langchain-eval-harness
Build reproducible evaluation pipelines for LangChain 1.0 chains and\ \ LangGraph 1.0\nagents \u2014 golden datasets, LangSmith evaluate(), ragas RAG\ \ metrics, deepeval\nLLM-as-judge, agent trajectory analysis, and CI gating on quality\ \ regressions.\nUse when setting up quality measurement for a new chain, diagnosing\ \ regression\nafter a model switch, or building an evaluation gate for a pull request.\n\ Trigger with \"langchain eval\", \"langsmith evaluate\", \"ragas\", \"llm-as-judge\"\ ,\n\"agent trajectory eval\", \"eval regression gate\".\n"
npx skills add jeremylongshore/claude-code-plugins-plus-skills --skill langchain-eval-harness --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# LangChain Eval Harness (Python) ## Overview A team swapped `gpt-4o` for `claude-sonnet-4-6` to save money and a week later CS noticed answer quality dropped on 15% of refund tickets — the regression was invisible in code review and invisible in CI because no golden set existed. Fix: a versioned golden set, a stacked eval pipeline (LangSmith + ragas + deepeval + custom trajectory), and a PR-block
What does the langchain-eval-harness skill do?
Build reproducible evaluation pipelines for LangChain 1.0 chains and\ \ LangGraph 1.0\nagents \u2014 golden datasets, LangSmith evaluate(), ragas RAG\ \ metrics, deepeval\nLLM-as-judge, agent trajectory analysis, and CI gating on quality\ \ regressions.\nUse when setting up quality measurement for a new chain, diagnosing\ \ regression\nafter a model switch, or building an evaluation gate for a pull request.\n\ Trigger with \"langchain eval\", \"langsmith evaluate\", \"ragas\", \"llm-as-judge\"\ ,\n\"agent trajectory eval\", \"eval regression gate\".\n"
How do I install it?
Run `npx skills add jeremylongshore/claude-code-plugins-plus-skills --skill langchain-eval-harness --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From jeremylongshore/claude-code-plugins-plus-skills, a repository with 2,596 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.