> ## Documentation Index > Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Document A document to rerank. Either a plain string, or a structured object with optional `text` and/or `image`. ## Supported Types ### ```go theme={null} document := operations.CreateDocumentStr(string{/* values here */}) ``` ### DocumentRequest ```go theme={null} document := operations.CreateDocumentDocumentRequest(operations.DocumentRequest{/* values here */}) ``` ## Union Discrimination Use the `Type` field to determine which variant is active, then access the corresponding field: ```go theme={null} switch document.Type { case operations.DocumentTypeStr: // document.Str is populated case operations.DocumentTypeDocumentRequest: // document.DocumentRequest is populated } ```