PII protection for LLMs

Use customer data in AI without sending the identifiers.

NoPII is an LLM privacy proxy that detects and tokenizes sensitive values before your application calls a model, then restores those values in the response.

One million protected tokens a month. No credit card. Live in minutes.

NoPII sits between your application and the model provider: real data is tokenized through the NoPII proxy so the provider receives tokens only.

Real data goes into your application.

Tokens go to the model provider.

Your users never see the difference.

Every prompt is a data transfer. Almost no one treats it like one.

The fastest-growing data flow in your company is the one with the least oversight: the prompts. Names, account numbers, clinical notes, and salary figures leave your environment thousands of times a day, bound for third-party model providers, because that is what makes the AI features work. Their logs. Their retention. Their jurisdictions. Your liability under HIPAA, GDPR, and every contract you have signed.

Compliance responds the only way it can: it says no. The roadmap stalls, or it routes around them. So engineers reach for redaction, stripping the sensitive values out before the prompt goes. And redaction breaks the model. Replace a customer's name with [REDACTED] in sentence one and the model can no longer connect it to the account in sentence three. You protected the data by removing the intelligence you shipped the feature for.

The model never needed the real values. It needed consistent ones.

The dilemma is false. Swap every sensitive value for a stable token before the prompt leaves, restore it when the response returns, and the model reasons exactly as before while the provider never holds a single real identifier. That is NoPII, and it deploys in the time it takes to change a base URL.

Many sources converging into a single point — every prompt is a data transfer.

Built for LLM traffic, not retrofitted from a data-loss tool.

01

Tokenization, not redaction

Redaction and masking destroy the context a model needs to reason. Deterministic tokens preserve it: same value, same token, full output quality.

02

Round-trip detokenization

Responses come back with real data restored. Your application behaves exactly as before. Users never see a token.

03

Fail-safe by default

If tokenization ever fails, the request is blocked. Sensitive data never leaks on a best-effort basis. That is not a setting, it is the architecture.

04

Context phrase neutralization

Phrases that trigger model safety refusals on tokenized data are neutralized in the proxy. A real failure mode that an in-house build rarely anticipates.

05

Secret and API key detection

Fourteen pattern families of credentials, from cloud keys to database connection strings to private keys, caught in the same pass as PII detection, on every request including streaming.

What two lines of code buys you.

The launch unblocked

Compliance gets architecture instead of assurances: tokenized traffic, per-request audit logs, block-by-default failure, BAA available. The “no” becomes “yes, through the proxy.” NoPII is not just a privacy layer; it is an AI adoption layer, built for teams navigating HIPAA, GDPR, CCPA, PCI DSS, SOX, and the EU AI Act.

Model freedom kept

One proxy fronts 9+ providers. Switch models, run several at once, test next week's release. Your privacy controls do not reset when your model choice changes.

Intelligence preserved

Deterministic tokens keep multi-turn conversations coherent and multi-step reasoning intact. You shipped an AI feature. NoPII does not lobotomize it at the proxy.

Tokenization is not masking. The difference decides whether your AI still works.

Most tools that touch sensitive data in the AI path redact: they replace values with placeholders or scrub them entirely. The data is protected and the reasoning is destroyed, in one move, and nothing can be restored in the response. NoPII tokenizes deterministically and round-trips, which protects the data and preserves the reasoning.

Broader data-loss suites and AI gateways are useful for their jobs; inline masking inside them is a feature. For NoPII, compliance-grade tokenization of LLM traffic is the entire product.

↳If your problem is employees pasting data into consumer chatbots across hundreds of SaaS apps, you need endpoint data-loss prevention, and we will tell you so. NoPII protects the LLM traffic your applications generate.

Redaction and maskingNoPII tokenization
Placeholders destroy entity relationshipsDeterministic tokens preserve them
Placeholder redaction leaves nothing to restoreNoPII restores its own tokens, so your app gets real data back
Models often refuse scrubbed promptsContext neutralization prevents refusals
Best effort on failureBlock-by-default on failure

Under the Hood

The details an engineer or auditor will ask for.

