langchain-components
Installation
SKILL.md
LangChain components
The LangChain stack changes every week: model IDs, streaming and interrupt interfaces, and Deep Agents backends all moved within months. This skill therefore holds no API listings. It holds the decisions the docs do not make for you, and it points to the live docs for syntax. Fetch the current API before writing code that calls it.
Core principles
| Principle | Meaning |
|---|---|
| Fetch, do not recall | Treat any remembered signature, model ID, or import path as stale until the docs confirm it |
| Match the installed version | Read versions from the lockfile first, then fetch docs for that line |
| Smallest layer that fits | Start at the highest-level tool that covers the need and drop down only when it cannot |
| One agent first | Add multi-agent structure only after a single agent with good tools and prompt fails |
| State must be persisted to pause | Interrupts, resume, and multi-turn memory all depend on a checkpointer |
| Model output is untrusted input | Tool arguments and retrieved text can be wrong or hostile |
Version matrix
Checked on 2026-10-21 against PyPI and the official release policy.