Muse Spark 1.3
Muse Spark 1.3 is Meta's September 2, 2026 hosted model for long-horizon agentic and coding work. The API ID is muse-spark-1.3, with a 1,048,576-token context window, text/image/video/PDF input, and text output.
Provider
Meta
Model family
Meta Muse
Hosted multimodal coding and agentic LLM
Cost tier
Spark
Status
Current
Release Sep 2, 2026
Why teams choose it
Standard-tier pricing matches Spark 1.2: $1.25 input / $0.15 cached / $4.25 output per 1M tokens
Contributor IDs (muse-spark-1.3-contributor) are $0.10 / $0.002 / $0.20 and permit training on prompts and completions.
Meta says 1.3 uses about 20% fewer tool calls and 25% fewer tokens than 1.2 in internal engineer comparisons
rematch on your harness.
Audio understanding on 1.3 is not fully supported
Meta tells teams to use Spark 1.2 or Muse Voice Transcribe for audio.
Tradeoffs to know
- Weights are not open; the announced Muse Spark open-weight release is still a roadmap item, not this checkpoint.
- Max reasoning is Standard-tier only. Muse Code docs still default to muse-spark-1.2 until you change the model.
- Contributor-tier data-use terms are not the Standard privacy path.
Benchmarks
No independent or vendor benchmark scores in this catalog entry.
Technical specs
- Inputs
- text, image, video, PDF
- Outputs
- text
- License
- Proprietary API
- API ID
muse-spark-1.3- Context tokens
- 1,048,576
- Capabilities
- coding
- long-horizon agents
- tool calling
- reasoning
- planning
- multitasking
- structured outputs
- search grounding
- image understanding
- video understanding
Sourcehttps://research.meta.ai/blog/introducing-muse-spark-1-3
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Muse Spark 1.3 FAQ
What is Muse Spark 1.3?
Muse Spark 1.3 is Meta's September 2, 2026 hosted model for long-horizon agentic and coding work. The API ID is muse-spark-1.3, with a 1,048,576-token context window, text/image/video/PDF input, and text output. Meta documents it in Muse Code and Meta Model API, with reasoning effort including max on the Standard tier. Official docs still list muse-spark-1.2 as the Muse Code default while recommending 1.3 for new API work.
When does Muse Spark 1.3 fit best?
Long-horizon coding agents in Muse Code and custom harnesses
What should teams watch out for with Muse Spark 1.3?
Weights are not open; the announced Muse Spark open-weight release is still a roadmap item, not this checkpoint.
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