C3

C3 Architecture Assistant

Skill Routing

REQUIRED: Check Activation

Before proceeding, check if .c3/README.md exists.

• If NO .c3/: This is Mode: Adopt. Suggest /onboard or proceed with adoption.
• If YES .c3/: Route based on intent (Audit stays here, others route to dedicated skills).

ADR Lifecycle

proposed → accepted → implemented

See references/adr-template.md for template.

Mode: Adopt

Template-first approach. Two rounds:

Round 1: Structure (User runs bash)

PROJECT="MyApp" C1="backend" C2="frontend" ./scripts/c3-init.sh

Creates:

.c3/
├── README.md                       (Context)
├── c3-1-backend/README.md          (Container)
├── c3-2-frontend/README.md         (Container)
└── adr/adr-00000000-c3-adoption.md (ADR)

Round 2: Fill (AI subagent)

Dispatch subagent to analyze codebase and fill templates:

Context (c3-0):

1. Analyze codebase for actors (users, schedulers, webhooks)
2. Confirm containers match code structure
3. Identify external systems (databases, APIs, caches)
4. Draw mermaid diagram with IDs (A1, c3-1, E1, etc.)
5. Fill linkages with REASONING (why they connect)

Each Container (c3-N):

1. Analyze container scope for components
2. Categorize by concern:
   • Foundation: entry, identity, integration
   • Auxiliary: library wrappers, framework usage, utilities
   • Business: domain services
   • Presentation: styling, composition, state (or N/A)
3. Draw internal mermaid diagram with component IDs
4. Fill fulfillment section (which components handle Context links)
5. Fill linkages with REASONING

ADR-000:

1. Document why C3 was adopted
2. List all containers created
3. Mark verification checklist

Reference: See references/container-patterns.md for component categorization patterns.

Subagent Prompt Template

You are filling C3 templates for {{PROJECT}}.

Templates are already in place at .c3/. Your job:
1. Analyze codebase
2. Fill inventory tables
3. Create mermaid diagrams with IDs
4. Add linkages with reasoning

Rules:
- Diagram goes FIRST, uses IDs from tables
- Every linkage needs REASONING (why, not just that)
- Foundation/Auxiliary/Business/Presentation categories
- Fulfillment section maps Context links to components
- Keep structure, fill content

Mode: Design

Defer to c3-alter skill for all architecture and code changes.

c3-alter enforces ADR-first workflow with impact discovery.

Mode: Audit

REQUIRED: Load references/audit-checks.md for comprehensive audit procedures.

Quick reference scopes:

• audit C3 - full system
• audit container c3-1 - single container
• audit adr adr-YYYYMMDD-slug - single ADR

The reference contains detailed checks for:

• Diagram-inventory consistency
• ID uniqueness
• Linkage reasoning
• Fulfillment coverage
• Orphan detection

Guidelines

• Diagram first, tables second, linkages third
• Every linkage needs reasoning
• Container fulfills Context links (documents constraints)
• Component documents implementation (technology, conventions, edge cases)
• Inventory ready for growth (empty sections OK)