ArcKit: The Enterprise Architecture Governance Harness

Build better enterprise architecture through structured strategy, design, delivery, and assurance workflows.

ArcKit is a toolkit for enterprise architects that transforms architecture governance from scattered documents into a systematic, AI-assisted workflow for:

• 🏛️ Establishing and enforcing architecture principles
• 👥 Analyzing stakeholder drivers, goals, and outcomes
• 🛡️ Risk management (HM Treasury Orange Book)
• 💼 Business case justification (HM Treasury Green Book SOBC)
• 📋 Creating comprehensive requirements documents
• 🗄️ Data modeling with ERD, GDPR compliance, and data governance
• 🔬 Technology research with build vs buy analysis (web search powered)
• ☁️ Azure-specific research using Microsoft Learn MCP for authoritative documentation
• 🗺️ Strategic planning with Wardley Mapping
• 📊 Generating visual architecture diagrams (Mermaid)
• 🤝 Managing vendor RFP and selection processes
• ✅ Conducting formal design reviews (HLD/DLD)
• 🔧 ServiceNow service management design
• 🔗 Maintaining requirements traceability
• 📎 Citation traceability for external documents (inline [DOC-CN] markers with source quotes)

ArcKit produces DRAFT artefacts for qualified people to review, not legal, regulatory, clinical, or security advice. See What ArcKit does not do.

Watch first

New to ArcKit, or explaining it to someone who doesn't use a coding assistant? Start with a film:

• ArcKit explained: what ArcKit is and how it keeps AI-drafted architecture documents reviewable, in under eight minutes.
• ArcKit for Beginners: one fictional council project, followed from its architecture principles to the release decision. One hour, or four shorter parts.
• ArcKit commands: a film of about a minute and a half for each command: what it is for, when to run it and what it produces.

The ArcKit YouTube channel also has a playlist for each overlay. The narration is AI-generated and the films are experimental; tell us on Discord what to cover next.

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Quick Start

Installation

Claude Code (premier experience) — install the ArcKit plugin (requires v2.1.287+):

First, make sure Claude Code is on the latest version:

claude install latest

Then in Claude Code:

/plugin marketplace add tractorjuice/arckit-claude

Then install from the Discover tab, or via CLI. The marketplace ships 17 plugins — install only the overlays you need:

# Core (76 commands — UK Government civilian + generic enterprise)
claude plugin install arckit@arckit-claude

# Core + UAE federal
claude plugin install arckit arckit-uae

# Broad overlay set (UK + UAE + FR + CA + EU + AT + AU + US + UK-NHS + UK-GCloud)
claude plugin install arckit arckit-{uae,fr,ca,eu,at,au,us,uk-nhs,uk-gcloud}

# Enterprise architecture and AI agent governance overlays
claude plugin install arckit arckit-togaf-adm arckit-agent-architecture

The standalone tractorjuice/arckit-claude marketplace hosts all Claude Code plugins: the arckit core plugin, regional overlays, sector overlays, the TOGAF ADM and AI agent architecture overlays, the arckit-fde tooling plugin, and the public-but-proprietary arckit-uk-gcloud supplier overlay. The 14 community plugins (arckit-uae, arckit-fr, arckit-ca, arckit-eu, arckit-at, arckit-au, arckit-au-energy, arckit-us, arckit-uk-finance, arckit-uk-nhs, arckit-uk-gcloud, arckit-togaf-adm, arckit-agent-architecture, arckit-oaa) require the arckit core plugin. arckit-au-energy (sector) additionally requires arckit-au (jurisdiction), which it composes — install with claude plugin install arckit arckit-au arckit-au-energy. arckit-uk-gcloud is a proprietary, Claude Code only supplier-side G-Cloud bid-authoring overlay — it is public for installation and inspection, but not MIT licensed and not distributed to the non-Claude extension formats. One tooling plugin — arckit-fde — is a lean, Claude Code only plugin with one command, /arckit-fde:create, that generates a brandable (white-label) Forward Deploy Engineering consulting website into docs/ (GitHub Pages ready), with UK Public Sector and Generic market presets; no dependencies, not converted to non-Claude formats, no governance doc-types.

The older tractorjuice/arc-kit marketplace remains available for compatibility, but new Claude Code installs should use tractorjuice/arckit-claude. Claude Code is the primary development platform for ArcKit and provides the most complete experience: all official commands, autonomous research agents, automation hooks, bundled MCP servers (AWS Knowledge, Microsoft Learn, Google Developer Knowledge, govreposcrape, uk-tenders), and automatic updates via the marketplace. See Why Claude Code? below.

Why v2.1.287? It adds Claude mods, which ArcKit uses to draw a status line above the prompt: how many projects and artefacts you have, how many are DRAFT, and how many reviews are overdue. It also fixes plugin SessionStart hooks not running in new cloud sessions, which skipped ArcKit's session set-up and version check there.

The floor also carries earlier releases ArcKit depends on:

Models

• v2.1.284 adds Claude Sonnet 5.5 (claude-sonnet-5-5), the default Sonnet model on the Anthropic API, with 1M context; earlier clients cannot select it. Like Opus 5.5 it always thinks and defaults to effort: medium, so ArcKit's effort: max commands run at max on it.
• v2.1.280 adds Claude Opus 5.5 (claude-opus-5-5), the default Opus model. It always thinks, so ArcKit's effort: max commands can no longer be quietly sent as high by a session with think