key runs the Qwen3.8 generation at $0 with 100 requests a day.
The bottom line
Qoduck was a four-day free stealth model inside Qoder, run during Qwen4 launch week, and it closed the morning Qwen4 Max Preview went live. The case that it was Qwen4 is strong on timing and ownership and weak on confirmation: nobody official has said so, and the Koduck report muddies it further. It no longer matters much in practice, because the window is closed and the thing you can actually call, qwen4-max-preview, is subscription-only on the Token Plan. Skip the dead-promo tutorials, verify any model against a live model list, and if you want free access that works today, the Qwen3.8 free lane on One AI API Key is real and running.