Message Type Guide

Each message type solves a different business problem. The right choice depends on urgency, deliverability, content richness, and whether you need Kakao-native UX.

Quick comparison

Type	Best for	Strengths	Tradeoffs
SMS	OTP, urgent alerts, universal reach	Highest reach, no template registration required	Limited formatting and length
LMS	Longer operational notices	More room for detail, optional subject	Higher cost than SMS
AlimTalk	Transactional Kakao notifications	High open rate, structured variables, lower cost than SMS in many flows	Kakao template setup required
FriendTalk	Promotional Kakao messages	Better visual/marketing experience	Requires Kakao channel relationship
RCS and others	Specialized provider-dependent flows	Rich messaging where supported	Availability depends on provider/runtime setup

When to choose SMS

Use SMS when:

• every phone number must be reachable
• the message is short and urgent
• pre-approved Kakao templates would slow you down

await kmsg.send({
  to: "01012345678",
  text: "Your verification code is 123456.",
});

When to choose LMS

Use LMS when:

• the message exceeds SMS length
• you need a subject line
• the user needs more operational detail in one message

await kmsg.send({
  type: "LMS",
  to: "01012345678",
  subject: "[Notice] Planned maintenance",
  text: "Maintenance is scheduled from 02:00 to 04:00 KST. Some services may be unavailable.",
});

When to choose AlimTalk

Use AlimTalk when:

• the message is transactional
• Kakao reach is acceptable for your audience
• a pre-approved template is operationally worth it

await kmsg.send({
  type: "ALIMTALK",
  to: "01012345678",
  templateId: "ORDER_CONFIRMED",
  variables: {
    orderNo: "20260307-001",
    customerName: "Jane",
  },
});

When to choose FriendTalk

Use FriendTalk when:

• the message is promotional or engagement-oriented
• button-rich Kakao UX matters
• your audience already has a Kakao channel relationship

Practical selection rules

• Start with SMS for OTP and high-risk delivery requirements.
• Start with AlimTalk for transactional commerce notifications.
• Use FriendTalk for marketing only after consent and channel relationship rules are satisfied.
• Keep LMS as the fallback when SMS is too short or you need more context.

Fallback strategy

For important transactional Kakao flows, consider an SMS or LMS fallback when Kakao delivery is not enough for the business SLA.

Next steps

• Provider Selection to check which provider best supports your chosen mix
• OTP Verification for SMS-first authentication
• Order Notifications for AlimTalk-first commerce flows