msd-core/gsd-core/workflows/undo.md

Safe git revert workflow. Rolls back GSD phase or plan commits using the phase manifest with dependency checks and a confirmation gate. Uses git revert --no-commit (NEVER git reset) to preserve history.

<required_reading> @/.claude/gsd-core/references/ui-brand.md @/.claude/gsd-core/references/gate-prompts.md </required_reading>

Display the stage banner:

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 GSD ► UNDO
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Parse $ARGUMENTS for the undo mode:

• --last N → MODE=last, COUNT=N (integer, default 10 if N missing)
• --phase NN → MODE=phase, TARGET_PHASE=NN (two-digit phase number)
• --plan NN-MM → MODE=plan, TARGET_PLAN=NN-MM (phase-plan ID)

If no valid argument is provided, display usage and exit:

Usage: /gsd:undo --last N | --phase NN | --plan NN-MM

Modes:
  --last N      Show last N GSD commits for interactive selection
  --phase NN    Revert all commits for phase NN
  --plan NN-MM  Revert all commits for plan NN-MM

Examples:
  /gsd:undo --last 5
  /gsd:undo --phase 03
  /gsd:undo --plan 03-02

Based on MODE, gather candidate commits.

MODE=last:

Run:

git log --oneline --no-merges -${COUNT}

Filter for GSD conventional commits matching type(scope): message pattern (e.g., feat(04-01):, docs(03):, fix(02-03):).

Display a numbered list of matching commits:

Recent GSD commits:
  1. abc1234 feat(04-01): implement auth endpoint
  2. def5678 docs(03-02): complete plan summary
  3. ghi9012 fix(02-03): correct validation logic

Text mode (workflow.text_mode: true in config or --text flag): Set TEXT_MODE=true if --text is present in $ARGUMENTS OR text_mode from init JSON is true. When TEXT_MODE is active, replace every AskUserQuestion call with a plain-text numbered list and ask the user to type their choice number. This is required for non-Claude runtimes (OpenAI Codex, Gemini CLI, etc.) where AskUserQuestion is not available. Use AskUserQuestion to ask:

• question: "Which commits to revert? Enter numbers (e.g., 1,3) or 'all'"
• header: "Select"

Parse the user's selection into COMMITS list.

---

MODE=phase:

Read .planning/.phase-manifest.json if it exists.

If the file exists and manifest.phases?.[TARGET_PHASE]?.commits is a non-empty array:

• Use manifest.phases[TARGET_PHASE].commits entries as COMMITS (each entry is a commit hash)

If the file does not exist, or manifest.phases?.[TARGET_PHASE] is missing:

• Display: "Manifest has no entry for phase ${TARGET_PHASE} (or file missing), falling back to git log search"
• Fallback: run git log and filter for the target phase scope:

  git log --oneline --no-merges --all | grep -E "\(0*${TARGET_PHASE}(-[0-9]+)?\):" | head -50
  

• Use matching commits as COMMITS

---

MODE=plan:

Run:

git log --oneline --no-merges --all | grep -E "\(${TARGET_PLAN}\)" | head -50

Use matching commits as COMMITS.

---

Empty check:

If COMMITS is empty after gathering:

No commits found for ${MODE} ${TARGET}. Nothing to revert.

Exit cleanly.

**Applies when MODE=phase or MODE=plan.**

Skip this step entirely for MODE=last.

---

MODE=phase:

Read .planning/ROADMAP.md inline.

Search for phases that list a dependency on the target phase. Look for patterns like:

• "Depends on: Phase ${TARGET_PHASE}"
• "Depends on: ${TARGET_PHASE}"
• "depends_on: [${TARGET_PHASE}]"

For each dependent phase N found:

1. Check if .planning/phases/${N}-*/ directory exists
2. If directory exists, check for any PLAN.md or SUMMARY.md files inside it

If any downstream phase has started work, collect warnings:

⚠  Downstream dependency detected:
   Phase ${N} depends on Phase ${TARGET_PHASE} and has started work.

---

MODE=plan:

Extract the phase number from TARGET_PLAN (the NN part of NN-MM). Extract the plan number (the MM part).

Look for later plans in the same phase directory (.planning/phases/${NN}-*/). For each later plan (plans with number > MM):

1. Read the later plan's PLAN.md
2. Check if its <files> sections or consumes fields reference outputs from the target plan

If any later plan references the target plan's outputs, collect warnings:

⚠  Intra-phase dependency detected:
   Plan ${LATER_PLAN} in phase ${NN} references outputs from plan ${TARGET_PLAN}.

