# Tracing silently not working: wrong env var names (LANGSMITH vs LANGCHAIN)

LangSmith tracing silently not working (no data traced) in Colab or anywhere else: check your env var names. The SDK reads LANGCHAIN_ENDPOINT and LANGCHAIN_API_KEY, not LANGSMITH_ENDPOINT and LANGSMITH_API_KEY. If you set the LANGSMITH_ prefixed names, nothing gets traced and there is no error. Rename them to the LANGCHAIN_ versions: os.environ['LANGCHAIN_ENDPOINT'] = 'https://api.smith.langchain.com'; os.environ['LANGCHAIN_API_KEY'] = '...'; plus LANGCHAIN_TRACING_V2 = 'true'. Commenter-verified.

## Context from the issue
gh:langchain-ai/langsmith-sdk#216: Issue langchain-ai/langsmith-sdk#216 (closed, 26 comments): I tried langsmith in google colab. Tracing does not work and no data is traced. Setup: os.environ['OPENAI_API_KEY'], os.environ['LANGCHAIN_TRACING_V2'] = 'true', os.environ['LANGCHAIN_ENDPOINT'] = 'https://api.smith.langchain.com', os.environ['LANGCHAIN_API_KEY'].