Muse Spark 1.3 (xhigh) vs Union Alpha (Stealth)
A direct, empirical evaluation of Muse Spark 1.3 (xhigh) (Meta AI) against Union Alpha (Stealth) (OpenRouter & OpenCode).
Muse Spark 1.3 (xhigh)
Developed by Meta AI · Proprietary Multimodal parameters
Autonomous codebase refactoring, terminal execution, million-token long context retrieval, and agentic workflows.
Union Alpha (Stealth)
Developed by OpenRouter & OpenCode · Multi-Model Ensemble Mixture parameters
Terminal coding agents, pull-request synthesis, multi-model consensus verification, and zero-cost autonomous refactoring.
| Metric | Muse Spark 1.3 (xhigh) | Union Alpha (Stealth) |
|---|---|---|
| SWE-bench Verified | 75.4% | 74.2% |
| MMLU-Pro | 88.4% | 89.8% |
| MATH-500 | 94.8% | 95.4% |
| Context Window | 1,000,000 tokens | 256,000 tokens |
| Input Pricing (per 1M) | $1.25 | $0.00 |
| Output Pricing (per 1M) | $5.00 | $0.00 |