---
name: azure-servicebus-ts
description: Build messaging applications using Azure Service Bus SDK for JavaScript (@azure/service-bus). Use when implementing queues, topics/subscriptions, message sessions, dead-letter handling, or enterprise messaging patterns.
license: MIT
metadata:
author: Microsoft
version: "1.0.0"
package: '@azure/service-bus'
---
# Azure Service Bus SDK for TypeScript
Enterprise messaging with queues, topics, and subscriptions.
## Installation
```bash
npm install @azure/service-bus @azure/identity
```
## Environment Variables
```bash
SERVICEBUS_NAMESPACE=<namespace>.servicebus.windows.net
SERVICEBUS_QUEUE_NAME=my-queue
SERVICEBUS_TOPIC_NAME=my-topic
SERVICEBUS_SUBSCRIPTION_NAME=my-subscription
AZURE_TOKEN_CREDENTIALS=prod # Required only if DefaultAzureCredential is used in production
```
## Authentication
```typescript
import { ServiceBusClient } from "@azure/service-bus";
import { DefaultAzureCredential, ManagedIdentityCredential } from "@azure/identity";
// Local dev: DefaultAzureCredential. Production: set AZURE_TOKEN_CREDENTIALS=prod or AZURE_TOKEN_CREDENTIALS=<specific_credential>
const credential = new DefaultAzureCredential({requiredEnvVars: ["AZURE_TOKEN_CREDENTIALS"]});
// Or use a specific credential directly in production:
// See https://learn.microsoft.com/javascript/api/overview/azure/identity-readme?view=azure-node-latest#credential-classes
// const credential = new ManagedIdentityCredential();
const fullyQualifiedNamespace = process.env.SERVICEBUS_NAMESPACE!;
const client = new ServiceBusClient(fullyQualifiedNamespace, credential);
```
## Core Workflow
### Send Messages to Queue
```typescript
const sender = client.createSender("my-queue");
// Single message
await sender.sendMessages({
body: { orderId: "12345", amount: 99.99 },
contentType: "application/json",
});
// Batch messages
const batch = await sender.createMessageBatch();
batch.tryAddMessage({ body: "Message 1" });
batch.tryAddMessage({ body: "Message 2" });
await sender.sendMessages(batch);
await sender.close();
```
### Receive Messages from Queue
```typescript
const receiver = client.createReceiver("my-queue");
// Receive batch
const messages = await receiver.receiveMessages(10, { maxWaitTimeInMs: 5000 });
for (const message of messages) {
console.log(`Received: ${message.body}`);
await receiver.completeMessage(message);
}
await receiver.close();
```
### Subscribe to Messages (Event-Driven)
```typescript
const receiver = client.createReceiver("my-queue");
const subscription = receiver.subscribe({
processMessage: async (message) => {
console.log(`Processing: ${message.body}`);
// Message auto-completed on success
},
processError: async (args) => {
console.error(`Error: ${args.error}`);
},
});
// Stop after some time
setTimeout(async () => {
await subscription.close();
await receiver.close();
}, 60000);
```
### Topics and Subscriptions
```typescript
// Send to topic
const topicSender = client.createSender("my-topic");
await topicSender.sendMessages({
body: { event: "order.created", data: { orderId: "123" } },
applicationProperties: { eventType: "order.created" },
});
// Receive from subscription
const subscriptionReceiver = client.createReceiver("my-topic", "my-subscription");
const messages = await subscriptionReceiver.receiveMessages(10);
```
## Message Sessions
```typescript
// Send session message
const sender = client.createSender("session-queue");
await sender.sendMessages({
body: { step: 1, data: "First step" },
sessionId: "workflow-123",
});
// Receive session messages
const sessionReceiver = await client.acceptSession("session-queue", "workflow-123");
const messages = await sessionReceiver.receiveMessages(10);
// Get/set session state
const state = await sessionReceiver.getSessionState();
await sessionReceiver.setSessionState(Buffer.from(JSON.stringify({ progress: 50 })));
await sessionReceiver.close();
```
## Dead-Letter Handling
```typescript
// Move to dead-letter
await receiver.deadLetterMessage(message, {
deadLetterReason: "Validation failed",
deadLetterErrorDescription: "Missing required field: orderId",
});
// Process dead-letter queue
const dlqReceiver = client.createReceiver("my-queue", { subQueueType: "deadLetter" });
const dlqMessages = await dlqReceiver.receiveMessages(10);
for (const msg of dlqMessages) {
console.log(`DLQ Reason: ${msg.deadLetterReason}`);
// Reprocess or log
await dlqReceiver.completeMessage(msg);
}
```
## Scheduled Messages
```typescript
const sender = client.createSender("my-queue");
// Schedule for future delivery
const scheduledTime = new Date(Date.now() + 60000); // 1 minute from now
const sequenceNumber = await sender.scheduleMessages(
{ body: "Delayed message" },
scheduledTime
);
// Cancel scheduled message
await sender.cancelScheduledMessages(sequenceNumber);
```
## Message Deferral
```typescript
// Defer message for later
await receiver.deferMessage(message);
// Receive deferred message by sequence number
const deferredMessage = await receiver.receiveDeferredMessages(message.sequenceNumber!);
await receiver.completeMessage(deferredMessage[0]);
```
## Peek Messages (Non-Destructive)
```typescript
const receiver = client.createReceiver("my-queue");
// Peek without removing
const peekedMessages = await receiver.peekMessages(10);
for (const msg of peekedMessages) {
console.log(`Peeked: ${msg.body}`);
}
```
## Key Types
```typescript
import {
ServiceBusClient,
ServiceBusSender,
ServiceBusReceiver,
ServiceBusSessionReceiver,
ServiceBusMessage,
ServiceBusReceivedMessage,
ProcessMessageCallback,
ProcessErrorCallback,
} from "@azure/service-bus";
```
## Receive Modes
```typescript
// Peek-Lock (default) - message locked until completed/abandoned
const receiver = client.createReceiver("my-queue", { receiveMode: "peekLock" });
await receiver.completeMessage(message); // Remove from queue
await receiver.abandonMessage(message); // Return to queue
await receiver.deferMessage(message); // Defer for later
await receiver.deadLetterMessage(message); // Move to DLQ
// Receive-and-Delete - message removed immediately
const receiver = client.createReceiver("my-queue", { receiveMode: "receiveAndDelete" });
```
## Best Practices
1. **Use Microsoft Entra Token Credential** - Use `DefaultAzureCredential` for local development; use `ManagedIdentityCredential` or `WorkloadIdentityCredential` for production
2. **Reuse clients** - Create `ServiceBusClient` once, share across senders/receivers
3. **Close resources** - Always close senders/receivers when done
4. **Handle errors** - Implement `processError` callback for subscription receivers
5. **Use sessions for ordering** - When message order matters within a group
6. **Configure dead-letter** - Always handle DLQ messages
7. **Batch sends** - Use `createMessageBatch()` for multiple messages
## Reference Documentation
For detailed patterns, see:
- [Queues vs Topics Patterns](references/queues-topics.md) - Queue/topic patterns, sessions, receive modes, message settlement
- [Error Handling and Reliability](references/error-handling.md) - ServiceBusError codes, DLQ handling, lock renewal, graceful shutdown