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Documentation Index

Fetch the complete documentation index at: https://docs.masker.dev/llms.txt

Use this file to discover all available pages before exploring further.

Masker is a privacy layer that sits between your voice platform and your upstream LLM. Every conversation turn is scanned for PHI — names, SSNs, dates of birth, phone numbers, and more — and each sensitive span is replaced with a stable, reversible token before being forwarded to OpenAI, Anthropic, or any OpenAI-compatible model. When the LLM responds, Masker swaps the tokens back so the caller hears a natural answer. Real PHI never leaves your regulated boundary.

Quick Start

Connect your first Vapi agent and place a masked call in under five minutes.

How It Works

Understand the request path from voice vendor to LLM and back.

Integrations

Connect Masker to Vapi, ElevenLabs, Bolna, or any OpenAI-compatible platform.

API Reference

Manage agents, list sessions, and download compliance reports via REST.

What Masker does

PHI Detection

Regex, spoken-form matching, and on-device NER detect SSN, phone, email, names, addresses, and more.

Reversible Tokenization

Two schemes — vault-deterministic HMAC and stateless AES-256-GCM-SIV AEAD — keep tokens rehydratable.

Compliance Reports

Every session generates an Ed25519-signed HIPAA Safe Harbor report as JSON and PDF.

Audit Chain

Each detection event is hash-chained for tamper evidence — verifiable offline with a single command.

Get started in three steps

1

Sign in to the portal

Open masker-voice.fly.dev/portal/login and sign in with GitHub. No API key required for the beta.
2

Create an agent and copy the proxy URL

Click New Agent, paste your Vapi API key, and copy the generated proxy URL. Masker configures Vapi automatically.
3

Place a test call and verify

Place a call through Vapi, then open OpenAI’s logs to confirm only tokens — not raw PHI — reached the model.
Masker is in private beta. The portal and live demo at try.masker.dev are functional today. Production beta launches May 30, 2026. Request access to get on the list.