Architecture

The Engine is split into UI-free Engine.Core, Engine and Engine.Windows projects. Desktop, CLI and tests are separate hosts. Engine.Core supplies primitives and declarative recipes, Engine owns shared workflows and evidence, and Engine.Windows registers the native providers.

Boundary

The Engine owns:

Bounded Windows evidence collection
Deterministic interpretation and correlation
Workflow and recipe catalogs
Repair eligibility and execution coordination
Durable journals and no-repeat reconciliation
Report models and knowledge-pack readers

The host owns:

Navigation, dialogs, controls, and presentation
User choices and consent
UAC relaunch behavior
Progress and cancellation controls
File pickers and report destinations
Product updates and deployment

Project relationships

Desktop / CLI / authorized embedded host
        |  WindowsEngine.Register()
        v
Engine.Windows (Windows providers)
        |
        v
Engine (shared workflows, evidence, coordination)
        |
        v
Engine.Core (primitives, packs and recipes)

Checks substitute providers across these boundaries

The Engine does not reference WPF or desktop controls. Tests can substitute provider and repair hosts so parsers, eligibility, safety gates, interruption behavior, and recovery can be verified without changing the development computer.

Internal layers

Layer	Responsibility
Capability collectors	Read bounded Windows state for one exact scope
Evidence parsers	Validate shape, identity, completeness, and limits
Diagnostic interpretation	Convert evidence into explicit workflow states
Workflow orchestration	Combine checks, progress, recipes, and journals
Repair coordinators	Recheck eligibility, prepare, mutate, verify, and reconcile
Reports	Present problems, actions, results, and limitations
Knowledge packs	Resolve versioned external reference data without changing logic

Windows and shell modes

The current native provider layer targets Windows and uses .NET, Windows APIs, PowerShell, and Windows command-line tools where appropriate. The Engine is not cross-platform today.

A future Bash provider would be a separate host implementation behind explicit interfaces. It would need its own capability catalog, evidence contracts, safety rules, and tests. Translating PowerShell command strings into Bash would not create equivalent diagnostics.

Failure model

Collectors fail closed when identity is ambiguous, output is malformed, a limit is exceeded, or required authority cannot be inspected. Repair coordinators separate preview, preparation, dispatch, verification, and reconciliation so an interrupted process does not automatically repeat a machine change.