langchain-python-quickstart

Gets a first LangChain agent running in Python, the small weather agent from LangChain's official quickstart, on whichever AI model you choose.

WHEN TO USE

SCOPE

USE FOR

Build the quickstart's weather agent exactly as the live docs show it.
Swap in your own model, such as GPT or Gemini, or keep the Claude Sonnet default.
Work in a separate new folder so nothing lands in your current project.
Run the example, see its output, then move on to LangChain fundamentals.

This is a saved copy of the skill's SKILL.md instructions. It may differ from the upstream file or the version you install.

In this document (2)

LangChain Python quickstart

Follow the live docs — do not invent an alternate API from memory:

https://docs.langchain.com/oss/python/langchain/quickstart

Fetch that page (Docs MCP or HTTP) and implement what it shows (weather agent + create_agent).

Local setup constraints

Apply these on top of the quickstart (they keep setup minimal and model-agnostic):

Ask which provider/model to use. Showcase that LangChain is model-agnostic. Suggested prompt:

Which model should this agent use? Pass a provider:model string — e.g. openai:gpt-5.5, anthropic:claude-sonnet-5, google_genai:gemini-2.5-flash-lite. Default if you're unsure: anthropic:claude-sonnet-5.

Swap the quickstart's model string for their choice (or the default).
Create a new directory (e.g. langchain-agent/) and do all work there — do not pollute the open project.
Only secret: the provider API key in .env (gitignored). No LangSmith / Tavily unless they ask. Prefer they edit .env themselves — don't paste keys into chat.
Install the provider package needed for their model if the quickstart's base install isn't enough.
Run the example, show output, then stop. Point to langchain-fundamentals for next steps.

Account or credentials required

1 FOR YOU

01
Put your model provider's API key in a .env file
Only secret: the provider API key in a gitignored .env file, ideally edited by you rather than pasted into chat; no LangSmith or Tavily keys unless you ask for them.

This skill ships inside the LangChain Agent-Building Skills plugin.

Install just this skill

Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 skips skill selection; prompts cancel installation without an interactive terminal. If choosing Project when asked about installation scope, open your project's folder before running this.

Install checklist

Check selected tools if a picker appears; Claude Code may be unchecked under Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms.
Without a tool picker, check Installing to: for your intended tool. Stop if it names a different tool.
If asked, choose Symlink (Recommended) for shared files or Copy to all agents for separate copies; review the summary before confirming installation.
Install the find-skills skill? defaults to Yes, adding another skill for all projects. Choose No if you don't want that extra installation.

Skills CLI 1.7.2 sends install data to skills.sh by default, including the source, skill names, target tools and file details; GitHub sources are reported only when GitHub confirms the repository is public, while other remote sources can also be reported. Confirmed-public GitHub sources also trigger a security-audit request. Before installing, set the environment variable DO_NOT_TRACK=1 or DISABLE_TELEMETRY=1 to disable both.

npx skills add langchain-ai/langchain-skills --skill "langchain-python-quickstart" --full-depth

After installing for Claude Code, open it in the installation project if you chose Project; Global makes the skill available across projects on this computer. Once Claude Code loads the skill, its description helps Claude decide when to use it.

If installation created a top-level skills folder that did not exist when your Claude Code session started, run /reload-skills in that session. Run it again after later changes in that folder.

Install the whole plugin

This route installs the LangChain Agent-Building Skills plugin package selected for your AI tool.

Claude Code

Add LangChain's marketplace, then install the plugin

Type both lines inside a Claude Code session, not at your shell prompt. The first adds LangChain's marketplace, which is this repository; the second opens the details of the langchain-skills plugin, and Claude Code installs it once you pick one of the install options shown. Afterwards, LangChain's README asks you to set OPENAI_API_KEY or ANTHROPIC_API_KEY, for whichever of those model providers you build with.

01

/plugin marketplace add langchain-ai/langchain-skills

02

/plugin install langchain-skills@langchain-skills

Open plugin page ↗

View on GitHub

The repository is licensed under MIT — use, modification, and redistribution are allowed under that license’s terms.

View the repository’s license file on GitHub →

LangChain Python quickstart

Local setup constraints

Account or credentials required

Install just this skill

Install the whole plugin

Add LangChain's marketplace, then install the plugin

More skills

deep-agents-core

deep-agents-memory

deep-agents-orchestration

deepagents-python-quickstart

deepagents-typescript-quickstart

ecosystem-primer