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meta/muse-spark-1-3
Muse Spark 1.3
Muse Spark 1.3 is a multimodal reasoning model from Meta for long-running agentic, multi-agent, and coding workflows. It is designed to keep track of information across extended tasks, work through...
9/2/2026
1,048,576 tokens
Input: ¥219.8968/M
Output: ¥747.6489/M
Specifications
Modalities
Input
text
image
video
file
audio
Output
text
Supported Parameters
include_reasoning
max_tokens
reasoning
reasoning_effort
repetition_penalty
response_format
structured_outputs
temperature
tool_choice
tools
top_k
top_p
Max Output Tokens
943,718Reasoning Configuration
- Default
- Thinking on (effort: medium)
- Selectable effort levels
- maxxhighhighmediumlowminimal
- Turning thinking off
- Not possible (always thinks)
Code Examples
curl https://api.fastmetal.ai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "muse-spark-1.3",
"messages": [{"role": "user", "content": "Hello!"}]
}'How Muse Spark 1.3 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 is **strawberry** — there are **3** 'r's in it.
Here's my reasoning step by step:
1. **Write out the word:**
strawberry
2. **Break it into individual letters:**
s - t - r - a - w - b - e - r - r - y
3. **Go through each letter one by one and check if it is 'r':**
1. s → not r, count = 0
2. t → not r, count = 0
3. r → is r, count = 1
4. a → not r, count = 1
5. w → not r, count = 1
6. b → not r, count = 1
7. e → not r, count = 1
8. r → is r, count = 2
9. r → is r, count = 3
10. y → not r, count = 3
4. **Total up the matches:**
The 'r' appears at position 3, 8, and 9.
**Final answer: 3**
10.5s response1063 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…
This error means `users` is `undefined` when your component tries to render.
`users.map(...)` only works if `users` is an array. On the first render, if you haven't passed the prop yet, or your data hasn't loaded from an API yet, `users` is `undefined`, so JavaScript throws:
> Cannot read properties of undefined (reading 'map')
This almost always happens in one of these 2 cases:
1. You forgot to pass the prop:
```js
<UserList /> // users is undefined!
```
vs.
```js
<UserList users={myUsers} />
```
2. Your data is async and is `undefined` on the first render:
```js
const [users, setUsers] = useState(); // undefined at first!
// ...
<UserList users={users} />
```
### How to fix it
**1.…
16.7s response1242 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 friendly review of your `get_data` function — it works, but there are a few readability, robustness, and performance issues worth fixing:
### 1. Readability Issues
**a) Imports inside the function**
```python
import requests
import time
```
This runs on every call (though Python caches it). Move to the top of the file per PEP 8.
**b) Poor variable names & magic numbers**
`r`, `i`, `data`, `2`, `10`, `200` don't tell the reader much.
**c) `== True` anti-pattern**
```python
if item["active"] == True:
```
Just use `if item.get("active"):` or `is True`. The current version will also crash with `KeyError` if `active` is missing.
**d) No docstring / type hints**
No one knows what `ur…
26.9s response2141 output tokens
Frequently asked questions
- How much does the Muse Spark 1.3 API cost?
- On FastMetal, Muse Spark 1.3 is billed per token in yen: ¥219.9 per 1M input tokens and ¥747.65 per 1M output tokens, before tax. Usage is drawn from a prepaid balance; there is no subscription or monthly fee.
- Can I call Muse Spark 1.3 with the OpenAI SDK?
- Yes. Point base_url at https://api.fastmetal.ai/v1 and pass "muse-spark-1.3" as the model; existing OpenAI-style code works unchanged, including streaming, tool calls and structured output.
- What is the context window of Muse Spark 1.3?
- 1,048,576 tokens, shared between the prompt and the response.
- What do I need to try Muse Spark 1.3?
- 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 Muse Spark 1.3 right now
Muse Spark 1.3 is available on FastMetal through one API key. Start in the browser, or call it from the OpenAI SDK.