# Request-Reply

> Need a response? Send a request message, wait for the reply on a dedicated channel.

- **Category**: Integration
- **Subcategory**: Message Construction
- **Canonical URL**: https://designpattern.fyi/patterns/request_reply/

---

## Description
Clean, reusable architecture pattern.


## Use Cases
Price calculation service — Order Service sends a PriceRequest message, includes its private reply queue address and a correlation ID. Pricing Service calculates and sends PriceResponse to the reply queue. Order Service matches it via correlation ID.





## Trade-offs


### Advantages

- Response semantics over messaging — get answers without sync HTTP

- Messaging benefits preserved — buffering, retry, broker persistence

- Supports async processing — requester can do other work while waiting

- Works across different tech stacks and languages




### Considerations & Drawbacks

- More complex than a plain REST call — needs correlation IDs, reply channels

- Latency is typically higher than direct HTTP due to broker hops

- Timeout management adds complexity

- Reply channels can proliferate and need lifecycle management







---
**Reference**: [Original Source](https://www.enterpriseintegrationpatterns.com/patterns/messaging/RequestReply.html)