# Voice Truthgate > Voice Truthgate™ - 1st Honest, on-device voice-deepfake detection by mosADD™ - **Type:** MCP server - **Install:** `agentstack add mcp-hei33enberg-voice-truthgate` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [Hei33enberg](https://agentstack.voostack.com/s/hei33enberg) - **Installs:** 0 - **Category:** [Integrations](https://agentstack.voostack.com/c/integrations) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [Hei33enberg](https://github.com/Hei33enberg) - **Source:** https://github.com/Hei33enberg/Voice-Truthgate-by-mosADD - **Website:** https://mosadd.com/voicecheck ## Install ```sh agentstack add mcp-hei33enberg-voice-truthgate ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Voice Truthgate by mosADD *(formerly VoiceCheck)* ### Is this really my contact — live? Honest voice authenticity. Open-core, MIT. [](https://github.com/Hei33enberg/voice-truthgate/actions/workflows/ci.yml) [](./LICENSE) [](https://www.npmjs.com/package/@mosadd/voice-truthgate-mcp) [](#privacy--on-device-by-design) [](https://github.com/Hei33enberg/mosADD-OS) [](https://mosadd.com/voice-truthgate) Voice authenticity that's **honest about its own limits**. It never gives you a bare "REAL / FAKE" — it gives you a **confidence signal** and a plain disclaimer, because getting this wrong about a real person is harmful. **[▶ Try it live](https://mosadd.com/voice-truthgate)**  ·  [How it works](https://mosadd.com/voice-truthgate/how-it-works)  ·  [Model card](https://mosadd.com/model-card)  ·  [API docs](./docs/VOICE-TRUTHGATE-API.md) --- ## Why "detect the deepfake" is the wrong game — and what we do instead The whole voice-AI industry races to **generate** speech; almost nobody ships an honest tool to tell you what's real. The naïve answer — a standalone "is this audio AI?" detector — is a **losing game**, and we have our own numbers to prove it: on modern premium TTS, our best single-clip detector measured **AUC ≈ 0.61** (barely better than a coin). Anyone selling you "99% deepfake detection" is selling snake oil. So Voice Truthgate asks a **better, answerable** question: **"is this really my contact, live?"** We answer it by **fusing signals**, not by guessing at a waveform: - **L0 — Identity.** *Who* is this, and are they a known human or a known agent? (An agent *should* sound synthetic — that's not an alarm.) - **L1 — Voiceprint.** Does the voice match *this specific person's* enrolled print? Strong at rejecting a **different** human (≈0% false accept in our tests, ~4.6% EER on clean speech). - **L2 — Acoustic.** A weak, abstain-heavy synthetic-speech signal (the on-device band below). - **L3 — Live rhythm.** *The un-copyable part* — see [the moat](#the-moat-fake-live-conversation-not-fake-file). Every layer is a **signal, not a verdict**, fused with the others and shipped with a disclaimer. We would rather abstain than be confidently wrong. ### The honest proof: why voiceprint alone isn't enough We ran a **targeted-clone test** on our own voiceprint engine — clone an enrolled person, then try to pass as them. Result: a targeted clone was **accepted 63% of the time** at our operating threshold, and **no threshold** cleanly separates "a clone of you" from "you" without also rejecting real callers. That's not a flaw we hide — it's *the reason the product fuses identity + voiceprint + liveness instead of trusting the voice alone.