c3-alter - SKILL.md Agent Skill

name: c3-alter description: | This skill should be used when the user asks to "add a component", "change architecture", "refactor X", "implement feature", "fix bug", "create new service", "update diagram", or "remove component". Requires .c3/ to exist. All changes flow through ADR process. For questions, route to c3-query instead.

C3 Alter - Change Through ADR

Every change flows through an ADR. No exceptions.

REQUIRED: Load References First

../../references/skill-harness.md - Routing and red flags
../../references/layer-navigation.md - How to traverse C3 docs

Core Loop (All Stages)

ANALYZE → ASK (until confident) → SYNTHESIZE → REVIEW
              │                        │
              └── until no open ───────┘
                  questions

On conflict: ASCEND → fix earlier stage → re-descend

Confident = No open questions. Don't proceed with "TODO" or unclear fields.

Stage 1: Intent

Step	Action
Analyze	Add/modify/remove/fix? What problem? Scope hint?
Ask	Use AskUserQuestion: feature vs fix? problem? urgency?
Synthesize	`Intent: [action] Goal: [outcome] Type: [feature/fix/refactor]`
Review	User confirms or corrects

Stage 2: Current State

Step	Action
Analyze	Read affected C3 docs via layer navigation
Ask	Are docs accurate? Recent code changes not documented?
Synthesize	List affected components, their current behavior, dependencies
Review	User confirms or corrects

Stage 3: Scope Impact

Step	Action
Analyze	Which layers change? Dependencies? Linkages? Diagrams?
Ask	External systems involved? Breaking changes? Keep or replace?
Synthesize	List all affected c3 IDs, note breaking changes
Review	User confirms or expands

Stage 4: Create ADR

Generate at .c3/adr/adr-YYYYMMDD-{slug}.md. Use ../../references/adr-template.md.

Key sections: Problem, Decision, Rationale, Affected Layers, References Affected, Verification

On Accept	Update status to `accepted`, proceed to Plan
On Reject	Return to Stage 1/3 based on what changed

Stage 5: Create Plan

Generate at .c3/adr/adr-YYYYMMDD-{slug}.plan.md.

Include:

Pre-execution checklist (update ## References in affected components)
Ordered steps: docs first, then code, then diagrams
Verification commands

Stage 6: Execute

Follow plan order:

Make change (doc or code)
Check for conflicts
Update ## References if code moved/added/removed

On conflict - Tiered response:

Impact	Action
High: scope expansion, breaking change, new layer	Ask user, update ADR if needed
Low: wording fix, diagram update, ID fix	Auto-fix, note in log

Ref Maintenance

If change affects a pattern:

Check if ref-* exists for pattern
Update ref if pattern changes
Create new ref if pattern is new and reusable

Stage 7: Verify

Run /c3 audit. Check diagrams, IDs, linkages, code-doc match.

On Pass	Update ADR status to `implemented`
On Fail	Fix issue, re-audit, loop until pass

Response Format

**Stage N: {Name}**
{findings}
**Open Questions:** {list or "None - confident"}
**Next:** {what happens next}