AuthenticationError
openai.error.AuthenticationError
Stack trace
openai.error.AuthenticationError: Invalid API key or endpoint URL provided for Azure OpenAI service.
Why it happens
This error happens because the Azure OpenAI client requires a valid API key and a correctly formatted endpoint URL. If either is missing, incorrect, or mismatched, the service rejects the request with an authentication failure.
Detection
Check for AuthenticationError exceptions when initializing or calling the Azure OpenAI client; log the API key and endpoint environment variables to verify correctness before requests.
Causes & fixes
API key environment variable is missing or empty
Set the environment variable AZURE_OPENAI_API_KEY with your valid Azure OpenAI API key before running the code.
Endpoint URL environment variable is missing or malformed
Set AZURE_OPENAI_ENDPOINT to the full Azure OpenAI endpoint URL including https:// and the correct resource name.
Using OpenAI SDK client without specifying Azure deployment and endpoint parameters
Use the Azure-specific parameters: set 'api_key', 'api_base', 'api_type'='azure', and 'api_version' when creating the OpenAI client.
Mixing OpenAI public API key with Azure endpoint or vice versa
Ensure you use the Azure API key with the Azure endpoint and specify 'api_type'='azure' to avoid authentication conflicts.
Code: broken vs fixed
from openai import OpenAI
client = OpenAI(api_key="wrong_or_missing_key") # causes AuthenticationError
response = client.chat.completions.create(model="gpt-4o", messages=[{"role": "user", "content": "Hello"}])import os
from openai import OpenAI
os.environ["AZURE_OPENAI_API_KEY"] = "your_azure_api_key_here"
os.environ["AZURE_OPENAI_ENDPOINT"] = "https://your-resource-name.openai.azure.com/"
client = OpenAI(
api_key=os.environ["AZURE_OPENAI_API_KEY"],
api_base=os.environ["AZURE_OPENAI_ENDPOINT"],
api_type="azure",
api_version="2023-05-15"
)
response = client.chat.completions.create(
model="gpt-4o",
messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content) # fixed: correct Azure auth and endpointWorkaround
Catch AuthenticationError exceptions and prompt the user or system to verify and reset the AZURE_OPENAI_API_KEY and AZURE_OPENAI_ENDPOINT environment variables before retrying.
Prevention
Use environment variables for Azure API key and endpoint, validate them at app startup, and always configure the OpenAI client with Azure-specific parameters to avoid auth errors.