Autumn-Py - Convention-Based YAML API Testing Framework for Python & FastAPI

Autumn-Py is a convention-based API automation testing framework designed to streamline and simplify the testing process, inspired by the Java Autumn library.

By integrating directly with pytest, Autumn-Py allows you to run clutter-free API tests based on YAML files, eliminating repetitive test code. It supports testing local FastAPI applications (using httpx.Client(app=...) under the hood) as well as external REST services.

Features

• No Boilerplate Code Required: Write tests in YAML, not Python.
• Convention-Based: Follows standard patterns, zero configuration to start.
• pytest Integration: Discovered and run automatically by pytest.
• FastAPI / Local Testing: Route requests directly against your FastAPI app via the autumn_app fixture.
• Arrange-Act-Assert Support: Set up preconditions, run the main API call, and assert expectations.
• Rich Data Generation: Dynamic random names, emails, UUIDs, datetimes, sentences, and more using faker.
• Placeholder Chaining: Reference responses of previous arrange steps in URLs, headers, and request bodies.
• Flexible JSON Assertions: Easily match dynamic fields with matchers (e.g. UUID, datetime, regex, types) and ignore extra fields if needed.
• Conditional Skip Scheduling: Restrict test execution by day or time of day.

Installation

pip install autumn-yaml-test

Quick Start

1. Define your test yml files (e.g. under tests/):

# tests/get_user.yml
name: Get User by ID
act:
  url: "https://jsonplaceholder.typicode.com/users/1"
  method: GET

asserts:
  status: 200
  body:
    id: 1
    name: "Leanne Graham"
    email: "${json-unit.matches:regex}[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}"

2. Run your tests:

pytest

That's it! The plugin discovers all .yml/.yaml files containing an act: block and executes them dynamically.

Testing a Local FastAPI App

To test your local FastAPI application without running a separate server, define an autumn_app fixture in your conftest.py:

# tests/conftest.py
import pytest
from my_app import app

@pytest.fixture
def autumn_app():
    return app

With autumn_app defined, Autumn-Py routes all requests in your YAML files directly through FastAPI's TestClient routing.

YAML Specification

Refer to the examples under tests/resources/ for a full showcase of features including:

• Data generation: ${generate:name}, ${generate:email}, ${generate:datetime:1minutesAgo}, ${generate:uuid}.
• Arrange steps: wait steps (type: wait), API dependencies (type: api), and saveResponseAs.
• Flexible asserts: ignore extra fields using customization.