name	plugin-improve
description	Fix bugs, add features to completed plugins. Includes versioning, backups, regression testing, changelog automation. Auto-detects deep-research handoffs to preserve investigation context. Trigger terms - improve, fix, add feature, modify plugin, version bump, rollback
allowed-tools	Read, Write, Edit, Bash, Task
preconditions	Plugin status must be ✅ Working OR 📦 Installed, Plugin must NOT be 🚧 In Development

plugin-improve Skill

Purpose: Make changes to completed plugins with versioning, backups, changelog automation, and root cause investigation.

Integration with deep-research:

**Trigger:** deep-research invokes plugin-improve via Skill tool **Detection:** Phase 0.45 scans conversation history for research findings (MANDATORY) **Action:** Extract research findings, skip investigation (Phase 0.5) **Benefits:** Preserve expensive research context (Opus + extended thinking)

Detection mechanism is implemented in Phase 0.45 below. See references/handoff-protocols.md for additional workflow documentation.

Workflow Overview

Phase 0: Specificity Detection (assess request clarity)
  ↓
[Specific?] ─NO→ Present menu (brainstorm OR investigate)
  ↓ YES
Phase 0.3: Clarification Questions (4 targeted questions)
  ↓
Phase 0.4: Decision Gate (confirm understanding)
  ↓
Phase 0.45: Research Detection (MANDATORY - scan conversation history)
  ↓
[Research found?] ─YES→ Skip to Phase 0.9
  ↓ NO
Phase 0.5: Investigation (Tier 1/2/3 auto-detected)
  ↓
Phase 0.9: Backup Verification (CRITICAL GATE - must pass to proceed)
  ↓
Phase 1: Pre-Implementation Checks (version, state, commits)
  ↓
Phase 2: Verify Rollback Path (confirm backup ready)
  ↓
Phase 3: Implementation (make changes)
  ↓
Phase 4: CHANGELOG Update (document changes)
  ↓
Phase 5: Build and Test (delegate to build-automation)
  ↓
Phase 5.5: Regression Testing (conditional: if plugin-testing + baseline exist)
  ↓
Phase 6: Git Workflow (stage changes, prepare commit)
  ↓
Phase 7: Installation (optional, delegate to plugin-lifecycle)
  ↓
Phase 8: Completion (decision menu)

Key:

MANDATORY: Always executes (Phase 0.45)
CRITICAL GATE: Blocks workflow if fails (Phase 0.9)
CONDITIONAL: Only if conditions met (Phase 5.5, Phase 7)

Progress Checklist

Copy this checklist and check off phases as you complete them:

Improvement Progress:
- [ ] Phase 0: Assessed request specificity
- [ ] Phase 0.3: Asked clarification questions (if needed)
- [ ] Phase 0.4: Confirmed understanding with user
- [ ] Phase 0.45: ✓ MANDATORY - Scanned conversation history for research
- [ ] Phase 0.5: Investigated root cause (if no handoff)
- [ ] Phase 0.9: ✓ CRITICAL - Backup verified (blocks if fails)
- [ ] Phase 1: Loaded current state, determined version bump
- [ ] Phase 2: Confirmed rollback path ready
- [ ] Phase 3: Implemented changes
- [ ] Phase 4: Updated CHANGELOG
- [ ] Phase 5: Built and tested (delegated to build-automation)
- [ ] Phase 5.5: Ran regression tests (if available)
- [ ] Phase 6: Staged git changes
- [ ] Phase 7: Installed plugin (if requested)
- [ ] Phase 8: Presented completion menu

## Precondition Checking

MUST execute before any other phase. BLOCK if conditions not met.

Before starting, verify:

Read PLUGINS.md:

grep "^### $PLUGIN_NAME$" PLUGINS.md

Check status:

If status = ✅ Working or 📦 Installed → OK to proceed

If status = 🚧 In Development → BLOCK with message:

[PluginName] is still in development (Stage [N]).
Complete the workflow first with /continue [PluginName].
Cannot use /improve on in-progress plugins.

Note: The workflow now has 3 stages with automatic validation.
Stage 1-3 complete = plugin ready for improvement.

If status = 💡 Ideated → BLOCK with message:

[PluginName] is not implemented yet (Status: 💡 Ideated).
Use /implement [PluginName] to build it first.

If not found → BLOCK with message:

Plugin [PluginName] not found in PLUGINS.md.

Phase 0: Specificity Detection

Check if request is specific:

Request IS specific if it has:

Feature name (e.g., "resonance parameter", "bypass switch")
Action (e.g., "add", "remove", "fix", "change from X to Y")
Acceptance criteria (e.g., "range 0-1", "increase to 500px", "reduce by 3dB")

Request IS vague if lacking above:

"improve the filters"
"better presets"
"UI feels cramped"
"make it sound warmer"

Assess specificity:

Specific enough (1-2 clarification questions max): Proceed to Phase 0.3 (4-question clarification batch)
Vague: Present inline decision menu:

Your request needs more detail. How should I proceed?

