Openrouter Fusion API

OpenRouter's Fusion API uses multiple expert models in parallel to analyze prompts with web search capabilities, then synthesizes their responses through a judge model to identify consensus, contradictions, and blind spots in a structured analysis. The service is free to use and features a 1-million token context window, with pricing based on the sum of all underlying model completions rather than a single model cost. Fusion is designed for high-stakes tasks where accuracy is critical, such as research and expert critique.