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

# Introduction

> Open source PII detection SDK for AI applications — protect sensitive data before sending to OpenAI, Anthropic Claude, Google Gemini, or any LLM

## What is Blindfold?

**Open source PII SDKs for AI applications.** Protect sensitive data before sending to OpenAI, Anthropic Claude, Google Gemini, or any LLM. Install the SDK, detect and tokenize PII locally — no API key, no signup, no network calls. Free forever.

Need NLP-powered detection (names, addresses, organizations), compliance policies, or audit logs? Upgrade to the Cloud API.

<CardGroup cols={2}>
  <Card title="Free Local Mode" icon="server">
    86 regex entity types, all 8 operations, zero network calls — your data never leaves your infrastructure
  </Card>

  <Card title="Cloud API (optional)" icon="cloud">
    60+ NLP entity types, custom entities, compliance policies, audit logs — pay only for what you use
  </Card>

  <Card title="Reversible" icon="rotate">
    Tokenize PII before sending to AI, restore original data after
  </Card>

  <Card title="Compliant" icon="scale-balanced">
    Meet GDPR, HIPAA, PCI DSS, and EU AI Act requirements
  </Card>
</CardGroup>

## How It Works

<Steps>
  <Step title="Send text with PII">
    Your application sends user data to Blindfold
  </Step>

  <Step title="Get protected text">
    PII is replaced with tokens like `<person_1>`, `<email_1>`
  </Step>

  <Step title="Send to AI safely">
    Protected text goes to OpenAI, Anthropic Claude, Google Gemini, or any LLM without exposing PII
  </Step>

  <Step title="Restore original (optional)">
    Convert AI response back to original data
  </Step>
</Steps>

## Privacy Methods

<Columns cols={3}>
  <Card title="Tokenization" icon="shuffle" href="/methods/tokenization">
    Reversible tokens for AI processing
  </Card>

  <Card title="Masking" icon="eye-slash" href="/methods/masking">
    Show last 4 digits (e.g., `***3456`)
  </Card>

  <Card title="Redaction" icon="eraser" href="/methods/redaction">
    Permanent removal
  </Card>

  <Card title="Hashing" icon="hashtag" href="/methods/hashing">
    Consistent IDs for analytics
  </Card>

  <Card title="Synthesis" icon="wand-magic-sparkles" href="/methods/synthesis">
    Fake data for testing
  </Card>

  <Card title="Encryption" icon="lock" href="/methods/encryption">
    AES-256 encryption
  </Card>
</Columns>

## Works With

<CardGroup cols={4}>
  <Card title="OpenAI" icon="robot" href="/integrations">
    GPT-4o, GPT-4, o1
  </Card>

  <Card title="Anthropic Claude" icon="robot" href="/integrations">
    Sonnet, Opus, Haiku
  </Card>

  <Card title="Google Gemini" icon="robot" href="/integrations">
    Gemini 2.5 Flash, Pro
  </Card>

  <Card title="LangChain" icon="link" href="/sdks/langchain">
    Official integration
  </Card>

  <Card title="LlamaIndex" icon="database" href="/integrations">
    Node postprocessor
  </Card>

  <Card title="Vercel AI SDK" icon="code" href="/integrations">
    generateText, streamText
  </Card>

  <Card title="AWS Bedrock" icon="cloud" href="/integrations">
    All Bedrock models
  </Card>

  <Card title="Any LLM" icon="sparkles" href="/integrations">
    Provider-agnostic SDK
  </Card>
</CardGroup>

## What Can Blindfold Protect?

<CardGroup cols={2}>
  <Card title="60+ Entity Types" icon="shield-check" href="/essentials/supported-entities">
    Names, emails, SSNs, credit cards, medical records, passports, and more
  </Card>

  <Card title="15+ Languages" icon="globe" href="/essentials/supported-languages">
    English, Spanish, German, French, Italian, and 10+ more
  </Card>

  <Card title="Custom Entities" icon="wand-sparkles" href="/essentials/supported-entities#custom-entity-types">
    Define your own using natural language descriptions
  </Card>

  <Card title="Policy-Based" icon="file-shield" href="/api-reference/rest-api#policy-based-detection">
    Pre-configured for GDPR, HIPAA, PCI DSS compliance
  </Card>
</CardGroup>

## Start in 5 Minutes (Free)

Install the SDK and start detecting PII immediately — no signup, no API key, free forever.

