Generate Swagger documentation as JSON/YAML in NestJS

Question

I've followed the instructions to create a Swagger documentation , and my documentation is now available using Swagger UI. I'd like to also generate the documentation as JSON or YAML so it's easy to import in eg Postman, but I can't find any suitable methods in the SwaggerModule , nor does the Swagger UI have any export button.

Answer 1

According to this github issue you can just stringify the created Swagger document and eg write it to the file system like this:

const app = await NestFactory.create(ApplicationModule);
const options = new DocumentBuilder()
    .setTitle("Title")
    .setDescription("description")
    .setVersion("1.0")
    .build();
const document = SwaggerModule.createDocument(app, options);

fs.writeFileSync("./swagger-spec.json", JSON.stringify(document));
SwaggerModule.setup("/api", app, document);

await app.listen(80);

Answer 2

如果您遵循https://docs.nestjs.com/recipes/swagger ，请尝试访问/api/json而不是/api-json 。

Answer 3

As well as the solution shown to write to disk ( https://stackoverflow.com/a/51736406/5693245 ), you can still access on your own API endpoint.

As per docs , depending on whether you use swagger-ui-express or fastify to serve docs the location will be different

To generate and download a Swagger JSON file, navigate to http://localhost:3000/api-json (swagger-ui-express) or http://localhost:3000/api/json (fastify-swagger) in your browser (assuming that your Swagger documentation is available under http://localhost:3000/api).

It also depends on where you serve your API from, and assumes you use /api . If this is not the case replace with your endpoint, or in case you are not using a base URL for swagger-ui-express this would be http://localhost:3000/-json

Answer 4

Tested in Nestjs v9

Suppose the docs path is as follows

http://localhost:3000/docs

Get JSON

http://localhost:3000/docs-json

Get YAML

http://localhost:3000/docs-yaml

Answer 5

Tested in Nestjs v8

GET http://{host}:{port}/docs

Get JSON

GET http://{host}:{port}/docs/json

Answer 6

With the latest version (v8 as of writing) of NestJS, following the setup in the openapi documentation , you should be able to access the json document without any extra setup with

GET http://{host}:{port}/api-docs