1. Brainstorm approaches together - I'll ask questions to explore options
2. Implement something reasonable - I'll investigate and propose a solution
3. Other

Choose (1-3): _

Handle responses:

Option 1 → Invoke plugin-ideation skill in improvement mode
Option 2 → Proceed to Phase 0.45 (Research Detection)
Option 3 → Collect free-form text, reassess

Phase 0.2: Headless Plugin Detection (GUI-Optional Flow)

Purpose: Detect headless plugins and offer "Create custom UI" option before proceeding to normal improvement flow.

Workflow:

Read .continue-here.md and check gui_type field
If gui_type: headless OR WebView UI files don't exist → Plugin is headless
If headless, present 4-option menu: Create UI, Keep headless, Explain headless, Other
If "Create UI" selected → Invoke ui-mockup skill, then gui-agent subagent
Update version to v1.1.0 (MINOR bump - new feature)
Update state files and commit changes

See: references/headless-ui-workflow.md for complete detection logic, menu flows, gui-agent invocation, state updates, and completion protocol.

If NOT headless: Skip to Phase 0.3 (normal flow)

Phase 0.3: Clarification Questions (If Specific)

See: references/clarification-protocol.md for 4 targeted questions (what to change, scope, version bump, testing approach). Collect all responses before proceeding to Phase 0.4.

Phase 0.4: Decision Gate

Show user what you understand, ask for confirmation:

I understand you want to:
- [Summary of change from Question 1]
- Scope: [Answer from Question 2]
- Version bump: [Answer from Question 3]
- Regression testing: [Answer from Question 4]

Is this correct?

1. Yes, proceed - Continue to Phase 0.45 (Research Detection)
2. No, refine - Ask me follow-up questions
3. No, cancel - Stop the workflow
4. Other

Choose (1-4): _

Handle responses:

Option 1 → Proceed to Phase 0.45
Option 2 → Return to Phase 0.3, ask follow-up questions
Option 3 → Stop workflow, wait for new instruction
Option 4 → Collect free-form text, reassess

Phase 0.45: Research Detection

MANDATORY: Scan conversation history for deep-research findings to avoid duplicate investigation.

See: references/research-detection.md for complete detection algorithm, extraction logic, and decision trees.

Decision: If research detected → Skip to Phase 0.9 | If not detected → Continue to Phase 0.5

Phase 0.5: Investigation (Auto-Tiered)

Purpose: Find root causes, prevent band-aid fixes

Workflow:

Analyze request and auto-detect tier (1/2/3) - never ask user which tier
Execute tier-appropriate investigation protocol
For Tier 3 (complex issues), delegate to deep-research skill
Present findings and wait for approval before implementing

See: references/investigation-tiers.md for complete tier detection algorithm and protocols for each tier (1: Basic Code Inspection, 2: Root Cause Analysis, 3: Deep Research Delegation).

## Phase 0.9: Backup Verification

CRITICAL INVARIANT: Phase 1 MUST NOT execute until backup verified. ENFORCEMENT: Block execution, halt workflow if backup fails. VIOLATION CONSEQUENCE: Data loss, no rollback path.

Goal: Ensure rollback is possible if improvement fails

Process:

Check if backup exists at backups/[PluginName]/v[CurrentVersion]/
If missing, create backup using rsync (exclude build/ and build.log)
Verify backup integrity: ./scripts/verify-backup.sh [PluginName] [CurrentVersion]
If verification fails, HALT workflow with error message
If verification succeeds, present confirmation and proceed

See: assets/backup-template.sh for complete backup creation script.

## Phase 1: Pre-Implementation Checks

DEPENDENCY: MUST NOT execute until Phase 0.9 (Backup Verification) completes.

Load current state (parallelize file reads):

Read these files in parallel using multiple Read tool calls:

CHANGELOG.md - Extract current version (e.g., v1.2.3)
PLUGINS.md - Get plugin entry for additional context
Git log - Check recent commits: git log --oneline plugins/[PluginName]/ -10

Determine version bump:

Present choice:

Current version: v[X.Y.Z]

What type of change is this?
1. PATCH (v[X.Y.Z] → v[X.Y.Z+1]) - Bug fixes, cosmetic changes
2. MINOR (v[X.Y] → v[X.Y+1]) - New features, enhancements
3. MAJOR (v[X] → v[X+1]) - Breaking changes (presets won't load, parameters changed)

Choose (1-3): _

If Major version selected, warn:

⚠️ Major version bump will break compatibility.

Breaking changes include:
- Changed parameter IDs (presets won't load)
- Removed parameters (sessions will have missing automation)
- Changed state format (existing sessions corrupted)

Are you sure? This should be rare. (y/n): _

Calculate new version based on selection.

Breaking Change Detection

Check for breaking changes BEFORE confirming version bump:

Breaking if:

❌ Parameter ID renamed (automation breaks)
❌ Parameter range changed (saved values invalid)
❌ Parameter removed (automation breaks)
❌ Parameter type changed (e.g., float → choice)
❌ State format changed (old presets won't load)
❌ Feature removed (users lose functionality)
❌ Public API signature changed

If breaking changes detected: Force MAJOR version bump, warn user, require confirmation.

See: references/breaking-changes.md for detailed detection criteria and edge cases.

