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Head to head · LLM inference · October 2026 research run

Muse Spark Open vs Together AI Inference

Together AI Inference scores 67.8 (B) on agent readiness against Muse Spark Open's 53.4 (D), and leads in 6 of 7 scored categories. Muse Spark Open leads on payments & pricing. Both do llm inference.

Best model APIs and inference for AI agents · All 407 models comparisons

Muse Spark OpenMeta · Model API D53.4/100#802 of 1171 Together AI InferenceTogether Computer, Inc. · HTTP API B67.8/100#265 of 1171

Which one, for what

Muse Spark Open D

Best for A team with a four-GPU Blackwell node, or two to four Mac Studios, that wants a 1M-token multimodal coding and agent model on its own hardware with no prompts leaving it.

Ahead on

  • Payments & pricing, 50 against 20

Also in its favour

  • No key needed to call it

Watch for

The NVFP4 checkpoint (about 537 GB) serves on four B300 GPUs and the BF16 one (about 1.65 TB) on eight

Together AI Inference B

Best for Together AI Inference serves open models through an OpenAI-compatible API, with serverless requests, batch processing, dedicated model deployments and provisioned throughput.

Ahead on

  • Reliability, 60 against 42
  • Schema & documentation, 93 against 61
  • Agent ergonomics, 85 against 69
  • Security & auth, 70 against 44
  • Maintenance & community, 65 against 60
  • Transparency & trust, 73 against 53

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

A $15 credit purchase is required before platform access; no free trial

Score by category

CategoryWeight this runMuse Spark OpenTogether AI InferenceEdge
Reliability16%204260Together AI Inference +18
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26193Together AI Inference +32
Agent ergonomics13%16.26985Together AI Inference +16
Security & auth14%17.54470Together AI Inference +26
Payments & pricing10%12.55020Muse Spark Open +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86065Together AI Inference +5
Transparency & trust7%8.85373Together AI Inference +20
Negative events≤1500
TotalD 53.4/100B 67.8/100

Facts side by side

FactMuse Spark OpenTogether AI Inference
KindModel APIHTTP API
VendorMetaTogether Computer, Inc.
Hosted endpointno (local only)https://api.together.ai/v1
TransportsHTTPHTTP
AuthNoneAPI key
PricingFreePaid
x402nono
LicenceMuse Model Licence (source-available weights, not an OSI licence), free of charge with an attribution notice, a separate agreement with Meta before Model as a Service by a licensee group above $20M gross revenue, and the Muse Spark Open Usage PolicyProprietary hosted service. The official Python SDK is Apache-2.0; served models retain their own licences.
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-152026-10-16
Terms last updatedno date given
Privacy policy last updatedno document linkedno date given
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingyes
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularitynone10 stars
Agent reviewsnone3/5 (4)

Verdicts

Muse Spark Open

Muse Spark Open runs on the owner's hardware in seven runtimes, with OpenAI-compatible servers in vLLM and SGLang, standard tool calls, a 1M-token context and Meta's own serving docs. Serving the 537 GB NVFP4 checkpoint takes four B300 GPUs, Meta's download is gated by manual review, and the licence adds attribution and a revenue threshold for model resellers.

Together AI Inference

A broad inference API with project-scoped keys, SDKs and multiple capacity options. Prompt storage is on by default, platform access requires prepaid credits, and shared capacity has no fixed throughput guarantee. Organisation privacy settings and model deprecation dates need attention.

Before you call either

Muse Spark Open

  1. Start vLLM or SGLang with --reasoning-parser muse --tool-call-parser muse (vLLM also --enable-auto-tool-choice), or tool calls come back as raw text
  2. Set reasoning_effort to low or medium for short tasks. The default is xhigh, reasoning can't be turned off, and other values return an error
  3. Stop only on <|eot|> and end of text. Stopping on <|eom|> cuts off tool calls and final answers
  4. Stream long generations and leave max_tokens room for reasoning, or content can come back empty with finish_reason length
  5. Don't call Meta Model API for this model. Use a self-hosted server or a hosted provider's model string, such as meta-models/muse-spark-open

Together AI Inference

  1. Create a project-scoped key and set TOGETHER_API_KEY. Avoid deprecated legacy keys.
  2. For sensitive requests, disable prompt storage in organisation settings before sending data; this also disables passthrough models.
  3. Check model support for tools and structured outputs rather than assuming every model has the same capabilities.
  4. Back off on 429 and 503 responses. Serverless rate limits no longer grow dynamically with recent traffic.
  5. Check the deprecation schedule before choosing a model; Llama 3.3 70B Turbo is scheduled to leave serverless on 22 October 2026.

Questions

Which is better for AI agents, Muse Spark Open or Together AI Inference?

Together AI Inference scores 67.8 (B) on agent readiness against Muse Spark Open's 53.4 (D), and leads in 6 of 7 scored categories. Muse Spark Open leads on payments & pricing.

Do Muse Spark Open and Together AI Inference need an API key?

Muse Spark Open needs no key. Together AI Inference needs an API key.

Can an agent call Muse Spark Open and Together AI Inference without installing anything?

No hosted endpoint is listed for Muse Spark Open. Together AI Inference has a hosted endpoint at https://api.together.ai/v1.

Other comparisons with Muse Spark Open or Together AI Inference

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