* Voice is one signal. Never the whole decision. --- ## Three ways to use it ### 1. Open SDK — on-device, MIT, zero infra The acoustic band (L2) runs **in the browser** — your audio never leaves the device. ```ts import { analyzeVoiceTruthgate } from "@mosadd/voice-truthgate"; // Decode your audio to mono PCM (a Float32Array), e.g. at 16 kHz. const result = await analyzeVoiceTruthgate({ samples, sampleRate: 16000 }); console.log(result.band.label); // "Likely authentic" | "Uncertain" | "Likely synthetic" console.log(result.confidence); // 0..1 — lead with the band, not this number console.log(result.disclaimer); // ALWAYS present — render it next to the result ``` Inject your own trained model as an optional server detector — the SDK never hard-codes an endpoint or key, and it **fails open** (unreachable model ⇒ the on-device band still stands and never silently becomes "authentic"): ```ts import { analyzeVoiceTruthgate, createHeuristicDetector, createServerDetector } from "@mosadd/voice-truthgate"; const server = createServerDetector({ analyze: async (payload) => callYourModel(payload), // → { confidence, modelVersion } version: "your-model-v1", }); const result = await analyzeVoiceTruthgate({ samples, sampleRate: 16000 }, { detectors: [createHeuristicDetector(), server] }); ``` > The SDK packages aren't on npm yet — clone this repo (`npm install` wires the workspaces) or > vendor `packages/*`. Runnable demo: **`npm run example`**, or open `examples/browser-check`. ### 2. MCP tool — give any AI agent an authenticity check Live on npm. Enrol a voice and verify a call clip **from Claude, Cursor, your own fleet — any MCP agent**: ```bash npx -y @mosadd/voice-truthgate-mcp ``` ```json { "mcpServers": { "voice-truthgate": { "command": "npx", "args": ["-y", "@mosadd/voice-truthgate-mcp"], "env": { "VTG_API_KEY": "vtg_live_your_key" } } } } ``` Tools: `voice_truthgate_enroll`, `voice_truthgate_verify`, `voice_truthgate_list_subjects`. See [`mcp/`](./mcp). ### 3. Market API — enrol / verify from any app For contact centres, IVRs, or any backend. Enrol the voices you protect, then verify a call clip against a subject → an honest banded verdict (`likely_same_person` / `likely_different_person` / `inconclusive`) with a synthetic-voice caution: ```bash curl -X POST "$VTG_URL" -H "X-API-Key: $KEY" \ -F action=verify -F subject_id=ceo -F audio=@incoming_call.wav ``` Full reference: **[docs/VOICE-TRUTHGATE-API.md](./docs/VOICE-TRUTHGATE-API.md)** · machine-readable **[OpenAPI spec](./docs/openapi.yaml)** (import as an OpenAI GPT Action / any tool). > **Drop it into your stack:** copy-paste recipes for **Claude, OpenAI (GPT Action + Agents SDK), > Vercel AI SDK, v0, and LangChain** → **[docs/USE-IN-YOUR-AGENT.md](./docs/USE-IN-YOUR-AGENT.md)**. > One MCP server, every ecosystem. --- ## The moat: fake live *conversation*, not fake *file* A live AI impersonation runs **speech → STT → LLM → TTS** — which is **half-duplex and turn-based**. It categorically **cannot** reply in **This is a signal, not a verdict.** Automated voice-authenticity detection is probabilistic > and can be wrong in both directions. Do not use this result alone to accuse, identify, or make > legal/forensic decisions about a person. ## Architecture (the open SDK) Two stages, both **on-device**; an optional trained model is *injected* by the host app. ``` ┌──────────────── your device / browser (nothing leaves it) ────────────────┐ mic / │ record or decode to STAGE 1: instant heuristic │ file ──┼─▶ upload ─────▶ 16 kHz mono ───▶ (pure DSP, 0 MB, default) ──────────────┼──▶ band │ Float32 PCM └▶ STAGE 2: stronger model (opt-in) ─────────┼──▶ + │ (a real classifier via transformers.js) │ disclaimer └──────────────────────────────────────────────────────────────────────────┘ (optional) injected SERVER detector — your model, your transport; authoritative when it answers, FAIL-OPEN when it doesn't. ``` Fusion is **band-first and fails to "unknown", never to "safe"** — nothing usable ⇒ `available: false`, band `uncertain`, never `likely-authentic`. Deeper design: [docs/ARCHITECTURE.md](./docs/ARCHITECTURE.md). ## Packages | Package | Role | |---|---| | [`@mosadd/voice-truthgate`](./packages/voice-truthgate) | The brains — fuses the stages into an honest band, always attaches the disclaimer. | | [`@mosadd/voice-analyzer-core`](./packages/voice-analyzer-core) | Stage 1: the instant, pure-DSP on-device heuristic. | | [`@mosadd/detection-sdk`](./packages/detection-sdk) | Pluggable `Detector` / `Verdict` frame + fail-open `runDetectors`. | | [`@mosadd/threat-engine`](./packages/threat-engine) | Shared severity/scoring primitives (transitive dependency). | | [`@mosadd/voice-truthgate-mcp`](./mcp) | **On npm** — the MCP server (enrol/verify tools for AI agents). | ## Honesty — the caveats, stated plainly - **Standalone detection is a losing game.