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Favicon for stealth

Stealth

Access 2 Stealth models through the OpenRouter unified API including Union Alpha and Ox Alpha. Compare pricing, context windows, benchmarks, and capabilities between different Stealth models.

Stealth tokens processed on OpenRouter

  • Favicon for stealth
    Union AlphaUnion Alpha
    55.4B tokens

    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 Terms

    by stealthSep 16, 2026262K context$0/M input tokens$0/M output tokens
  • Favicon for stealth
    Ox AlphaOx Alpha

    Ox Alpha is a reasoning model designed for coding, sustained agentic work, and production workloads. It is suited for long-horizon software engineering, complex reasoning, and workflows that combine text with visual context. Ox 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 are retained by the provider and are not used for training; all other use is governed by the Stealth Model Terms.

    by stealthAug 20, 20261.05M context

Frequently asked questions

OpenRouter serves 2 Stealth models behind one OpenAI-compatible API. Create an OpenRouter API key, point your client at https://openrouter.ai/api/v1, and set the model to an ID such as stealth/union-alpha. The quickstart has request examples for every supported SDK.

Union Alpha is available at no cost through the OpenRouter API.

Ox Alpha has the largest context window of any Stealth model on OpenRouter, accepting up to 1,048,576 tokens per request.

Union Alpha is the most recently added Stealth model on OpenRouter, listed on September 16, 2026.