EngageLab OTP API Skill

This skill enables interaction with the EngageLab OTP REST API. The OTP service handles one-time password generation, multi-channel delivery (SMS, WhatsApp, Email, Voice), verification, and fraud monitoring.

It covers six areas:

1. OTP Send — Platform-generated OTP code delivery
2. Custom OTP Send — User-generated OTP code delivery
3. OTP Verify — Validate OTP codes
4. Custom Messages Send — Send custom template messages (notifications, marketing)
5. Template Management — Create, list, get, and delete OTP templates
6. Callback & SMPP — Webhook configuration and SMPP protocol integration

Resources

scripts/

• otp_client.py — Python client class (EngageLabOTP) wrapping all API endpoints: send_otp(), send_custom_otp(), verify(), send_custom_message(), and template CRUD. Handles authentication, request construction, and typed error handling. Use this as a ready-to-run helper or import it into the user's project.
• verify_callback.py — HMAC-SHA256 signature verifier for incoming OTP callback webhooks. Parses the X-CALLBACK-ID header and validates authenticity. Drop into any web framework (Flask, FastAPI, Django) to secure callback endpoints.

references/

• error-codes.md — Complete error code tables for all OTP APIs
• template-api.md — Full template CRUD specs with all channel configurations
• callback-config.md — Webhook setup, security, and all event types
• smpp-guide.md — SMPP protocol connection, messaging, and delivery reports

Authentication

All EngageLab OTP API calls use HTTP Basic Authentication.

• Base URL: https://otp.api.engagelab.cc
• Header: Authorization: Basic <base64(dev_key:dev_secret)>
• Content-Type: application/json

The user must provide their dev_key and dev_secret. Encode them as base64("dev_key:dev_secret") and set the Authorization header.

Example (using curl):

curl -X POST https://otp.api.engagelab.cc/v1/messages \
  -H "Content-Type: application/json" \
  -H "Authorization: Basic $(echo -n 'YOUR_DEV_KEY:YOUR_DEV_SECRET' | base64)" \
  -d '{ ... }'

If the user hasn't provided credentials, ask them for their dev_key and dev_secret before generating API calls.

Quick Reference — All Endpoints

Operation	Method	Path
Send OTP (platform-generated)	POST	/v1/messages
Send OTP (custom code)	POST	/v1/codes
Verify OTP	POST	/v1/verifications
Send custom message	POST	/v1/custom-messages
List templates	GET	/v1/template-configs
Get template details	GET	/v1/template-configs/:templateId
Create template	POST	/v1/template-configs
Delete template	DELETE	/v1/template-configs/:templateId

OTP Send (Platform-Generated Code)

Use this when you want EngageLab to generate the verification code and deliver it according to the template's channel strategy (SMS, WhatsApp, Email, Voice).

Endpoint: POST /v1/messages

Request Body

{
  "to": "+8618701235678",
  "template": {
    "id": "test-template-1",
    "language": "default",
    "params": {
      "key1": "value1"
    }
  }
}

Parameters

Field	Type	Required	Description
to	string	Yes	Phone number (with country code, e.g., +8613800138000) or email address
template.id	string	Yes	Template ID
template.language	string	No	Language: default, zh_CN, zh_HK, en, ja, th, es. Defaults to default
template.params	object	No	Custom template variable values as key-value pairs

Notes on params

• Preset variables like {{brand_name}}, {{ttl}}, {{pwa_url}} are auto-filled from template settings — no need to pass them.
• For custom variables in the template (e.g., Hi {{name}}, your code is {{code}}), pass values via params: {"name": "Bob"}.
• If the template's from_id field is preset and you pass {"from_id": "12345"}, the preset value is overridden.

Response

Success:

{
  "message_id": "1725407449772531712",
  "send_channel": "sms"
}

Field	Type	Description
message_id	string	Unique message ID, used for verification and tracking
send_channel	string	Current delivery channel: whatsapp, sms, email, or voice

The send_channel indicates the initial channel — if fallback is configured (e.g., WhatsApp → SMS), the final delivery channel may differ.

For error codes, read references/error-codes.md.

Custom OTP Send (User-Generated Code)

Use this when you want to generate the verification code yourself and have EngageLab deliver it. This API does not generate codes and does not require calling the Verify API afterward.

Endpoint: POST /v1/codes

Request Body

{
  "to": "+8618701235678",
  "code": "398210",
  "template": {
    "id": "test-template-1",
    "language": "default",
    "params": {
      "key1": "value1"
    }
  }
}

Parameters

Field	Type	Required	Description
to	string	Yes	Phone number or email address
code	string	Yes	Your custom verification code
template.id	string	Yes	Template ID
template.language	string	No	Language (same options as OTP Send). Defaults to default
template.params	object	No	Custom template variable values

Response

Same format as OTP Send — returns message_id and send_channel.

OTP Verify

Validate a verification code that was sent via the OTP Send API (/v1/messages). Only applicable to platform-generated codes — not needed for Custom OTP Send.

