redacit

A local privacy layer that anonymizes sensitive data before it reaches a cloud LLM, then restores original values in the response. No data leaves your machine as-is. No Docker required.

---

How it works

Your prompt
    ↓
Anonymizer  →  detects PII spans (Presidio, in-process)
            →  replaces each span with a tagged placeholder  e.g. <PERSON_0>
            →  records a placeholder → original mapping
    ↓
Cloud LLM  (sees only anonymized text)
    ↓
Deanonymizer  →  replaces placeholders in the response with original values
    ↓
Your app  (receives the reply with real names / emails / etc. restored)

---

Detected entity types

Entity	Example
PERSON	John Smith
EMAIL_ADDRESS	john@acme.com
PHONE_NUMBER	+1 (415) 555-0192
CREDIT_CARD	4532-0151-1283-0366
US_SSN	346-12-5678
IP_ADDRESS	203.0.113.42
LOCATION	Austin, TX
ORGANIZATION	Acme Holdings
DATE_TIME	2024-04-15
IBAN_CODE	GB29NWBK60161331926819
URL	acme.com
US_PASSPORT	938475610
US_DRIVER_LICENSE	—
US_BANK_ACCOUNT	7823901645 (custom)
US_ROUTING_NUMBER	021000021 (custom)
EIN	12-3456789 (custom)
API_KEY	sk-xK92mLp… (custom)

---

Setup

Requires Python 3.11+ and uv.

pip install redacit                  # base install — regex-only PII detection
python -m spacy download en_core_web_sm          # + person names, locations (11 MB)
python -m spacy download en_core_web_md          # + word vectors, recommended (43 MB)
# Or use the interactive wizard: redacit init

Copy .env.example to .env and add your API key for live LLM calls:

cp .env.example .env
# set OPENAI_API_KEY=sk-...

---

Model options

redacit auto-detects the best available spaCy model at startup. No configuration needed — it just uses whatever is installed.

Install command	Model	Size	Detects
pip install redacit	none (regex-only)	0 MB	emails, SSNs, credit cards, phones, IBANs, API keys, bank accounts, EINs, URLs, IPs
`python -m spacy download en_core_web_sm # + person names, locations (11 MB)
`python -m spacy download en_core_web_md # + word vectors, recommended (43 MB)
`# Or use the interactive wizard: redacit init

For most use cases, en_core_web_md is the best balance of size and accuracy. Use en_core_web_sm for minimal footprint, or the base install for structured-PII-only use cases (financial data, API key scrubbing).

You can also select the model explicitly in code:

from redacit import Anonymizer

anon = Anonymizer()                          # auto-detect best available
anon = Anonymizer(model="en_core_web_sm")    # explicit small model
anon = Anonymizer(model=None)                # regex-only, no NLP model

---

Usage

1. CLI — no code needed

redacit anonymize "Schedule a call with John Smith at john@acme.com"

# Anonymized:
# Schedule a call with <PERSON_0> at <EMAIL_ADDRESS_0>
#
# Mapping:
#   <PERSON_0>                       John Smith
#   <EMAIL_ADDRESS_0>                john@acme.com

Filter entity types or tune the confidence threshold:

redacit anonymize "John Smith, card 4111-1111-1111-1111" --entity PERSON
redacit anonymize "..." --threshold 0.6

Analyse an audit log:

redacit stats privacy_audit.jsonl --top 5

Start the REST API server (requires the server extra):

uv add 'redacit[server]'
redacit serve --host 0.0.0.0 --port 8000

---

2. Drop-in OpenAI replacement

The fastest path if you already have OpenAI code — change one line:

# Before
from openai import OpenAI
client = OpenAI()

# After
from redacit import PrivacyOpenAI
client = PrivacyOpenAI()

# Everything else stays identical
response = client.chat.completions.create(
    model="gpt-4o",
    messages=[{"role": "user", "content": "Summarise Alice Jones's contract at alice@corp.com"}],
)
# Alice Jones and alice@corp.com are anonymized before the API call
# and restored in response.choices[0].message.content automatically

Tools, response_format, streaming, embeddings, and all other SDK call patterns work unchanged.

