MetaText Generation/v1/ai/chat

Muse Spark Open API

Access Muse Spark Open through one API key. Meta Open-Weight Coding Model.

Muse Spark Open is Meta's coding-optimized open-weight model, trained for agentic coding workflows. It suits coding agents and IDE assistants that need high first-attempt accuracy, reliable tool calling and a good grasp of large codebases.

Full Docs Get API Key — Free $5 Credit

No credit card required. Takes 30 seconds.

Muse Spark Open API pricing

Pay per request from your YepAPI balance — no subscription, no monthly minimum. Prices updated October 23, 2026.

Token type	Price
Input	$1.85 / 1M tokens
Output	$6.28 / 1M tokens
Context window	1.0M tokens

What it costs	Per job	Per 1,000
Chat reply1K input + 500 output tokens	$0.005	$4.99
RAG answer8K input + 800 output tokens	$0.02	$19.82
Agent step with tools30K input + 2K output tokens	$0.068	$68.06
Long document summary100K input + 2K output tokens	$0.198	$197.56

2,400+

Developers

1.2M+

API calls served

100+

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see Muse Spark Open respond in real time.

POST/v1/ai/chatmeta/muse-spark-open

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

Muse Spark Open specs

Provider	Meta
Model ID	meta/muse-spark-open
Endpoint	/v1/ai/chat
Type	Text Generation
Context window	1.05M tokens
Max output	944K tokens
Reasoning	No
OpenAI-compatible	Yes — /v1/ai/chat/completions

How to get a Muse Spark Open API key

1
Create a free account
Sign up at yepapi.com with Google or email. It takes about 30 seconds and needs no card.
2
Create an API key
Open the dashboard, go to API Keys and create a key. Copy it — it starts with yep_sk_.
3
Call Muse Spark Open
Send a request to /v1/ai/chat with the x-api-key header and model "meta/muse-spark-open".
4
Pay as you go
Usage is billed per request from your balance. Top up any amount; there is no subscription.

Strengths

✓

Built for coding agents

Trained for agentic coding with higher first-attempt accuracy on real repository tasks.

✓

Reliable tool calling

Consistent function calls for agents that read files, run tests and apply edits.

✓

1M token context

Up to 1,048,576 input tokens, so large codebases fit in context.

✓

Open weights

An open-weight model at $1.85 / $6.28 per 1M tokens.

Quick start

Copy this snippet and start making calls with Muse Spark Open.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "meta/muse-spark-open",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

Muse Spark Open vs similar models

Every model below runs on the same API key — switch by changing the model ID.

Model	Provider	Price	Context
Muse Spark Open	Meta	$1.85 in / $6.28 out per 1M	1.0M
Muse Spark 1.3	Meta	$1.85 in / $6.28 out per 1M	1.0M
Muse Wonder	Meta	$5.91 in / $29.54 out per 1M	1.0M
Nemotron 3 Super	NVIDIA	$0 in / $0 out per 1M	262K
Qwen3.7 Flash	Qwen	$0.04 in / $0.19 out per 1M	1M
Solar Mini 4	Upstage	$0.07 in / $0.30 out per 1M	524K
Nemotron 3.5 Lightning	NVIDIA	$0.10 in / $0.30 out per 1M	262K
DeepSeek V4 Flash	DeepSeek	$0.13 in / $0.27 out per 1M	1.0M

Why use Muse Spark Open through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

Muse Spark Open API — pricing, context window & access

Muse Spark Open is Meta's coding-optimized open-weight model, trained for agentic coding workflows. It pairs a 1,048,576-token context window with up to 943,718 output tokens per response, at $1.85 per 1M input and $6.28 per 1M output tokens through YepAPI.

Through YepAPI you call Muse Spark Open on an OpenAI-compatible endpoint with a single key — the same key that reaches GPT-6, Claude, Gemini, Grok and the SEO, SERP and scraping APIs. Input: text, images, video, audio, files.

What is Muse Spark Open?

Muse Spark Open is Meta's coding-optimized open-weight model, trained for agentic coding workflows. It is the open-weight member of the Muse Spark line and is tuned for coding rather than general chat. It accepts text, images, video, audio, files as input, handles up to 1,048,576 tokens of context and returns up to 943,718 output tokens per call.

Build with Muse Spark Open via YepAPI

YepAPI serves Muse Spark Open on the OpenAI-compatible /v1/ai/chat endpoint. Point your base URL at YepAPI, add your key, and set the model string to muse-spark-open (or the full meta/muse-spark-open). Function calling, structured outputs and reasoning settings pass straight through, and switching to any other model on the platform is a one-string change per request.

Muse Spark Open API pricing — $1.85 / 1M input, $6.28 / 1M output

Muse Spark Open costs $1.85 per 1M input tokens and $6.28 per 1M output tokens through YepAPI, pay per token with no minimums. Failed calls are never charged, and every request is itemised in your dashboard API Logs.

Muse Spark Open use cases

It suits coding agents and IDE assistants that need high first-attempt accuracy, reliable tool calling and a good grasp of large codebases.

Try Muse Spark Open free

Every new YepAPI account includes $5 in free credit with no card required — enough to test Muse Spark Open on your own prompts before committing to paid usage. Create an account, copy your key, and call muse-spark-open right away.

Start generating in 30 seconds

$5 free credit on signup. No credit card required. Pay per call.

Get API Key

What developers say

“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
Marcus T.
SEO Platform Founder

“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
Priya S.
Full-Stack Developer

“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Jake R.
Indie Hacker

Frequently asked questions

Muse Spark Open costs $1.85 per 1M input tokens and $6.28 per 1M output tokens through YepAPI, billed per request with no monthly fee. For example, a chat reply (1K input + 500 output tokens) costs about $0.005.

Sign up at yepapi.com (Google or email, about 30 seconds), open the dashboard and create an API key. The same key works for Muse Spark Open and every other model — no separate Meta account or waitlist.

New YepAPI accounts in most countries get free signup credit, enough to test Muse Spark Open without a card. After that you pay per request at the rates above — there is no subscription.

Use "meta/muse-spark-open" as the model on /v1/ai/chat. The short alias "muse-spark-open" also works.

Yes. Point the OpenAI SDK at https://api.yepapi.com/v1/ai with your YepAPI key and set model to "meta/muse-spark-open". Streaming works the same way, so existing OpenAI code only needs the base URL and key changed.

Muse Spark Open supports a 1.0M token context window with up to 944K output tokens per request.