langchain-classic

Building applications with LLMs through composability

langchain-classic Permissive license MIT Active ★ 144,174 v1.0.8 released 2026-06-10

Install

langchain-classic on PyPI

pip

pip install langchain-classic

uv

uv add langchain-classic

poetry

poetry add langchain-classic

Package facts

License	MIT (permissive)
Python support	supports the current Python release (<4.0.0,>=3.10.0)
Install friction	low — pure-Python wheel
Runtime dependencies	8 — async-timeout, langchain-core, langchain-text-splitters, langsmith, pydantic, pyyaml, requests, sqlalchemy
Maintenance	actively maintained — 64 days since the last release
Last repo commit	2026-08-13
First released	2025-10-07
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: langchain_classic-1.0.8-py3-none-any.whl

Development Status :: 5 - Production/StableIntended Audience :: DevelopersLicense :: OSI Approved :: MIT LicenseProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Topic :: Scientific/Engineering :: Artificial IntelligenceTopic :: Software Development :: Libraries :: Python Modules

About langchain-classic

from the package's own PyPI description — quoted content, verbatim

🦜️🔗 LangChain Classic

PyPI - Version (image) PyPI - License (image) PyPI - Downloads (image) Twitter (image)

Looking for the JS/TS version? Check out LangChain.js.

To help you ship LangChain apps to production faster, check out LangSmith. LangSmith is a unified developer platform for building, testing, and monitoring LLM applications.

Quick Install

pip install langchain-classic

🤔 What is this?

Legacy chains, langchain-community re-exports, indexing API, deprecated functionality, and more.

In most cases, you should be using the main langchain package.

📖...

Read as markdown · JSON record · Source repository · Homepage · Docs

AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

LangChain Classic provides legacy chains, community re-exports, indexing APIs, and deprecated functionality for LLM application development, intended as a compatibility layer rather than primary entry point.

Low friction: pure Python wheel with 8 runtime dependencies including langchain-core, langsmith, and pydantic. Active maintenance with last commit on 2026-08-13 indicates ongoing support.

MIT license (permissive) allows unrestricted use, modification, and distribution in commercial and private projects with minimal obligations.

Usage

pip install langchain-classic

from langchain_classic import legacy_chains
# Access legacy chain implementations and community re-exports

Requires Python 3.10 or later (supports 3.10–3.13); intended as a compatibility layer—most new projects should use the main langchain package instead.

Verdict: Actively maintained compatibility package for legacy LangChain code with permissive MIT licensing and low install friction. Suitable for projects requiring deprecated functionality or community re-exports, but new development should prefer the main langchain package. No known vulnerabilities.

Needs verification

Whether this package is appropriate for new projects or primarily for migration/legacy support
Specific deprecation timeline and migration path for code currently using langchain-classic

langchain legacy chainsllm application framework pythonlangchain deprecated functionalitylangchain community re-exportsbuilding llm apps composabilitylangchain indexing apilegacy langchain compatibility