---
title: "Langchain"
slug: "langchain-authorizer"
updated: 2025-08-17T14:00:39Z
published: 2025-08-17T14:00:39Z
canonical: "docs.plainid.io/langchain-authorizer"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.plainid.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Langchain

LangChain is a framework in Python designed to facilitate the development of applications powered by large language models (LLMs). It simplifies the creation of agents, chains, tools, and retrieval-augmented generation (RAG) workflows. LangChain's modular architecture supports the integration of various components, including vector databases, LLMs, and external tools, for building AI applications.

This article provides a comprehensive introduction to the **PlainID LangChain Authorizer**, covering its general functionality and including instructional code blocks. For additional information on integration and specific use cases, refer to the following related articles:

 > * [Integrating the Langchain Authorizer in PlainID](/v1/docs/integrating-the-langchain-authorizer-in-plainid){target=`_blank`}
 > * [Langchain Authorizer Use-case](/v1/docs/langchain-authorizer-use-case){target=`_blank`}

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## PlainID LangChain Authorizer: Implementing Access Control

The PlainID LangChain Authorizer is a component that enforces access control policies within LangChain-based AI workflows. It establishes security guardrails to determine user permissions for asking questions, accessing data, or receiving masked responses, based on business policies defined in PlainID.

PlainID provides a specialized integration library (`langchain_plainid`) to embed policy enforcement directly into LangChain applications without requiring custom logic.

### PlainID Guardrails – Security Enforcement Points

PlainID utilizes **three guardrails** for LangChain-based AI systems:

| **Guardrail** | **Description** | **Enforcement Type** |
| :------------------- | :------------------------------------------------------------------------------------------------------ | :------------------- |
| **Categorizer** | Classifies user prompts and verifies if the topic is permitted based on Policies.                       | Pre-Query            |
| **Retriever Filter** | Filters documents from the vector store based on user permissions.                                      | During Retrieval     |
| **Anonymizer** | Masks or redacts sensitive data in the response based on the user's privileges.                         | Post-Query           |

> For more information, see the [Langchain Authorizer Integration](/v1/docs/integrating-the-langchain-authorizer-in-plainid){target=`_blank`} documentation.

The PlainID LangChain Authorizer offers a robust solution for implementing fine-grained access control within your LangChain-powered applications. Its three key guardrails—the Categorizer, Retriever Filter, and Anonymizer—ensure that LLM interactions are not only intelligent but also secure and compliant.