---

3. Simple chat client (OpenAI)

from redacit import OpenAIPrivacyClient

client = OpenAIPrivacyClient()    # reads OPENAI_API_KEY from env
reply  = client.chat("Draft a letter to John Smith at john@acme.com")
# PII stripped before the call, restored in the reply

Stream the response:

for chunk in client.stream("Summarise the following contract: ..."):
    print(chunk, end="", flush=True)

3b. Unified client — any SDK

from redacit import PrivacyClient
from openai import OpenAI              # or anthropic.Anthropic, google.genai.Client

client = PrivacyClient(OpenAI())
reply  = client.query("Draft a letter to John Smith at john@acme.com")
# Works identically with any supported SDK

---

4. Low-level anonymizer (manage the LLM call yourself)

from redacit import anonymize, deanonymize

result   = anonymize("SSN: 346-12-5678, card: 4111-1111-1111-1111")
raw      = your_llm_call(result.anonymized_text)
restored = deanonymize(raw, result.mapping)

Restrict which entity types are detected for a single call:

result = anonymize(text, entities=["PERSON", "EMAIL_ADDRESS"])

---

5. Multi-turn conversations

PrivacySession accumulates the placeholder-to-original mapping across turns so PII introduced in one message stays resolvable in later responses:

from redacit import OpenAIPrivacyClient, PrivacySession

session = PrivacySession()
client  = OpenAIPrivacyClient(session=session)

client.chat("My name is Alice Jones")       # <PERSON_0> → Alice Jones stored
client.chat("What did I just tell you?")    # placeholder resolved from session
session.clear()                             # start a new conversation

---

6. REST API

# Anonymize
curl -s -X POST http://localhost:8000/anonymize \
  -H "Content-Type: application/json" \
  -d '{"text": "Email alice@corp.com by Friday"}' | jq
# { "anonymized_text": "Email <EMAIL_ADDRESS_0> by Friday",
#   "mapping": {"<EMAIL_ADDRESS_0>": "alice@corp.com"} }

# Restore
curl -s -X POST http://localhost:8000/deanonymize \
  -H "Content-Type: application/json" \
  -d '{"text": "Email <EMAIL_ADDRESS_0> by Friday",
       "mapping": {"<EMAIL_ADDRESS_0>": "alice@corp.com"}}' | jq
# { "text": "Email alice@corp.com by Friday" }

# Chat proxy (requires OPENAI_API_KEY on the server)
curl -s -X POST http://localhost:8000/chat \
  -H "Content-Type: application/json" \
  -d '{"prompt": "Summarise the contract for John Smith"}' | jq

Full OpenAPI docs available at http://localhost:8000/docs when the server is running.

---

7. Structured data — CSV and JSON files

from redacit import CsvAnonymizer, JsonAnonymizer

# CSV — one result per row
for row in CsvAnonymizer().anonymize_file("customers.csv"):
    print(row.anonymized)      # dict with PII replaced per column
    print(row.flat_mapping)    # combined placeholder map for this row

# JSON — one result per record
for rec in JsonAnonymizer().anonymize_file("records.json"):
    print(rec.anonymized)      # nested dict with PII replaced at leaf strings

Add a sidecar config file to control per-column or per-path rules:

// customers.json  (placed alongside customers.csv)
{
  "fields": {
    "name":    { "entities": ["PERSON"] },
    "email":   { "entities": ["EMAIL_ADDRESS"] },
    "amount":  { "skip": true },
    "date":    { "skip": true }
  }
}

Field option	Effect
"entities": [...]	Only those PII types detected for this field
"skip": true	Field passed through unchanged
"score_threshold": N	Per-field confidence threshold
(no entry)	Full default entity list at default threshold

---

8. Audit logging

AuditLogger writes append-only JSONL. Raw text and mapping values are never stored — only metadata safe for compliance review:

from redacit import OpenAIPrivacyClient, AuditLogger

with AuditLogger("privacy_audit.jsonl") as log:
    client = OpenAIPrivacyClient(audit_logger=log)
    client.chat("Wire $50,000 to account 7823901645")

# Appended record:
# {
#   "ts": "2024-11-01T12:00:00+00:00",
#   "input_hash": "a3f9b2c1...",          ← SHA-256[:16] of the input
#   "entity_counts": {"US_BANK_ACCOUNT": 1},
#   "total_redacted": 1,
#   "provider": "openai",
#   "model": "gpt-4o-mini"
# }

