swagger-ui-express vs swagger-parser vs swagger-jsdoc vs openapi-validator-middleware
OpenAPI and Swagger Tools Comparison
1 Year
swagger-ui-expressswagger-parserswagger-jsdocopenapi-validator-middleware
What's OpenAPI and Swagger Tools?

OpenAPI and Swagger tools are essential for designing, documenting, and validating APIs. They provide a standardized way to describe RESTful APIs, enabling developers to generate documentation, client libraries, and server stubs automatically. These tools enhance collaboration between frontend and backend teams, streamline API development, and ensure that APIs adhere to defined specifications, improving overall quality and usability.

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swagger-ui-express2,234,2511,48024 kB50a year agoMIT
swagger-parser1,045,7251,150-554 years agoMIT
swagger-jsdoc727,4691,749712 kB362 years agoMIT
openapi-validator-middleware13,44614443.6 kB31-Apache-2.0
Feature Comparison: swagger-ui-express vs swagger-parser vs swagger-jsdoc vs openapi-validator-middleware

Validation

  • swagger-ui-express:

    Swagger UI does not perform validation but provides a visual representation of the API, allowing users to interact with the API endpoints. Validation should be handled by other packages.

  • swagger-parser:

    Swagger-parser validates OpenAPI definitions to ensure they conform to the specification. It can detect issues such as missing required fields or incorrect data types, making it a valuable tool for maintaining API quality.

  • swagger-jsdoc:

    This package does not provide validation capabilities directly. Instead, it focuses on generating documentation from JSDoc comments, which can be complemented by other tools for validation purposes.

  • openapi-validator-middleware:

    This middleware validates incoming requests and outgoing responses against an OpenAPI specification, ensuring that your API behaves as expected and adheres to defined constraints. It helps catch errors early in the development process, improving API reliability.

Documentation Generation

  • swagger-ui-express:

    Swagger-ui-express serves the generated OpenAPI documentation in a user-friendly interface, allowing developers to view and interact with the API. It enhances the documentation generated by other tools.

  • swagger-parser:

    Swagger-parser does not generate documentation but can be used in conjunction with other tools to ensure that the OpenAPI definitions are correctly formatted and valid before documentation generation.

  • swagger-jsdoc:

    Swagger-jsdoc excels at generating OpenAPI documentation directly from JSDoc comments in your code. This approach keeps your documentation closely tied to your implementation, reducing the risk of discrepancies between the two.

  • openapi-validator-middleware:

    This package does not generate documentation. Its primary focus is on validation, so you will need to use other tools for documentation generation.

Ease of Use

  • swagger-ui-express:

    This package is user-friendly and easy to set up within an Express application. It provides an interactive UI that allows developers to test API endpoints directly from the documentation.

  • swagger-parser:

    Swagger-parser is a bit more complex as it requires understanding OpenAPI specifications. However, its robust parsing capabilities make it a powerful tool for developers needing to work with API definitions.

  • swagger-jsdoc:

    Swagger-jsdoc is easy to use for developers familiar with JSDoc. By simply adding comments to your code, you can generate comprehensive API documentation without needing to maintain separate files.

  • openapi-validator-middleware:

    This middleware is straightforward to integrate into an Express application, requiring minimal configuration. It allows developers to focus on building their APIs while ensuring compliance with OpenAPI specifications.

Integration

  • swagger-ui-express:

    This package is specifically designed for Express applications, making it easy to serve Swagger UI alongside your API. It integrates well with other middleware and tools.

  • swagger-parser:

    This package can be used independently or in conjunction with other tools. It is versatile and can be integrated into build processes or used in development environments to validate API definitions.

  • swagger-jsdoc:

    Swagger-jsdoc can be integrated into any Node.js application that uses JSDoc comments. Its flexibility allows it to fit into various development workflows easily.

  • openapi-validator-middleware:

    Designed specifically for use with Express, this middleware integrates seamlessly into existing applications, allowing for quick validation of API requests and responses.

Community and Support

  • swagger-ui-express:

    As part of the Swagger ecosystem, this package enjoys strong community support and regular updates, ensuring compatibility with the latest versions of OpenAPI.

  • swagger-parser:

    Swagger-parser is widely used and has extensive documentation and community support, making it a reliable choice for parsing and validating OpenAPI definitions.

  • swagger-jsdoc:

    Swagger-jsdoc benefits from a large community of users and contributors, ensuring that it remains up-to-date with the latest OpenAPI specifications and best practices.

  • openapi-validator-middleware:

    This package has a growing community and is actively maintained, providing a good level of support and documentation for developers.

How to Choose: swagger-ui-express vs swagger-parser vs swagger-jsdoc vs openapi-validator-middleware
  • swagger-ui-express:

    Use this package if you want to serve Swagger UI in your Express application. It provides a user-friendly interface for exploring and testing your API endpoints, making it an excellent choice for improving API usability and developer experience.

  • swagger-parser:

    Opt for this package if you require a robust solution for parsing and validating OpenAPI definitions. It can handle both JSON and YAML formats and is useful for tasks such as resolving references and validating the structure of your API definitions.

  • swagger-jsdoc:

    Select this package if you want to generate Swagger documentation from JSDoc comments in your code. It's ideal for developers who prefer to document their API directly in the source code, making it easier to keep documentation in sync with implementation.

  • openapi-validator-middleware:

    Choose this package if you need to validate incoming requests and outgoing responses against an OpenAPI specification in your Node.js middleware. It helps ensure that your API adheres to the defined schema, providing immediate feedback during development.

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