Union Alpha is a new stealth AI model available through OpenRouter.
Key numbers:
- 256K context window
- 128K max output
- $0 input
- $0 output
- Around 20 tokens/second
- Around 10 seconds initial latency
- Multimodal
- Tool calling supported
- Structured/JSON outputs supported
The biggest attraction is simple: 256K context + 128K output + free access.
For now, the provider behind Union Alpha remains undisclosed, so its real origin and long-term pricing are still unknown.