Meta

Meta

Muse Spark Open

Meta's open-weight Muse Spark (816B MoE, 42B active), trained for agentic coding: higher first-attempt accuracy, reliable tool calling and deep codebase understanding. 1M context, image input, reasoning.

Modalities

Text+Image → Text

Below release

Not established

Weights

Published

meta-models/Muse-Spark-Open-816B-A42B

Where it sits in the catalogue Kyma measures

Every number against every text model Kyma prices per token — a stated rule, not a chosen line-up.

Price · input#52/84

$1.6875

output $5.7375

median $1.013 · best $0.0494

Price · output#54/83

$5.7375

per 1M tokens generated

median $3.645 · best $0.218

Availability · 30d#1/55

100%

30 observations since 2026-10-25

median 100.0% · best 100.0%

Throughput#1/23

160 tok/s

probe median, one fixed prompt

median 46.1 tok/s · best 160.1 tok/s

Response time#12/23

1.33 s

probe median, to a complete answer

median 1.33 s · best 0.46 s

Context

1.05M

max output 943,718

published by Meta, not measured here

Tick above each rail is this model, below it the other 83. Dashed rule is the field median, solid is its best. Better is left; the axis stops at the 90th percentile, so a few models sit past its right edge.

Usage

How much this model is actually called here.

Rank

#85

of 112 active models

Tokens served

16.2K

all-time

Platform share

0.0%

of all tokens

Pricing

Pay per token. Cached input bills at this model’s own cached rate, listed below.

$1.6875 /1M input$5.7375 /1M output
Hobby10 req/day · 2K in / 500 out
~$1.87/mo
Production1,000 req/day · 2K in / 500 out
~$187/mo
Scale20,000 req/day · 2K in / 500 out
~$3,746/mo
+ Estimate your workload
1,000
2,000
500

Estimated monthly cost

$187

$6.24 / day on Muse Spark Open

Same workload on:

Llama 4 Maverick$40.12-79%
Muse Spark 1.1$171-9%

Estimates use list pricing. Actual bills depend on real token counts, and every response includes its exact cost.

How it compares

Against the peers people actually weigh it against.

SpecMuse Spark OpenLlama 4 MaverickMuse Spark 1.1
Input /1M$1.6875$0.3344$1.542
Output /1M$5.7375$1.337$5.243
Context1M1M1M
ToolsYesYesYes
ReasoningYesNoYes
Throughput160 tok/s

Quick start

Up and running in under two minutes.

  1. 1

    Create an API key

    Sign up and grab a key from the dashboard. Muse Spark Open needs a top-up — the signup credit covers the free tier.

    Get API key →
  2. 2

    Make your first request

    Drop in your key and send a chat completion — fully OpenAI-compatible.

    curl https://kymaapi.com/v1/chat/completions \
      -H "Authorization: Bearer YOUR_API_KEY" \
      -H "Content-Type: application/json" \
      -d '{
        "model": "muse-spark-open",
        "messages": [
          {"role": "user", "content": "Explain prompt caching in one paragraph."}
        ]
      }'
  3. 3

    Stream responses

    Add "stream": true to receive tokens as they arrive.

    curl https://kymaapi.com/v1/chat/completions \
      -H "Authorization: Bearer YOUR_API_KEY" \
      -H "Content-Type: application/json" \
      -d '{
        "model": "muse-spark-open",
        "stream": true,
        "messages": [{"role": "user", "content": "Hello!"}]
      }'

FAQ

Common questions about this model.

What is the context window of Muse Spark Open?

Muse Spark Open has a 1M-token context window — roughly 1542 pages of text in a single request.

How much does the Muse Spark Open API cost?

$1.6875 per 1M input tokens and $5.7375 per 1M output tokens. No subscription; you pay only for what you use.

Does Muse Spark Open support function calling?

Yes — Muse Spark Open supports tool/function calling and structured outputs (JSON mode), so it works with agent frameworks out of the box.

Are the weights for Muse Spark Open publicly available?

Yes. Meta publishes Muse Spark Open's weights as meta-models/Muse-Spark-Open-816B-A42B, so you can download and run the model yourself (https://huggingface.co/meta-models/Muse-Spark-Open-816B-A42B, read 2026-10-25). Kyma serves it because it is convenient and has failover behind it, not because it is the only way to reach it.

Is Muse Spark Open ever served below the precision its creator released it at?

Kyma cannot say. Answering it needs the precision Meta released Muse Spark Open in, and we could not source that from Meta's own material — so there is nothing to compare a route against. We publish "not established" rather than reading a low format as a downgrade: on several models in this catalogue a low format is exactly how the creator ships it.

How do I use Muse Spark Open?

Kyma is OpenAI-compatible: point your SDK's base URL at https://kymaapi.com/v1, use your Kyma API key, and set the model to muse-spark-open. Signing up is free, but this model needs a top-up: the $0.50 signup credit covers the free tier only.

Needs a top-up — the signup credit covers the free tier.Create account →

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