> ## Documentation Index
> Fetch the complete documentation index at: https://docs.synheart.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> One-line definitions of every Synheart concept, product, and acronym you'll encounter in these docs.

A quick reference for terms used throughout the docs. Follow the links for full pages.

## Products

* **[Synheart Core](/synheart-core/overview)** — The on-device SDK that fuses biosignals, behavior, and phone context into a single human-state stream. Available in Flutter, Kotlin, and Swift.
* **[Synheart Wear](/synheart-wear/overview)** — Standalone wearable SDK that normalizes data from Apple Watch, WHOOP, Garmin, Fitbit, Health Connect, Oura, and BLE HRMs into a single API.
* **[Synheart Behavior](/synheart-behavior/overview)** — Standalone SDK for behavioral signals (taps, scrolls, typing cadence, app context). Content-free; timing and motion only.
* **[Synheart Session](/synheart-session/overview)** — Standalone SDK for watch-driven session capture with pluggable biosignal and behavior providers.
* **[Synheart Auth](/synheart-auth/overview)** — Hardware-backed device identity and request signing (RFC-AUTH-MOBILE-0001).
* **[Syni](/syni/overview)** — On-device adaptive LLM stack: a native runtime, a versioned persona / safety spec, and language SDKs.
* **[Synheart CLI](/synheart-cli)** — Command-line tool for installing the runtime + spec, running a local platform mock, mocking wearable streams, and CI/CD pinning.

## Concepts

* **[HSI — Human State Interface](/hsi/overview)** — The wire-format JSON contract for exchanging human-state signals. Language-agnostic; versioned (current `1.3`).
* **HSV — Human State Vector** — The typed in-memory representation Synheart Core emits before packing into HSI. See [HSV specification](/synheart-core/hsv-specification).
* **Flux** — The step inside the Synheart Runtime that packs `HSV[]` outputs into an HSI 1.3 envelope.
* **[RAMEN](/ramen/overview)** — Real-time event delivery backplane that pushes vendor webhooks and platform events to connected clients over gRPC.
* **Capability tier** — App-level access scope (`core`, `extended`, `research`). See [Capability system](/synheart-core/capability-system).
* **Consent type** — User-level grant for a specific data class (`biosignals`, `behavior`, `phoneContext`, `cloudUpload`, `vendorSync`, `research`). See [Consent system](/synheart-core/consent-system).
* **Persona** — A versioned behavioral contract Syni resolves at inference time (e.g. `focus.coach.v1`). Pinned via the [Syni Spec](/syni-spec/overview).

## How the pieces relate

* **HSI** is the contract; **HSV** is the typed intermediate; **Flux** is the packing step.
* **Capabilities** define what an app *can* request; **consents** define what the user *allows*. Data access requires **both**.
* **Synheart Core** consumes Wear, Behavior, and Phone module signals and produces HSI. The standalone SDKs (Wear, Behavior, Session) can also be used independently of Core.
* **Syni** consumes HSI as a conditioning input but works without it (any `Map<String, dynamic>` will do).