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What is the Ascender Framework?

The Ascender Framework is a modern Python API framework maintained by the Ascender Team for building scalable, maintainable, and efficient backend applications. It is built on top of FastAPI — so you keep FastAPI's performance, async support, and OpenAPI generation — and adds the structure that large applications need: dependency injection, modules, controllers, and guards, inspired by Angular and NestJS but tailored for Python.

A taste of Ascender

src/users/users_controller.py
from ascender.core import Controller, Get, Post
from .users_service import UsersService
from .users_dto import UserDTO


@Controller(standalone=True, providers=[UsersService], tags=["users"])
class UsersController:
    def __init__(self, users: UsersService):  # injected automatically
        self.users = users

    @Get()
    async def list_users(self):
        return await self.users.all()

    @Post(response_model=UserDTO, status_code=201)
    async def create_user(self, data: UserDTO):
        return await self.users.create(data)

One CLI command scaffolds it for you:

ascender g controller users/users

Core principles

  • Class-Based Architecture

    Clear separation of modules, services, and controllers following the Single Responsibility Principle.

  • Dependency Injection

    A hierarchical, Angular-style DI system built into the framework — clean, testable code with constructor injection.

  • Modularity

    Encapsulation through modules that export only what other parts of the app should see.

  • Performance-Oriented

    Built on FastAPI and optimized for Python 3.11+ with modern language features and minimal runtime overhead.

  • Batteries-Included CLI

    Scaffold controllers, services, modules, and guards with ascender g — and ship your own commands with the CLI engine.

  • Guards & Validation

    Declarative route protection and pydantic-powered DTO validation out of the box.

How it relates to FastAPI

Every Ascender endpoint is a FastAPI path operation. Anything you know from FastAPI — Body(), Query(), Header(), pydantic models, Request, dependency semantics — works unchanged inside controller methods. Ascender adds the architectural layer on top: who provides what, where routes live, and how the pieces are wired together.

Next steps