svcs 25.1.0
A Flexible Service Locator
Requires Python: >=3.9
Keywords: aiohttp, dependency injection, fastapi, flask, inversion of control, pyramid, service locator, starlette

<p align="center">
  <a href="https://github.com/hynek/svcs/">
    <img src="https://raw.githubusercontent.com/hynek/svcs/main/docs/_static/logo_with_name.svg" width="35%" alt="svcs logo showing a hexagon-shaped radar"" />
  </a>
</p>

<p align="center">
  <em>A Flexible Service Locator for Python.</em>
</p>
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*svcs* (pronounced *services*) is a **dependency container** for Python.
It gives you a central place to register factories for types/interfaces and then imperatively acquire instances of those types with **automatic cleanup** and **health checks**.

It's suitable for implementing [Inversion of Control](https://svcs.hynek.me/en/latest/glossary.html#term-Inversion-of-Control) using either **dependency injection** or **service location** while not requiring global state, decorators, or mangling of function signatures.

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Benefits:

- Eliminates tons of repetitive **boilerplate** code,
- unifies **acquisition** and **cleanups** of services,
- provides full *static* **type safety** for them,
- simplifies **testing** through **loose coupling**,
- improves *live* **introspection** and **monitoring** with **health checks**.

The goal is to minimize the code for acquiring pluggable services to:

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```python
from svcs.your_framework import svcs_from

def view(request):
    db, api, cache = svcs_from(request).get(Database, WebAPIClient, Cache)
```

... or less!

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To a type checker like [Mypy](https://mypy-lang.org), `db` has the type `Database`, `api` has the type `WebAPIClient`, and `cache` has the type `Cache`.
`db`, `api`, and `cache` will be automatically cleaned up when the request ends -- it's context managers all the way down.
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*svcs* comes with seamless integration for **AIOHTTP**, **FastAPI**, **Flask**, **Pyramid**, and **Starlette**.

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While *svcs* also has first-class support for static typing, it is **strictly optional** and will always remain so.
*svcs* also doesn't check your types at runtime.
It only forwards the type you have asked for to the type checker.
If you don't use a type checker, that information is ignored without any runtime overhead.
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Read on in [*Why?*](https://svcs.hynek.me/en/latest/why.html) or watch this short video if you're intrigued:

[![Watch the video](https://img.youtube.com/vi/d1elMD9WgpA/maxresdefault.jpg)](https://youtu.be/d1elMD9WgpA)


## Project Links

- [**PyPI**](https://pypi.org/project/svcs/)
- [**GitHub**](https://github.com/hynek/svcs)
- [**Documentation**](https://svcs.hynek.me)
- [**Changelog**](https://github.com/hynek/svcs/blob/main/CHANGELOG.md)
- [**Funding**](https://hynek.me/say-thanks/)
- [**Third-party extensions**](https://github.com/hynek/svcs/wiki/Third%E2%80%90party-Extensions)

## Release Information

### Added

- Python 3.13 support.

- `svcs.Registry` now implements a `__iter__` method that allows to iterate over its registered services.
  [#106](https://github.com/hynek/svcs/pull/106)


### Removed

- Python 3.8 support.


### Changed

- Flask: The registry is now stored on `app.extensions`, not `app.config`.
  This is an implementation detail.
  If you are directly accessing the registry via `app.config`, this is a breaking change, though you should ideally move to `svcs.flask.registry` anyway.
  [#71](https://github.com/hynek/svcs/discussions/71)
  [#72](https://github.com/hynek/svcs/issues/72)
  [#73](https://github.com/hynek/svcs/pull/73)

- `Registry.register_factory()` is now more lenient regarding the arguments of the factory.
  It only looks at the first argument (if present) and ignores the rest.
  [#110](https://github.com/hynek/svcs/pull/110)


### Fixed

- `Container.aget()` now also enters and exits synchronous context managers.
  [#93](https://github.com/hynek/svcs/pull/93)

- `Container.aget()` now also enters and exits context managers that are returned by async factories.
  [#105](https://github.com/hynek/svcs/pull/105)


---

[Full Changelog →](https://github.com/hynek/svcs/blob/main/CHANGELOG.md)


## Credits

*svcs* is written by [Hynek Schlawack](https://hynek.me/) and distributed under the terms of the [MIT](https://github.com/hynek/svcs/blob/main/LICENSE) license.

The development is kindly supported by my employer [Variomedia AG](https://www.variomedia.de/) and all my fabulous [GitHub Sponsors](https://github.com/sponsors/hynek).

The [Bestagon](https://www.youtube.com/watch?v=thOifuHs6eY) radar logo is made by [Lynn Root](https://www.roguelynn.com), based on an [Font Awesome](https://fontawesome.com) icon.
*svcs* has started out as a wrapper around [*wired*](https://wired.readthedocs.io/) by [Michael Merickel](https://michael.merickel.org/) and has been heavily influenced by it.