Hono, Koa & NestJS Adapters

Overview

@authrim/server provides adapters for Hono, Koa, and NestJS. Each adapter validates access tokens (Bearer and DPoP) and exposes the authenticated user context through the framework’s idiomatic patterns.

For Express and Fastify, see Express & Fastify Adapters.

Hono Adapter

Import from @authrim/server/adapters/hono.

Hono uses context variables (not direct request properties) for authentication data. Use the getAuth() and getAuthTokenType() helper functions to access them.

authrimMiddleware()

Required authentication — returns 401 for unauthenticated requests:

import { Hono } from 'hono';
import { createAuthrimServer } from '@authrim/server';
import {
  authrimMiddleware,
  getAuth,
  getAuthTokenType,
} from '@authrim/server/adapters/hono';

const server = createAuthrimServer({
  issuer: 'https://auth.example.com',
  audience: 'https://api.example.com',
});

const app = new Hono();

// Protect all routes under /api
app.use('/api/*', authrimMiddleware(server));

app.get('/api/profile', (c) => {
  const auth = getAuth(c);         // ValidatedToken (guaranteed)
  const type = getAuthTokenType(c); // 'Bearer' | 'DPoP'

  return c.json({ sub: auth.sub, tokenType: type });
});

authrimOptionalMiddleware()

Optional authentication — continues for unauthenticated requests:

import {
  authrimOptionalMiddleware,
  getAuth,
} from '@authrim/server/adapters/hono';

app.get('/api/feed', authrimOptionalMiddleware(server), (c) => {
  const auth = getAuth(c);

  if (auth) {
    return c.json({ feed: getPersonalizedFeed(auth.sub) });
  }
  return c.json({ feed: getPublicFeed() });
});

Helper Functions

Function	Return Type	Description
getAuth(c)	ValidatedToken | undefined	Get the validated token from Hono context
getAuthTokenType(c)	'Bearer' | 'DPoP' | undefined	Get the token type from Hono context

Cloudflare Workers Example

Hono is commonly deployed on Cloudflare Workers. Here is a complete example:

src/index.ts

import { Hono } from 'hono';
import { createAuthrimServer } from '@authrim/server';
import {
  authrimMiddleware,
  authrimOptionalMiddleware,
  getAuth,
} from '@authrim/server/adapters/hono';

type Bindings = {
  AUTHRIM_ISSUER: string;
  AUTHRIM_AUDIENCE: string;
};

const app = new Hono<{ Bindings: Bindings }>();

app.use('/api/*', async (c, next) => {
  const server = createAuthrimServer({
    issuer: c.env.AUTHRIM_ISSUER,
    audience: c.env.AUTHRIM_AUDIENCE,
  });

  return authrimMiddleware(server)(c, next);
});

app.get('/api/profile', (c) => {
  const auth = getAuth(c);
  return c.json({ sub: auth!.sub });
});

app.get('/health', (c) => c.json({ status: 'ok' }));

export default app;

wrangler.toml

name = "my-api"
main = "src/index.ts"
compatibility_date = "2024-12-01"

[vars]
AUTHRIM_ISSUER = "https://auth.example.com"
AUTHRIM_AUDIENCE = "https://api.example.com"

Scope Validation in Hono

import { createMiddleware } from 'hono/factory';

function requireScope(...scopes: string[]) {
  return createMiddleware(async (c, next) => {
    const auth = getAuth(c);

    if (!auth) {
      return c.json({ error: 'unauthorized' }, 401);
    }

    const tokenScopes = auth.scope?.split(' ') ?? [];
    const hasAll = scopes.every((s) => tokenScopes.includes(s));

    if (!hasAll) {
      return c.json({
        error: 'insufficient_scope',
        required: scopes,
      }, 403);
    }

    await next();
  });
}

app.get('/api/admin', authrimMiddleware(server), requireScope('admin:read'), (c) => {
  return c.json({ admin: true });
});

Koa Adapter

Import from @authrim/server/adapters/koa.

