Litestar library documentation#

Litestar is a powerful, flexible, highly performant, and opinionated ASGI framework.

The Litestar framework supports Plugins, ships with dependency injection, security primitives, OpenAPI schema generation, MessagePack, middlewares, a great CLI experience, and much more.

Installation#

pip install litestar

Tip

litestar[standard] includes commonly used extras like uvicorn and jinja2 (for templating).

Minimal Example#

At a minimum, make sure you have installed litestar[standard], which includes uvicorn.

First, create a file named app.py with the following contents:

from litestar import Litestar, get

@get("/")
async def index() -> str:
    return "Hello, world!"

@get("/books/{book_id:int}")
async def get_book(book_id: int) -> dict[str, int]:
    return {"book_id": book_id}

app = Litestar([index, get_book])

Then, run the following command:

litestar run
# Or you can run Uvicorn directly:
uvicorn app:app --reload

You can now visit http://localhost:8000/ and http://localhost:8000/books/1 in your browser and you should see the responses of your two endpoints:

"Hello, world!"

and

{"book_id": 1}

Tip

You can also check out the automatically generated OpenAPI-based documentation at:

http://localhost:8000/schema (for ReDoc),
http://localhost:8000/schema/swagger (for Swagger UI),
http://localhost:8000/schema/elements (for Stoplight Elements)
http://localhost:8000/schema/rapidoc (for RapiDoc)

You can check out a more in-depth tutorial in the Developing a basic TODO application section!

Expanded Example#

Define your data model using pydantic or any library based on it (for example ormar, beanie, SQLModel):

from pydantic import BaseModel, UUID4


class User(BaseModel):
    first_name: str
    last_name: str
    id: UUID4

You can also use dataclasses (standard library and Pydantic), typing.TypedDict, or msgspec.Struct.

from uuid import UUID

from dataclasses import dataclass
from litestar.dto import DTOConfig, DataclassDTO


@dataclass
class User:
    first_name: str
    last_name: str
    id: UUID


class PartialUserDTO(DataclassDTO[User]):
    config = DTOConfig(exclude={"id"}, partial=True)

Define a Controller for your data model:

Python 3.8+

from typing import List

from litestar import Controller, get, post, put, patch, delete
from litestar.dto import DTOData
from pydantic import UUID4

from my_app.models import User, PartialUserDTO


class UserController(Controller):
    path = "/users"

    @post()
    async def create_user(self, data: User) -> User:
        ...

    @get()
    async def list_users(self) -> List[User]:
        ...

    @patch(path="/{user_id:uuid}", dto=PartialUserDTO)
    async def partial_update_user(self, user_id: UUID4, data: DTOData[User]) -> User:
        ...

    @put(path="/{user_id:uuid}")
    async def update_user(self, user_id: UUID4, data: User) -> User:
        ...

    @get(path="/{user_id:uuid}")
    async def get_user(self, user_id: UUID4) -> User:
        ...

    @delete(path="/{user_id:uuid}")
    async def delete_user(self, user_id: UUID4) -> None:
        ...

Python 3.9+

from litestar import Controller, get, post, put, patch, delete
from litestar.dto import DTOData
from pydantic import UUID4

from my_app.models import User, PartialUserDTO


class UserController(Controller):
    path = "/users"

    @post()
    async def create_user(self, data: User) -> User:
        ...

    @get()
    async def list_users(self) -> list[User]:
        ...

    @patch(path="/{user_id:uuid}", dto=PartialUserDTO)
    async def partial_update_user(self, user_id: UUID4, data: DTOData[User]) -> User:
        ...

    @put(path="/{user_id:uuid}")
    async def update_user(self, user_id: UUID4, data: User) -> User:
        ...

    @get(path="/{user_id:uuid}")
    async def get_user(self, user_id: UUID4) -> User:
        ...

    @delete(path="/{user_id:uuid}")
    async def delete_user(self, user_id: UUID4) -> None:
        ...

When instantiating your app, import your controller into your application’s entry-point and pass it to Litestar:

from litestar import Litestar

from my_app.controllers.user import UserController

app = Litestar(route_handlers=[UserController])

To run your application, use an ASGI server such as uvicorn :

uvicorn my_app.main:app --reload

Philosophy#

Litestar is a community-driven project. This means not a single author, but rather a core team of maintainers is leading the project, supported by a community of contributors. Litestar currently has 5 maintainers and is being very actively developed.
Litestar draws inspiration from NestJS - a contemporary TypeScript framework - which places opinions and patterns at its core.
While still allowing for function-based endpoints, Litestar seeks to build on Python’s powerful and versatile OOP, by placing class-based controllers at its core.
Litestar is not a microframework. Unlike frameworks such as FastAPI, Starlette, or Flask, Litestar includes a lot of functionalities out of the box needed for a typical modern web application, such as ORM integration, client- and server-side sessions, caching, OpenTelemetry integration, and many more. It’s not aiming to be “the next Django” (for example, it will never feature its own ORM), but its scope is not micro either.

Feature comparison with similar frameworks#

	Litestar	FastAPI	Starlette	Sanic	Quart
OpenAPI
Automatic API documentation	Swagger, ReDoc, Stoplight Elements	Swagger, ReDoc
Data validation
Dependency Injection
Class based routing		(Through extension)
ORM integration	SQLAlchemy, Tortoise, Piccolo				(Through extension)
Templating	Jinja, Mako	Jinja	Jinja	Jinja	Jinja
MessagePack
CORS					(Through extension)
CSRF
Rate-limiting				(Through extension)
JWT
Sessions		Client-side	Client-side		Client-side
Authentication	JWT / Session based
Caching

Example Applications#

litestar-pg-redis-docker : In addition to Litestar, this demonstrates a pattern of application modularity, SQLAlchemy 2.0 ORM, Redis cache connectivity, and more. Like all Litestar projects, this application is open to contributions, big and small.
litestar-fullstack : A fully-capable, production-ready fullstack Litestar web application configured with best practices. It includes SQLAlchemy 2.0, VueJS, Vite, :doc:`SAQ job queue <https://saq-py.readthedocs.io/en/latest/>`_, Jinja templates and more. Read more.
litestar-hello-world: A bare-minimum application setup. Great for testing and POC work.