tiangolo/fastapi · error · HTTPException

Item not found, there's only a plumbus here

Error message

Item not found, there's only a plumbus here

What it means

Same 404 "Item not found, there's only a plumbus here" as error 24, in the non-Annotated Depends style. Raised when item_id is not "plumbus" and not "portal-gun".

Source

Thrown at docs_src/dependencies/tutorial008c_py310.py:24

class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except InternalError:
        print("Oops, we didn't raise again, Britney 😱")


@app.get("/items/{item_id}")
def get_item(item_id: str, username: str = Depends(get_username)):
    if item_id == "portal-gun":
        raise InternalError(
            f"The portal gun is too dangerous to be owned by {username}"
        )
    if item_id != "plumbus":
        raise HTTPException(
            status_code=404, detail="Item not found, there's only a plumbus here"
        )
    return item_id

View on GitHub (pinned to 42a41db11f)

Solutions

1. Call /items/plumbus.
2. Document the allowed id set and validate input early.
3. Keep 404 detail text consistent across endpoints.
4. Test the negative path.

Example fix

# before
if item_id != "plumbus":
    raise HTTPException(status_code=404, detail="Item not found, there's only a plumbus here")

# after
if item_id not in {"plumbus"}:
    raise HTTPException(status_code=404, detail=f"Unknown item '{item_id}'")

if item_id not in {"plumbus", "portal-gun"}:
    raise ValueError("unsupported item id")

def is_known_item(item_id: str) -> bool:
    return item_id in {"plumbus", "portal-gun"}

r = client.get(f"/items/{item_id}")
if r.status_code == 404:
    ...

When it happens

Trigger: GET /items/<not-plumbus-and-not-portal-gun> using the default-value Depends form of the endpoint.

Common situations: Same as error 24; encountered when the older tutorial variant is in use.

Related errors

• Item not found
• Item not found, there's only a plumbus here
• Item not found, there's only a plumbus here
• Item not found, there's only a plumbus here
• Item not found

AI-assisted analysis of tiangolo/fastapi@42a41db11f (2026-08-04). Data as JSON: /data/errors/061107824f7ddefa.json. Report an issue: GitHub.