** Our own single-clip detector measured **AUC ≈ 0.61** on modern premium TTS. The product's value is **fusion + honesty**, not a magic detector. - **Voiceprint is foolable by a targeted clone** (~63% accepted in our test) → it's a signal to *fuse*, never a standalone verdict. Great at rejecting a *different* human; weak against a clone *of you*. - **Codec compression is the #1 accuracy killer** (Opus / MP3 / telephony, −10–40%). Prefer uploaded, less-compressed clips. - **L3 live-rhythm is un-calibrated today** — it measures but does not accuse until fit on real labelled turn logs (weight-zero-until-calibrated). - **Short, noisy, or distressed real speech** raises false positives; accuracy varies by language and accent. - **npm:** the MCP server is published; the SDK packages are publish-*ready* but not yet on npm. - **Not for accusations, forensics, or legal decisions.** See each package's `MODEL_CARD.md`. ## Privacy — on-device by design The public checker has nowhere to send your audio: Stage 1 and the opt-in Stage 2 run locally. The SDK ships **no** transport and **no** endpoint. A server model (or the market API) is something you *opt into*; the SDK sends nothing on its own. The market API holds enrolled voiceprints server-side under strict access control and returns only a **signal**, never the raw biometric. ## Part of the mosADD ecosystem Voice Truthgate is the **authenticity / trust layer** of [mosADD](https://mosadd.com) — the open comms stack for AI agents and the humans who direct them. It composes with: - **[mosADD-OS](https://github.com/Hei33enberg/mosADD-OS)** — the **comms layer**: E2EE DMs, channels, web rooms, and email, all exposed as MCP tools (`npx -y @mosadd/mcp`). Your agents talk and coordinate there; Voice Truthgate answers *"is this contact really who they claim, live?"* on the same channel. - **[mosadd.com](https://mosadd.com)** — the product + the live checker + the in-app add-on. Both are open, both publish under the `@mosadd/*` npm scope. (mosADD-OS is Apache-2.0; this repo is MIT — the public authenticity SDK stays maximally permissive.) ## Roadmap - [x] Publish the MCP server to npm (`@mosadd/voice-truthgate-mcp`) - [ ] Publish the SDK packages to npm (`@mosadd/*`) - [ ] Calibrate L3 live-rhythm on real labelled turn logs (the moat — turn it from measure to trigger) - [ ] Threat-informed, always-fresh accuracy benchmark (per-condition numbers, no headline claim) - [ ] Quantize the opt-in Stage-2 model (~379 MB → ~95 MB) ## Contributing Issues and PRs welcome — see [CONTRIBUTING.md](./CONTRIBUTING.md) and the [Code of Conduct](./CODE_OF_CONDUCT.md). **Keep the honesty rails intact** (no bare verdicts, keep the disclaimer, no accuracy claims). Security: [SECURITY.md](./SECURITY.md). ## License [MIT](./LICENSE) © mosADD. Third-party attributions (transformers.js, the referenced Hugging Face model) are in [NOTICE](./NOTICE). ## Source & license This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [Hei33enberg](https://github.com/Hei33enberg) - **Source:** [Hei33enberg/Voice-Truthgate-by-mosADD](https://github.com/Hei33enberg/Voice-Truthgate-by-mosADD) - **License:** MIT - **Homepage:** https://mosadd.com/voicecheck Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** yes - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/mcp-hei33enberg-voice-truthgate - Seller: https://agentstack.voostack.com/s/hei33enberg - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.