Deterministic tokenization
The same plaintext always produces the same token. “John Smith” in message 1 and message 10 map to the same [NAME: Ry0Ixd1] token, preserving cross-message context without ever exposing real data to the model.
Context phrase neutralization
NoPII does not just mask values. It neutralizes data-type labels that could trigger model safety refusals or re-identify sensitive categories. Social security number becomes ID number, credit card number becomes account number, date of birth becomes date, so the model processes tokens without recognizing the underlying data type.
Fail-safe architecture
If detection encounters an error, the proxy blocks the request rather than letting unprotected data through. Every decision is logged for audit.
Streaming support
Standard and streaming SSE responses are both supported. Token replacement happens on the fly as chunks arrive, so latency impact is minimal even for long streaming completions.
Configurable token retention
Vault tokens carry a time-to-live that controls how long tokenized data is stored. Free tier tokens expire after one day. Pro and Enterprise can set retention from one day to permanent. When a token expires, the underlying data is permanently deleted from the vault.
Secret and API key detection
Cloud provider keys, model API keys, payment and code-platform tokens, database connection strings, private keys, and auth tokens are detected across 14 pattern families, replaced with vault tokens, restored in the response, and logged in the audit trail. On by default for new accounts.

Admin Console

One dashboard for three teams.

Security, compliance, and engineering share one admin console.

Dashboard

A real-time view of your deployment: total requests, detections, entity-type distribution, provider breakdown.

PII settings

Choose which entity types to detect and adjust detection sensitivity, per tenant.

Configuration

Manage provider keys, configure behavior, connect Langfuse for per-tenant observability.

Live chat playground

See the raw input, the tokenized version sent to the model, and the restored response, side by side.

Usage dashboard

API volume, detection rates, and token usage, plus exportable audit and request logs.

Audit log

Every detection and tokenization event logged with timestamp, entity type, and tenant context.

Token purge

Delete every token for a list of values in one request, to fulfill a GDPR erasure request. The proof is in the log.

Supported Entity Types

30+ configurable entity types, across five categories.

Identity
Person names Email addresses Phone numbers Physical addresses
Government IDs
Social Security numbers Passport numbers Driver's license numbers Tax identification numbers
Financial
Credit card numbers Bank account numbers IBAN codes
Technical
IP addresses MAC addresses Crypto wallet addresses
Security
API keys and secrets Database connection strings Private keys and certificates JWTs and auth tokens

The numbers.

2 lines
total code change to deploy
<5 min
from signup to protected traffic
9+ LLMs
supported under one proxy
109 tests
published test report
Built on the Enigma Vault, which is PCI DSS Level 1 and SOC 2 Type II · BAA available · Patent Pending

Ship the AI feature. Keep the data.

Start free with one million protected tokens a month, or talk to us about Enterprise.

How NoPII protects each LLM request.

The integration is a base URL swap. Behind it, a full tokenization pipeline built on the Enigma Vault.

# Before: PII goes straight to OpenAI
client = OpenAI(api_key="sk-...")

# After: PII is intercepted and tokenized by NoPII
client = OpenAI(
  api_key="sk-...",
  base_url="https://api.nopii.co"
)

No new SDK. No middleware rewrite. No re-architecture. SSE streaming fully supported.

How PII tokenization works for LLM APIs.

01

Intercept

Your app calls the same SDK it always has. NoPII receives the request first, before it reaches the provider.

02

Detect

30+ configurable entity types are identified in free text, validated in a published 109-test report, with adjustable detection sensitivity. Secrets and API keys are caught in the same pass, across 14 credential pattern families.

03

Tokenize

Each detected value is replaced with a deterministic token stored in Enigma Vault. Same value, same token, every time, so the model's reasoning stays consistent across the prompt.

04

Forward

A tokenized request reaches the model provider, which never sees the real data.

05

Detokenize

Tokens in the response are swapped back to real values before your application sees them. Your app receives a normal response and never knows the difference.

