Clerk Hono

Source: honojs/middleware - packages/clerk-auth

Setup

• Install: pnpm add @hono/clerk-auth (or npm). No custom auth middleware - use the package directly.
• Env: CLERK_SECRET_KEY, CLERK_PUBLISHABLE_KEY (e.g. in wrangler or .dev.vars).

Usage

Apply middleware to the routes that need auth, then use getAuth(c) in handlers:

import { clerkMiddleware, getAuth } from '@hono/clerk-auth';
import { Hono } from 'hono';

const app = new Hono();
app.use('/push/*', clerkMiddleware());
app.use('/orgs/*', clerkMiddleware());
app.route('/', sessionRouter);

In route handlers:

app.get('/', (c) => {
  const { userId, orgId } = getAuth(c);
  if (!userId) {
    return c.json({ message: 'You are not logged in.' }, 401);
  }
  if (!orgId) {
    return c.json({ message: 'No active organization selected.' }, 400);
  }
  return c.json({ userId, orgId });
});

• Backend API: const clerkClient = c.get('clerk') then e.g. clerkClient.users.getUser(...).

API keys

Use when the route is a resource server or machine-to-machine and should accept Clerk-issued API keys instead of (or in addition to) session tokens.

Using API keys in requests

Once you have an API key, use it to authenticate requests to your application's API. Send the API key as a Bearer token in the Authorization header:

await fetch('https://your-api.com/users', {
  method: 'GET',
  headers: {
    'Content-Type': 'application/json',
    Authorization: `Bearer ${apiKey}`,
  },
});

On your backend, verify the API key using Clerk's SDK (e.g. @hono/clerk-auth with getAuth(c, { acceptsToken: 'api_key' })). See the verifying API keys guide for framework-specific examples.

Verifying API keys on the backend

By default getAuth(c) only accepts session tokens; API keys are rejected unless you pass acceptsToken.

• Single token type (API keys only):

const { userId } = getAuth(c, { acceptsToken: 'api_key' });
if (!userId) {
  return c.json({ error: 'Unauthorized' }, 401);
}

• Multiple token types (sessions + API keys):

const { userId, tokenType, scopes } = getAuth(c, {
  acceptsToken: ['session_token', 'oauth_token', 'api_key'],
});
if (!userId) {
  return c.json({ error: 'Unauthorized' }, 401);
}
// Optional: enforce scopes for api_key
if (tokenType === 'api_key' && !scopes?.includes('write:users')) {
  return c.json({ error: 'API key missing required scope' }, 403);
}

Clerk API keys are in beta; behavior may change. Full details: Verify API keys (Clerk).

Do not add a custom clerkAuthMiddleware or re-export from a local auth.ts; import clerkMiddleware and getAuth from @hono/clerk-auth in app and routers.