Skip to main content

Guardian Layer Overview

Guardian Layer is Custodian Labs' privacy data transformation layer for sensitive text and documents.

Use it when your application needs to detect or de-identify sensitive information before content is sent to an AI model, stored, shared, or used in another workflow.

What You Can Do

Guardian Layer helps you:

  • Detect sensitive information in text.
  • Transform sensitive values into safer alternatives.
  • Redact sensitive values when they should be hidden.
  • Limit processing to selected sensitive data categories.
  • Process plain text and supported files.

Start Here If

Use Guardian Layer when you need to:

  • Prepare user input before sending it to an LLM.
  • De-identify customer records, support tickets, notes, or internal documents.
  • Remove or transform sensitive values before sharing data with another system.
  • Build privacy-aware review, moderation, or data preparation workflows.

If you are building a conversational assistant with memory, examples, and RAG, start with the Python SDK Overview instead.

Main Concepts

These concepts appear throughout the Guardian Layer documentation.

ConceptWhat it means
DetectionFinds sensitive content without changing the input.
De-identificationProduces safer output by changing detected sensitive content.
Supported entitiesThe sensitive data categories Guardian Layer can target, such as names, email addresses, phone numbers, and IDs.
TransformReplaces sensitive values with safer alternatives while keeping the text readable.
Redact / maskingHides sensitive values with visible masking marks.
Placeholder-style labelsLabel-style replacements such as [PERSON]; treat this as implementation-dependent unless explicitly exposed by the API.

Supported Inputs

Guardian Layer can be used with:

  • Text strings.
  • CSV, XLSX, and XLS files.
  • DOCX files.
  • PDF files with extractable text.
  • TXT files.

Use the file-specific pages when integrating document workflows.

  1. Detection vs De-identification
  2. Supported Entities
  3. Transform (Proprietary)
  4. Redact / Masking / Placeholder
  5. Guardian Layer
  6. File De-identification
  7. Image