Secure Cookies

Crossmint Auth is designed for staging and moving fast. For production applications, Crossmint strongly recommends connecting your own authentication provider for full control over user management. See the Bring Your Own Auth guide.

Authentication tokens are accessible to client-side JavaScript by default through non-HttpOnly cookies. For stronger security, you can store tokens in HttpOnly cookies, which are accessible only on the server side. This setup requires custom routes for refreshing tokens and logging out, using utilities from @crossmint/server-sdk.

Configure the cookie options

When initializing the server SDK, configure secure cookie options:

import { createCrossmint, CrossmintAuth } from "@crossmint/server-sdk";

const crossmint = createCrossmint({ apiKey: process.env.SERVER_CROSSMINT_API_KEY });
const crossmintAuth = CrossmintAuth.from(crossmint, {
    cookieOptions: {
        httpOnly: true,
        secure: true, // Only send cookies over HTTPS
        domain: ".yourdomain.com", // Optional: specify cookie domain
    },
});

Note: The httpOnly flag only applies to the refresh token. The session JWT remains accessible to client-side JavaScript since it’s needed for API calls.

Add the token refresh route

Next.js (App Router)
Express.js

import { createCrossmint, CrossmintAuth } from "@crossmint/server-sdk";
import { NextRequest } from "next/server";

const crossmint = createCrossmint({ apiKey: process.env.SERVER_CROSSMINT_API_KEY! });
const crossmintAuth = CrossmintAuth.from(crossmint);

export async function POST(request: NextRequest) {
    return await crossmintAuth.handleCustomRefresh(request);
}

import express from "express";
import { createCrossmint, CrossmintAuth } from "@crossmint/server-sdk";

const app = express()
const crossmint = createCrossmint({ apiKey: process.env.SERVER_CROSSMINT_API_KEY! });
const crossmintAuth = CrossmintAuth.from(crossmint);

app.post("/api/auth/refresh", async (req, res) => {
    await crossmintAuth.handleCustomRefresh(req, res);
    res.end();
});

Add the logout route

Next.js (App Router)
Express.js

import { createCrossmint, CrossmintAuth } from "@crossmint/server-sdk";
import { NextRequest } from "next/server";

const crossmint = createCrossmint({ apiKey: process.env.SERVER_CROSSMINT_API_KEY! });
const crossmintAuth = CrossmintAuth.from(crossmint);

export async function POST(request: NextRequest) {
    return await crossmintAuth.logout(request);
}

import express from "express";
import { createCrossmint, CrossmintAuth } from "@crossmint/server-sdk";

const app = express()
const crossmint = createCrossmint({ apiKey: process.env.SERVER_CROSSMINT_API_KEY! });
const crossmintAuth = CrossmintAuth.from(crossmint);

app.post("/api/auth/logout", async (req, res) => {
    await crossmintAuth.logout(req, res);
    res.end();
});

Configure the client SDK

Configure the client SDK to use your custom routes:

TypeScript
React

import { createCrossmint, CrossmintAuth } from "@crossmint/client-sdk-auth";

const crossmint = createCrossmint({ apiKey: process.env.NEXT_PUBLIC_CLIENT_CROSSMINT_API_KEY! });
const crossmintAuth = CrossmintAuth.from(crossmint, {
    refreshRoute: "/api/auth/refresh",
    logoutRoute: "/api/auth/logout"
});

import { CrossmintProvider, CrossmintAuthProvider } from "@crossmint/client-sdk-react-ui";

<CrossmintProvider apiKey={process.env.NEXT_PUBLIC_CLIENT_CROSSMINT_API_KEY ?? ""}>
    <CrossmintAuthProvider
        refreshRoute="/api/auth/refresh"
        logoutRoute="/api/auth/logout"
    >
        {children}
    </CrossmintAuthProvider>
</CrossmintProvider>

Note: Depending on the framework you’re using, you might need to set the whole URL in the refreshRoute and logoutRoute options.

Introduction

User Identity

User Authentication

API Reference