@better-auth/expo/dist/index.mjs

Better Auth integration for Expo and React Native applications.

import { createAuthMiddleware } from "@better-auth/core/api";
import { HIDE_METADATA } from "better-auth";
import { APIError, createAuthEndpoint } from "better-auth/api";
import * as z from "zod";

//#region src/routes.ts
const expoAuthorizationProxy = createAuthEndpoint("/expo-authorization-proxy", {
	method: "GET",
	query: z.object({
		authorizationURL: z.string(),
		oauthState: z.string().optional()
	}),
	metadata: HIDE_METADATA
}, async (ctx) => {
	const { oauthState } = ctx.query;
	if (oauthState) {
		const oauthStateCookie = ctx.context.createAuthCookie("oauth_state", { maxAge: 600 * 1e3 });
		ctx.setCookie(oauthStateCookie.name, oauthState, oauthStateCookie.attributes);
		return ctx.redirect(ctx.query.authorizationURL);
	}
	const { authorizationURL } = ctx.query;
	const state = new URL(authorizationURL).searchParams.get("state");
	if (!state) throw new APIError("BAD_REQUEST", { message: "Unexpected error" });
	const stateCookie = ctx.context.createAuthCookie("state", { maxAge: 300 * 1e3 });
	await ctx.setSignedCookie(stateCookie.name, state, ctx.context.secret, stateCookie.attributes);
	return ctx.redirect(ctx.query.authorizationURL);
});

//#endregion
//#region src/index.ts
const expo = (options) => {
	return {
		id: "expo",
		init: (ctx) => {
			return { options: { trustedOrigins: process.env.NODE_ENV === "development" ? ["exp://"] : [] } };
		},
		async onRequest(request, ctx) {
			if (options?.disableOriginOverride || request.headers.get("origin")) return;
			/**
			* To bypass origin check from expo, we need to set the origin
			* header to the expo-origin header
			*/
			const expoOrigin = request.headers.get("expo-origin");
			if (!expoOrigin) return;
			const req = request.clone();
			req.headers.set("origin", expoOrigin);
			return { request: req };
		},
		hooks: { after: [{
			matcher(context) {
				return !!(context.path?.startsWith("/callback") || context.path?.startsWith("/oauth2/callback") || context.path?.startsWith("/magic-link/verify") || context.path?.startsWith("/verify-email"));
			},
			handler: createAuthMiddleware(async (ctx) => {
				const headers = ctx.context.responseHeaders;
				const location = headers?.get("location");
				if (!location) return;
				if (location.includes("/oauth-proxy-callback")) return;
				if (!ctx.context.trustedOrigins.filter((origin) => !origin.startsWith("http")).some((origin) => location?.startsWith(origin))) return;
				const cookie = headers?.get("set-cookie");
				if (!cookie) return;
				const url = new URL(location);
				url.searchParams.set("cookie", cookie);
				ctx.setHeader("location", url.toString());
			})
		}] },
		endpoints: { expoAuthorizationProxy },
		options
	};
};

//#endregion
export { expo };