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Guide Origin: Official | ArcKit Version: 4.4.0

/arckit:gov-reuse searches 24,500+ UK government open-source repositories to discover existing implementations that can be reused, forked, or referenced before building from scratch.

Agent Architecture: This command runs as an autonomous agent via the Task tool. The agent performs multiple govreposcrape searches per capability and uses WebFetch to assess each candidate's GitHub repository, keeping the main conversation clean. The slash command is a thin wrapper that delegates to the agent.

Prerequisites

govreposcrape MCP Server (AUTO-INSTALLED)

This command uses the govreposcrape MCP server which is automatically included with the ArcKit plugin. No manual setup required.

Endpoint: https://govreposcrape-api-1060386346356.us-central1.run.app/mcp

Project Prerequisites

  • Requirements document (ARC-*-REQ-*.md) - MANDATORY
  • Architecture principles (ARC-000-PRIN-*.md) - Recommended
  • Stakeholder analysis (ARC-*-STKE-*.md) - Optional

Scenario Matrix

Scenario Prompt seed Focus
Pre-build check "Check for existing government code for <capability>" Capability-by-capability reuse search
Open source evaluation "Find government open source for <domain>" License and code quality assessment
UK Government project "Assess government reuse for UK Government <project>" OGL-licensed, GDS-standard code
Specific tech stack "Find government <language/framework> implementations for <use case>" Tech stack alignment
Cost reduction "What can we reuse to reduce build effort for <project>?" Effort savings estimation

Add constraints (language, framework, license) in the prompt for tailored results.

Command

/arckit:gov-reuse <capability or domain>

Outputs: projects/<id>/research/ARC-<id>-GOVR-v1.0.md

Auto-versioning: Re-running this command when a document already exists automatically increments the version.

How It Works

The agent uses the govreposcrape semantic search API to query 24,500+ UK government repositories:

Step Action
1 Extract capabilities from project requirements
2 Search govreposcrape with 3-5 query variations per capability
3 Fetch GitHub repo details via WebFetch for each candidate
4 Score candidates on 5 criteria (1-5 scale)
5 Recommend strategy: Fork, Library, Reference, or None

Scoring Criteria

Criterion Weight 5 (Best) 1 (Worst)
License compatibility Equal OGL / MIT Proprietary
Code quality Equal Tests, CI, clean No tests, unmaintained
Documentation Equal Comprehensive README, guides No documentation
Tech stack alignment Equal Same stack Incompatible
Activity / maintenance Equal Active (recent commits) Abandoned (>2 years)

Output Highlights

  • Reuse candidates per capability with scores and strategies
  • License compatibility matrix across all candidates
  • Tech stack alignment comparison with your project
  • Gap analysis for capabilities with no reusable code
  • Effort savings estimates vs building from scratch

Follow-on Actions

  • Run /arckit:research to feed reuse findings into build vs buy analysis
  • Run /arckit:adr to document reuse decisions
  • Run /arckit:requirements to refine requirements based on discovered capabilities

Comparison with /arckit:research

Feature /arckit:gov-reuse /arckit:research
Scope UK government repos only Multi-cloud, SaaS, open-source
Focus Code reuse and adaptation Build vs buy, vendor comparison
Source govreposcrape + GitHub Web search, vendor sites
Output Reuse assessment with scoring Market research with TCO
When to use Before building, to find existing code To evaluate commercial options

Workflow: Run /arckit:gov-reuse first, then /arckit:research to compare reuse candidates against commercial alternatives.

Resources