New stealth model: Union Alpha

OpenRouter listed a new stealth model called Union Alpha on September 16, 2026, developed and operated by an anonymous third-party provider. Union Alpha is a multimodal model built for research, coding, and agentic workflows with a 262K context window, offered free of charge, with prompts and completions that may be retained by the provider but not used for training. OpenRouter routes requests to the model and states it is not the developer, owner, or provider.

This stealth model is developed and operated by a third-party model provider. Prompts and completions for this model may retained by the provider but are not used for training; all other use is governed by Stealth Model TermsOpens in new tab https://openrouter.ai/terms/stealth Union Alpha is a multimodal model built for research, coding, and agentic workflows, while delivering frontier-level performance across a broad range of general-purpose tasks. Union Alpha is a stealth model. It is developed and operated by a third-party provider who has chosen to remain anonymous during this preview. OpenRouter routes requests to it and is not its developer, owner, or provider. Prompts and completions may be retained by the provider but are not used for training; all other use is governed by the Stealth Model TermsOpens in new tab https://openrouter.ai/terms/stealth Modalities Price Free Context 262K Released Sep 16, 2026 | | Free | Free | 29.62s | 19 tps | | Throughput 19tok/s P50, best across providers Latency 29.62s P50, best provider 100.00% 98.12% When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API https://openrouter.ai/docs/api/api-reference/endpoints/list-endpoints . Learn more https://openrouter.ai/docs/provider-routing about our load balancing and customization options.