Send Login MFA Code

POST/web/v1/system/auth/login/mfa/send None

Secure Channel Required

This endpoint requires Secure Channel v2 encryption. All request and response payloads are encrypted in transit. See Secure Channel Protocol for full protocol details.

Required Gateway Headers

All API requests require gateway headers. See Required Headers for the complete list. In local/test environments, you must also include Cloudflare simulation headers (CF-Connecting-IP, Cf-Ray, cf-ipcountry).

Sends a multi-factor authentication code to the user during the login flow. The code is sent via the specified MFA method (e.g., email).

Required Headers

Header	Example Value	Description
Content-Type	application/json;charset=UTF-8	Request content type
Accept	application/json	Expected response type
X-Client-Hash		Client device fingerprint
X-SC-Session-Id		Secure Channel session ID
X-SC-Version	2	Secure Channel protocol version
Accept-Language	en, zh, zh-Hant, ja, vi	Response language (default: en)

Business Parameters

Name	Type	Required	In	Description
sessionId	String	Required	body	Login session ID from the initiate step
method	Integer	Required	body	MFA method code: 10011001 (EMAIL), 10011002 (OTP), 10011005 (BACKUP_CODE)

Business Parameters (before encryption)

The following JSON is what gets encrypted before transmission:

{
  "sessionId": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
  "method": 10011001
}

How to Call This Endpoint

Step 1: Establish Secure Channel Session (if not already active)

If you don't have an active SC session, create one first:

1. Get server public key: GET /web/v1/secure-channel/public-key
2. Create SC session: POST /web/v1/secure-channel/session — exchanges AES session key, returns sessionId

Step 2: Prepare the Request

Construct the JSON payload with the business parameters:

{
  "sessionId": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
  "method": 10011001
}

Step 3: Encrypt and Send

1. Encrypt the JSON string using the AES session key (from Step 1)
2. Send the HTTP request with:
   • Header: X-SC-Session-Id: {sessionId}
   • Header: X-SC-Version: 2
   • Header: Content-Type: application/json;charset=UTF-8
   • Body: the encrypted binary payload (SCv2 envelope format)

Step 4: Decrypt the Response

The response body is also encrypted. Decrypt using the same AES session key to get the JSON response.

Success Response

Success 200

{
  "version": "2.0.0",
  "timestamp": 1711929600000,
  "success": true,
  "code": "2000",
  "message": "SUCCESS",
  "data": {
    "sent": true,
    "cooldownSeconds": 60,
    "codeExpiresIn": 300
  }
}

Error Responses

Too Many Requests 429

{
  "success": false,
  "code": "AUTH.MFA_SEND_COOLDOWN",
  "message": "Please wait before requesting another code"
}

Notes

• Rate limited to 5 requests per 60-second window.
• The sessionId must come from a prior initiateLogin call.
• The method field specifies which MFA channel to use (e.g., EMAIL, OTP).
• Request body is strictly validated — unknown or unexpected fields will be rejected with HTTP 400.