Model comparison

Fugu Ultra v2 vs GLM 5.2

Pricing, context window and real answers (September 2026)

Fugu Ultra v2 (Sakana AI) and GLM 5.2 (Z.ai), 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 v2z-ai logoGLM 5.2
ProviderSakana AIZ.ai
Input (per 1M tokens)¥893.5¥235.2
Output (per 1M tokens)¥5,361¥739.2
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥3,574¥605
Context window1,000,000 tokens1,048,576 tokens
Release date9/11/20266/16/2026
Input modalitiestext, image, filetext
Throughput (p50)
Arena · overallUnranked#38 · ELO 1,472
Arena · JapaneseUnranked#28 · ELO 1,452
Arena · codingUnranked#48 · ELO 1,510

Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.

Which should you pick?

  • On price, GLM 5.2: ¥739.2 per 1M output tokens, 86% less than Fugu Ultra v2.
  • For long documents, GLM 5.2: a 1,048,576-token context window against 1,000,000 for 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

GLM 5.2

To count the number of 'r's in the word 'strawberry', let's look at the word letter by letter: 1. **s** - no 'r' 2. **t** - no 'r' 3. **r** - this is the 1st 'r' 4. **a** - no 'r' 5. **w** - no 'r' 6. **b** - no 'r' 7. **e** - no 'r' 8. **r** - this is the 2nd 'r' 9. **r** - this is the 3rd 'r' 10. **y** - no 'r' Total count: 3 There are **3** 'r's in the word 'strawberry'.
2.6s439 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

GLM 5.2

The error `TypeError: Cannot read properties of undefined (reading 'map')` happens because the `users` prop being passed to your `UserList` component is currently `undefined`. When JavaScript tries to call `.map()` on `undefined`, it throws this error. Here are the best ways to fix this: ### Fix 1: Provide a default value (Recommended) You can provide a default empty array `[]` when destructuring the props. This ensures that even if `users` is not passed down, the `.map()` function will still have an array to iterate over (resulting in an empty list rather than a crash). ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</…
8.3s1006 output tokens

Code Review

Please review the following Python function and suggest improvements for readability, performance, and best practices: def get_data(url, retries=3): import requests import time for i in range(retries):…

Fugu Ultra v2

# Final Code Review: `get_data` The function is compact and its intent is clear, but as written it will **fail silently in production**. Two defects dominate everything else: 1. The bare `except:` swallows every error — including `KeyboardInterrupt` and genuine logic bugs. 2. A total failure and a legitimately empty dataset both return `[]`, so callers cannot tell "the service is down" from "there are no active records." Together these mean an outage looks exactly like a successful empty response. Everything else below is meaningful improvement; those two are the difference between code that fails loudly and code that fails invisibly. --- ## 1. Correctness and error handling ### 1.1 `e…
281.1s23317 output tokens

GLM 5.2

Here is a review of your Python function, broken down by readability, performance, and best practices, followed by a refactored version of the code. ### 1. Best Practices * **Move imports to the top:** Importing modules inside a function is generally discouraged. While Python caches imports, putting `import requests` and `import time` at the top of your file is the standard convention and improves readability. * **Avoid bare `except:` blocks:** Using a bare `except:` catches everything, including `KeyboardInterrupt` and `SystemExit`. This makes it hard to interrupt your program if it gets stuck in a loop. You should catch specific exceptions, such as `requests.exceptions.RequestException` (…
10.9s2061 output tokens

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Frequently asked questions

Which is cheaper, Fugu Ultra v2 or GLM 5.2?
Per 1M output tokens, Fugu Ultra v2 is ¥5,361 and GLM 5.2 is ¥739.2 on FastMetal (yen, before tax), so GLM 5.2 is cheaper.
How do the context windows of Fugu Ultra v2 and GLM 5.2 compare?
Fugu Ultra v2 takes 1,000,000 tokens; GLM 5.2 takes 1,048,576.
Can I use Fugu Ultra v2 and GLM 5.2 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-ultra-v2" or "glm-5.2" 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 GLM 5.2 from the browser chat and the API. No monthly fee.

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