@wisemen/nestjs-async-api

A TypeScript package for generating AsyncAPI v3.0.0 documentation for NestJS applications. Automatically generate YAML specifications and HTML documentation for your asynchronous APIs (WebSockets, message queues, event-driven architectures).

Features

• AsyncAPI v3.0.0 Types: Complete TypeScript type definitions for AsyncAPI specification
• Channel Definitions: Type-safe channel definitions with parameter extraction
• YAML Generation: Automatically generate AsyncAPI YAML specifications from your code
• HTML Documentation: Generate beautiful HTML documentation using AsyncAPI templates
• NestJS Integration: Seamlessly integrates with NestJS decorators and DTOs
• Schema Generation: Automatic schema generation from TypeScript classes using NestJS Swagger decorators

Installation

npm install @wisemen/nestjs-async-api

Usage

Define a Channel

Create channels using the createChannel function with type-safe address parameters:

import { createChannel } from '@wisemen/nestjs-async-api'

export const userNotificationsChannel = createChannel(
  'users.{userId}.notifications',
  {
    parameters: {
      userId: {
        description: 'The ID of the user receiving notifications'
      }
    },
    operations: {
      subscribe: {
        action: 'receive',
        summary: 'Subscribe to user notifications',
        description: 'Receive real-time notifications for a specific user',
        messages: [
            UserNotificationEvent // a DTO decorated with @nestjs/swagger properties
        ]
      }
    }
  }
)

Define Your AsyncAPI Specification

Create an AsyncAPI definition that points to your channel files:

import { AsyncAPIDefinition } from '@wisemen/nestjs-async-api'

export const asyncApiDefinition: AsyncAPIDefinition = {
  asyncapi: '3.0.0',
  defaultContentType: 'application/json',
  info: {
    title: 'My Application API',
    version: '1.0.0',
    description: 'Real-time event API for My Application',
    contact: {
      name: 'API Support',
      email: '[email protected]'
    }
  },
  channels: 'src/**/*.channel.ts'  // Glob pattern to find channel files
}

Generate YAML Documentation

Generate AsyncAPI YAML specification from your definitions:

import { generateAsyncApiYaml } from '@wisemen/nestjs-async-api'
import { asyncApiDefinition } from './async-api.definition'

const yaml = await generateAsyncApiYaml(asyncApiDefinition)
console.log(yaml)

Generate HTML Documentation

Generate beautiful HTML documentation from your YAML specification:

import { generateAsyncAPIHTML } from '@wisemen/nestjs-async-api'

await generateAsyncAPIHTML(
  yaml,                    // AsyncAPI YAML string
  './docs',                // Output directory
  'async-api.html'         // Output filename
)

Integration with NestJS

This package works seamlessly with NestJS decorators from @nestjs/swagger. Use @ApiProperty() decorators on your DTOs, and they will be automatically converted to AsyncAPI schemas:

import { ApiProperty } from '@nestjs/swagger'

export class UserNotificationEvent {
  @ApiProperty({ description: 'Notification ID' })
  id: string

  @ApiProperty({ description: 'Notification message' })
  message: string

  @ApiProperty({ description: 'Timestamp', type: Date })
  timestamp: Date
}

License

GPL