---
title: "Get user ID"
method: POST
path: "/public/get-user-id"
tags: ["User"]
---

# Get user ID

`POST /public/get-user-id`

Get the internal user ID for a user by looking them up via email or username. At least one of email or username must be provided.

Authentication with the "FERMION-API-KEY" header is required to use this endpoint.

Rate limit: Maximum 60 requests in a window of 1m.

## Request body

- object
  - `data` object[], required
    - `data` object, required
      - `userEmail` string, email — Email of the user
      - `username` string — Username of the user

## Response `200`

API Response Body

- object[]
  - `output` union, required
    - object
      - `status` 'ok', required
      - `data` object, required
        - `customUserId` union, required — Internal userId for the user provided by you. This would be blank if you did not create this user via API
          - string
          - unknown
          - unknown
        - `internalUserId` string, required — Internal userId for the user autogenerated by our system
    - object
      - `status` 'error', required
      - `errorMessage` string, required

---

[API](https://skmtc.net/fermion/apis/fermion-backend-api.md) · [All operations](https://skmtc.net/fermion/apis/fermion-backend-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/fermion/fermion-backend-api/versions/7ce364c8820b/schema)