# Claude Mythos 5.2 vs Muse Spark Open (slim)

> Claude Mythos 5.2 scores 76.1 (BB) to Muse Spark Open's 53.4 (D) for llm inference. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/claude-mythos-5-2-vs-muse-spark-open.md (~7,550 tokens) · this version ~1,080 tokens · JSON https://www.anchorterminal.com/compare/claude-mythos-5-2-vs-muse-spark-open.json · canonical https://www.anchorterminal.com/compare/claude-mythos-5-2-vs-muse-spark-open
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-09
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Claude Mythos 5.2 scores 76.1 (BB) 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.

- Claude Mythos 5.2: BB 76.1, rank #51 of 1517 · https://www.anchorterminal.com/tools/claude-mythos-5-2.min.md
- Muse Spark Open: D 53.4, rank #954 of 1517 · https://www.anchorterminal.com/tools/muse-spark-open.min.md
- Claude Mythos 5.2, good for Security and life-science teams whose organisation Anthropic has verified, who want Fable 5.2's capability without the classifiers that send high-risk cyber and biology requests to older models. Ahead on Reliability, 60 against 42; Schema & documentation, 90 against 61; Agent ergonomics, 95 against 69; Security & auth, 92 against 44; Maintenance & community, 91 against 60; Transparency & trust, 85 against 53. Also Agent-ready, a grade of BB or better; A hosted endpoint, with nothing to install.
- Muse Spark Open, 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. Ahead on Payments & pricing, 50 against 20. Also No key needed to call it.

| Category | Claude Mythos 5.2 | Muse Spark Open |
| --- | --- | --- |
| Reliability (16%) | 60 | 42 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 90 | 61 |
| Agent ergonomics (13%) | 95 | 69 |
| Security & auth (14%) | 92 | 44 |
| Payments & pricing (10%) | 20 | 50 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 91 | 60 |
| Transparency & trust (7%) | 85 | 53 |

| Fact (where they differ) | Claude Mythos 5.2 | Muse Spark Open |
| --- | --- | --- |
| Vendor | Anthropic | Meta |
| Hosted endpoint | `https://api.anthropic.com/v1` | no (local only) |
| Transports |  | HTTP |
| Auth | API key | None |
| Pricing | Pay per use | Free |
| Licence | Closed model, used through the Claude API and cloud platforms under Anthropic's Commercial Terms of Service | 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 |
| Last release | 2026-11-09 | 2026-10-15 |
| Terms last updated | no date given | 2026-10-15 |
| Privacy policy last updated | no date given | no document linked |
| Customer content may train models | yes, with an opt-out | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |

Why the edge:
- Security & auth, Claude Mythos 5.2 +48: Claude Mythos 5.2 92 (Model reading for claude-mythos-5-2 on the Claude API.); Muse Spark Open 44 (Read as software the owner runs.)
- Transparency & trust, Claude Mythos 5.2 +32: Claude Mythos 5.2 85 (Model reading for claude-mythos-5-2 on the Claude API.); Muse Spark Open 53 (Weights are downloadable under the Muse Model Licence, which is clear and broad in its grant but not an OSI licence.)
- Maintenance & community, Claude Mythos 5.2 +31: Claude Mythos 5.2 91 (Model reading for claude-mythos-5-2 on the Claude API.); Muse Spark Open 60 (Read for an open-weight model released three weeks ago.)
- Payments & pricing, Muse Spark Open +30: Claude Mythos 5.2 20 (Model reading for claude-mythos-5-2 on the Claude API.); Muse Spark Open 50 (Self-hosted rule.)
- Schema & documentation, Claude Mythos 5.2 +29: Claude Mythos 5.2 90 (Model reading for claude-mythos-5-2 on the Claude API.); Muse Spark Open 61 (Read for a model the owner serves.)
- Agent ergonomics, Claude Mythos 5.2 +26: Claude Mythos 5.2 95 (Model reading for claude-mythos-5-2 on the Claude API.); Muse Spark Open 69 (Model reading of the checklist (tool use, structured output, caching, context, throughput, defaults and SDKs, errors).)