↳And if tokenization ever fails at any step, the request is blocked, not forwarded. Default-closed, by architecture.

Before and after

See exactly what changes.

Before: the raw prompt

Please update the account for John Smith (SSN: 123-45-6789) at john@acme.com

Names, government IDs, and email addresses all exposed.

After: the tokenized prompt

Please update the account for [NAME: Ry0Ixd1] (ID number: [IDENTIFIER: k8Lm2n]) at [EMAIL: bN3dF5h]

Every sensitive element replaced with a deterministic, reversible token. Context is preserved and the model still understands the prompt.

Context phrase neutralization

PII and API-key detection.

NoPII also neutralizes the labels that tell the model what kind of data it is looking at.

Without this, models recognize tokenized data as sensitive and trigger safety refusals, breaking the user experience and pushing teams to bypass privacy controls entirely.

Without neutralization

The model still reads the category labels.

social security number
credit card number
date of birth
bank account
passport number

The model recognizes sensitive data categories and refuses to process the request.

With NoPII

With NoPII

Categories become neutral, harmless labels.

social security number→ID number
credit card number→account number
date of birth→date
bank account number→account number
passport number→document number

Neutral labels let the model process the request without safety refusals.

Why teams route their AI through it.

Diagram: tokenization adds milliseconds to a prompt round trip
01

Fastest time to protected

No SDK to adopt, no middleware project, no re-architecture. Signup to protected production traffic in minutes, on the free tier, without talking to us.

Diagram: the model keeps full context after tokenization
02

Protection that preserves intelligence

Deterministic tokens keep reasoning intact across related data and across conversation turns. The feature you shipped still works.

Diagram: sensitive values held in vault custody, never sent to the model provider
03

Built on certified custody

Tokens map to values held in the Enigma Vault, which is PCI DSS Level 1 and SOC 2 Type II, under per-customer keys. The two-line integration stands on enterprise-grade ground.

The questions an engineer asks next.

Streaming and multi-turn token restoration

SSE responses detokenize in flight, so real-time chat keeps streaming. Deterministic tokens keep multi-turn conversations coherent: the same person is the same token across every turn of the session.

Why tokens, not redaction

NoPII restores its own tokens on the way back, so your application receives real values in the response. Placeholder redaction destroys the entity relationships a model needs to reason. Tokens preserve structure in both directions, which is the only approach that protects data without breaking the model.

The same AI feature, two realities.

Without NoPII

Sensitive data rides the prompt, and redaction breaks the model.

Customer data accumulates in model provider logs
Redaction breaks the model's reasoning
Compliance approval rests on provider promises
A detection failure leaks silently
Erasure means chasing third-party retention
With NoPII

With NoPII

Tokens ride the prompt, and your app gets real data back.

Providers receive tokens that reference nothing
Deterministic tokens preserve it in both directions
Compliance approval rests on your own architecture
A detection failure blocks loudly
Erasure resolves at the vault level

Why not build it yourself?

Teams that build this in-house end up assembling and maintaining a stitched stack: a detection library, a token vault, a proxy layer, an admin console, and audit logging. Each piece works. The seams are where data leaks. And the stack is never finished: new providers, new streaming formats, new entity types, and new compliance questions arrive faster than a side project can absorb them.

NoPII replaces the entire build with one base URL swap, maintained as a product instead of a backlog item.

Detection library
Token vault
Proxy layer
Admin console
Audit logging

● Each piece works. The seams are where data leaks.

The architecture, in writing.

Infrastructure

Built on the Enigma Vault, which is PCI DSS Level 1 and SOC 2 Type II.

Encryption

AES-256 at the field level on vaulted data.

Key management

Per-customer AES-256 keys in a managed secrets store, rolled over after a specified time. No key is shared between customers.

Authentication

OAuth2 machine-to-machine, client credentials.

Audit

Request-level logging, reviewable in the admin console. BAA available.

Research

See the results of 109 automated tests on the NoPII engine.

