> ## 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. # PrivateEndpointReasoningReturnMechanism Where the upstream puts reasoning tokens in its response: `reasoning` and `reasoning-content` are response fields, `content-string` is inline in the message, `none` returns no reasoning. `null` uses the provider default. ## Example Usage ```go theme={null} import ( "github.com/OpenRouterTeam/go-sdk/models/components" ) value := components.PrivateEndpointReasoningReturnMechanismContentString // Open enum: custom values can be created with a direct type cast custom := components.PrivateEndpointReasoningReturnMechanism("custom_value") ``` ## Values | Name | Value | | - | - | | `PrivateEndpointReasoningReturnMechanismContentString` | content-string | | `PrivateEndpointReasoningReturnMechanismReasoningContent` | reasoning-content | | `PrivateEndpointReasoningReturnMechanismReasoning` | reasoning | | `PrivateEndpointReasoningReturnMechanismNone` | none |