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Head to head · LLM inference · October 2026 research run

Muse Spark Open vs Vercel AI Gateway

Vercel AI Gateway scores 66.7 (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 326 models comparisons

Muse Spark OpenMeta · Model API D53.4/100#789 of 1133 Vercel AI GatewayVercel Inc. · Model router B66.7/100#302 of 1133

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
  • No incidents deducted, where Vercel AI Gateway loses 3 points for them

Watch for

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

Vercel AI Gateway B

Best for Teams that want one key, one bill, budgets and failover in front of many model providers, especially on Vercel with OIDC.

Ahead on

  • Reliability, 74 against 42
  • Schema & documentation, 74 against 61
  • Agent ergonomics, 83 against 69
  • Security & auth, 79 against 44
  • Maintenance & community, 79 against 60
  • Transparency & trust, 70 against 53

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

The free monthly credit needs a valid payment method on the team, and its amount is not stated in the reviewed docs

Score by category

CategoryWeight this runMuse Spark OpenVercel AI GatewayEdge
Reliability16%204274Vercel AI Gateway +32
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26174Vercel AI Gateway +13
Agent ergonomics13%16.26983Vercel AI Gateway +14
Security & auth14%17.54479Vercel AI Gateway +35
Payments & pricing10%12.55020Muse Spark Open +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86079Vercel AI Gateway +19
Transparency & trust7%8.85370Vercel AI Gateway +17
Negative events≤150-3
TotalD 53.4/100B 66.7/100

Facts side by side

FactMuse Spark OpenVercel AI Gateway
KindModel APIModel router
VendorMetaVercel Inc.
Hosted endpointno (local only)https://ai-gateway.vercel.sh/v1
TransportsHTTPHTTP
AuthNoneOAuth or key
PricingFreePay per use
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 service under Vercel's Terms of Service and AI Product Terms, with Token Pass terms on its docs page. Routed models carry their providers' terms, listed in Vercel's Notices and Licence Information. The @ai-sdk/gateway provider is Apache-2.0
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-152026-10-17
Terms last updated2026-06-01
Privacy policy last updatedno document linked2026-06-01
Customer content may train modelsyes, with an opt-out
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waiveryes
Popularitynone29.6M npm/wk
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.

Vercel AI Gateway

Token prices pass through with no markup, prompts are not stored by the gateway, and budgets, provider failover and per-request logs are built in. The free monthly credit needs a card on file, rate limits are not published as numbers, no SLA covers the API, and the contractual promise not to train on content applies to Enterprise subscriptions only.

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

Vercel AI Gateway

  1. Read GET https://ai-gateway.vercel.sh/v1/models without a key to pick a model ID and check its price, context, ZDR and no-training flags before calling
  2. Set zeroDataRetention or disallowPromptTraining to true in providerOptions.gateway on sensitive requests. Default routing ignores provider retention and training policies
  3. Treat a 429 as retryable and honour retry-after when present. A 402 with quota_for_entity_exceeded is a spent budget, so do not retry it
  4. On a Token Pass key, a 403 with no_providers_available means spent credit or a model outside the pass. Retry with a standard AI Gateway key, which bills credits
  5. Set inferenceRegion when data residency matters. The default global may run inference outside the user's jurisdiction

Questions

Which is better for AI agents, Muse Spark Open or Vercel AI Gateway?

Vercel AI Gateway scores 66.7 (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 Muse Spark Open and Vercel AI Gateway need an API key?

Muse Spark Open needs no key. Vercel AI Gateway takes an API key or an OAuth sign-in.

Can an agent call Muse Spark Open and Vercel AI Gateway without installing anything?

No hosted endpoint is listed for Muse Spark Open. Vercel AI Gateway has a hosted endpoint at https://ai-gateway.vercel.sh/v1.

Other comparisons with Muse Spark Open or Vercel AI Gateway

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