# Users ## Add **post** `/v1/express/{expressCustomerId}/users` Associates an existing user with a customer, granting them access to customer-specific resources and studies. ### Path Parameters - `expressCustomerId: string` Unique Express customer identifier. Format: cus_{32-hex-chars} ### Body Parameters - `userId: string` User ID to add to the Express customer. Format: usr_{32-hex-chars} ### Returns - `success: boolean` - `message: optional string` ### Example ```http curl https://api.avarasoftware.com/v1/express/$EXPRESS_CUSTOMER_ID/users \ -H 'Content-Type: application/json' \ -H "Authorization: Bearer $AVARA_API_KEY" \ -d '{ "userId": "usr_1234567890abcdef1234567890abcdef" }' ``` ## Remove **delete** `/v1/express/{expressCustomerId}/users` Removes a user's association with a customer, revoking their access to customer-specific resources. The user account remains active but is no longer linked to this customer. ### Path Parameters - `expressCustomerId: string` Unique Express customer identifier. Format: cus_{32-hex-chars} ### Body Parameters - `userId: string` User ID to remove from the Express customer. Format: usr_{32-hex-chars} ### Returns - `success: boolean` - `message: optional string` ### Example ```http curl https://api.avarasoftware.com/v1/express/$EXPRESS_CUSTOMER_ID/users \ -X DELETE \ -H "Authorization: Bearer $AVARA_API_KEY" ```