index.js

import { Router, createCors, error, json } from 'itty-router';

// import the routes
import { chatHandler } from './routes/chat';
import { completionHandler } from './routes/completion';
import { embeddingsHandler } from './routes/embeddings';
import { transcriptionHandler, translationHandler } from './routes/audio';
import { getImageHandler, imageGenerationHandler } from './routes/image';
import { modelsHandler } from './routes/models';

const { preflight, corsify } = createCors();

// Create a new router
const router = Router({ base: '/v1' });

function extractToken(authorizationHeader) {
	if (authorizationHeader) {
		const parts = authorizationHeader.split(' ');
		if (parts.length === 2 && parts[0] === 'Bearer') {
			return parts[1];
		}
	}
	return null;
}
// MIDDLEWARE: withAuthenticatedUser - embeds user in Request or returns a 401
const bearerAuthentication = (request, env) => {
	const authorizationHeader = request.headers.get('Authorization');
	if (!authorizationHeader) {
		return error(401, 'Unauthorized');
	}
	const access_token = extractToken(authorizationHeader);
	if (env.ACCESS_TOKEN !== access_token) {
		return error(403, 'Forbidden');
	}
};

// CORS, see https://itty.dev/itty-router/cors
router.all('*', preflight);

router
	.all('*', bearerAuthentication)
	.post('/chat/completions', chatHandler)
	.post('/completions', completionHandler)
	.post('/embeddings', embeddingsHandler)
	.post('/audio/transcriptions', transcriptionHandler)
	.post('/audio/translations', translationHandler)
	.post('/images/generations', imageGenerationHandler)
	.get('/images/get/:name', getImageHandler)
	.get('/models', modelsHandler);

// 404 for everything else
router.all('*', () => new Response('404, not found!', { status: 404 }));

export default {
	fetch: (request, env, ctx) =>
		router
			.handle(request, env, ctx)

			// catch any errors
			.catch(e => {
				console.error(e);
				return error(e);
			})

			// add CORS headers to all requests,
			// including errors
			.then(corsify),
};