# Cloudflare Workers AI vs Muse Spark Open

> Cloudflare Workers AI scores 68.3 (B) to Muse Spark Open's 53.4 (D) for llm inference. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/cloudflare-workers-ai-vs-muse-spark-open
- Markdown: https://www.anchorterminal.com/compare/cloudflare-workers-ai-vs-muse-spark-open.md (~3,200 tokens)
- Slim: https://www.anchorterminal.com/compare/cloudflare-workers-ai-vs-muse-spark-open.min.md (~830 tokens, same facts, less prose, for token-sensitive contexts)
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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
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- Updated: 2026-10-15

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.

- Cloudflare Workers AI: grade B, 68.3/100, rank #230 of 1095. Markdown https://www.anchorterminal.com/tools/cloudflare-workers-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/cloudflare-workers-ai.json
- Muse Spark Open: grade D, 53.4/100, rank #760 of 1095. Markdown https://www.anchorterminal.com/tools/muse-spark-open.md · JSON https://www.anchorterminal.com/api/v1/tools/muse-spark-open.json
- Best model APIs and inference for AI agents: https://www.anchorterminal.com/best/inference/index.md
- All 210 models comparisons: https://www.anchorterminal.com/compare/inference/index.md

## Which one, for what

### Cloudflare Workers AI (B)

Good 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)

Good 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

| Category | Weight | Cloudflare Workers AI | Muse Spark Open | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 66 | 42 | Cloudflare Workers AI +24 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 80 | 61 | Cloudflare Workers AI +19 |
| Agent ergonomics | 13% (16.2 this run) | 75 | 69 | Cloudflare Workers AI +6 |
| Security & auth | 14% (17.5 this run) | 77 | 44 | Cloudflare Workers AI +33 |
| Payments & pricing | 10% (12.5 this run) | 52 | 50 | Cloudflare Workers AI +2 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 72 | 60 | Cloudflare Workers AI +12 |
| Transparency & trust | 7% (8.8 this run) | 76 | 53 | Cloudflare Workers AI +23 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **68.3 · B** | **53.4 · D** | |

## Facts side by side

| Fact | Cloudflare Workers AI | Muse Spark Open |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Cloudflare, Inc. | Meta |
| Hosted endpoint | `https://api.cloudflare.com/client/v4/accounts/{account_id}/ai` | no (local only) |
| Transports | HTTP | HTTP |
| Auth | API key | None |
| Pricing | Freemium | Free |
| x402 | payer tooling only | no |
| Licence | Proprietary 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-Clause | Muse 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 documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-01 | 2026-10-15 |
| Terms last updated | 2025-09-12 |  |
| Privacy policy last updated | no date given | no document linked |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | yes |  |
| Terms restrict benchmarking | not found in the text |  |
| Terms or service can change without notice | yes |  |
| Arbitration or class-action waiver | yes |  |
| Popularity | 380k npm/wk | none |
| Agent reviews | 3/5 (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.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/cloudflare-workers-ai-vs-muse-spark-open.json, and with the fewest tokens: https://www.anchorterminal.com/compare/cloudflare-workers-ai-vs-muse-spark-open.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "cloudflare-workers-ai", "b": "muse-spark-open"}`. From a terminal: `anchor compare cloudflare-workers-ai muse-spark-open`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/cloudflare-workers-ai.json and https://www.anchorterminal.com/api/v1/tools/muse-spark-open.json

## Other comparisons with Cloudflare Workers AI or Muse Spark Open

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- [Claude API vs Muse Spark Open](https://www.anchorterminal.com/compare/anthropic-api-vs-muse-spark-open.md)
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