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.

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Quick Start

Installation

Claude Code (premier experience) — install the ArcKit plugin (requires v2.1.280+):

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 (75 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 v2.1.280? v2.1.280 adds Claude Opus 5.5 (claude-opus-5-5), the default Opus model. Opus 5.5 always thinks, so ArcKit's effort: max commands can no longer be quietly sent as high by a session with thinking off, and the Effective Effort row in each artefact's Build Provenance is accurate. The floor carries v2.1.251, which stops the file tools (Read, Write, Edit) following a symlink swapped inside the working directory after the permission check, and makes Grep and Glob honour Read() deny rules through a symlinked search path — the same class of bypass the v2.1.222–v2.1.224 fixes closed for Bash, and the class ArcKit's file-protection and secret-file-scanner gates sit in front of. The same release sends Opus 5 effort: xhigh/max as high when thinking is off instead of failing, so ArcKit's 18 effort: max commands complete on thinking-off sessions. v2.1.246 fixed four plugin-loading bugs that hit ArcKit's exact layout: /reload-plugins counted 0 skills for plugins that define skills under skills/*/SKILL.md, hook error messages showed a literal ${CLAUDE_PLUGIN_ROOT} instead of the resolved path, the plugin cache created duplicate SHA-named directories, and claude plugin update <bare-name> failed. The floor carries forward v2.1.234, which stops Claude Code's MCP diagnostics printing resolved secrets — ArcKit bundles two keyed MCP servers whose ${user_config.*} API keys sit in request headers, and on a session with no keys configured those connections fail by design, so ArcKit routinely produces exactly the diagnostics this fixed. v2.1.221 fixed WebSearch returning a 400 at effort: xhigh/max when thinking is disabled — silently breaking ArcKit's 18 effort: max commands and its three max-effort research agents for anyone running with thinking off. v2.1.222 stopped PreToolUse auto-allow hooks bypassing tool restrictions inside background agent tasks, which became load-bearing when v2.1.232 made subagent spawns background by default. v2.1.223 and v2.1.224 close Bash permission-check bypasses, a sandbox denyRead/denyWrite trailing-slash bypass, and a bug where project paths over 200 characters resolved into another project's session directory; v2.1.224 also surfaces sandbox violation details in Bash results. It also carries v2.1.219's Claude Opus 5 (claude-opus-5), the current default Opus model with 1M context and fast mode, which earlier clients cannot select; v2.1.200's fix for project-scoped plugin loading from git worktrees and claude agents --plugin-dir <dir> visibility, which makes ArcKit's branch and test-repo workflows reliable; the v2.1.198-v2.1.199 background-subagent reliability, parent error-propagation, and hook stderr-visibility fixes that matter to /arckit:build, reader/writer handoffs, and hook diagnosis; v2.1.197's Claude Sonnet 5 default with native 1M context; and v2.1.172's fix for wildcard-domain WebFetch rules (WebFetch(domain:*.gov.uk)) that never matched subdomains on earlier clients — the exact shape ArcKit recommends for confining research-agent traffic in OFFICIAL-SENSITIVE deployments. It also carries the v2.1.156 Opus 4.8 thinking-block fix, v2.1.154 plugin defaultEnabled: false, v2.1.144 session-title and headless Skill tool fixes, v2.1.143 plugin dependency enforcement, v2.1.139 hook args: string[], v2.1.129 monitor layout and prompt-cache fixes, v2.1.121 MCP/provenance hook unlocks, v2.1.118-v2.1.119 release/telemetry unlocks, and the earlier /context, Auto mode, plugin update, MCP leak, retry, and subagent working-directory fixes.

Gemini CLI — install the ArcKit extension:

gemini extensions install https://github.com/tractorjuice/arckit-gemini

Zero-config: all 75 official commands, templates, scripts, and bundled MCP servers (AWS Knowledge, Microsoft Learn). Updates via gemini extensions update arckit.

GitHub Copilot (VS Code) — install the ArcKit CLI and scaffold prompt files:

# Install with pip
pip install git+https://github.com/tractorjuice/arc-kit.git

# Scaffold a project with Copilot prompt files
arckit init my-project --ai copilot

Creates .github/prompts/arckit-*.prompt.md (165 prompt files — the 75 official commands plus the community overlays), .github/agents/arckit-*.agent.md (10 custom agents), and .github/copilot-instructions.md (repo-wide context). Invoke commands in Copilot Chat as /arckit-requirements, /arckit-stakeholders, etc.

Codex CLI — install the ArcKit CLI:

# Install with pip
pip install git+https://github.com/tractorjuice/arc-kit.git

# Or with uv
uv tool install arckit-cli --from git+https://github.com/tractorjuice/arc-kit.git

# Or run without installing
uvx --from git+https://github.com/tractorjuice/arc-kit.git arckit init my-project

Mistral Vibe CLI — link the ArcKit extension:

# Clone the standalone extension repository
git clone https://github.com/tractorjuice/arckit-vibe.git
cd arckit-vibe

# Create extensions directory and link
mkdir -p ~/.vibe/extensions/
ln -s $(pwd) ~/.vibe/extensions/arckit

Zero-config: 75 official commands as skills, 10 specialized agents, all templates, and bundled MCP servers (AWS Knowledge, Microsoft Learn, Google Developer Knowledge, GovRepoScrape).

Kimi Code CLI — start kimi, then install the ArcKit plugin from the prompt:

/plugins install https://github.com/tractorjuice/arckit-kimi.git

Every ArcKit command ships as an Agent Skill, invoked with /skill:arckit-<command> (for example /skill:arckit-requirements). The kimi.plugin.json manifest carries all six bundled MCP servers and auto-loads the architecture-workflow skill at session start.

Latest Release: v6.15.0

OKF Interoperability

ArcKit can exchange Markdown knowledge bundles using an Open Knowledge Format-shaped frontmatter layer:

• /arckit:export-okf copies ArcKit ARC-*.md artifacts into an OKF bundle with portable type, title, resource, tags, timestamp, and arckit metadata.
• /arckit:import-okf scans an OKF bundle, writes .arckit/tmp/okf-import-report.json, and materializes safe imports as RSCH review notes by default.
• Native ArcKit files remain unchanged unless you explicitly enable source frontmatter stamping with ARCKIT_OKF_FRONTMATTER=1 or .arckit/config.json containing { "okfFrontmatter": true }.

Platform Support

| Platform | Claude Code Plugin | Gemini CLI Extension | GitHub Copilot | Codex / OpenCode CLI | Mistral Vibe | Kimi Code CLI | |----------|-------------------|---------------------|----------------|---------------------|--------------|----------------| | macOS | Full support | Full support | Full support | Full support | Full support | Full support | | Linux | Full support | Full support | Full support | Full support | Full support | Full support | | Windows (WSL2) | Full support | Full support | Full support | Full support | Full support | Full support | | Windows (native) | Fu