swagger-ui-express vs @fastify/swagger-ui
API Documentation Middleware Comparison
1 Year
swagger-ui-express@fastify/swagger-ui
What's API Documentation Middleware?

API documentation middleware packages are essential tools in web development that facilitate the creation and presentation of interactive API documentation. They allow developers to generate and serve documentation for their APIs, making it easier for users to understand how to interact with the API endpoints. These packages leverage the OpenAPI Specification (formerly known as Swagger) to provide a user-friendly interface for exploring API capabilities, testing endpoints, and viewing request/response formats. By integrating these tools, developers can enhance the usability and accessibility of their APIs, ultimately leading to better adoption and user experience.

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swagger-ui-express1,847,4131,44424 kB489 months agoMIT
@fastify/swagger-ui249,2991512.35 MB42 days agoMIT
Feature Comparison: swagger-ui-express vs @fastify/swagger-ui

Framework Compatibility

  • swagger-ui-express:

    swagger-ui-express is designed for Express applications, providing a simple middleware solution to serve Swagger UI. It works seamlessly with Express's routing and middleware architecture, making it easy to integrate into existing Express projects.

  • @fastify/swagger-ui:

    @fastify/swagger-ui is tailored for the Fastify framework, leveraging its asynchronous capabilities and performance optimizations. It integrates smoothly with Fastify's plugin system, making it easy to set up and configure for Fastify applications.

Performance

  • swagger-ui-express:

    swagger-ui-express is built on top of Express, which is generally performant, but may not match the speed of Fastify. While it is suitable for most applications, developers should be mindful of performance considerations in high-load scenarios.

  • @fastify/swagger-ui:

    @fastify/swagger-ui benefits from Fastify's high performance and low overhead, ensuring that serving API documentation does not significantly impact the application's response time. Fastify's architecture allows for efficient handling of requests, making this package a great choice for performance-sensitive applications.

Ease of Use

  • swagger-ui-express:

    swagger-ui-express provides a simple API for integrating Swagger UI into Express applications. Its ease of use makes it accessible for developers who are already familiar with Express, allowing for quick implementation of API documentation.

  • @fastify/swagger-ui:

    @fastify/swagger-ui offers a straightforward setup process that aligns with Fastify's conventions. It allows developers to easily define routes and serve documentation with minimal configuration, making it user-friendly for Fastify developers.

Customization

  • swagger-ui-express:

    swagger-ui-express supports customization of the Swagger UI through options that can be passed during setup. This allows developers to tailor the documentation to their specific requirements, including modifying the layout and available features.

  • @fastify/swagger-ui:

    @fastify/swagger-ui allows for customization of the Swagger UI interface and behavior through Fastify's configuration options. Developers can modify the documentation's appearance and functionality to better suit their API's needs.

Community and Support

  • swagger-ui-express:

    swagger-ui-express is widely used in the Express community and has extensive documentation and community support. Its popularity ensures that developers can find help and resources easily, making it a reliable choice for Express applications.

  • @fastify/swagger-ui:

    @fastify/swagger-ui benefits from the growing Fastify community, which provides support and resources for developers. As Fastify gains popularity, the ecosystem around it, including this package, continues to expand.

How to Choose: swagger-ui-express vs @fastify/swagger-ui
  • swagger-ui-express:

    Choose swagger-ui-express if you are using the Express framework and need a straightforward way to serve Swagger UI documentation. This package is well-suited for Express applications and provides a simple setup for integrating Swagger UI.

  • @fastify/swagger-ui:

    Choose @fastify/swagger-ui if you are using the Fastify framework and want a seamless integration that takes advantage of Fastify's performance optimizations and plugin architecture. This package is specifically designed for Fastify, ensuring compatibility and efficiency.

README for swagger-ui-express

Swagger UI Express

| Statements | Branches | Functions | Lines | | --------------------------- | ----------------------- | ------------------------- | -------------------- | | Statements | Branches | Functions | Lines |

This module allows you to serve auto-generated swagger-ui generated API docs from express, based on a swagger.json file. The result is living documentation for your API hosted from your API server via a route.

Swagger version is pulled from npm module swagger-ui-dist. Please use a lock file or specify the version of swagger-ui-dist you want to ensure it is consistent across environments.

You may be also interested in:

  • swagger-jsdoc: Allows you to markup routes with jsdoc comments. It then produces a full swagger yml config dynamically, which you can pass to this module to produce documentation. See below under the usage section for more info.
  • swagger tools: Various tools, including swagger editor, swagger code gen etc.

Usage

Install using npm:

$ npm install swagger-ui-express

Express setup app.js

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));

or if you are using Express router

const router = require('express').Router();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

router.use('/api-docs', swaggerUi.serve);
router.get('/api-docs', swaggerUi.setup(swaggerDocument));

Open http://<app_host>:<app_port>/api-docs in your browser to view the documentation.

