The goal of this package is to help you to implement the Health Check API pattern.

pip install fastapi-health

Create the health check endpoint dynamically using different conditions. Each condition is a callable, and you can even have dependencies inside of it:

from fastapi import FastAPI, Depends
from fastapi_health import health


def get_session():
    return True


def is_database_online(session: bool = Depends(get_session)):
    return session


app = FastAPI()
app.add_api_route("/health", health([is_database_online]))

The health() method receives the following parameters:

• conditions: A list of callables that represents the conditions of your API, it can return either bool or a dict.
• success_output: An optional callable which receives the conditions results and returns a dictionary that will be the content response of a successful health call.
• failure_output: An optional callable analogous to success_output for failure scenarios.
• success_status: An integer that overwrites the default status (200) in case of success.
• failure_status: An integer that overwrites the default status (503) in case of failure.

It's important to notice that you can have a peculiar behavior in case of hybrid return statements (bool and dict) on the conditions. For example:

from fastapi import FastAPI
from fastapi_health import health


def healthy_condition():
    return {"database": "online"}


def sick_condition():
    return False


app = FastAPI()
app.add_api_route("/health", health([healthy_condition, sick_condition]))

This will generate a response composed by the status being 503 (default failure_status), because sick_condition returns False, and the JSON body {"database": "online"}. It's not wrong, or a bug. It's meant to be like this.

This project is licensed under the terms of the MIT license.