Fugu Ultra v2 vs Qwen3.8 Max
Pricing, context window and real answers (September 2026)
Fugu Ultra v2 (Sakana AI) and Qwen3.8 Max (Qwen), compared as you can actually call them on FastMetal. Both are served from the same OpenAI-compatible endpoint and API key; switching is a change to the model string.
Specs and pricing
| Fugu Ultra v2 |  Qwen3.8 Max | |
|---|---|---|
| Provider | Sakana AI | Qwen |
| Input (per 1M tokens) | ¥893.5 | ¥357.4 |
| Output (per 1M tokens) | ¥5,361 | ¥1,072.2 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥3,574 | ¥894 |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Release date | 9/11/2026 | 8/3/2026 |
| Input modalities | text, image, file | text, image |
| Throughput (p50) | — | — |
| Arena · overall | Unranked | #22 · ELO 1,481 |
| Arena · Japanese | Unranked | #18 · ELO 1,469 |
| Arena · coding | Unranked | #24 · ELO 1,522 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Qwen3.8 Max: ¥1,072.2 per 1M output tokens, 80% less than Fugu Ultra v2.
- If in doubt, try both on the same key. Switching is a change to the model string, and each is billed at its own rate.
Real answers to the same prompts
Exactly what the FastMetal gateway returned, side by side. Not benchmark scores: actual output.
Count the number of 'r's in 'strawberry'
Count the number of 'r's in 'strawberry'. Explain your reasoning step by step.
Fugu Ultra v2
**Answer: 3**
**Step-by-step reasoning:**
1. **Write out the word letter by letter**, assigning each a position:
| Position | Letter | Is it 'r'? |
|---|---|---|
| 1 | s | no |
| 2 | t | no |
| 3 | **r** | ✅ yes |
| 4 | a | no |
| 5 | w | no |
| 6 | b | no |
| 7 | e | no |
| 8 | **r** | ✅ yes |
| 9 | **r** | ✅ yes |
| 10 | y | no |
2. **Tally the matches:** positions 3, 8, and 9 are 'r'.
3. **Sanity check by chunks:** "straw" contains one 'r' (str**a**w → the r in "str"), and "berry" contains two 'r's (be**rr**y). 1 + 2 = 3.
4. **Verify length:** the letters counted total 10, which matches the length of "strawberry" — so no letter was skipped or double-counted.
**Conclusion:** There a…
10.2s435 output tokens
Qwen3.8 Max
The word **strawberry** is spelled:
**s t r a w b e r r y**
Now count the letter **r**:
1. s
2. t
3. **r** ← first r
4. a
5. w
6. b
7. e
8. **r** ← second r
9. **r** ← third r
10. y
There are **3** letters **r** in **strawberry**.
3.5s156 output tokens
Debug This Error
I'm getting the following error in my Node.js application: TypeError: Cannot read properties of undefined (reading 'map') at UserList (/app/components/UserList.js:12:25) at renderWithHooks (/app/node_modules/rea…
Fugu Ultra v2
## What the error means
`TypeError: Cannot read properties of undefined (reading 'map')` means that when `UserList` rendered, `users` was `undefined`, and JavaScript can't read the `.map` property off `undefined`.
The important detail: **the bug isn't really in `UserList`** — that's just where it surfaces. Destructuring `function UserList({ users })` does *not* throw when the prop is missing; it silently gives you `undefined`. The crash is deferred to the first property access, which is `.map` on line 12.
So the real question is: why is `props.users` not an array?
## Why `users` is undefined
**1. Async data hasn't arrived yet — by far the most common cause.**
```jsx
const [users, setUs…
70.8s5286 output tokens
Qwen3.8 Max
The error means `users` is `undefined` when `UserList` tries to render:
```js
{users.map(user => ...)}
```
JavaScript cannot call `.map()` on `undefined`, so React throws:
```text
Cannot read properties of undefined (reading 'map')
```
## Most likely cause
The parent component is rendering `UserList` without passing a valid `users` array, or it is passing `users` before the data has loaded.
For example:
```jsx
<UserList />
```
or:
```jsx
<UserList users={undefined} />
```
or:
```jsx
const [users, setUsers] = useState(); // undefined initially
```
Then later:
```jsx
<UserList users={users} />
```
On the first render, `users` is still `undefined`.
---
## Fix 1: Give `users` a d…
17.7s1020 output tokens
Professional Email
Write a professional email to a client explaining that the project delivery will be delayed by two weeks due to unexpected technical challenges discovered during integration testing. The tone should be apologetic but con…
Fugu Ultra v2
**Subject:** [Project Name] — Revised Delivery Date of [New Date] and Our Plan to Get There
Dear [Client Name],
I'm writing to let you know that we need to move the delivery date for [Project Name] from [Original Date] to [New Date] — a shift of two weeks. I'm sorry to be bringing you this news, and I want to give you the full picture of what we found, what we're doing about it, and how we'll keep you informed between now and delivery.
**What we found**
During integration testing, we uncovered a set of issues that only appear when the individual components run together under production-like conditions. Specifically, [brief, concrete description — e.g., "the data synchronization layer bet…
86.5s5107 output tokens
Qwen3.8 Max
Subject: Revised Project Delivery Timeline – Updated Schedule and Next Steps
Dear [Client Name],
I hope this message finds you well.
I am writing to provide an update on the current status of the project and to inform you that, during our recent integration testing phase, we encountered several unexpected technical challenges that will impact the original delivery timeline. After careful review with the technical team, we now anticipate the revised delivery date will be [insert date – two weeks from original delivery date].
Please accept my sincere apologies for this delay. We understand the importance of this project and the expectations tied to the original schedule. While this situati…
11.9s547 output tokens
Frequently asked questions
- Which is cheaper, Fugu Ultra v2 or Qwen3.8 Max?
- Per 1M output tokens, Fugu Ultra v2 is ¥5,361 and Qwen3.8 Max is ¥1,072.2 on FastMetal (yen, before tax), so Qwen3.8 Max is cheaper.
- How do the context windows of Fugu Ultra v2 and Qwen3.8 Max compare?
- Fugu Ultra v2 takes 1,000,000 tokens; Qwen3.8 Max takes 1,000,000.
- Can I use Fugu Ultra v2 and Qwen3.8 Max with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-ultra-v2" or "qwen3.8-max" as the model. Each is billed at its own rate from the same prepaid balance.
Try both on one API key
Create an account and add credit to call Fugu Ultra v2 and Qwen3.8 Max from the browser chat and the API. No monthly fee.