Koa stores authentication data on ctx.state.

authrimMiddleware()

Required authentication:

import Koa from 'koa';
import Router from '@koa/router';
import { createAuthrimServer } from '@authrim/server';
import { authrimMiddleware } from '@authrim/server/adapters/koa';

const server = createAuthrimServer({
  issuer: 'https://auth.example.com',
  audience: 'https://api.example.com',
});

const app = new Koa();
const router = new Router();

// Protect all API routes
app.use(authrimMiddleware(server));

router.get('/api/profile', (ctx) => {
  ctx.body = {
    sub: ctx.state.auth.sub,
    tokenType: ctx.state.authTokenType,
  };
});

app.use(router.routes());
app.listen(3000);

authrimOptionalMiddleware()

Optional authentication:

import { authrimOptionalMiddleware } from '@authrim/server/adapters/koa';

router.get('/api/feed', authrimOptionalMiddleware(server), (ctx) => {
  if (ctx.state.auth) {
    ctx.body = { feed: getPersonalizedFeed(ctx.state.auth.sub) };
  } else {
    ctx.body = { feed: getPublicFeed() };
  }
});

State Properties

Property	Type	Description
ctx.state.auth	ValidatedToken | undefined	Validated token claims
ctx.state.authTokenType	'Bearer' | 'DPoP' | undefined	Token type used

Complete Koa Example

import Koa from 'koa';
import Router from '@koa/router';
import { createAuthrimServer } from '@authrim/server';
import {
  authrimMiddleware,
  authrimOptionalMiddleware,
} from '@authrim/server/adapters/koa';

const server = createAuthrimServer({
  issuer: 'https://auth.example.com',
  audience: 'https://api.example.com',
});

const app = new Koa();
const router = new Router();

// Health check — no auth
router.get('/health', (ctx) => {
  ctx.body = { status: 'ok' };
});

// Optional auth
router.get('/api/posts', authrimOptionalMiddleware(server), (ctx) => {
  const user = ctx.state.auth?.sub ?? 'anonymous';
  ctx.body = { user, posts: getPosts(user) };
});

// Protected routes
const protectedRouter = new Router({ prefix: '/api/me' });
protectedRouter.use(authrimMiddleware(server));

protectedRouter.get('/profile', (ctx) => {
  ctx.body = { sub: ctx.state.auth.sub, email: ctx.state.auth.email };
});

protectedRouter.get('/settings', (ctx) => {
  ctx.body = { settings: getUserSettings(ctx.state.auth.sub) };
});

app.use(router.routes());
app.use(protectedRouter.routes());
app.listen(3000);

TypeScript Type Extension for Koa

import type { ValidatedToken } from '@authrim/server';

declare module 'koa' {
  interface DefaultState {
    auth: ValidatedToken;
    authTokenType: 'Bearer' | 'DPoP';
  }
}

NestJS Adapter

Import from @authrim/server/adapters/nestjs.

NestJS uses Guards for route protection. The adapter provides factory functions that create Guard classes compatible with NestJS’s dependency injection system.

createAuthrimGuard()

Required authentication — throws HttpException(401) on invalid tokens:

import { Module, Controller, Get, UseGuards } from '@nestjs/common';
import { HttpException } from '@nestjs/common';
import { createAuthrimServer } from '@authrim/server';
import {
  createAuthrimGuard,
  getAuthFromRequest,
  getAuthTokenTypeFromRequest,
} from '@authrim/server/adapters/nestjs';

const server = createAuthrimServer({
  issuer: 'https://auth.example.com',
  audience: 'https://api.example.com',
});

const AuthGuard = createAuthrimGuard(server, HttpException);

@Controller('api')
@UseGuards(AuthGuard)
export class ApiController {
  @Get('profile')
  getProfile(@Req() req: Request) {
    const auth = getAuthFromRequest(req);
    const tokenType = getAuthTokenTypeFromRequest(req);

    return { sub: auth?.sub, tokenType };
  }
}

createAuthrimOptionalGuard()

