@openauth/kakao

Kakao OAuth 2.0 client.

Install

# Deno
deno add jsr:@denostack/openauth

# Node.js / Bun
npx jsr add @denostack/openauth
# or
npm install @openauth/kakao

Usage

// Deno
import { KakaoOAuth } from "@denostack/openauth/kakao";

// Node.js / Bun
import { KakaoOAuth } from "@openauth/kakao";

const oauth = new KakaoOAuth({
  clientId: "your_client_id",
  clientSecret: "your_client_secret",
  redirectUri: "https://example.com/callback/kakao",
});

// 1. Generate the authorization URL and redirect the user
const url = await oauth.getAuthRequestUri({ state: "random_state" });

// 2. Exchange the authorization code for an access token
const token = await oauth.getAccessTokenResponse(code);

// 3. Fetch the user profile
const user = await oauth.getUserProfile(token.accessToken);
// => { id, nickname, picture, email, raw }

Verify ID Token

Kakao returns an id_token alongside the access token when OpenID Connect is enabled for your app and the openid scope is included in the request. You can verify it and extract the user profile without calling the userinfo endpoint:

const oauth = new KakaoOAuth({
  clientId: "your_client_id",
  clientSecret: "your_client_secret",
  redirectUri: "https://example.com/callback/kakao",
  scope: ["openid"],
});

const token = await oauth.getAccessTokenResponse(code);
const user = await oauth.getUserProfileFromIdToken(token.idToken!);

This verifies:

• Signature against Kakao's JWKS (https://kauth.kakao.com/.well-known/jwks.json)
• Issuer matches https://kauth.kakao.com
• Audience matches your clientId
• Expiration (exp) is in the future

If any check fails, a JwtVerifierError is thrown.

OpenID Connect must be activated in your Kakao app console (My Application → Product Settings → Kakao Login → OpenID Connect) before the id_token is issued.

If you have already validated the token elsewhere and just want to decode the payload, pass withoutValidation:

const user = await oauth.getUserProfileFromIdToken(token.idToken!, {
  withoutValidation: true,
});

Custom Scopes

No scopes are requested by default. You can add scopes in the constructor or per request:

// Set scopes in the constructor
const oauth = new KakaoOAuth({
  clientId: "your_client_id",
  clientSecret: "your_client_secret",
  redirectUri: "https://example.com/callback/kakao",
  scope: ["profile_nickname", "account_email"],
});

// Or override per request
const url = await oauth.getAuthRequestUri({
  state: "random_state",
  scope: ["profile_nickname", "profile_image", "account_email"],
});