API Overview

The amqp-contract library consists of core packages and framework integrations:

Core Packages

@amqp-contract/contract

The core package for defining AMQP contracts.

import { defineContract, defineExchange, defineQueue } from '@amqp-contract/contract';

Key exports:

• defineContract - Define a complete AMQP contract
• defineExchange - Define an exchange
• defineQueue - Define a queue
• defineBinding - Define a binding
• definePublisher - Define a publisher with schema
• defineConsumer - Define a consumer with schema

@amqp-contract/client

Type-safe client for publishing messages.

import { TypedAmqpClient } from '@amqp-contract/client';

Key exports:

• TypedAmqpClient.create - Create a type-safe AMQP client
• TypedAmqpClient - The client class type

@amqp-contract/worker

Type-safe worker for consuming messages.

import { TypedAmqpWorker } from '@amqp-contract/worker';

Key exports:

• TypedAmqpWorker.create - Create a type-safe AMQP worker
• TypedAmqpWorker - The worker class type

@amqp-contract/asyncapi

Generate AsyncAPI 3.0 specifications from contracts.

import { generateAsyncAPI } from '@amqp-contract/asyncapi';

Key exports:

• generateAsyncAPI - Generate AsyncAPI specification
• Various TypeScript types for AsyncAPI documents

NestJS Integration

@amqp-contract/client-nestjs

NestJS integration for the type-safe AMQP client.

import { AmqpClientModule, AmqpClientService } from '@amqp-contract/client-nestjs';

Key exports:

• AmqpClientModule - NestJS dynamic module for client
• AmqpClientService - Injectable service for publishing messages

Features:

• ✅ Automatic lifecycle management
• ✅ Dependency injection
• ✅ forRoot/forRootAsync configuration
• ✅ Graceful shutdown

@amqp-contract/worker-nestjs

NestJS integration for the type-safe AMQP worker.

import { AmqpWorkerModule, AmqpWorkerService } from '@amqp-contract/worker-nestjs';

Key exports:

• AmqpWorkerModule - NestJS dynamic module for worker
• AmqpWorkerService - Injectable service managing the worker

Features:

• ✅ Automatic lifecycle management
• ✅ Dependency injection in handlers
• ✅ forRoot/forRootAsync configuration
• ✅ Graceful shutdown

Type Inference

All packages leverage TypeScript's type inference:

import { defineContract, definePublisher } from '@amqp-contract/contract';
import { TypedAmqpClient } from '@amqp-contract/client';
import { TypedAmqpWorker } from '@amqp-contract/worker';
import { connect } from 'amqplib';
import { z } from 'zod';

// Types are inferred from the contract
const contract = defineContract({
  publishers: {
    orderCreated: definePublisher('orders', z.object({
      orderId: z.string(),
    })),
  },
});

// Connect to RabbitMQ
const connection = await connect('amqp://localhost');

// Client knows about 'orderCreated' and its schema
const client = await TypedAmqpClient.create({ contract, connection });
await client.publish('orderCreated', { orderId: 'ORD-123' });

// Worker handler is fully typed
const worker = await TypedAmqpWorker.create({
  contract,
  handlers: {
    processOrder: async (message) => {
      message.orderId; // string
    },
  },
  connection,
});

Common Types

ContractDefinition

The base type for all contracts:

interface ContractDefinition {
  exchanges?: Record<string, ExchangeDefinition>;
  queues?: Record<string, QueueDefinition>;
  bindings?: Record<string, BindingDefinition>;
  publishers?: Record<string, PublisherDefinition>;
  consumers?: Record<string, ConsumerDefinition>;
}

Schema Types

amqp-contract uses Standard Schema, supporting:

• Zod
• Valibot
• ArkType
• Any Standard Schema-compatible library

Next Steps

For Framework-Agnostic Usage

• Explore the @amqp-contract/contract API
• Learn about the @amqp-contract/client API
• Understand the @amqp-contract/worker API
• Check out @amqp-contract/asyncapi generation

For NestJS Applications

• Get started with NestJS Client Usage
• Learn about NestJS Worker Usage
• Explore @amqp-contract/client-nestjs API
• Understand @amqp-contract/worker-nestjs API