## Phase 2: Verify Rollback Path

Baseline backup verified in Phase 0.9. Confirm ready to proceed:

✓ Backup verified: backups/[PluginName]/v[CurrentVersion]/
Ready to implement changes for v[NewVersion]

## Phase 3: Implementation

DEPENDENCY: MUST NOT execute until Phase 2 (Backup Creation) completes. SAFETY: If implementation fails, rollback path guaranteed by Phase 2 backup.

Execute the change:

Modify source files according to investigation findings
Update build configuration if needed (CMakeLists.txt)
Adjust UI if required (PluginEditor.cpp)
Update parameter definitions if needed (PluginProcessor.cpp)

Follow best practices:

Real-time safety in processBlock
No allocations in audio thread
Thread-safe parameter access
JUCE API correctness

Log changes as you go for CHANGELOG.

Phase 4: CHANGELOG Update

Add version entry at top of CHANGELOG.md with technical details:

Required fields:

Date in ISO format (YYYY-MM-DD)
Root cause for fixes (from Phase 0.5 investigation)
Testing notes (regression test results if Phase 5.5 ran)

Sections by version type:

PATCH (0.0.X): Use "Fixed" section primarily
MINOR (0.X.0): Use "Added" and/or "Changed" sections
MAJOR (X.0.0): Include "Breaking Changes" and "Migration Notes"

See: references/changelog-format.md for complete template structure, section usage guide, and examples by version type (PATCH/MINOR/MAJOR).

## Phase 5: Build and Test

DELEGATION: MUST invoke build-automation skill for all build operations. REASON: Centralized build logic, 7-phase pipeline with verification.

1. Build: Invoke build-automation skill - handles full build pipeline, installation, cache clearing, and failure protocol.

2. Test: After build succeeds, invoke plugin-testing skill - present 4-option menu (automated tests, pluginval, manual DAW testing, skip).

## Phase 5.5: Regression Testing

GATE CONDITION: Conditional - only runs if both conditions met GATE FAILURE: Present rollback options, require user decision

Conditions required:

plugin-testing skill exists
Baseline backup exists at backups/[Plugin]/v[baseline]/

If conditions not met: Skip regression tests, warn user, add note to CHANGELOG, continue to Phase 6.

If conditions met:

Build baseline version from backup
Run plugin-testing on baseline (capture results)
Run plugin-testing on current version (capture results)
Compare results and present findings with decision menu

See: references/regression-testing.md for complete RegressionReport interface, comparison logic, and rollback decision trees.

Phase 6: Git Workflow

Stage changes: git add plugins/[PluginName]/ backups/[PluginName]-v[X.Y.Z]-[timestamp]/

Commit format: improve: [PluginName] v[X.Y.Z] - [description]

Tag release: git tag -a "v[X.Y.Z]" -m "[PluginName] v[X.Y.Z]"

Note: Display git commands for user to run manually. Do not execute git commit or git push.

## Phase 7: Installation (Optional)

If user requested installation: Invoke plugin-lifecycle skill, then update PLUGINS.md and NOTES.md (version, status, timeline entry).

## Phase 8: Completion

Present numbered decision menu (inline format, NOT AskUserQuestion tool):

Options: Test in DAW, Make another improvement, Create new plugin, Document this change, Other

Version History

Phase 7 enhancements (2025-11):

Regression testing integration (Phase 5.5)
Enhanced changelog format (Phase 4)
Backup verification protocol (Phase 0.9)
One-command rollback mechanism
Breaking change detection

See: architecture/17-testing-strategy.md, scripts/verify-backup.sh, references/regression-testing.md

Integration Points

Invoked by:

/improve command
Natural language: "Fix [plugin]", "Add [feature] to [plugin]"
plugin-ideation skill (after improvement brief)

Invokes:

plugin-ideation skill (if vague request, user chooses brainstorm)
deep-research skill (Tier 3 investigation) - Phase 7
build-automation skill (building) - Phase 4
plugin-testing skill (validation)
plugin-lifecycle skill (installation)

Updates:

CHANGELOG.md (adds version entry)
PLUGINS.md (table row: version, last updated, status)
plugins/[Name]/NOTES.md (status, version, timeline entries, known issues)
Source files (implementation changes)

Creates:

Backup in backups/[PluginName]-v[X.Y.Z]-[timestamp]/
Git tag v[X.Y.Z]

Error Handling

Build failure: Present investigation menu, wait for user decision.

Test failure: Present investigation menu, don't proceed to installation.

Breaking change detected: Warn user, require confirmation, force MAJOR version.

Backup creation fails: STOP immediately, don't proceed with changes.

Git operations fail: Log warning, continue (non-critical).

Success Criteria

Improvement is successful when:

Root cause investigated (not band-aid fix)
Backup created before changes
Changes implemented correctly
CHANGELOG updated with version entry
Build succeeds without errors
Tests pass
Git staged with conventional commit message
PLUGINS.md table row updated (version, status, last updated)
NOTES.md updated (status, version, timeline entry)
User knows how to rollback if needed

plugin-improve

Install Skill

SKILL.md