Write a review

Head to head · LLM inference · October 2026 research run

Cohere Chat API (Command models) vs Muse Spark Open

Cohere Chat API (Command models) scores 64.7 (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 210 models comparisons

Cohere Chat API (Command models)Cohere · Model API B64.7/100#367 of 1095 Muse Spark OpenMeta · Model API D53.4/100#760 of 1095

Which one, for what

Cohere Chat API (Command models) B

Best for Teams that want Command models for RAG with citations, tool use and multilingual work, and that may later move to a private deployment or Model Vault.

Ahead on

  • Reliability, 64 against 42
  • Schema & documentation, 84 against 61
  • Security & auth, 57 against 44
  • Maintenance & community, 72 against 60
  • Transparency & trust, 74 against 53

Also in its favour

  • A hosted endpoint, with nothing to install
  • Free to start without a card

Watch for

Production keys work like trial keys on Command A+, Reasoning, Translate and Vision. The docs send production use of those models to sales or to Model Vault

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 30

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

Score by category

CategoryWeight this runCohere Chat API (Command models)Muse Spark OpenEdge
Reliability16%206442Cohere Chat API (Command models) +22
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28461Cohere Chat API (Command models) +23
Agent ergonomics13%16.27269Cohere Chat API (Command models) +3
Security & auth14%17.55744Cohere Chat API (Command models) +13
Payments & pricing10%12.53050Muse Spark Open +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87260Cohere Chat API (Command models) +12
Transparency & trust7%8.87453Cohere Chat API (Command models) +21
Negative events≤1500
TotalB 64.7/100D 53.4/100

Facts side by side

FactCohere Chat API (Command models)Muse Spark Open
KindModel APIModel API
VendorCohereMeta
Hosted endpointhttps://api.cohere.com/v2/chatno (local only)
TransportsHTTPHTTP
AuthAPI keyNone
PricingFreemiumFree
x402nono
LicenceProprietary service under Cohere's Commercial SaaS Agreement. The SDKs are MITMuse 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 Policy
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-092026-10-15
Terms last updated2025-04-08
Privacy policy last updated2026-05-01no document linked
Customer content may train modelsyes
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingyes
Terms or service can change without noticeyes
Arbitration or class-action waivernot found in the text

Verdicts

Cohere Chat API (Command models)

A public OpenAPI file, Markdown twins of every docs page and SDKs in four languages make the Chat API easy for an agent to read. Production keys do not cover the four newest Command models, whose limits are set by sales, and the SaaS agreement lets Cohere share API data with third parties.

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.

Before you call either

Cohere Chat API (Command models)

  1. Call POST https://api.cohere.com/v2/chat with Authorization: bearer <key>. model and messages are the only required fields
  2. Use command-a-03-2025, command-r-08-2024, command-r-plus-08-2024 or command-r7b-12-2024 for production traffic. Newer variants stay at trial limits on a production key
  3. Keep a trial key under 20 chat requests a minute and 1,000 calls a month, and do not use it for commercial work
  4. Set response_format with a json_schema for structured output, and tell the model to produce JSON when using json_object without a schema
  5. Ask the account Owner to turn off training under Data Controls in the dashboard before sending confidential prompts

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

Questions

Which is better for AI agents, Cohere Chat API (Command models) or Muse Spark Open?

Cohere Chat API (Command models) scores 64.7 (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 Cohere Chat API (Command models) and Muse Spark Open need an API key?

Cohere Chat API (Command models) needs an API key. Muse Spark Open needs no key.

Can an agent call Cohere Chat API (Command models) and Muse Spark Open without installing anything?

Cohere Chat API (Command models) has a hosted endpoint at https://api.cohere.com/v2/chat. No hosted endpoint is listed for Muse Spark Open.

Other comparisons with Cohere Chat API (Command models) or Muse Spark Open

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report