The Developer's Dilemma

You're debugging a production issue. The stack trace includes customer email addresses. The fastest solution? Paste it into Claude and ask for help.

But that customer data is now:

  • Stored in Anthropic's systems
  • Potentially used for training (depending on your plan)
  • Visible to anyone with access to your chat history

77% of developers paste sensitive data into AI tools. Most don't realize the implications until it's too late. Beyond individual mistakes, 34.8% of all ChatGPT inputs in enterprise environments contain confidential business information — and organisational policies alone cannot stop it: 77% of employees share sensitive data with AI tools even when prohibitive policies are in place.

Why policies fail

A government contractor uploaded FEMA applicant personal and health data to ChatGPT for processing — despite a clear policy against it. Samsung suffered three source code leaks within one month after lifting a ChatGPT ban. Human error is the #1 cause of AI-related data leaks. Technical controls that operate automatically are the only reliable defence.
Source: anonym.community — From FEMA to Finance (March 2026)

La solución MCP Server

El servidor Model Context Protocol (MCP) actúa como un proxy transparente entre usted y los asistentes de IA. Este:

  1. Intercepta sus prompts antes de que lleguen a la IA
  2. Detecta y anonimiza la PII automáticamente
  3. Envía a la IA únicamente datos anonimizados
  4. Desanonimiza las respuestas para que usted vea el contexto original

You interact with AI normally — the protection is invisible.

Setting Up MCP Server

Prerequisites

  • Claude Desktop, Cursor, or VS Code with Claude extension
  • anonym.legal account on the Pro or Business plan (MCP Server requires a paid plan)
  • anonym.legal API key — get one at anonym.legal

No Node.js or npm install needed — anonym.legal's MCP Server is HTTP transport only.

Step 1: Get Your API Key

  1. Regístrese en anonym.legal/auth/signup
  2. Vaya a Settings → API Tokens
  3. Genere un nuevo token
  4. Copie el token (solo lo verá una vez)

Paso 2: configure Claude Desktop

Edite el archivo de configuración de Claude Desktop:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows: %APPDATA%\Claude\claude_desktop_config.json

Linux: ~/.config/Claude/claude_desktop_config.json

JSON — claude_desktop_config.json 
{
  "mcpServers": {
    "anonym-legal": {
      "type": "http",
      "url": "https://anonym.legal/mcp",
      "headers": {
        "Authorization": "Bearer your-api-key-here"
      }
    }
  }
}

Paso 3: reinicie Claude Desktop

Cierre y vuelva a abrir Claude Desktop. Debería ver "anonym-legal" en la lista de servidores MCP.

Configuración para Cursor IDE

Cursor utiliza el mismo protocolo MCP. Añádalo a la configuración de Cursor:

JSON — Cursor MCP Settings 
{
  "mcp": {
    "servers": {
      "anonym-legal": {
        "url": "https://anonym.legal/mcp",
        "headers": {
          "Authorization": "Bearer your-api-key-here"
        }
      }
    }
  }
}

Qué se anonimiza

El MCP Server detecta y anonimiza más de 267 tipos de entidades:

Category Examples
Personal Names, emails, phone numbers, DOB
Financial Credit cards, bank accounts, IBANs
Government SSNs, passport numbers, driver's licenses
Technical IP addresses, API keys, tokens
Healthcare MRNs, patient IDs, insurance numbers
Corporate Employee IDs, account numbers

Ejemplo de transformación

Su prompt:

Debug this error from user john.smith@acme.com:
Error: Payment failed for card 4532-1234-5678-9012
Customer ID: CUST-12345
IP: 192.168.1.100

Lo que ve Claude:

Debug this error from user [EMAIL_1]:
Error: Payment failed for card [CREDIT_CARD_1]
Customer ID: [CUSTOMER_ID_1]
IP: [IP_ADDRESS_1]

La respuesta de Claude (para usted):

The error for john.smith@acme.com suggests the card
4532-1234-5678-9012 may have insufficient funds...

Usted ve los datos originales; Claude solo llegó a ver tokens.

Advanced Configuration

Custom Entity Types

Defina patrones adicionales a detectar:

JSON 
{
  "env": {
    "ANONYM_API_KEY": "your-api-key",
    "CUSTOM_PATTERNS": "JIRA-[0-9]+,TICKET-[A-Z0-9]+"
  }
}

Allowlist Specific Data

Some data shouldn't be anonymized (public company names, product names):

{
  "env": {
    "ANONYM_API_KEY": "your-api-key",
    "ALLOWLIST": "Anthropic,Claude,anonym.legal"
  }
}

Consideraciones de seguridad

Component Location
MCP Server Your machine (local)
PII Detection API anonym.legal / cloak.business servers (Germany, Hetzner)
AI Model Anthropic/OpenAI servers

anonym.legal no almacena sus prompts ni respuestas. La API recibe el texto para su análisis, devuelve las posiciones de las entidades y descarta la entrada de inmediato. Consulte la política de privacidad para más detalles.

Precios

Planes de anonym.legal: MCP Server requiere Pro o Business:

Plan Tokens/month Price
Free 200 €0
Basic 1,000 €3/month
Pro 4,000 €15/month
Business 10,000 €29/month

El MCP Server está disponible en los planes Pro (15 €/mes) y Business (29 €/mes).

Conclusión

AI assistants are essential for modern development, but they don't need to see your customers' data.

La integración con MCP Server no requiere cambios en su flujo de trabajo, protege la PII automáticamente y funciona con Claude Desktop, Cursor y VS Code. Configúrela una vez: sus datos quedarán protegidos por defecto.

Fuentes