Deterministic PII Tokenization for LLM API Traffic: Test Suite Results and Empirical Analysis of the NOπI Redaction Engine

Read the whole page, or just change the base URL and watch the logs.

NOPII · USE CASES

Where LLM data privacy becomes business-critical.

PII protection for workflows already in production, where sensitive data is already reaching model providers. For sector context, see AI data security by industry, and NoPII pricing for what each plan covers. Find yours below, and trace exactly where it leaks.

TRACE 01

Healthcare and life sciences: the deepest exposure in the market.

Clinical AI is not coming; it is deployed. Ambient documentation tools sit in thousands of exam rooms. Chart abstraction runs across records for real-world evidence. Coding automation reads encounters to bill them. Prior authorization platforms process millions of requests a year.

Where the PII actually leaks

Trace one ambient documentation session end to end. The clinician greets the patient by name, and the transcript captures it. The patient recites their date of birth for verification, mentions their address changed, describes their diagnosis history. All of it lands in the transcript, the transcript becomes the prompt, and the prompt lands in a model provider's infrastructure, under their logs, their retention, their jurisdiction. Multiply by every visit, every day. The same trace runs through chart abstraction, where the record itself is the input; through coding, where the encounter note carries the MRN; and through prior auth, where patient notes, documentation, and orders travel together. None of these leaks is a bug. Each one is the workflow operating as designed, which is exactly why nobody has mapped it.

That unmapped flow is the regulatory exposure. Enforcement in this space keeps tracing back to one finding: a defective risk analysis, meaning the organization could not say where its protected data went. A BAA with your model provider does not close the gap, because a BAA is a liability contract, not a control: it decides who pays after the data has moved, and it has never been the mitigating factor in a settlement. Regulators also pursue software vendors directly, not just the health systems using them.

Where NoPII sits

In front of every one of these workflows, tokenizing patient identifiers before the prompt reaches the model provider. The scribe drafts a perfect note on consistent tokens. The abstraction pipeline reasons over de-identified structure. The coding engine reads the encounter without reading the patient. Real values restored on the response path, every detection logged, BAA available, and a defensible sentence for your risk analysis: the model provider never held an identifier.

Point it at first Ambient documentation Adverse event narratives Chart abstraction Coding and revenue cycle Prior authorization

See your own PHI exposure this week. Route one workflow through the free tier and read the detection log. The first million protected tokens cost nothing, and the log is usually the whole argument.

TRACE 02

Pharmacovigilance and clinical operations: mandated work, regulated data.

Safety teams do not choose whether to process adverse event reports; the obligation is regulatory, and AI-assisted intake and triage is now standard practice.

Where the PII actually leaks

An adverse event case arrives as a narrative: the patient's name, age, medications, dosing history, and outcome, written as prose, because that is what a case narrative is. AI triage means that narrative becomes a prompt, verbatim. Trial operations leak the same way: pre-screening runs patient EHR data through eligibility logic, monitoring agents read patient records and lab results, and submission drafting is built on clinical study data. For US sponsors running EU trials, the European layer sharpens it: regulators have said plainly that a trained model cannot be assumed anonymous, and unlawful processing upstream can taint everything downstream. The only control that holds is removing identifiers before the data reaches the model provider.

Where NoPII sits

Between your PV and clinical systems and every model call, with deterministic tokens keeping each case narrative internally coherent so causality assessment still works, and an exportable per-transaction audit trail for inspection readiness.

Bring your inspection-readiness question to a working session. Thirty minutes, your workflow, your regulators.

TRACE 04

Financial services: identifiers in every prompt, regulators at the door.

Where the PII actually leaks

A support agent opens the copilot and pastes the case: customer name, full account number, recent transactions, the complaint. That paste is the leak, and it happens hundreds of times a day per team. Fraud narratives leak by design, because the narrative is the transaction history with a name attached. Compliance review leaks in bulk, because the documents under review are dense with customer identifiers. And one leak nobody budgets for: engineers and analysts paste connection strings, API keys, and credentials into internal copilots daily. All of it moves under GLBA, SOX, PCI DSS, and state privacy law simultaneously.

