This page shows how to customize your fastapi errors. I found this very useful to setup common templates so that I can return the same 404's both programatically and by default, so it all looks the same to the end user.
``` python
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
class UnicornException(Exception):
def __init__(self, name: str):
self.name = name
app = FastAPI()
@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
return JSONResponse(
status_code=418,
content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
)
@app.get("/unicorns/{name}")
async def read_unicorn(name: str):
if name == "yolo":
raise UnicornException(name=name)
return {"unicorn_name": name}
```
---
This post sat in draft for months. I stumbled upon it again and found great success returning good error messages based on user preferences. the default remains json, but if a user requests `text/html` it will be an html response, and text for `application/rtf` or `text/plain`
!!! note
This post is a thought. It's a short note that I make
about someone else's content online #thoughts
