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deepseek/deepseek-v4-flash-0731
deepseek-v4-flash-0731
Global: DeepSeek's V4 Flash 0731
Input: ¥39.314/M
Output: ¥117.942/M
Specifications
Modalities
Input
text
Output
text
Code Examples
curl https://api.fastmetal.ai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "deepseek-v4-flash-0731",
"messages": [{"role": "user", "content": "Hello!"}]
}'How deepseek-v4-flash-0731 actually answers
Real responses to our standard prompts, recorded on FastMetal.
Count the number of 'r's in 'strawberry'
Count the number of 'r's in 'strawberry'. Explain your reasoning step by step.
The word **“strawberry”** is spelled:
**s t r a w b e r r y**
Now count the **r**’s:
1. First **r** in “str” → **1**
2. Second **r** in “be**r**ry” → **2**
3. Third **r** in “ber**r**y” → **3**
So, there are **3** “r”s in **“strawberry”**.
5.6s response375 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…
The error happens because `users` is `undefined` when the component renders. Your code calls `users.map(...)`, but you can’t call `.map()` on `undefined`.
## Why this happens
The `UserList` component expects a prop called `users` that is an array, but nothing passed it, or it was explicitly set to `undefined`.
Example of calling it wrong:
```jsx
<UserList /> // users is undefined
<UserList users={undefined} />
```
## How to fix it
### 1. Provide a default value for `users`
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}
```
Now if `users` is missing, it will default to an empty ar…
12.0s response514 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):…
Here’s a revised version with clearer control flow, better exception handling, and more idiomatic Python:
```python
import time
from typing import Any
import requests
def get_data(url: str, retries: int = 3, timeout: int = 10) -> list[dict[str, Any]]:
"""
Fetch a JSON list of items from url and return only active items
as [{"name": ..., "id": ...}, ...].
"""
with requests.Session() as session:
for attempt in range(1, retries + 1):
try:
response = session.get(url, timeout=timeout)
response.raise_for_status()
data = response.json()
return [
{"name": item["name"], "id…
108.8s response11660 output tokens
Frequently asked questions
- How much does the deepseek-v4-flash-0731 API cost?
- On FastMetal, deepseek-v4-flash-0731 is billed per token in yen: ¥39.31 per 1M input tokens and ¥117.94 per 1M output tokens, before tax. Usage is drawn from a prepaid balance; there is no subscription or monthly fee.
- Can I call deepseek-v4-flash-0731 with the OpenAI SDK?
- Yes. Point base_url at https://api.fastmetal.ai/v1 and pass "deepseek-v4-flash-0731" as the model; existing OpenAI-style code works unchanged, including streaming, tool calls and structured output.
- What do I need to try deepseek-v4-flash-0731?
- Create an account and add credit; the model is then available both in the browser chat and over the API. There is no contract or minimum spend.
Try deepseek-v4-flash-0731 right now
deepseek-v4-flash-0731 is available on FastMetal through one API key. Start in the browser, or call it from the OpenAI SDK.