@amqp-contract/core

Core utilities for AMQP setup and management in amqp-contract.

This package provides centralized functionality for establishing AMQP topology (exchanges, queues, and bindings) from contract definitions, and defines the Logger interface used across amqp-contract packages.

📖 Full documentation →

Installation

npm install @amqp-contract/core
# or
pnpm add @amqp-contract/core
# or
yarn add @amqp-contract/core

Usage

AmqpClient

The core package exports an AmqpClient class that handles the creation of all AMQP resources defined in a contract.

// contract.ts
import {
  defineContract,
  defineEventPublisher,
  defineEventConsumer,
  defineExchange,
  defineQueue,
  defineQueueBinding,
  defineMessage,
} from "@amqp-contract/contract";
import { z } from "zod";

// Define resources
const ordersExchange = defineExchange("orders");
const ordersDlx = defineExchange("orders-dlx");
const orderProcessingQueue = defineQueue("order-processing", {
  deadLetter: { exchange: ordersDlx },
});
// A dead-letter exchange with nothing bound to it discards every rejected
// message, so declare the DLQ and bind it. `orders-dlx` is topic, so `#`
// catches whatever routing key the message arrived with.
const orderDlq = defineQueue("order-processing-dlq");
const orderMessage = defineMessage(z.object({ orderId: z.string() }));

const orderCreatedEvent = defineEventPublisher(ordersExchange, orderMessage, {
  routingKey: "order.created",
});

// Define your contract
export const contract = defineContract({
  publishers: {
    orderCreated: orderCreatedEvent,
  },
  consumers: {
    processOrder: defineEventConsumer(orderCreatedEvent, orderProcessingQueue),
  },
  queues: { orderDlq },
  bindings: { orderDlqBinding: defineQueueBinding(orderDlq, ordersDlx, { routingKey: "#" }) },
});

Hand that contract to an AmqpClient, which asserts its topology on connect:

import { AmqpClient } from "@amqp-contract/core";

import { contract } from "./contract.js";

// Setup AMQP resources
const amqpClient = new AmqpClient(contract, {
  urls: ["amqp://localhost"],
});

// Clean up — close() returns an AsyncResult with an empty error channel
await amqpClient.close().get();

For advanced channel configuration options (custom setup, prefetch, publisher confirms), see the Channel Configuration Guide.

Logger Interface

The core package exports a Logger interface that can be used to implement custom logging for AMQP operations:

import type { Logger } from "@amqp-contract/core";

const logger: Logger = {
  debug: (message, context) => console.debug(message, context),
  info: (message, context) => console.info(message, context),
  warn: (message, context) => console.warn(message, context),
  error: (message, context) => console.error(message, context),
};

// Pass the logger to client or worker
import { TypedAmqpClient } from "@amqp-contract/client";

const client = await TypedAmqpClient.create({
  contract,
  urls: ["amqp://localhost"],
  logger, // Optional: logs published messages
}).getOrThrow();

API

For complete API documentation, see the @amqp-contract/core API Reference.

Documentation

📖 Read the full documentation →

License

MIT