---
id: oslo-messaging
version: "18.2.0"
license: unclear
license_treatment: permissive
maintenance: active
---

# oslo.messaging — Oslo Messaging API

License: permissive · Maintenance: active · Downloads: 502.2K/mo

## What it is and what it does

Oslo Messaging is an OpenStack library that provides a standardized API for sending RPC calls and notifications across distributed systems. It abstracts the underlying message transport layer, allowing applications to work with different brokers without changing application code. The library handles serialization, routing, and delivery semantics, making it easier to build loosely coupled microservices and distributed components.

The package is designed for infrastructure and cloud applications that need reliable inter-process communication. It brings in 17 runtime dependencies including kombu, amqp, oslo.config, oslo.log, oslo.serialization, and others. It requires Python 3.11 or later and a running message broker backend to function.

Use it for:

- Building OpenStack services that need to communicate via RPC calls across multiple nodes.
- Sending notifications from one service to many subscribers in a distributed system.
- Abstracting message transport details to allow switching between different brokers.
- Implementing request-reply patterns in microservices without direct broker coupling.
- Centralizing messaging configuration and serialization logic across multiple applications.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Oslo Messaging provides a unified API for RPC and notification messaging across multiple transport backends, abstracting away the complexity of different messaging systems.

Yes, if you are building OpenStack services or distributed systems that require a standardized messaging abstraction. The active maintenance, low install friction, permissive license, and zero known vulnerabilities make it a solid choice. No, if you need a lightweight messaging client for simple use cases—the 17 dependencies and Python 3.11+ requirement add overhead. Yes-with-conditions if evaluating for non-OpenStack projects: verify that the oslo.* ecosystem and its dependency footprint align with your architecture.

## Install

pip install oslo-messaging
uv add oslo-messaging
poetry add oslo-messaging

## Installing oslo.messaging

Before you install: Low install friction with a pure-Python wheel. Active maintenance as of 35 days ago. Requires Python 3.11 or later and brings in 17 runtime dependencies including kombu, amqp, and several other oslo.* libraries, which is typical for OpenStack infrastructure components.

License in practice: Licensed under Apache License, Version 2.0 (permissive). Safe for commercial and proprietary use with standard attribution requirements.

Quickstart:

pip install oslo.messaging

from oslo_messaging import rpc
from oslo_messaging import transport

trans = transport.get_transport(transport_url)

Requires a message broker backend to be running and accessible; Python 3.11 or later.

Verify before relying:

- Whether all 17 runtime dependencies are truly required for basic RPC/notification use or if some are optional.
- Performance characteristics and throughput limits for different transport backends.
- Whether the package supports async/await patterns or is callback-based only.
- Specific message broker versions and configurations supported.

## Package facts

- License: not declared (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 502.2K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

RPC messaging library, message queue abstraction, oslo messaging transport, distributed messaging API, notification messaging, openstack messaging, message broker abstraction, openstack, message-queue, rpc

[View on SkillFed](https://skillfed.io/packages/oslo-messaging) · [View on PyPI](https://pypi.org/project/oslo-messaging/)