Working on Delta Skill

Orchestrates the per-delta workflow from spec through implementation.

When to Load

Load this skill when executing:

• /katachi:spec-delta <ID>
• /katachi:design-delta <ID>
• /katachi:plan-delta <ID>
• /katachi:implement-delta <ID>
• /katachi:review-delta <ID>
• /katachi:retrofit-design <ID> (retrofit mode)

Key References

Guidance documents (how to write each document type):

• references/spec-template.md - How to write delta specifications
• references/design-template.md - How to write design rationale
• references/plan-template.md - How to write implementation plans

Document templates (actual templates to follow):

• references/delta-spec.md - Delta specification template
• references/delta-design.md - Design document template
• references/implementation-plan.md - Implementation plan template

Workflow

1. Pre-Check

Before starting any per-delta command:

# Check delta exists in DELTAS.md
delta = get_delta(FEATURE_ID)
if not delta:
    error("Delta not found in DELTAS.md")

# Check dependencies are complete (for design/plan/implement)
if command in ["design", "plan", "implement"]:
    deps = get_dependencies(FEATURE_ID)
    incomplete = [d for d in deps if not is_complete(d)]
    if incomplete:
        warn(f"Dependencies not complete: {incomplete}")

2. Status Update (Start)

Update status when starting:

# spec-delta
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "⧗ Spec"

# design-delta
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "⧗ Design"

# plan-delta
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "⧗ Plan"

# implement-delta
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "⧗ Implementation"

3. Document Creation Workflow

For spec/design/plan commands:

1. Research Phase (Silent)

- Read relevant context (DELTAS.md) - Read previous documents (spec before design, design before plan) - Read relevant ADRs and DES patterns - Research any libraries/APIs involved

1. Draft Proposal

- Create complete document following template - Note uncertainties and assumptions - Base choices on research

1. Present for Review

- Show complete document to user - Highlight uncertainties - Ask: "What needs adjustment?"

1. Iterate

- Apply user corrections - Repeat until approved

1. Validate

- Dispatch reviewer agent - Review findings with user - Apply accepted recommendations

1. Finalize

- Write document to file - Update status

4. Agent Dispatch

Each command dispatches its reviewer agent:

Dispatch pattern:

Task(
    subagent_type="katachi:spec-reviewer",
    prompt=f"""
Review this delta specification:

## Delta Description (from DELTAS.md)
{delta_description}

## Completed Spec
{spec_content}

Provide structured critique following your review criteria.
"""
)

5. Status Update (Complete)

Update status when completing:

# After successful completion
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "✓ Spec"
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "✓ Design"
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "✓ Plan"
python ${CLAUDE_PLUGIN_ROOT}/scripts/deltas.py status set FEATURE-ID "✓ Implementation"

Command Summary