Nest plugin can be found under your node_modules directory under: @nestjs/swagger/dist/plugin

This should be set in your complier options:

"compilerOptions": {
     "plugins": ["@nestjs/swagger/dist/plugin"]
}

It was an issue with global dependencies conflicting with local ones, as well as the old build (set to incremental mode) conflicting with the new property generation. Did the following to resolve the issue:

• If nest cli is globally installed, manually upgrade it: yarn global upgrade upgrade @nestjs/cli, or with npm (npm update -g @nestjs/cli)
• Upgrade local service nest to most recent version: nest update
• Add the following to your nest-cli.json:

  "compilerOptions": {
    "plugins": ["@nestjs/swagger/plugin"]
  }

• Remove your local dist folder (or do a yarn build)
• Start the server with the nest cli commands (i.e. nest start or nest start:dev)

NestJS 9 was recently released (2 days ago).

https://trilon.io/blog/nestjs-9-is-now-available.

Changes have been made to the @nestjs/swagger package. You are installing the latest version which has peer dependencies on NestJS 9 while your project is still on version 8.4.7.

The error is saying it cannot resolve the requested peer dependency @nestjs/common@^9.0.0. It does find @nestjs/common@8.4.7 instead, but that's not compatible.

Either upgrade NestJS or install an older version of the @nestjs/swagger package that is compatible with the NestJS version your application uses. Version 5.2.1 should work for you.

yarn add @nestjs/swagger@5.2.1
OR
npm i @nestjs/swagger@5.2.1

You may have forgotten to load metadata (that was generated by the plugin).

From https://docs.nestjs.com/openapi/cli-plugin#swc-builder

  import metadata from './metadata';
  ...
  await SwaggerModule.loadPluginMetadata(metadata);
  const document = SwaggerModule.createDocument(app, config);