Endpoint: POST /v1/verifications

Request Body

{
  "message_id": "1725407449772531712",
  "verify_code": "667090"
}

Parameters

Field	Type	Required	Description
message_id	string	Yes	The message_id returned by /v1/messages
verify_code	string	Yes	The code the user entered

Response

Success:

{
  "message_id": "1725407449772531712",
  "verify_code": "667090",
  "verified": true
}

Field	Type	Description
message_id	string	Message ID
verify_code	string	The submitted code
verified	boolean	true = valid, false = invalid

Important: Successfully verified codes cannot be verified again — subsequent attempts will fail. Expired codes return error 3003.

Custom Messages Send

Send custom template content (verification codes, notifications, or marketing messages) using templates created on the OTP platform.

Endpoint: POST /v1/custom-messages

Request Body

{
  "to": "+8618701235678",
  "template": {
    "id": "test-template-1",
    "params": {
      "code": "123456",
      "var1": "value1"
    }
  }
}

Parameters

Field	Type	Required	Description
to	string or string[]	Yes	Single recipient (string) or multiple (array). Phone number or email
template.id	string	Yes	Template ID
template.params	object	No	Template variable values
template.params.code	string	Conditional	Required if template type is verification code

Notes on params

• Preset variables ({{brand_name}}, {{ttl}}, {{pwa_url}}) are auto-replaced from template settings.
• For verification code templates, you must pass {{code}} or an error will occur.
• Custom variables need values via params, e.g., {"name": "Bob"} for Hi {{name}}.

Response

Same format as OTP Send — returns message_id and send_channel.

Use Case Examples

Verification code:

{
  "to": "+8618701235678",
  "template": { "id": "code-template", "params": { "code": "123456" } }
}

Notification:

{
  "to": ["+8618701235678"],
  "template": { "id": "notification-template", "params": { "order": "123456" } }
}

Marketing:

{
  "to": ["+8618701235678"],
  "template": { "id": "marketing-template", "params": { "name": "EngageLab", "promotion": "30%" } }
}

Template Management

OTP templates define the message content, channel strategy, and verification code settings. Templates support multi-channel delivery with fallback (e.g., WhatsApp → SMS).

For full request/response details including all channel configurations (WhatsApp, SMS, Voice, Email, PWA), read references/template-api.md.

Quick Summary

Create — POST /v1/template-configs

{
  "template_id": "my-template",
  "description": "Login verification",
  "send_channel_strategy": "whatsapp|sms",
  "brand_name": "MyApp",
  "verify_code_config": {
    "verify_code_type": 1,
    "verify_code_len": 6,
    "verify_code_ttl": 5
  },
  "sms_config": {
    "template_type": 1,
    "template_default_config": {
      "contain_security": false,
      "contain_expire": false
    }
  }
}

List all — GET /v1/template-configs (returns array of templates without detailed content)

Get details — GET /v1/template-configs/:templateId (returns full template with channel configs)

Delete — DELETE /v1/template-configs/:templateId

Template Status

Value	Status
1	Pending Review
2	Approved
3	Rejected

Channel Strategy

Use | to define fallback chains. Examples:

• "sms" — SMS only
• "whatsapp|sms" — Try WhatsApp first, fall back to SMS
• "whatsapp|sms|email" — WhatsApp → SMS → Email

Supported channels: whatsapp, sms, voice, email

Verification Code Config

Field	Range	Description
verify_code_type	1–7	1=Numeric, 2=Lowercase, 4=Uppercase. Combine: 3=Numeric+Lowercase
verify_code_len	4–10	Code length
verify_code_ttl	1–10	Validity in minutes. With WhatsApp: only 1, 5, or 10

Callback Configuration

Configure webhook URLs to receive real-time delivery status, notification events, message responses, and system events.

For the full callback data structures, security mechanisms, and event types, read references/callback-config.md.

SMPP Integration

For TCP-based SMPP protocol integration (used in carrier-level SMS delivery), read references/smpp-guide.md.

Generating Code

When the user asks to send OTPs or manage templates, generate working code. Default to curl unless the user specifies a language. Supported patterns:

• curl — Shell commands with proper auth header
• Python — Using requests library
• Node.js — Using fetch or axios
• Java — Using HttpClient
• Go — Using net/http

Always include the authentication header and proper error handling. Use placeholder values like YOUR_DEV_KEY and YOUR_DEV_SECRET if the user hasn't provided credentials.

Python Example — Send OTP and Verify

import requests
import base64

DEV_KEY = "YOUR_DEV_KEY"
DEV_SECRET = "YOUR_DEV_SECRET"
BASE_URL = "https://otp.api.engagelab.cc"

auth_string = base64.b64encode(f"{DEV_KEY}:{DEV_SECRET}".encode()).decode()
headers = {
    "Content-Type": "application/json",
    "Authorization": f"Basic {auth_string}"
}

# Step 1: Send OTP
send_resp = requests.post(f"{BASE_URL}/v1/messages", headers=headers, json={
    "to": "+8618701235678",
    "template": {"id": "my-template", "language": "default"}
})
result = send_resp.json()
message_id = result["message_id"]

# Step 2: Verify OTP (after user enters the code)
verify_resp = requests.post(f"{BASE_URL}/v1/verifications", headers=headers, json={
    "message_id": message_id,
    "verify_code": "123456"
})
verification = verify_resp.json()
print(f"Verified: {verification['verified']}")