Have you had experience using Swagger for documenting or testing APIs?

Yes, I have used Swagger for documenting and testing REST APIs. Swagger allows for automatically generating interactive documentation based on the OpenAPI specification, which simplifies understanding and using the API.

In Python projects, I often used libraries like flasgger or drf-yasg for Django REST Framework, which integrate with the code and allow describing endpoints using decorators or YAML/JSON.

An example of a simple endpoint description using Flasgger:

from flask import Flask, jsonify
from flasgger import Swagger

app = Flask(__name__)
swagger = Swagger(app)

@app.route('/api/hello')
def hello():
    """
    Greeting endpoint
    ---
    responses:
      200:
        description: Returns a greeting
        examples:
          application/json: {"message": "Hello, World!"}
    """
    return jsonify(message="Hello, World!")

if __name__ == '__main__':
    app.run()

Swagger UI allows testing the API directly from the browser, which is convenient for verification and demonstration.