MODELS
by OpenRouter
OpenRouter Fusion is a beta multi-model deliberation capability that runs multiple models in parallel and fuses their results into a single response.
OpenRouter describes Fusion as turning a prompt into a small multi-model deliberation: a panel of expert models analyzes the prompt in parallel with web search and web fetch enabled, then a judge workflow produces the result. OpenRouter documents the router model slug `openrouter/fusion` and also documents `openrouter:fusion` as a beta server tool that lets any model invoke multi-model deliberation and configure analysis models and a judge. OpenRouter’s announcement describes Model Fusion as routing a prompt to multiple models in parallel, synthesizing their responses into one answer, and making it available as an API plugin, server tool, and chatroom composer feature.
Use when you want an OpenRouter-hosted workflow that compares or combines outputs from multiple models instead of relying on a single model response. Use for research or analysis prompts where parallel model deliberation web search web fetch and a judge workflow are useful. Use when building on OpenRouter and you want either the `openrouter/fusion` router model or the beta `openrouter:fusion` server tool interface.
Last updated Jun 4, 2026
