langchain-dependencies

1<overview>
2The LangChain ecosystem is split into focused, independently-versioned packages. Understanding which packages you need — and their version constraints — prevents incompatibilities and keeps upgrades predictable.
3 
4**Key principles:**
5- **LangChain 1.0 is the current LTS release.** Always start new projects on 1.0+. LangChain 0.3 is legacy maintenance-only — do not use it for new work.
6- **langchain-core** is the shared foundation: always install it explicitly alongside any other package.
7- **langchain-community** (Python only) does NOT follow semantic versioning; pin it conservatively.
8- **LangGraph vs Deep Agents:** choose one orchestration approach based on your use case — they are alternatives, not a required stack (see [Framework Choice](#framework-choice) below).
9- Provider integrations (model, vector store, tools) are installed separately so you only pull in what you use.
10</overview>
11 
12---
13 
14## Environment Requirements
15 
16<environment-requirements>
17 
18| Requirement | Python | TypeScript / Node |
19|-------------|--------|-------------------|
20| Runtime minimum | **Python 3.10+** | **Node.js 20+** |
21| LangChain | **1.0+ (LTS)** | **1.0+ (LTS)** |
22| LangSmith SDK | >= 0.3.0 | >= 0.3.0 |
23 
24</environment-requirements>
25 
26---
27 
28## Framework Choice
29 
30<framework-choice>
31Pick **one** agent orchestration layer. You do not need both.
32 
33| Framework | When to use | Core extra package |
34|-----------|-------------|--------------------|
35…