Julien 🍁
Julien 🍁
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BABetter Auth
Created by Julien 🍁 on 5/18/2025 in #help
OAuth with TikTok failing — “code_challenge” error on redirect
Hi! I’m integrating BetterAuth in my Next.js app with a custom PostgreSQL schema via Prisma. Everything works fine locally, but when I try to sign in with the TikTok provider on my deployed Vercel app, I’m redirected to a TikTok error page saying: “An error occurred. TikTok login failed. This may be due to application-specific settings. If you’re a developer, fix the following and try again: code_challenge.” I’m not doing any manual PKCE handling in my code, and I assumed BetterAuth manages it internally. Here’s my current BetterAuth config: 
export const auth = betterAuth({
  database: prismaAdapter(prisma, { provider: "postgresql" }),
  emailAndPassword: { enabled: true },
  socialProviders: {
    tiktok: {
      clientId: process.env.TIKTOK_CLIENT_ID,
      clientSecret: process.env.TIKTOK_CLIENT_SECRET,
      clientKey: process.env.TIKTOK_CLIENT_KEY,
    },
  },
});
export const auth = betterAuth({
  database: prismaAdapter(prisma, { provider: "postgresql" }),
  emailAndPassword: { enabled: true },
  socialProviders: {
    tiktok: {
      clientId: process.env.TIKTOK_CLIENT_ID,
      clientSecret: process.env.TIKTOK_CLIENT_SECRET,
      clientKey: process.env.TIKTOK_CLIENT_KEY,
    },
  },
});
Also, my signIn call looks like this: 
await signIn.social(
  {
    provider: "tiktok",
    callbackURL: "/dashboard/settings",
  },
  {
    onRequest: () => setLoading(true),
    onResponse: () => setLoading(false),
  }
);
await signIn.social(
  {
    provider: "tiktok",
    callbackURL: "/dashboard/settings",
  },
  {
    onRequest: () => setLoading(true),
    onResponse: () => setLoading(false),
  }
);
Is there something I’m missing regarding PKCE or TikTok support on BetterAuth? Thanks a lot for your help!
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