Starception

Beautiful exception page for Starlette and FastAPI apps.

Installation

Install starception using PIP or poetry:

pip install starception
# or
poetry add starception

Screenshot

Features

• secrets masking
• solution hints
• code snippets
• display request info: query, body, headers, cookies
• session contents
• request and app state
• platform information
• environment variables

The middleware will automatically mask any value which key contains key, secret, token, password.

Quick start

See example application in examples/ directory of this repository.

Usage

To render a beautiful exception page you need to install a custom error handler to your application. The error handler must be registered to Exception class or to 500 status code.

To create the handler use create_exception_handler(debug: bool) function.

Note, the handler won't do anything if debug=False, instead it will display a plain string "Internal Server Error". Also, I would recommend to add it only for local development, as such error page, when enabled on production by mistake, can expose sensitive data.

import typing

from starlette.applications import Starlette
from starlette.requests import Request
from starlette.routing import Route

from starception import create_exception_handler


async def index_view(request: Request) -> typing.NoReturn:
    raise TypeError('Oops, something really went wrong...')


app = Starlette(
    routes=[Route('/', index_view)],
    exception_handlers={Exception: create_exception_handler(debug=True)}
)

Integration with FastAPI

Create a FastAPI exception handler and register it with your app:

import typing
from fastapi import FastAPI, Request, Response
from starception import exception_handler

app = FastAPI()


@app.route('/')
async def index_view(request: Request) -> typing.NoReturn:
    raise TypeError('Oops, something really went wrong...')


def custom_exception_handler(request: Request, exc: Exception) -> Response:
    return exception_handler(request, exc, debug=True)

Solution hints

If exception class has solution attribute then its content will be used as a solution hint.

class WithHintError(Exception):
    solution = (
        'The connection to the database cannot be established. '
        'Either the database server is down or connection credentials are invalid.'
    )

Credentials

• Look and feel inspired by Phoenix Framework.