---
title: "Login with WebAuthn MFA"
method: POST
path: "/auth/login/mfa/webauthn"
tags: ["Auth"]
---

# Login with WebAuthn MFA

`POST /auth/login/mfa/webauthn`

Complete login by verifying WebAuthn response during MFA. Requires the MFA ticket from initial login attempt.

## Request body

- WebAuthnMfaRequest
  - `response` WebAuthnAuthenticationResponse, required
    - `id` string, required
    - `rawId` string, required
    - `type` 'public-key', required
    - `authenticatorAttachment` 'cross-platform' | 'platform'
    - `clientExtensionResults` object, required
      - `appid` boolean
      - `credProps` object
        - `rk` boolean
      - `hmacCreateSecret` boolean
    - `response` object, required
      - `clientDataJSON` string, required
      - `authenticatorData` string, required
      - `signature` string, required
      - `userHandle` string
  - `challenge` string, required — The challenge string from authentication options
  - `ticket` string, required — The MFA ticket from the login response

## Response `200`

Success

- AuthTokenWithUserIdResponse
  - `token` string, required — Authentication token for API requests
  - `user_id` string, snowflake, required
  - `user` UserPartialResponse, required
    - `id` string, snowflake, required
    - `username` string, required — The username of the user, not unique across the platform
    - `discriminator` string, required — The four-digit discriminator tag of the user
    - `global_name` string, nullable, required — The display name of the user, if set
    - `avatar` string, nullable, required — The hash of the user avatar image
    - `avatar_color` integer, required
    - `bot` boolean — Whether the user is a bot account
    - `system` boolean — Whether the user is an official system user
    - `flags` integer, required — The public flags on the user account
    - `mention_flags` 0 | 1 | 2 — Reply mention preference

## Other responses

- `400` — Bad Request - The request was malformed or contained invalid data
- `429` — Too Many Requests - You are being rate limited
- `500` — Internal Server Error - An unexpected error occurred

## Changes

> 14 revisions in range; 1 not diffed.

- **2026-09-18** `dd0ad4ea1c88` — 2 breaking, 2 info
  - the response property `user/avatar` became nullable for the status `200`
  - the response property `user/global_name` became nullable for the status `200`
  - response property `user/avatar` list-of-types was narrowed by removing types `null` from media type `application/json` of response `200`
  - response property `user/global_name` list-of-types was narrowed by removing types `null` from media type `application/json` of response `200`
- **2026-09-06** `a52a2cf49d9b` — 16 warning, 100 info
  - added the new `IP_BAN_DECLINED` enum value to the `code` response property for the response status `400`
  - added the new `IP_BAN_DECLINED` enum value to the `code` response property for the response status `500`
  - added the new `PHONE_COUNTRY_NOT_SUPPORTED` enum value to the `code` response property for the response status `400`
  - added the new `PHONE_COUNTRY_NOT_SUPPORTED` enum value to the `code` response property for the response status `500`
  - …112 more
  - …this revision’s changelog is incomplete
- **2026-09-05** `4dbb738a3e22` — 2 info
  - removed the `NSFW_EMOJI_STICKER_BLOCKED` enum value from the `code` response property for the response status `400`
  - removed the `NSFW_EMOJI_STICKER_BLOCKED` enum value from the `code` response property for the response status `500`
- …earlier changes not shown

[Full history](https://skmtc.dev/fluxer/apis/fluxer-api/changes/auth/login/mfa/webauthn/post.md)

---

[API](https://skmtc.dev/fluxer/apis/fluxer-api.md) · [All operations](https://skmtc.dev/fluxer/apis/fluxer-api/llms.txt) · [OpenAPI document](https://skmtc.dev/fluxer/apis/fluxer-api/revisions/a54a86d62719?raw)