Architecture

FusionLayer Engine Architecture

FusionLayer is a context engine: it captures user and app signals, stores them as structured artifacts, and delivers the right context to downstream models and tools. The system is designed around privacy modes, a portable artifact model, and a clean boundary between engine internals and cross-vendor protocols.

Overview

The engine is organized into three high-level layers that map cleanly to what an application needs when it wants “memory” without giving up control over privacy, portability, or vendor choice.

Three Layers

Capture: ingest signals (user edits, explicit saves, connector events) and normalize them into artifacts.

Storage: persist artifacts with privacy-aware retention and retrieval semantics.

Delivery: assemble context bundles for a request and deliver them to the model/tool layer.

Artifact Model

An artifact is a typed, portable unit of context. Artifacts are the only thing that crosses boundaries between apps, vendors, and protocols.

FusionLayer uses eight canonical artifact kinds:

Memory Facts about the user or project that should persist (when allowed by privacy mode).
Persona A reusable tone/style/role profile that shapes responses.
Rule Hard constraints that must always be followed.
Redaction Pattern Patterns used to detect and remove sensitive data from stored or exported artifacts.
Source A trusted reference channel or feed used during research and synthesis.
Theme A reusable aesthetic or framing preset used for presentation and writing.
Pack A curated bundle of multiple artifacts meant to be applied together.
Playbook A multi-step workflow artifact that the system can follow (review, research, support, etc.).

Privacy Architecture

Privacy modes are a first-class part of the system. The same capture and delivery workflows can run under different storage rules, allowing applications to choose a stronger privacy floor without rewriting logic.

Mode What It Stores What It Avoids
Smart Stores artifacts by default, with redaction and sensible retention. Avoids persisting known sensitive patterns when configured.
Private Stores only artifacts that are explicitly marked as safe to persist. Avoids “ambient” capture becoming long-term memory.
Incognito Stores nothing long-term; artifacts are ephemeral to the session/request. Avoids any durable storage of user context.

ADR Decisions

FusionLayer documents major technical decisions as Architecture Decision Records (ADRs). Each ADR captures a decision, the context that led to it, and the tradeoffs that were accepted.

ADR Topic
ADR 0014 Privacy modes (Smart / Private / Incognito) as an engine-level contract.
ADR 0033 UACP scope boundary: cross-vendor artifact formats only; engine internals stay out of protocol.
ADR 0034 Terminology rename: the legacy "primitive" concept is now "artifact" across all code and documentation (clean break, no backward-compatibility shims).
ADR 0036 Admin split: separating privileged administration workflows from normal app traffic.
ADR 0017 ArangoDB as a graph store for artifact relationships and retrieval.

Engine ≠ Inkfold

FusionLayer Engine is infrastructure for developers. Inkfold is one consumer application that uses the engine. Keeping this separation clear prevents protocol drift and ensures the engine remains broadly useful. 

App (Inkfold or any other app)
  |
  |  API calls (capture / query / delivery)
  v
FusionLayer Engine
  |
  |  Artifact storage + retrieval + privacy enforcement
  v
Artifact model (portable artifacts)
  |
  |  Export/import via open protocols
  v
UACP (Unified AI Context Protocol)