langchain-ai/langsmith-skills.

langsmith-custom-apps

INVOKE THIS SKILL when building, iterating on, copying, or sharing a LangSmith Custom App — a React/TypeScript UI that runs inside LangSmith and reads the LangSmith API. Covers the langsmith apps CLI, pulling an existing app's source, replicating an app into another workspace, verifying app logic without a browser, and sanitizing an app before sending it outside your org. Uses the langsmith CLI tool.

langsmith-experiment-diagnosis

Investigate a LangSmith experiment with the LangSmith CLI, identify examples with poor evaluator results, explain likely causes using run evidence, and propose targeted fixes. Use when a user asks why an experiment performed badly or which evaluated examples need attention.

langsmith-online-eval-engineering

Design, test, create, and attach LangSmith online evaluators for production traces or conversation threads. Use for workspace evaluators, run or thread rules, sampling, filters, backfills, and evaluator monitoring; use eval-engineering for Harbor tasks and agent benchmarks.