Where NoPII sits

Tokenizing financial identifiers in transit while deterministic tokens preserve analytical structure: the same account is the same token across a multi-step fraud narrative, so the reasoning holds while the identifiers never reach the model provider. Secret and API key detection runs in the same pass across fourteen credential pattern families, on by default.

Run one week of copilot traffic through the free tier. The detection dashboard tells you what has been leaving the building.

TRACE 05

Insurance: the densest files anyone sends to a model.

Where the PII actually leaks

An adjuster drops a claims file into the summarization tool. That single PDF holds medical records, financial details, an identity document, and payment data, four regulated categories, one prompt. Triage and correspondence drafting repeat the same transfer across the whole book of claims, and underwriting and fraud workflows carry the identical shape. No other industry concentrates this much regulated data into one routine AI action.

Where NoPII sits

One control point in front of claims, underwriting, and service AI, tokenizing across every category simultaneously, so the model summarizes the claim while the provider holds nothing real. Erasure resolves at the vault, not across a provider's retention policy, and every detection is logged for the market-conduct exam.

See what one claims file actually contains. Run a redacted sample through the live playground and watch the detections light up.

TRACE 06

Customer support: volume, streaming, and erasure rights.

Where the PII actually leaks

Support AI runs at conversation speed. The customer types their name, order number, address, and card's last digits into chat; the ticket history carries every previous interaction; summarization, drafting, and routing each re-send the thread to the model, streaming, in real time. The exposure compounds with volume, and once customer data is distributed across provider logs, GDPR and CCPA erasure requests become promises you cannot keep.

Where NoPII sits

In the streaming path, tokenizing in real time with SSE support so the chat experience is unchanged, and resolving right-to-erasure at the vault level with token purge: delete every token for a list of values in one request.

Protect your first million support tokens free. Two lines of code, live before the next shift starts.

TRACE 07

HR and people operations: the data your own employees would object to.

Where the PII actually leaks

A recruiter pastes a resume into the assistant: name, address, work history, sometimes visa status. Feedback summarization reads performance reviews with names attached. People analytics reads compensation by employee. Every one of these is employee and candidate data leaving for a third-party model, with employment law exposure in every jurisdiction you operate, and it is exactly the data internal AI pilots reach for first, usually before legal has seen the tool.

Where NoPII sits

Tokenizing employee identifiers, salaries, and personal details before people workflows touch a model, preserving the analytical value while giving legal the control layer they need to approve the program at all.

Get the people-AI pilot approved. Bring legal to a demo; the audit trail does the convincing.

TRACE 08

Software teams everywhere: the secrets nobody meant to send.

Where the PII actually leaks

An engineer pastes a failing config into the AI assistant, and the config contains the database connection string. A stack trace carries a bearer token. A debugging session includes a cloud key. None of it was meant to leave; all of it did. This exposure crosses every vertical, because it is not a workflow, it is a habit.

Where NoPII sits

Fourteen credential pattern families detected in the same pass as PII, on every request including streaming, replaced with vault tokens, restored in the response, logged on every catch. On by default, because the first week of logs is usually the argument.

Turn it on and read Friday's log.

Different industries. Same blocker.

The pattern is remarkably consistent. Teams want AI, the workflows are obvious, and the value is real. The hesitation starts when sensitive data enters the picture. NoPII exists to remove that hesitation without wrecking usability: it is not just a privacy layer, it is an AI adoption layer. Sensitive data is detected, tokenized, logged, and handled through a controlled layer, which makes AI projects easier to approve, easier to explain, and much easier to move forward.

What the audit trail actually looks like.

Every detection is logged with entity type, confidence score, session ID, provider, model, and timestamp. Searchable, filterable, exportable.

DETECTION LOG
{
  "timestamp": "2026-03-24T09:14:03Z",
  "session_id": "sess_7f2a9c",
  "provider": "openai",
  "model": "gpt-4o",
  "entities": [
    { "type": "PERSON", "score": 0.98 },
    { "type": "SSN", "score": 1.00 }
  ],
  "tokens_issued": 2,
  "action": "TOKENIZED_AND_FORWARDED"
}

If sensitive data appears in the workflow, the privacy layer cannot be optional.

