langchain.tools.SerpAPIWrapper throws Invalid API Key despite valid key
Spotted this today while wiring a quick search tool.
from langchain.tools import SerpAPIWrapper
tool = SerpAPIWrapper()
print(tool.run("Sydney weather"))
Console spat back:
SerpApiError: Invalid API key
Key worked in curl. Quota fine.
Python 3.11, langchain 0.1.12, serpapi 0.6.2. Environment variable SERPAPI_API_KEY was set.
Problem: SerpAPI upgraded to require SERPAPI_API_KEY in the process environment and a serpapi_api_key parameter in the LangChain wrapper after 0.1.7.
Fix:
tool = SerpAPIWrapper(serpapi_api_key=os.environ["SERPAPI_API_KEY"])
or pin versions:
pip install "langchain<0.1.7" "serpapi<0.6"
After passing the key explicitly the request returned JSON as expected.
If the wrapper still raises check for hidden whitespace in the key; LangChain leaves it untrimmed.