> ## 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. # CreateExternalUserRequest ## Example Usage ```typescript theme={null} import { CreateExternalUserRequest } from "@openrouter/sdk/models"; let value: CreateExternalUserRequest = { user: "employee_123", }; ``` ## Fields | Field | Type | Required | Description | Example | | - | - | - | - | - | | `user` | *string* | ✔️ | Immutable case-sensitive tracking string supplied as user on inference requests or as external.user on API keys: 1 to 512 characters, well-formed Unicode, no NUL, no surrounding whitespace. URL-encode it in resource paths; an ID of `.` or `..` cannot be addressed by path, so look it up with the list filter. | employee\_123 |