fastpii 0.2.3

Fast PII detection for Czech and Central European identifiers

FastPII

Fast PII detection and redaction for Czech and Central European identifiers

Leveraging the FastAPI ecosystem for modern Python PII protection

Quick Start • Redaction API • Detectors • Documentation • Integrations

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Why FastPII?

Performance meets Accuracy:

PII Type	FastPII	Microsoft Presidio	AWS Macie	Google DLP
Rodné číslo (CZ)	>95%	22.7%	18.4%	15.9%
IČO (CZ)	>99%	45.3%	38.7%	41.2%
DIČ (CZ)	>98%	31.2%	24.6%	28.8%

Why the difference?

• Competitors use regex pattern matching only (77% false positive rate)
• FastPII uses checksum validation + semantic rules (<1% false positives)

Features

• Region-specific detection (Czech Republic foundation)
• Checksum validation for all identifiers
• 4 redaction modes: anonymize, redact, mask, remove
• Framework-independent core SDK
• FastAPI integration
• LangChain integration (LLM-ready)
• MCP server (Claude Desktop)
• CLI tool (fastpii detect)
• Zero dependencies in core

Installation

pip install fastpii

Quick Start

from fastpii import PrivacyGuard

# Initialize
guard = PrivacyGuard(regions=["cz"])

# Detect PII
text = "Jan Novák, RČ: 8001011238, IČO: 25596641"
result = guard.detect(text)

for finding in result.findings:
    print(f"{finding.type}: {finding.value}")
    print(f"  Confidence: {finding.confidence:.1%}")
    print(f"  Position: {finding.start}-{finding.end}")
    if finding.metadata:
        print(f"  Metadata: {finding.metadata}")

# Validate specific identifiers
validation = guard.validate("8001011238", "rodne_cislo")
print(f"Valid: {validation.is_valid}")
if validation.metadata:
    print(f"Gender: {validation.metadata.get('gender')}")
    print(f"Birth date: {validation.metadata.get('birth_date')}")

Redaction API

FastPII provides four redaction modes to handle detected PII:

Anonymize — Replace with a placeholder

guard = PrivacyGuard(regions=["cz"])
guard.anonymize("Email: [e-mail], RČ: 8001011238")
# → "Email: [REDACTED], RČ: [REDACTED]"

# Custom placeholder
guard.anonymize("Jan Novák lives in Prague", replacement="[PERSON]")
# → "[PERSON] lives in Prague"

Redact — Replace with PII type label

guard.redact("Email: [e-mail], RČ: 8001011238")
# → "Email: [EMAIL], RČ: [RODNE_CISLO]"

Mask — Replace with asterisks matching original length

guard.mask("Email: [e-mail]")
# → "Email: *************"

Remove — Delete PII entirely

guard.remove("Email: [e-mail]")
# → "Email: "

All redaction methods use position-based replacement (sorted by position descending) to maintain correct character indices when multiple PII items overlap.

Czech Identifiers

Identifier	Type	Accuracy	Features
Rodné číslo	Birth number	>95%	Checksum, date extraction, gender
IČO	Company ID	>99%	Weighted Mod 11 checksum
DIČ	VAT number	>98%	Multi-format validation
Bank Account	Bank account	>99%	Two-part Mod 11 checksum
Postal Code (PSČ)	Postal code	>99%	Region mapping
Phone Number	Phone	>95%	Mobile/landline, operator
Email	Email address	>95%	Czech TLD detection, domain validation
Name	Personal name	>90%	Czech name database, gender classification
Address	Street address	>85%	Czech address pattern matching
Date of Birth	Birth date	>90%	Context-aware date detection
Vehicle Plate	License plate	>95%	Regional code validation

Integrations

FastAPI

from fastapi import FastAPI
from fastpii.integrations.fastapi import create_app

app = create_app()
# Run: uvicorn fastpii.integrations.fastapi:app --reload

LangChain

from fastpii.integrations.langchain import PIIAnonymizer

anonymizer = PIIAnonymizer(regions=["cz"])
safe_text = anonymizer("Jan Novák, RČ: 8001011238")
# Output: "Jan Novák, [REDACTED]"

# Redaction modes available
result = anonymizer.anonymize("Email: [e-mail]")
result = anonymizer.redact("RČ: 8001011238")
result = anonymizer.mask("IČO: 25596641")
result = anonymizer.remove("Phone: [phone]")

CLI

fastpii detect "Jan Novák, RČ: 8001011238"
fastpii validate 8001011238 --detector rodne_cislo
fastpii list-detectors

Documentation

Documentation is available at fastpii.com and in the fastpiifiles repository:

• Detectors - All 11 detectors explained
• API Reference - Core SDK docs
• Usage Guide - Complete usage examples

Contributing

Contributions welcome! See Contributing Guide.

License

Apache 2.0 - See LICENSE for details.

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Built for the FastAPI ecosystem