HTTP Error 401: {"finance":{"result":null,"error":{"code":"Unauthorized","description":"Invalid Crumb"}}}

[gps1539]

1st thanks for creating yfinance

I started to receive 401 errors when I call yfinance from one PC, but not from another. It looks like one PC/user became "Unauthorized" and I don't understand why. I'm using yfinance for personal reasons and not excessively. The error provides a link https://bit.ly/yahoo-finance-api-feedback

Quick background. I use yfinance in stock_quote and I started to see the 401 errors when I ran stock_quote from my main PC, however it still runs from my laptop (which runs the same version of stock_quote, yfinance and python). I certainly call yfinance more from my main PC as develop and test stock_quote on it, however my usage is light and I guess around 100-200 API call / day on average.

Is becoming "Unauthorized" expected? If so what are the usage limits? Can it be reset?

Note. I'm not looking forward to rewriting my app without yfinance, but I currently can not test or maintain it.

I can reproduce the issue directly in python

``Python 3.14.4 (main, Apr 8 2026, 17:48:49) [GCC 15.2.1 20260209] on linux
Type "help", "copyright", "credits" or "license" for more information.

import yfinance as yf
...
... yf.enable_debug_mode()
... dat = yf.Ticker("AAPL")
... print(dat.info)
...
/usr/lib/python3.14/site-packages/yfinance/utils.py:167: DeprecationWarning: enable_debug_mode() is replaced by: yf.config.debug.logging = True (or False to disable)
warnings.warn("enable_debug_mode() is replaced by: yf.config.debug.logging = True (or False to disable)", DeprecationWarning)
ERROR HTTP Error 401: {"finance":{"result":null,"error":{"code":"Unauthorized","description":"Invalid Crumb"}}}
ERROR HTTP Error 401: {"finance":{"result":null,"error":{"code":"Unauthorized","description":"User is unable to access this feature - https://bit.ly/yahoo-finance-api-feedback"}}}
Traceback (most recent call last):
File "", line 5, in
print(dat.info)
^^^^^^^^
File "/usr/lib/python3.14/site-packages/yfinance/ticker.py", line 159, in info
return self.get_info()
~~~~~~~~~~~~~^^
File "/usr/lib/python3.14/site-packages/yfinance/base.py", line 282, in get_info
data = self._quote.info
^^^^^^^^^^^^^^^^
File "/usr/lib/python3.14/site-packages/yfinance/scrapers/quote.py", line 505, in info
self._fetch_info()
~~~~~~~~~~~~~~~~^^
File "/usr/lib/python3.14/site-packages/yfinance/scrapers/quote.py", line 629, in _fetch_info
if quote in result and len(result[quote]["result"]) > 0:
^^^^^^^^^^^^^^^
TypeError: argument of type 'NoneType' is not a container or iterable

[ValueRaider]

What does that bitly link resolve to? No one should be clicking mystery links.

[gps1539]

To a unique (to me) google form @ https://docs.google.com/forms//d/e/1FAIpQLS.......

It contains the follow

We’re sorry for the inconvenience, but API-level access to Yahoo Finance quotes data has been disabled.

Yahoo Finance licenses data from 3rd-party providers that do not currently authorize us to redistribute these data in API form. Licenses that authorize redistribution come with a greater cost that varies depending on a number of factors, including whether the data is for personal or commercial use, the type of data, the volume of queries, and additional features which may be available.

We would appreciate your feedback to ensure that we can continue to serve your needs. By understanding your intended use of these API data, we will be better able to acquire the appropriate licenses. We appreciate your feedback, and we read every response.

Then a bunch of questions about usage, language.

[ValueRaider]

the volume of queries

Are you spamming the API?

https://github.com/ValueRaider/yfinance-cache

[gps1539]

Nope, maybe 200 API calls / day

[gps1539]

I found a conversation @ sstrickx/yahoofinance-api#206 that lead to a finding.

From a browser if I call "https://query1.finance.yahoo.com/v7/finance/quote?symbols=ORCL" I get an "Unauthorized" error. However if I ask yahoo for a crumb and append that to the call it works i.e.

https://query1.finance.yahoo.com/v1/test/getcrumb
https://query1.finance.yahoo.com/v7/finance/quote?symbols=ORCL&crumb=<CRUMB_RESULT>

Is there a method to get or replace a crumb in yfinance? I don't see yfinance documentation on handing crumbs.
Does yfinance stores the crumb, if so is it part of .cache/py-yfinance/cookies.db (on linux) or somewhere else?

[ValueRaider]

Crumb is linked to cookie, you can't copy it from your browser.

YfData handles cookie and crumb https://github.com/ranaroussi/yfinance/blob/main/yfinance/data.py

[gps1539]

Thanks, any idea why getting a crumb via https works from a browser, but doesn't work from yfinance data.py on one PC, but does on another?

[gps1539]

I tried a quick experiment

1. delete cookies.db on the failing PC and run python -c "import yfinance as yf; dat = yf.Ticker('AAPL'); print(dat.info)". Still fails
2. copy cookies.db from working PC to the failing PC and run python -c "import yfinance as yf; dat = yf.Ticker('AAPL'); print(dat.info)". Works as expected.

Any idea why yfinance isn't recreating a cookies.db that works?

[ValueRaider]

No idea, the cookie algo isn't mine. A miracle that it works at all.

Try this #2761

[gps1539]

Thanks
I get "module 'yfinance' has no attribute 'Auth'". It looks like it was merged recently and not in an installable release for arch (or pip). I will try when I see the new release.