https://github.com/invokermain/engin
A lightweight Application Framework for Python powered by Dependency Injection
https://github.com/invokermain/engin
application-framework dependency-graph dependency-injection python
Last synced: 9 days ago
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A lightweight Application Framework for Python powered by Dependency Injection
- Host: GitHub
- URL: https://github.com/invokermain/engin
- Owner: invokermain
- License: mit
- Created: 2024-10-13T07:51:58.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-12-15T11:08:18.000Z (about 2 months ago)
- Last Synced: 2025-12-16T17:28:11.270Z (about 2 months ago)
- Topics: application-framework, dependency-graph, dependency-injection, python
- Language: Python
- Homepage: https://engin.readthedocs.io/en/latest/
- Size: 772 KB
- Stars: 20
- Watchers: 2
- Forks: 2
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
- awesome-dependency-injection-in-python - engin - a dependency injection powered application framework, inspired by [Uber's fx framework](https://github.com/uber-go/fx). [🐍, MIT License]. (Software / DI Frameworks / Containers)
README
# Engin 🏎️
[](https://codecov.io/gh/invokermain/engin)
---
**Documentation**: [https://engin.readthedocs.io/](https://engin.readthedocs.io/)
**Source Code**: [https://github.com/invokermain/engin](https://github.com/invokermain/engin)
---
Engin is a lightweight application framework powered by dependency injection. It helps
you build and maintain everything from large monoliths to hundreds of microservices.
## Features
Engin provides:
- A fully-featured dependency injection system.
- A robust runtime with lifecycle hooks and supervised background tasks.
- Zero-boilerplate code reuse across applications.
- Integrations for popular frameworks like FastAPI.
- Full asyncio support.
- A CLI for development utilities.
## Installation
Engin is available on PyPI, install it using your favourite dependency manager:
- `pip install engin`
- `poetry add engin`
- `uv add engin`
## Example
Here’s a minimal example showing how Engin wires dependencies, manages background tasks, and
handles graceful shutdown.
```python
import asyncio
from httpx import AsyncClient
from engin import Engin, Invoke, Lifecycle, OnException, Provide, Supervisor
def httpx_client_factory(lifecycle: Lifecycle) -> AsyncClient:
client = AsyncClient()
lifecycle.append(client) # easily manage the AsyncClient's lifecycle concerns
return client
async def main(httpx_client: AsyncClient, supervisor: Supervisor) -> None:
async def long_running_task():
while True:
await httpx_client.get("https://example.org/")
await asyncio.sleep(1.0)
supervisor.supervise(long_running_task) # let the app run the task in a supervised manner
engin = Engin(Provide(httpx_client_factory), Invoke(main)) # define our modular application
asyncio.run(engin.run()) # run it!
```
Expected output (with logging enabled):
```
[INFO] engin: starting engin
[INFO] engin: startup complete
[INFO] engin: supervising task: long_running_task
[INFO] httpx: HTTP Request: GET https://example.org/ "HTTP/1.1 200 OK"
[INFO] httpx: HTTP Request: GET https://example.org/ "HTTP/1.1 200 OK"
[INFO] httpx: HTTP Request: GET https://example.org/ "HTTP/1.1 200 OK"
[DEBUG] engin: received signal: SIGINT
[DEBUG] engin: supervised task 'long_running_task' was cancelled
[INFO] engin: stopping engin
[INFO] engin: shutdown complete
```
## Inspiration
Engin is heavily inspired by [Uber's Fx framework for Go](https://github.com/uber-go/fx)
and the [Injector framework for Python](https://github.com/python-injector/injector).
They are both great projects, go check them out.
## Benchmarks
Automated performance benchmarks for Engin are available [here](https://invokermain.github.io/engin/dev/bench/).