code-first-using-apiflask

Code-first using APIFlask

This is an example of using annotations in Python code - also known as "code-first design" - to generate an OpenAPI description.

Pre-requisites

This is a Python application. You'll need Python 3 available, ideally at 3.12 or above with virtualenv and pip installed.

Installation

First up you'll need to create a virtual environment and then activate it. Use your favorite environment manager like pyenv, or use the following boilerplate commands (assuming you are in this directory already):

virtualenv ./venv
source ./venv/bin/activate

With your fresh environment activated, you can install the dependencies using pip:

pip install -r requirements.txt

You are then set to run the application and generate the specification.

Running the Application

To run the application and send requests to its API run the flask command with the run subcommand:

flask --app server:app run

You can then send a request to the API running on port 5000 using curl and format the output using a tool like jq:

curl http://localhost:5000/pets | jq '' -

Will give you the following response:

chapter-4-examples/code-first-using-apiflask ❮ on  main [!] curl http://localhost:5000/pets  | jq '' -
[
  {
    "id": 1,
    "name": "Barnaby",
    "tag": "Vicious"
  },
  {
    "id": 2,
    "name": "Colin",
    "tag": "Accountant"
  }
]
chapter-4-examples/code-first-using-apiflask ❯ on  main [!]

If you just want to regenerate the OpenAPI description document then you can run flask again with the spec subcommand:

flask --app server:app spec

Which will output a fresh copy of the document to stdout.

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