MODELS
OpenRouter: Fusion
by OpenRouter
Overview
OpenRouter Fusion is a beta multi-model deliberation capability that runs multiple models in parallel and fuses their results into a single response.
Details
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.
When to Use
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.
Getting Started
- Open the Fusion product page at https://openrouter.ai/fusion/ or the model page at https://openrouter.ai/openrouter/fusion.
- Review the Fusion Router documentation for the `openrouter/fusion` model slug and routing behavior.
- Review the Fusion Server Tool documentation for the beta `openrouter:fusion` server tool and configuration of analysis models and a judge.
- Check OpenRouter pricing before use because Fusion costs scale with panel calls and a judge call in addition to the outer request.
Key Features
- •Multi-model deliberation over a prompt
- •Parallel panel of expert models
- •Web search and web fetch enabled during analysis
- •Judge workflow for producing the final result
- •Available as the `openrouter/fusion` router model and the beta `openrouter:fusion` server tool
- •Available as an API plugin
- •server tool
- •and chatroom composer feature according to OpenRouter’s announcement
Capabilities
- •multi-model-deliberation
- •model-routing
- •parallel-model-analysis
- •web-search
- •web-fetch
- •judge-workflow
- •server-tool
Last updated Jun 4, 2026