Optional authentication — does not reject unauthenticated requests:

import { createAuthrimOptionalGuard } from '@authrim/server/adapters/nestjs';

const OptionalAuthGuard = createAuthrimOptionalGuard(server);

@Controller('public')
@UseGuards(OptionalAuthGuard)
export class PublicController {
  @Get('feed')
  getFeed(@Req() req: Request) {
    const auth = getAuthFromRequest(req);
    if (auth) {
      return { feed: getPersonalizedFeed(auth.sub) };
    }
    return { feed: getPublicFeed() };
  }
}

Helper Functions

Function	Return Type	Description
getAuthFromRequest(context)	ValidatedToken | undefined	Extract auth from ExecutionContext or Request
getAuthTokenTypeFromRequest(context)	'Bearer' | 'DPoP' | undefined	Extract token type

Custom @Auth() Parameter Decorator

Create a convenient parameter decorator for cleaner controller code:

import { createParamDecorator, ExecutionContext } from '@nestjs/common';
import { getAuthFromRequest } from '@authrim/server/adapters/nestjs';
import type { ValidatedToken } from '@authrim/server';

export const Auth = createParamDecorator(
  (data: unknown, ctx: ExecutionContext): ValidatedToken | undefined => {
    const request = ctx.switchToHttp().getRequest();
    return getAuthFromRequest(request);
  },
);

Use it in controllers:

@Controller('api')
@UseGuards(AuthGuard)
export class ApiController {
  @Get('profile')
  getProfile(@Auth() auth: ValidatedToken) {
    return { sub: auth.sub, email: auth.email };
  }
}

Complete NestJS Example

auth.module.ts

import { Module, Global } from '@nestjs/common';
import { HttpException } from '@nestjs/common';
import { createAuthrimServer } from '@authrim/server';
import { createAuthrimGuard, createAuthrimOptionalGuard } from '@authrim/server/adapters/nestjs';

const server = createAuthrimServer({
  issuer: process.env.AUTHRIM_ISSUER!,
  audience: process.env.AUTHRIM_AUDIENCE!,
});

export const AuthGuard = createAuthrimGuard(server, HttpException, {
  realm: 'my-api',
  onError: (err) => console.warn('Auth error:', err.code),
});

export const OptionalAuthGuard = createAuthrimOptionalGuard(server);

@Global()
@Module({})
export class AuthModule {}

users.controller.ts

import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard, OptionalAuthGuard } from './auth.module';
import { Auth } from './auth.decorator';
import type { ValidatedToken } from '@authrim/server';

@Controller('users')
export class UsersController {
  @Get('me')
  @UseGuards(AuthGuard)
  getMe(@Auth() auth: ValidatedToken) {
    return { sub: auth.sub, email: auth.email };
  }

  @Get()
  @UseGuards(OptionalAuthGuard)
  listUsers(@Auth() auth: ValidatedToken | undefined) {
    if (auth) {
      return { users: getAllUsers(), requestedBy: auth.sub };
    }
    return { users: getPublicUsers() };
  }
}

Framework Comparison

Aspect	Express	Fastify	Hono	Koa	NestJS
Auth location	req.auth	request.auth	getAuth(c)	ctx.state.auth	getAuthFromRequest(req)
Required middleware	authrimMiddleware()	authrimPreHandler()	authrimMiddleware()	authrimMiddleware()	createAuthrimGuard()
Optional middleware	authrimOptionalMiddleware()	authrimOptionalPreHandler()	authrimOptionalMiddleware()	authrimOptionalMiddleware()	createAuthrimOptionalGuard()
App-wide support	app.use(...)	authrimPlugin()	app.use(path, ...)	app.use(...)	@UseGuards() on controller
Type safety	declare global	declare module	Context variables	declare module	Param decorators

Next Steps

• Express & Fastify Adapters — Express and Fastify integration details
• Error Handling — Error codes and response utilities
• Configuration Reference — Server configuration options