# Digital Twin

Design and operate trustworthy digital twins for software systems, engineering processes, infrastructure, agentic software factories, and cyber-physical operations.

## Why Install This Skill

A digital twin is easy to misuse as a label for a dashboard, dependency graph, emulator, or “AI-powered” model. This skill helps your agent decide what kind of representation you actually have, define its synchronization and fidelity contract, and build the evidence needed before it informs or changes a real system.

After installation, your agent can design federated twin architectures, establish identity/event/provenance contracts, choose appropriate modeling and simulation boundaries, evaluate twin and agent health, govern authority and privacy, and manage the twin through growth, incident response, and retirement. It treats a dark factory as an authority state that must be earned, not as an excuse to remove accountability.

## What You Get

| Directory | What it provides |
|---|---|
| `SKILL.md` | Core workflow, routing, boundaries, release packet, and exit criteria |
| `references/architecture.md` | Layered architecture, component-twin manifest, federation, tradeoffs, failure modes |
| `references/implementation.md` | Event/state/provenance, semantic contracts, standards, simulation, versioning, deployment |
| `references/evaluation.md` | VVUQ, five health planes, metrics, SLOs, drift, agent evaluation, chaos, stop gates |
| `references/governance.md` | Security, privacy, decision rights, earned autonomy, and authority boundaries |
| `references/lifecycle.md` | Lifecycle gates, maintenance, incident response, and decommissioning |
| `references/source-index.md` | Source map, evidence boundaries, and further reading |
| `templates/twin-manifest.yaml` | Fillable twin identity, source, synchronization, validity, and authority contract |
| `templates/evaluation-plan.md` | Fillable evaluation and release-gate plan |
| `templates/release-evidence.md` | Fillable release evidence and authority decision packet |
| `evals/evals.json` | Six output-quality cases covering architecture, implementation, evaluation, governance, lifecycle, and boundary handling |

## Quick Start

No runtime dependencies, API keys, or scripts are required. Ask your agent to design a twin, review a proposed twin architecture, create an evaluation plan, or define safe authority and retirement gates. The templates can be copied and filled by any agent or human.

## Triggers

Load this skill when the task involves:

- Digital-twin architecture, implementation, or maturity
- Digital thread, twin composition, or a “digital twin universe”
- Software-process, DevOps, infrastructure, or cyber-cyber twins
- Simulation, virtual commissioning, predictive maintenance, or counterfactual testing
- Twin synchronization, fidelity, VVUQ, calibration, drift, or health monitoring
- Agent authority, shadow operation, dark factories, or human override
- Twin governance, privacy, security, lifecycle, or decommissioning

## Requirements

- No runtime dependencies or credentials.
- External standards and source URLs are listed in `references/source-index.md`.
- The skill is methodology and contract guidance; adopting systems must implement and test their own connectors, stores, policy enforcement, and action adapters.