That does not mean adoption has to become painful. Two lines of code, live in minutes, first million tokens free every month.

Your questions about NoPII, answered.

Privacy and tokenization

What is NoPII?
NoPII is a PII-tokenizing reverse proxy for LLM APIs, built by Enigma Vault. It sits between your application and model providers, detects sensitive data across 30+ configurable entity types, tokenizes it before it reaches the model provider, and detokenizes responses on the way back. Your application works with real data; the provider only ever sees tokens.
How is tokenization different from redaction or masking?
NoPII restores its own tokens in the response, so your application receives real values back. Placeholder redaction replaces sensitive values with text that destroys the relationships a model needs to reason. NoPII tokenizes deterministically: the same value always maps to the same token, so reasoning stays intact, and round-trip detokenization returns real data to your application. Tokens preserve structure in both directions; redaction preserves it in neither.
What happens if detection or tokenization fails?
The request is blocked, not forwarded. NoPII is fail-safe by default: sensitive data never proceeds on a best-effort basis. The block is logged so your team sees it immediately. This is architecture, not a configurable setting.
Does it catch API keys and secrets, not just personal data?
Yes. Fourteen credential pattern families are detected in the same pass as PII: cloud provider keys, model API keys, payment and code-platform tokens, database connection strings, private keys, and auth tokens. Detected secrets are replaced with vault tokens, restored in the response, and logged in the audit trail. It is on by default for new accounts.
How accurate is detection?
Detection covers 30+ configurable entity types and is validated in a published 109-test report. Detection sensitivity is adjustable, and custom phrase rules are available on paid plans.
Does NoPII support HIPAA and GDPR workloads?
Yes. It is built for HIPAA, GDPR, CCPA, and PCI DSS requirements, with BAA availability for healthcare deployments and request-level audit logs for every transaction. Right-to-erasure resolves at the vault level, because identifiers never reach provider logs in the first place, and token purge deletes every token for a list of values in one request.
Does NoPII protect consumer chatbot websites?
No. NoPII protects application traffic that is routed through its proxy. If your application calls an LLM API through the NoPII base URL, every request and response on that path is covered. Traffic that never passes through the proxy, such as an employee pasting data into a consumer chatbot website in their browser, is outside its scope.

Providers and integration

How long does integration take?
Two lines of code. Point your existing SDK at the NoPII base URL, https://api.nopii.co. No new SDK, no middleware, no application logic changes. Most teams go from signup to protected traffic in under five minutes.
Which model providers does it support?
OpenAI, Anthropic, Google Gemini, DeepSeek, and any OpenAI-compatible API, 9+ providers under one proxy. It also works with LangChain, LangGraph, LlamaIndex, LiteLLM, and the Vercel AI SDK, with Langfuse tracing available. Switching providers does not reset your privacy controls.
Does it work with streaming responses?
Yes. SSE responses detokenize in flight, so real-time chat keeps streaming while detection and restoration run in the path.
Does it stay coherent across a multi-turn conversation?
Yes. Because tokenization is deterministic, the same entity carries the same token across every turn of a session, so the model's context and reasoning hold across the whole conversation.
Why not build this in-house?
Building it yourself means assembling and maintaining a stitched stack: a detection library, a token vault, a proxy layer, an admin console, and audit logging. Each piece works; the seams are where data leaks. And the stack is never finished, because new providers, streaming formats, entity types, and compliance questions keep arriving. NoPII is that entire build, maintained as a product.

Retention and pricing

What is the security and certification posture?
NoPII is built on the Enigma Vault, which is PCI DSS Level 1 and SOC 2 Type II. Tokenized values are stored in the Vault with AES-256 encryption and per-customer keys.
What does it cost to try?
Nothing. The free tier covers one million protected tokens per month with no credit card, indefinitely.

Still reading? The free tier answers faster.