better-auth-credentials-plugin

import { betterAuth } from "better-auth"; import { credentials } from "better-auth-credentials-plugin"; // --- Server-side configuration (e.g., in auth.ts) --- export const auth = betterAuth({ // ... other Better Auth configurations ... // Disable default email and password if this plugin replaces it for a specific flow emailAndPassword: { enabled: false, }, plugins: [ credentials({ autoSignUp: true, // Automatically create a new user if not found async callback(ctx, parsed) { // 'parsed' contains the validated input credentials (e.g., username, password) // Implement your external authentication logic here (e.g., LDAP, external API) const { email, password } = parsed; // Example: Authenticating against a hypothetical external API const externalAuthServiceUrl = process.env.EXTERNAL_AUTH_SERVICE_URL ?? 'http://localhost:4000/login'; const response = await fetch(externalAuthServiceUrl, { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ email, password }), }); if (!response.ok) { // Handle authentication failure from the external system const errorData = await response.json().catch(() => ({ message: 'Authentication failed' })); throw new Error(errorData.message || 'Invalid credentials'); } const { token, user: apiUser } = await response.json(); // Return user data, including a unique 'email' field, to Better Auth. // This data will be used to create/update the user and link the account. return { // 'email' is mandatory for Better Auth user linking/creation email: apiUser.email, // Additional fields to store on the user or account (e.g., token, name) name: apiUser.name, externalAuthToken: token, }; }, }), ], }); // --- Client-side usage (e.g., in authClient.ts) --- // Requires 'better-auth/client' and '/client' subpath for credentialsClient // import { createAuthClient } from 'better-auth/client'; // import { credentialsClient } from 'better-auth-credentials-plugin/client'; // const authClient = createAuthClient({ // baseURL: "/api/auth", // plugins: [ // // If you customized the path or schema, you'd pass generic types here // credentialsClient(), // ], // });