npm install swagger-ui-express swagger-jsdoc
npm install -D @types/swagger-ui-express

import swaggerUi from 'swagger-ui-express';
import swaggerJsdoc from 'swagger-jsdoc';

const spec = swaggerJsdoc({
  definition: {
    openapi: '3.0.0',
    info: { title: 'My API', version: '1.0.0' },
  },
  apis: ['./src/routes/*.ts'],
});

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(spec));
// Visit http://localhost:3000/api-docs

/**
 * @openapi
 * /users:
 *   get:
 *     summary: List all users
 *     responses:
 *       200:
 *         description: Array of users
 */
app.get('/users', (req, res) => res.json(users));