---

If any warnings exist (from either mode):

• Display all warnings
• Use AskUserQuestion with approve-revise-abort pattern:
  • question: "Downstream work depends on the target being reverted. Proceed anyway?"
  • header: "Confirm"
  • options: Proceed | Abort

If user selects "Abort": exit with "Revert cancelled. No changes made."

Display the confirmation gate using approve-revise-abort pattern from gate-prompts.md.

Show:

The following commits will be reverted (in reverse chronological order):

  {hash} — {message}
  {hash} — {message}
  ...

Total: {N} commit(s) to revert

Use AskUserQuestion:

• question: "Proceed with revert?"
• header: "Approve?"
• options: Approve | Abort

If "Abort": display "Revert cancelled. No changes made." and exit. If "Approve": ask for a reason:

AskUserQuestion(
  header: "Reason",
  question: "Brief reason for the revert (used in commit message):",
  options: []
)

Store the response as REVERT_REASON. Continue to execute_revert.

**HARD CONSTRAINT: Use git revert --no-commit. NEVER use git reset (except for conflict cleanup as documented below).**

Dirty-tree guard (run first, before any revert):

Run git status --porcelain. If the output is non-empty, display the dirty files and abort:

Working tree has uncommitted changes. Commit or stash them before running /gsd:undo.

Exit immediately — do not proceed to any revert operations.

---

Sort COMMITS in reverse chronological order (newest first). If commits came from git log (already newest-first), they are already in correct order.

For each commit hash in COMMITS:

git revert --no-commit ${HASH}

If any revert fails (merge conflict or error):

1. Display the error message
2. Run cleanup — handle both first-call and mid-sequence cases:

   # Try git revert --abort first (works if this is the first failed revert)
   git revert --abort 2>/dev/null
   # If prior --no-commit reverts already staged cleanly before this failure,
   # revert --abort may be a no-op. Clean up staged and working tree changes:
   git reset HEAD 2>/dev/null
   git restore . 2>/dev/null
   

3. Display:

   ╔══════════════════════════════════════════════════════════════╗
   ║  ERROR                                                       ║
   ╚══════════════════════════════════════════════════════════════╝
   
   Revert failed on commit ${HASH}.
   Likely cause: merge conflict with subsequent changes.
   
   **To fix:** Resolve the conflict manually or revert commits individually.
   All pending reverts have been aborted — working tree is clean.
   

4. Exit with error.

After all reverts are staged successfully, create a single commit:

For MODE=phase:

git commit -m "revert(${TARGET_PHASE}): undo phase ${TARGET_PHASE} — ${REVERT_REASON}"

For MODE=plan:

git commit -m "revert(${TARGET_PLAN}): undo plan ${TARGET_PLAN} — ${REVERT_REASON}"

For MODE=last:

git commit -m "revert: undo ${N} selected commits — ${REVERT_REASON}"

Display the completion banner:

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 GSD ► UNDO COMPLETE ✓
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Show summary:

  ✓ ${N} commit(s) reverted
  ✓ Single revert commit created: ${REVERT_HASH}

Show next steps:

───────────────────────────────────────────────────────────────

## ▶ Next Up — [${PROJECT_CODE}] ${PROJECT_TITLE}

**Review state** — verify project is in expected state after revert

/clear then:

/gsd:progress

───────────────────────────────────────────────────────────────

**Also available:**
- `/gsd:execute-phase ${PHASE}` — re-execute if needed
- `/gsd:undo --last 1` — undo the revert itself if something went wrong

───────────────────────────────────────────────────────────────

<success_criteria>

• Arguments parsed correctly for all three modes
• --phase mode reads .planning/.phase-manifest.json using manifest.phases[TARGET_PHASE].commits
• --phase mode falls back to git log if manifest entry missing
• Dependency check warns when downstream phases have started (MODE=phase)
• Dependency check warns when later plans reference target plan outputs (MODE=plan)
• Dirty-tree guard aborts if working tree has uncommitted changes
• Confirmation gate shown before any revert execution
• Reverts use git revert --no-commit in reverse chronological order
• Single commit created after all reverts staged
• Error handling cleans up both first-call and mid-sequence conflict cases
• git reset --hard is NEVER used anywhere in this workflow </success_criteria>