Union Alpha—the free AI model that appeared on OpenRouter, OpenCode, and Cloudflare in “stealth” mode—has officially revealed its true identity: It is Pareto 26.9 from Unbiased AI, a platform built by Circuit & Chisel. This is a company founded in 2025 by two former Stripe executives, Louis Amira (CEO) and David Noël-Romas (CTO), specializing in payment infrastructure and automated workflows for AI agents.
It took the community just one day to uncover this information, demonstrating that the anonymity window for models on routers is shrinking rapidly.
Official specifications of Pareto 26.9
As previously known, Union Alpha, or Pareto 26.9, is a free multimodal model featuring a 262,144-token context window, support for text and image inputs, tool-calling capabilities, and structured outputs.
According to data from its homepage, Union Alpha served approximately 1 billion tokens per minute. The most active consumer platforms included omp (965 million tokens), Cline (342 million), Hermes Agent (317 million), and ZCode (206 million).
However, the model exhibits clear weaknesses: a P50 latency of around 17.6 seconds and a generation speed of just 14 tokens per second, making it far more suitable for batch processing than real-time chat. Its three-day uptime reached 98.08%.
On benchmarks, Pareto 26.9 competes directly with Anthropic’s Fable 5.1, OpenAI’s GPT-6 Astra, and DeepSeek 4.1 Flash, claiming up to a 75% cost reduction compared to frontier models.
In terms of pricing, for every 1 million tokens, Pareto costs $2.50 for input, $0.25 for cached input, and $7.50 for output.
Notably, this is not a standalone AI model but an orchestration layer, meaning it routes user requests across multiple frontier and open-source models simultaneously, then selects the best output at the most cost-effective price.
The stealth model approach on OpenRouter is shifting
Pareto is not an isolated case. Last month, Zhipu AI’s GLM 5.3 Flash model, which operated anonymously under the name Ox Alpha on OpenRouter, had its true identity uncovered by the community after drawing more than 50 trillion tokens during five days of stealth testing.
This pattern is turning into a new release strategy: launch a model for free and anonymously on routers, let the community evaluate it without brand bias, and once sufficient data is gathered, step forward and declare success.
However, the window of anonymity is growing shorter. Union Alpha remained secret for only a single day. Ox Alpha lasted slightly longer. As the community grows increasingly sophisticated at analyzing model fingerprints, the stealth window continues to narrow.