# Muse Ember vs Muse Spark Open (slim)

> Muse Spark Open scores 53.4 (D) to Muse Ember's 51.8 (D) for llm inference. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/muse-ember-vs-muse-spark-open.md (~5,350 tokens) · this version ~830 tokens · JSON https://www.anchorterminal.com/compare/muse-ember-vs-muse-spark-open.json · canonical https://www.anchorterminal.com/compare/muse-ember-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
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Muse Spark Open scores 53.4 (D) on agent readiness against Muse Ember's 51.8 (D), and leads in 4 of 7 scored categories. Muse Ember leads on security & auth. Both do llm inference.

- Muse Ember: D 51.8, rank #1017 of 1515 · https://www.anchorterminal.com/tools/muse-ember.min.md
- Muse Spark Open: D 53.4, rank #952 of 1515 · https://www.anchorterminal.com/tools/muse-spark-open.min.md
- Muse Ember, good for Agents that hand out many small, bounded tasks (sub-agents, tool loops, routing, extraction over thousands of files) and want a cheap multimodal model with a 1M context behind the same API as a bigger Muse model. Ahead on Security & auth, 64 against 44. Also 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; Maintenance & community, 60 against 46. Also No key needed to call it.

| Category | Muse Ember | Muse Spark Open |
| --- | --- | --- |
| Reliability (16%) | 40 | 42 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 60 | 61 |
| Agent ergonomics (13%) | 72 | 69 |
| Security & auth (14%) | 64 | 44 |
| Payments & pricing (10%) | 20 | 50 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 46 | 60 |
| Transparency & trust (7%) | 53 | 53 |

| Fact (where they differ) | Muse Ember | Muse Spark Open |
| --- | --- | --- |
| Hosted endpoint | `https://api.meta.ai/v1` | no (local only) |
| Transports |  | HTTP |
| Auth | API key | None |
| Pricing | Pay per use | Free |
| Licence | Closed model, used through Meta Model API and Muse Code under the Meta Model API Terms of Service (last updated 9 October 2026). No open weights; Meta's open-weight models are Muse Spark Open and Muse Glimmer | 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 | 2026-10-02 | 2026-10-15 |
| Privacy policy last updated | couldn't be read | no document linked |
| Customer content may train models | yes | 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:
- Payments & pricing, Muse Spark Open +30: Muse Ember 20 (Published rubric.); Muse Spark Open 50 (Self-hosted rule.)
- Security & auth, Muse Ember +20: Muse Ember 64 (Platform readings are the meta-model-api listing's of 4 November.); Muse Spark Open 44 (Read as software the owner runs.)
- Maintenance & community, Muse Spark Open +14: Muse Ember 46 (Model reading.); Muse Spark Open 60 (Read for an open-weight model released three weeks ago.)