messaging

# Messaging & Event-Driven Skill

**Bonded to:** `architecture-patterns-agent` (Secondary)

---

## Quick Start

```bash
# Invoke messaging skill
"Set up RabbitMQ for my microservices"
"Implement event-driven order processing"
"Configure Kafka for high-throughput messaging"
```

---

## Message Broker Comparison

| Broker | Best For | Throughput | Ordering |
|--------|----------|------------|----------|
| RabbitMQ | Task queues, RPC | Medium | Per queue |
| Kafka | Event streaming, logs | Very high | Per partition |
| Redis Pub/Sub | Real-time, simple | High | None |
| SQS | AWS serverless | Medium | FIFO optional |

---

## Examples

### RabbitMQ Producer/Consumer
```python
import pika
import json

# Producer
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.queue_declare(queue='orders', durable=True)

def publish_order(order):
    channel.basic_publish(
        exchange='',
        routing_key='orders',
        body=json.dumps(order),
        properties=pika.BasicProperties(delivery_mode=2)  # persistent
    )

# Consumer
def process_order(ch, method, properties, body):
    order = json.loads(body)
    print(f"Processing order: {order['id']}")
    ch.basic_ack(delivery_tag=method.delivery_tag)

channel.basic_qos(prefetch_count=1)
channel.basic_consume(queue='orders', on_message_callback=process_order)
channel.start_consuming()
```

### Kafka Event Streaming
```python
from kafka import KafkaProducer, KafkaConsumer
import json

# Producer
producer = KafkaProducer(
    bootstrap_servers=['localhost:9092'],
    value_serializer=lambda v: json.dumps(v).encode('utf-8')
)

producer.send('user-events', {'type': 'USER_CREATED', 'user_id': '123'})

# Consumer
consumer = KafkaConsumer(
    'user-events',
    bootstrap_servers=['localhost:9092'],
    group_id='notification-service',
    auto_offset_reset='earliest',
    value_deserializer=lambda m: json.loads(m.decode('utf-8'))
)

for message in consumer:
    p