If you want to set up routing based on the swagger document checkout swagger-express-router

swagger-jsdoc

If you are using swagger-jsdoc simply pass the swaggerSpec into the setup function:

// Initialize swagger-jsdoc -> returns validated swagger spec in json format
const swaggerSpec = swaggerJSDoc(options);

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerSpec));

Swagger Explorer

By default the Swagger Explorer bar is hidden, to display it pass true as the 'explorer' property of the options to the setup function:

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  explorer: true
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

Custom swagger options

To pass custom options e.g. validatorUrl, to the SwaggerUi client pass an object as the 'swaggerOptions' property of the options to the setup function:

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  swaggerOptions: {
    validatorUrl: null
  }
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

For all the available options, refer to Swagger UI Configuration

Custom CSS styles

To customize the style of the swagger page, you can pass custom CSS as the 'customCss' property of the options to the setup function.

E.g. to hide the swagger header:

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customCss: '.swagger-ui .topbar { display: none }'
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

Custom CSS styles from Url

You can also pass the url to a custom css file, the value must be the public url of the file and can be relative or absolute to the swagger path.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customCssUrl: '/custom.css'
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

You can also pass an array of css urls to load multiple css files.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customCssUrl: [
    '/custom.css',
    'https://example.com/other-custom.css'
  ]
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

Custom JS

If you would like to have full control over your HTML you can provide your own javascript file, value accepts absolute or relative path. Value must be the public url of the js file.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customJs: '/custom.js'
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

You can also pass an array of js urls to load multiple js files.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customJs: [
    '/custom.js',
    'https://example.com/other-custom.js'
  ]
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

It is also possible to add inline javascript, either as string or array of string.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customJsStr: 'console.log("Hello World")'
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));
const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
  customJsStr: [
    'console.log("Hello World")',
    `
    var x = 1
    console.log(x)
    `
  ]
};

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument, options));

Load swagger from url

To load your swagger from a url instead of injecting the document, pass null as the first parameter, and pass the relative or absolute URL as the 'url' property to 'swaggerOptions' in the setup function.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');

var options = {
  swaggerOptions: {
    url: 'http://petstore.swagger.io/v2/swagger.json'
  }
}

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(null, options));

To load multiple swagger documents from urls as a dropdown in the explorer bar, pass an array of object with name and url to 'urls' property to 'swaggerOptions' in the setup function.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');

var options = {
  explorer: true,
  swaggerOptions: {
    urls: [
      {
        url: 'http://petstore.swagger.io/v2/swagger.json',
        name: 'Spec1'
      },
      {
        url: 'http://petstore.swagger.io/v2/swagger.json',
        name: 'Spec2'
      }
    ]
  }
}

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(null, options));

Make sure 'explorer' option is set to 'true' in your setup options for the dropdown to be visible.

Load swagger from yaml file

To load your swagger specification yaml file you need to use a module able to convert yaml to json; for instance yaml.

npm install yaml
const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const fs = require("fs")
const YAML = require('yaml')

const file  = fs.readFileSync('./swagger.yaml', 'utf8')
const swaggerDocument = YAML.parse(file)

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));

Modify swagger file on the fly before load

To dynamically set the host, or any other content, in the swagger file based on the incoming request object you may pass the json via the req object; to achieve this just do not pass the the swagger json to the setup function and it will look for swaggerDoc in the req object.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {}

app.use('/api-docs', function(req, res, next){
    swaggerDocument.host = req.get('host');
    req.swaggerDoc = swaggerDocument;
    next();
}, swaggerUi.serveFiles(swaggerDocument, options), swaggerUi.setup());

Two swagger documents

To run 2 swagger ui instances with different swagger documents, use the serveFiles function instead of the serve function. The serveFiles function has the same signature as the setup function.

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocumentOne = require('./swagger-one.json');
const swaggerDocumentTwo = require('./swagger-two.json');

var options = {}

app.use('/api-docs-one', swaggerUi.serveFiles(swaggerDocumentOne, options), swaggerUi.setup(swaggerDocumentOne));

app.use('/api-docs-two', swaggerUi.serveFiles(swaggerDocumentTwo, options), swaggerUi.setup(swaggerDocumentTwo));

app.use('/api-docs-dynamic', function(req, res, next){
  req.swaggerDoc = swaggerDocument;
  next();
}, swaggerUi.serveFiles(), swaggerUi.setup());

Link to Swagger document

To render a link to the swagger document for downloading within the swagger ui - then serve the swagger doc as an endpoint and use the url option to point to it:

const express = require('express');
const app = express();
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = require('./swagger.json');

var options = {
    swaggerOptions: {
        url: "/api-docs/swagger.json",
    },
}
app.get("/api-docs/swagger.json", (req, res) => res.json(swaggerDocument));
app.use('/api-docs', swaggerUi.serveFiles(null, options), swaggerUi.setup(null, options));

Requirements

  • Node v0.10.32 or above
  • Express 4 or above

Testing

  • Install phantom
  • npm install
  • npm test