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langchain

The agent engineering platform. Available in TypeScript!

Best fitUsers who want source-backed project understanding before installing it.

Check whether this project matches your task before installing it.

What it can doskill, recipe, host_instruction, eval, preflight

Review the portable capability path.

Before continuingVerify in a sandbox

Do not treat a preview pack as a proven local install.

GitHub snapshot136k stars

23k forks · 3.7k contributors

Official first step Read manual preview Source repository

Preview status · 2026-05-16

What is langchain?

LangChain is a comprehensive framework designed for building agents and LLM-powered applications. It enables developers to chain together interoperable components and third-party integrati...
Best fit: Users who want source-backed project understanding before installing it.
Capability added to an AI workflow: skill, recipe, host_instruction, eval, preflight
Evidence base: https://github.com/langchain-ai/langchain, https://github.com/langchain-ai/langchain, https://github.com/langchain-ai/langchain#readme
Preview pages are noindex until English quality, canonical, and citation gates pass.
langchain still needs sandbox verification before production use.

Quick decision

Use this section to decide whether the project is worth a deeper read.

Best forUsers who want source-backed project understanding before installing it.

Match the project to your task before installing it.

Capabilityskill, recipe, host_instruction, eval, preflight

The agent engineering platform. Available in TypeScript!

Repositorylangchain-ai/langchain

136k stars · 23k forks

What it can do

Translate the upstream project into concrete capabilities the user can judge before installing.

Introduction to LangChain

Related topics: Runnable and Execution Model, Getting Started with LangChain

Source: https://github.com/langchain-ai/langchain / Human Manual

Getting Started with LangChain

Related topics: Introduction to LangChain, Runnable and Execution Model

Sources: [README.md](https://github.com/langchain-ai/langchain/blob/main/README.md)

Runnable and Execution Model

Related topics: Introduction to LangChain, Callbacks and Tracing Infrastructure, Agents Framework

Sources: [libs/core/langchain_core/runnables/base.py](https://github.com/langchain-ai/langchain/blob/main/libs/core/langchain_core/runnables/base.py)

Messages and Prompt System

Related topics: Chat Models and Embeddings

Sources: [libs/core/langchain_core/callbacks/base.py](libs/core/langchain_core/callbacks/base.py)

Chat Models and Embeddings

Related topics: Introduction to LangChain, Messages and Prompt System

Sources: [libs/core/langchain_core/language_models/chat_models.py](https://github.com/langchain-ai/langchain/blob/main/libs/core/langchain_core/language_models/chat_models.py)

Sources: https://github.com/langchain-ai/langchain, Human Manual, Project Pack evidence, and downstream validation signals.

Community Discussion Evidence

Project-level external discussion stays visible on the detail page, not only inside the manual.

Stars136k stars

Forks23k forks

Contributors3.7k contributors

Licenseunknown

Community Discussion Evidence

12 source-linked items

Review these external discussions before using langchain with real data or production workflows. They are review inputs, not standalone proof that the project is production-ready.

01
[Integration] MINT Protocol - Agents earn crypto for execution
github / github_issue
02
Feature Request: Payment primitive integration — x402 payment layer for
github / github_issue
03
Cryptographic agent identity, intent verification, and kill switch for p
github / github_issue
04
Progress-aware termination: detect no-progress loops in agent tool execu
github / github_issue
05
Harmony: bad request on gpt-oss-120b and tool calls with `create_react_a
github / github_issue
06
Feature: callback handler for AI agent threat detection (Agent Threat Ru
github / github_issue
07
Feature: callback handler for AI agent threat detection (Agent Threat Ru
github / github_issue
08
Bug: SSRF bypass in validate_safe_url when LANGCHAIN_ENV=local_test
github / github_issue
09
create_agent Does Not Handle invalid_tool_calls from JSON Parsing Errors
github / github_issue
10
Easier multimodal tool
github / github_issue
11
Schema class for multimodal message
github / github_issue
12
Security: OWASP Agent Memory Guard – protect against memory poisoning at
github / github_issue

How to start

Only source-backed commands are shown here. Verify them in an isolated environment first.

Try the prompt first

Test the workflow without installing the upstream project.

preview

Read the Human Manual

Understand inputs, outputs, limits, and failure modes.

manual

Take context to your AI host

Use the compiled assets in your preferred AI environment.

context

Run sandbox verification

Confirm install commands and rollback before using a primary environment.

verify

pip install langchain

Official start command · https://github.com/langchain-ai/langchain#readme · verified: yes

Human Manual

The English page must expose the real manual, not a short placeholder.

8+ sections · Human Manual

langchain Manual

LangChain is a comprehensive framework designed for building agents and LLM-powered applications. It enables developers to chain together interoperable components and third-party integrati...

Open the full manual

langchain Human Manual
Table of Contents
Introduction to LangChain
Related Pages
Overview
Architecture Overview
Core Packages
langchain-core

Introduction to LangChain

Related topics: Runnable and Execution Model, Getting Started with LangChain

Source: https://github.com/langchain-ai/langchain / Human Manual

Getting Started with LangChain

Related topics: Introduction to LangChain, Runnable and Execution Model

Sources: [README.md](https://github.com/langchain-ai/langchain/blob/main/README.md)

Runnable and Execution Model

Related topics: Introduction to LangChain, Callbacks and Tracing Infrastructure, Agents Framework

Sources: [libs/core/langchain_core/runnables/base.py](https://github.com/langchain-ai/langchain/blob/main/libs/core/langchain_core/runnables/base.py)

Messages and Prompt System

Related topics: Chat Models and Embeddings

Sources: [libs/core/langchain_core/callbacks/base.py](libs/core/langchain_core/callbacks/base.py)

Chat Models and Embeddings

Related topics: Introduction to LangChain, Messages and Prompt System

Sources: [libs/core/langchain_core/language_models/chat_models.py](https://github.com/langchain-ai/langchain/blob/main/libs/core/langchain_core/language_models/chat_models.py)

AI Context Pack and portable assets

After deciding to continue, take the project context into your own AI host.

Complete pack plus user-owned assets

These files are planning and verification assets for Claude Code, Codex, Gemini, Cursor, ChatGPT, and other AI hosts.

Download complete pack Read Human Manual

BundleComplete Project Pack AssetAI Context Pack AssetBoundary & Risk Card AssetHuman Manual AssetPitfall Log AssetPrompt Preview AssetQuick Start ManifestPROJECT_PACK.json

Preflight checks

Treat this preview as a planning asset, not proof that your local environment is ready.

The manual is generated from source-linked project files and Doramagic validation signals.
Community evidence warnings stay visible instead of being converted into marketing claims.
The preview remains noindex until English quality and reciprocal indexing gates are explicitly opened.
Use the upstream repository as the final authority for installation commands, license, and version-specific behavior.

Pitfall Log and verification risks

Doramagic surfaces high-risk items before users treat a candidate capability as verified.

medium

Review upstream issue

README/documentation is current enough for a first validation pass.

medium

Review upstream issue

The source signal needs review before production use.

medium

Review upstream issue

no_demo

medium

Review upstream issue

no_demo

low

Review upstream issue

issue_or_pr_quality=unknown。

low

Review upstream issue

release_recency=unknown。