Is LangSmith Down?

If Prismix shows LangSmith as "Operational" but you're having issues:

• Traces not appearing (missing LANGCHAIN_TRACING_V2 env var) — LangSmith tracing is opt-in and requires two environment variables: LANGCHAIN_TRACING_V2=true and LANGCHAIN_API_KEY=<your-key>. If either is missing or set after the LangChain import, traces are silently discarded. Verify both variables are set in the process environment before importing any LangChain modules.
• Evaluation run stalled — LangSmith evaluation runs execute LLM-as-judge calls for each example in your dataset. If the evaluator model (often GPT-4 or Claude) is slow or rate-limited, the evaluation can pause for extended periods without an obvious error. Check the run's "Traces" tab in the LangSmith UI to see which evaluator calls are pending and which provider is the bottleneck.
• Dataset upload too large — LangSmith datasets have a per-example and total-size limit. Very large datasets (millions of examples or examples with large embedded images/documents) can fail to upload via the UI or the SDK with a timeout error. Split large datasets into batches and use the SDK's client.create_examples() method in chunks of 100–500 examples.
• API key missing required permissions — LangSmith API keys can be scoped to specific permissions (read-only, dataset-write, full-access). If you create a read-only key and then try to push traces or create datasets, operations silently fail with a 403. Generate a new key with the correct permissions in the LangSmith organization settings.
• Hub pull rate limit exceeded — LangChain Hub (hub.pull("owner/prompt")) is rate-limited per API key. Applications that pull prompts on every request (instead of caching the pulled prompt object) quickly exhaust the limit and receive 429 errors. Cache pulled prompts at startup or use a functools.lru_cache decorator to avoid redundant hub calls.
• Webhook not firing on run completion — LangSmith supports webhooks that notify an endpoint when a trace or evaluation run completes. Webhooks fail silently if your endpoint URL is not publicly accessible, returns a non-2xx status, or times out within 5 seconds. Test webhook delivery manually by triggering a test event from the LangSmith webhook settings page.