Analyse a log file from the CLI:

redacit stats privacy_audit.jsonl

# Audit log : privacy_audit.jsonl
# Records   : 142
# Total PII : 389
#
# Top 5 entity types:
#   PERSON                         98
#   EMAIL_ADDRESS                  71
#   US_BANK_ACCOUNT                54
#   CREDIT_CARD                    41
#   PHONE_NUMBER                   38

---

Demo

uv run python demo.py                        # run all demo datasets
uv run python demo.py general_pii            # plain text PII samples
uv run python demo.py financial              # financial prose samples
uv run python demo.py financial_transactions # CSV with per-column config
uv run python demo.py financial_records      # nested JSON with sidecar

Adding a demo dataset

Plain text — add a .py file to demo_data/:

# demo_data/my_dataset.py
TITLE = "My Dataset"
SAMPLES = [
    "Text with sensitive data here.",
    "Another sample with John Doe at john@example.com.",
]

CSV — drop a .csv into demo_data/ and optionally a .json sidecar with the same stem. demo.py auto-discovers both.

---

Tests

uv run pytest                        # full suite
uv run pytest tests/unit/            # recognizer unit tests only
uv run pytest tests/test_samples.py  # data-driven leakage and roundtrip tests

---

Project structure

redacit/
├── src/redacit/
│   ├── __init__.py             # public API — all exports live here
│   ├── anonymizer.py           # core PII detection and placeholder replacement
│   ├── _types.py               # FieldConfig, SidecarConfig, LLMClient protocol
│   ├── session.py              # PrivacySession — multi-turn mapping accumulator
│   ├── audit.py                # AuditLogger — append-only JSONL compliance log
│   ├── cli.py                  # redacit CLI (anonymize / serve / stats)
│   ├── server.py               # FastAPI server (optional — requires [server] extra)
│   ├── client/
│   │   ├── base.py             # BaseLLMClient — anonymize → call → deanonymize lifecycle
│   │   ├── privacy_client.py   # PrivacyClient — unified drop-in proxy for any SDK
│   │   ├── openai_client.py    # OpenAIPrivacyClient + PrivacyOpenAI
│   │   └── litellm_client.py   # LiteLLMPrivacyClient (optional — requires [litellm] extra)
│   ├── formats/
│   │   ├── csv.py              # CsvAnonymizer — row-by-row CSV processing
│   │   ├── json_format.py      # JsonAnonymizer — record-by-record JSON processing
│   │   └── _helpers.py         # flatten / unflatten / load_sidecar / anonymize_flat
│   └── recognizers/
│       ├── bank_account.py     # UsBankAccountRecognizer
│       ├── routing_number.py   # UsRoutingNumberRecognizer
│       ├── ein.py              # EinRecognizer
│       └── api_key.py          # ApiKeyRecognizer (sk-*, Bearer tokens, hex secrets)
├── demo_data/                  # sample datasets for demo.py
├── tests/
│   ├── fixtures/sample_prompts.py
│   ├── test_anonymizer.py
│   ├── test_samples.py
│   ├── test_cli.py
│   ├── test_server.py
│   └── unit/test_recognizers.py
├── demo.py
└── pyproject.toml

Optional extras

Extra	Installs	Enables
redacit[server]	fastapi, uvicorn	redacit serve, REST API
redacit[litellm]	litellm	LiteLLMPrivacyClient (Anthropic, Gemini, Ollama, …)

---

Known limitations

Limitation	Detail
Non-US phone numbers	UK/EU mobile numbers may fall below the default confidence threshold without a country-specific recognizer
Numeric pattern collisions	Bank account and routing numbers can overlap with PHONE_NUMBER detections; overlap resolution keeps the higher-confidence span
Credit card Luhn validation	Card numbers must pass checksum validation — synthetic or invalid numbers are not caught
LLM response paraphrasing	If the LLM rewrites a placeholder (e.g. expands <PERSON_0> to Person Zero), deanonymization will not restore it
Streaming deanonymization	The streaming client buffers the full response before deanonymizing, since placeholders may span token boundaries