<CardGroup cols={3}>
  <Card title="Python" icon="python" href="/quickstart">
    ```bash theme={null}
    pip install blindfold-sdk
    ```
  </Card>

  <Card title="JavaScript" icon="js" href="/quickstart">
    ```bash theme={null}
    npm install @blindfold/sdk
    ```
  </Card>

  <Card title="Java" icon="java" href="/quickstart">
    ```xml theme={null}
    dev.blindfold:blindfold-sdk
    ```
  </Card>

  <Card title="Go" icon="golang" href="/sdks/go-sdk">
    ```bash theme={null}
    go get github.com/blindfold-dev/Blindfold/packages/go-sdk
    ```
  </Card>

  <Card title=".NET" icon="microsoft" href="/sdks/dotnet-sdk">
    ```bash theme={null}
    dotnet add package Blindfold.Sdk
    ```
  </Card>

  <Card title="REST API" icon="terminal" href="/quickstart">
    ```bash theme={null}
    curl https://api.blindfold.dev
    ```
  </Card>
</CardGroup>

<Card title="5-Minute Quickstart" icon="bolt" href="/quickstart" horizontal>
  Try local mode instantly or set up the Cloud API in under 5 minutes
</Card>

## Popular Use Cases

<CardGroup cols={2}>
  <Card title="AI Chatbots" icon="robot">
    Tokenize PII before OpenAI, Anthropic Claude, or Google Gemini processes user messages
  </Card>

  <Card title="RAG Pipelines" icon="database">
    Redact PII at ingestion, tokenize at query time — PII never reaches your vector DB or LLM
  </Card>

  <Card title="AI Agents" icon="sparkles">
    Protect sensitive data in multi-step agent workflows (CrewAI, LangChain agents, custom)
  </Card>

  <Card title="Compliance" icon="scale-balanced">
    Meet GDPR, HIPAA, PCI DSS, and EU AI Act requirements with built-in policies
  </Card>
</CardGroup>

## Documentation

<CardGroup cols={2}>
  <Card title="Python SDK" icon="python" href="/sdks/python-sdk">
    Complete guide with async support
  </Card>

  <Card title="JavaScript SDK" icon="js" href="/sdks/javascript-sdk">
    Node.js and browser support
  </Card>

  <Card title="Java SDK" icon="java" href="/sdks/java-sdk">
    Sync and async clients, Maven/Gradle
  </Card>

  <Card title="Go SDK" icon="golang" href="/sdks/go-sdk">
    Zero dependencies, context-aware
  </Card>

  <Card title=".NET SDK" icon="microsoft" href="/sdks/dotnet-sdk">
    async/await, net6.0/net8.0
  </Card>

  <Card title="REST API" icon="code" href="/api-reference/rest-api">
    Use with any programming language
  </Card>

  <Card title="Supported Entities" icon="list" href="/essentials/supported-entities">
    60+ entity types detected
  </Card>

  <Card title="Languages" icon="language" href="/essentials/supported-languages">
    15+ supported languages
  </Card>

  <Card title="Examples" icon="book" href="/examples">
    Real-world code examples
  </Card>
</CardGroup>

## Need Help?

<Card title="Get Support" icon="circle-question" href="mailto:hello@blindfold.dev" horizontal>
  Questions? Contact us at **[hello@blindfold.dev](mailto:hello@blindfold.dev)**
</Card>