> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onlyfansapi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Start Authentication (/api-reference/fansly/connect-fansly-account/start-authentication)

Start the authentication process for a new Fansly account using the account's username (or email) and password. If Fansly requires verification, the response status will indicate a pending challenge — either an emailed code (new IP) or an authenticator-app code — which you submit via the Submit 2FA endpoint. Credentials are stored securely and encrypted at rest.

## OpenAPI

````yaml https://app.onlyfansapi.com/scribe-fansly-docs/openapi.yaml post /api/fansly/authenticate
openapi: 3.0.3
info:
  title: Fansly API Documentation
  description: ""
  version: 1.0.0
servers:
  - url: https://app.onlyfansapi.com
security:
  - default: []
tags:
  - name: Account
    description: Endpoints for your linked Fansly accounts
  - name: Chats
    description: Endpoints for Fansly chats (messaging groups)
  - name: Connect Fansly Account
    description: ""
  - name: Earnings
    description: Endpoints for Fansly Earnings — wallets, balances, transactions,
      payouts, and statements.
  - name: Followers
    description: Endpoints for Fansly followers.
  - name: Lists
    description: Endpoints for Fansly subscriber/fan lists (e.g. "VIP", "Spenders").
  - name: Profile Statistics
    description: Endpoints for Fansly Profile Statistics (viewer engagement insights).
  - name: Subscribers
    description: Endpoints for Fansly subscribers and subscription tiers.
  - name: Top Supporters
    description: Endpoints for the Fansly "Top Supporters" view — see who spends the
      most and what they spend on.
  - name: Tracking Links
    description: Endpoints for Fansly tracking links — per-source attribution links
      (e.g. "Twitter bio", "FYP", "Search").
  - name: Users
    description: APIs for fetching Fansly users
paths:
  /api/fansly/authenticate:
    post:
      summary: Start Authentication
      operationId: startAuthentication
      description: Start the authentication process for a new Fansly account using the
        account's username (or email) and password. If Fansly requires
        verification, the response status will indicate a pending challenge —
        either an emailed code (new IP) or an authenticator-app code — which you
        submit via the Submit 2FA endpoint. Credentials are stored securely and
        encrypted at rest.
      parameters: []
      responses:
        "200":
          description: ""
          content:
            application/json:
              schema:
                type: object
                example:
                  account_id: fansly_acct_123
                  message: Authentication process started. Query the polling_url to check the
                    progress.
                  polling_url: https://api.example.com/api/fansly/authenticate/fansly_acct_123
                properties:
                  account_id:
                    type: string
                    example: fansly_acct_123
                  message:
                    type: string
                    example: Authentication process started. Query the polling_url to check the
                      progress.
                  polling_url:
                    type: string
                    example: https://api.example.com/api/fansly/authenticate/fansly_acct_123
      tags:
        - Connect Fansly Account
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                name:
                  type: string
                  description: A display name for the account. If omitted, defaults to the
                    username.
                  example: nihil
                username:
                  type: string
                  description: The Fansly username or email used to sign in.
                  example: incidunt
                password:
                  type: string
                  description: The Fansly account password.
                  example: T{$k6he2Fqe4o7ty>C*
                proxyCountry:
                  type: string
                  description: The country of the managed proxy server you want to use. Eg. "us"
                    for United States. Cannot be used together with customProxy.
                  example: us
                  enum:
                    - us
                    - uk
                customProxy:
                  type: object
                  description: Custom proxy configuration. Cannot be used together with
                    proxyCountry.
                  example: []
                  properties:
                    host:
                      type: string
                      description: The hostname or IP address of your custom proxy server
                      example: proxy.example.com
                    port:
                      type: integer
                      description: The port number of your custom proxy server (1-65535)
                      example: 8080
                    username:
                      type: string
                      description: The username for proxy authentication (optional)
                      example: molestiae
                    password:
                      type: string
                      description: The password for proxy authentication (optional)
                      example: "'LRZ1\"1"
                force_connect:
                  type: boolean
                  description: Set to true to connect the account even if it already exists
                  example: false
              required:
                - username
                - password
components:
  securitySchemes:
    default:
      type: http
      scheme: bearer
      description: Get your API Key from OnlyFansAPI Console -
        https://app.onlyfansapi.com/api-keys
````