---
title: "FusionPlugin"
---

## Fields

| Field                                                                                                                                                                                                                                                                                                                                                            | Type                                                                                                                                                                                                                                                                                                                                                             | Required                                                                                                                                                                                                                                                                                                                                                         | Description                                                                                                                                                                                                                                                                                                                                                      | Example                                                                                                                                                                                                                                                                                                                                                          |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `analysis_models`                                                                                                                                                                                                                                                                                                                                                | List[*str*]                                                                                                                                                                                                                                                                                                                                                      | :heavy_minus_sign:                                                                                                                                                                                                                                                                                                                                               | Slugs of models to run in parallel as the "expert panel" the judge analyzes. Each model receives the same user prompt with web_search + web_fetch enabled. Capped at 8 models to bound cost amplification. When omitted, defaults to the Quality preset from the /labs/fusion UI (~anthropic/claude-opus-latest, ~openai/gpt-latest, ~google/gemini-pro-latest). | [<br/>"~anthropic/claude-opus-latest",<br/>"~openai/gpt-latest",<br/>"~google/gemini-pro-latest"<br/>]                                                                                                                                                                                                                                                           |
| `enabled`                                                                                                                                                                                                                                                                                                                                                        | *Optional[bool]*                                                                                                                                                                                                                                                                                                                                                 | :heavy_minus_sign:                                                                                                                                                                                                                                                                                                                                               | Set to false to disable the fusion plugin for this request. Defaults to true.                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                  |
| `id`                                                                                                                                                                                                                                                                                                                                                             | [components.FusionPluginID](../components/fusionpluginid.mdx)                                                                                                                                                                                                                                                                                                     | :heavy_check_mark:                                                                                                                                                                                                                                                                                                                                               | N/A                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                  |
| `max_tool_calls`                                                                                                                                                                                                                                                                                                                                                 | *Optional[int]*                                                                                                                                                                                                                                                                                                                                                  | :heavy_minus_sign:                                                                                                                                                                                                                                                                                                                                               | Maximum number of tool-calling steps each panelist (analysis model) and the judge model may take during their agentic web-research loop. Models with web_search/web_fetch enabled iterate until they produce a text response or hit this ceiling. Defaults to 8. Capped at 16.                                                                                   | 12                                                                                                                                                                                                                                                                                                                                                               |
| `model`                                                                                                                                                                                                                                                                                                                                                          | *Optional[str]*                                                                                                                                                                                                                                                                                                                                                  | :heavy_minus_sign:                                                                                                                                                                                                                                                                                                                                               | Slug of the model that performs both the judge step (with web_search + web_fetch) and the final synthesis. When omitted, defaults to the first model in the Quality preset.                                                                                                                                                                                      | ~anthropic/claude-opus-latest                                                                                                                                                                                                                                                                                                                                    |
| `preset`                                                                                                                                                                                                                                                                                                                                                         | [Optional[components.PresetEnum]](../components/presetenum.mdx)                                                                                                                                                                                                                                                                                                   | :heavy_minus_sign:                                                                                                                                                                                                                                                                                                                                               | A curated OpenRouter fusion preset (slugs follow `<task>-<tier>`, e.g. `general-high`). Expands server-side into the preset's analysis_models panel and judge model, so callers never name individual models. Explicitly provided `analysis_models` / `model` take precedence.                                                                                   | general-high                                                                                                                                                                                                                                                                                                                                                     |
| `tools`                                                                                                                                                                                                                                                                                                                                                          | List[[components.FusionPluginTool](../components/fusionplugintool.mdx)]                                                                                                                                                                                                                                                                                           | :heavy_minus_sign:                                                                                                                                                                                                                                                                                                                                               | Server tools available to panelist and judge inner calls. Each entry uses the same `{ type, parameters? }` shorthand as the outer Chat Completions request. When omitted, defaults to `[{ type: "openrouter:web_search" }, { type: "openrouter:web_fetch" }]`. Pass an empty array to disable tools entirely (panelists answer from parametric knowledge only).  | [<br/>\{<br/>"parameters": \{<br/>"excluded_domains": [<br/>"example.com"<br/>]<br/>},<br/>"type": "openrouter:web_search"<br/>},<br/>\{<br/>"type": "openrouter:web_fetch"<br/>}<br/>]                                                                                                                                                                             |