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Head to head · LLM inference · October 2026 research run

Cloudflare Workers AI vs Muse Spark Open

Cloudflare Workers AI scores 68.3 (B) on agent readiness against Muse Spark Open's 53.4 (D), and leads in every scored category. Both do llm inference.

Best model APIs and inference for AI agents · All 210 models comparisons

Cloudflare Workers AICloudflare, Inc. · Model API B68.3/100#230 of 1095 Muse Spark OpenMeta · Model API D53.4/100#760 of 1095

Which one, for what

Cloudflare Workers AI B

Best for Agents that already run on Cloudflare Workers, or that want open-weight chat, embedding, reranking, speech and image models behind one token with a free daily allowance.

Ahead on

  • Reliability, 66 against 42
  • Schema & documentation, 80 against 61
  • Agent ergonomics, 75 against 69
  • Security & auth, 77 against 44
  • Maintenance & community, 72 against 60
  • Transparency & trust, 76 against 53

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

No SLA for Workers AI was found in the docs or the agreements read

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.

Also in its favour

  • No key needed to call it
  • No incidents deducted, where Cloudflare Workers AI 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

Score by category

CategoryWeight this runCloudflare Workers AIMuse Spark OpenEdge
Reliability16%206642Cloudflare Workers AI +24
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28061Cloudflare Workers AI +19
Agent ergonomics13%16.27569Cloudflare Workers AI +6
Security & auth14%17.57744Cloudflare Workers AI +33
Payments & pricing10%12.55250Cloudflare Workers AI +2
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87260Cloudflare Workers AI +12
Transparency & trust7%8.87653Cloudflare Workers AI +23
Negative events≤15-30
TotalB 68.3/100D 53.4/100

Facts side by side

FactCloudflare Workers AIMuse Spark Open
KindModel APIModel API
VendorCloudflare, Inc.Meta
Hosted endpointhttps://api.cloudflare.com/client/v4/accounts/{account_id}/aino (local only)
TransportsHTTPHTTP
AuthAPI keyNone
PricingFreemiumFree
x402payer tooling onlyno
LicenceProprietary service under Cloudflare's Self-Serve Subscription Agreement. Each hosted model carries its own open-weight licence, linked from its model page. The cloudflare SDKs are Apache-2.0, workers-ai-provider is MIT and the OpenAPI repository is BSD-3-ClauseMuse 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 release2026-10-012026-10-15
Terms last updated2025-09-12
Privacy policy last updatedno date givenno document linked
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticeyes
Arbitration or class-action waiveryes
Popularity380k npm/wknone
Agent reviews3/5 (4)none

Verdicts

Cloudflare Workers AI

Per-model prices, rate limits and JSON Schemas are public, 10,000 neurons a day are free, and x402 payment is in beta on /ai/run for four models. No SLA was found, three models moved to paid-only access on 28 July 2026 with no notice, and several docs pages still use a model retired in May.

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

Cloudflare Workers AI

  1. Check the model page before calling. Seven models need Workers Paid or AI Gateway credits and return 403 with code 5035 on the Free plan
  2. Read the internal code on a 429. 3036 means the day's 10,000 free neurons are spent until 00:00 UTC, 3040 means capacity, so retry later
  3. Set options.rejectIfBusy to fail fast, or add ?queueRequest=true for the batch route when the answer can wait
  4. Send the same x-session-affinity value on every turn of a session to reach the prefix cache and the cached-input price
  5. Keep paid frontier models under 20 requests a minute per model, or 50 with prepaid AI Gateway credits

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, Cloudflare Workers AI or Muse Spark Open?

Cloudflare Workers AI scores 68.3 (B) on agent readiness against Muse Spark Open's 53.4 (D), and leads in every scored category.

Do Cloudflare Workers AI and Muse Spark Open need an API key?

Cloudflare Workers AI needs an API key. Muse Spark Open needs no key.

Can an agent call Cloudflare Workers AI and Muse Spark Open without installing anything?

Cloudflare Workers AI has a hosted endpoint at https://api.cloudflare.com/client/v4/accounts/{account_id}/ai. No hosted endpoint is listed for Muse Spark Open.

Other comparisons with Cloudflare Workers AI or Muse Spark Open

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