Type Safety & Validation
End-to-end TypeScript inference with automatic runtime validation using Zod, Valibot, or ArkType.
amqp-contractType-safe contracts for AMQP/RabbitMQ
End-to-end type safety · Runtime validation · Reliable retry patterns
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Reliable Retry
Built-in immediate or exponential backoff retry mechanisms.
AsyncAPI Compatible
Generate AsyncAPI 3.1 specs for documentation, visualization, and breaking change detection.
Quick Example
Define your contract once — get type safety everywhere:
typescript
import {
defineContract,
defineExchange,
defineQueue,
defineQueueBinding,
defineEventPublisher,
defineEventConsumer,
defineMessage,
} from "@amqp-contract/contract";
import { z } from "zod";
const ordersExchange = defineExchange("orders");
const ordersDlx = defineExchange("orders-dlx");
const orderProcessingQueue = defineQueue("order-processing", {
deadLetter: { exchange: ordersDlx },
retry: { mode: "ttl-backoff" }, // Automatic retry with exponential backoff
});
// A dead-letter exchange with no queue bound to it drops what it receives.
// Declare the dead-letter queue and the binding, or `deadLetter` keeps nothing.
const orderDlq = defineQueue("order-processing-dlq");
const orderMessage = defineMessage(
z.object({
orderId: z.string(),
amount: z.number(),
}),
);
// Event pattern: publisher broadcasts, consumers subscribe
const orderCreatedEvent = defineEventPublisher(ordersExchange, orderMessage, {
routingKey: "order.created",
});
// Compose contract - exchanges, queues, bindings auto-extracted
export const contract = defineContract({
publishers: {
// EventPublisherConfig → auto-extracted to publisher
orderCreated: orderCreatedEvent,
},
consumers: {
// EventConsumerResult → auto-extracted to consumer + binding
processOrder: defineEventConsumer(orderCreatedEvent, orderProcessingQueue),
},
// Standalone topology: the DLQ is declared, never consumed
queues: { orderDlq },
bindings: { orderDlq: defineQueueBinding(orderDlq, ordersDlx, { routingKey: "#" }) },
});typescript
import { TypedAmqpClient } from "@amqp-contract/client";
import { contract } from "./contract.js";
const client = await TypedAmqpClient.create({
contract,
urls: ["amqp://localhost"],
}).get();
await client
.publish("orderCreated", {
orderId: "ORD-123", // ✅ TypeScript knows!
amount: 99.99,
})
.getOrThrow();typescript
import { TypedAmqpWorker } from "@amqp-contract/worker";
import { OkAsync } from "unthrown";
import { contract } from "./contract.js";
const worker = await TypedAmqpWorker.create({
contract,
handlers: {
processOrder: ({ payload }) => {
console.log(payload.orderId); // ✅ Fully typed!
return OkAsync();
},
},
urls: ["amqp://localhost"],
}).get();