merge-resolver

name	merge-resolver
version	2.2.0
description	Resolve merge conflicts by analyzing git history and commit intent. Handles PR conflicts, branch conflicts, and session file conflicts with automated resolution for known patterns. Use when you say "resolve merge conflicts", "fix conflicts on this branch", "PR has conflicts with main", "can't merge due to conflicts", or "resolve PR conflicts". Do NOT use for rebasing, cherry-picking, or complex history rewrites (use git-advanced-workflows).
license	MIT
model	claude-opus-4-6
metadata	{"domains":["git","github","merge-conflicts","pr-maintenance"],"type":"workflow","complexity":"advanced"}

Merge Resolver

Resolve merge conflicts by analyzing git history and commit intent.

Quick Start

# Resolve conflicts for a specific PR
python3 .claude/skills/merge-resolver/scripts/resolve_pr_conflicts.py \
    --pr-number 123 --branch-name "fix/my-feature" --target-branch "main"

# Dry-run mode (no side effects)
python3 .claude/skills/merge-resolver/scripts/resolve_pr_conflicts.py \
    --pr-number 123 --branch-name "fix/test" --dry-run

Triggers

Trigger Phrase	Operation
resolve merge conflicts	Auto-detect branch/PR and resolve
fix conflicts on this branch	Context-aware conflict resolution
PR has conflicts with main	Merge-based conflict resolution
can't merge due to conflicts	Analyze and fix blocking conflicts
resolve PR conflicts	Resolve conflicts for a specific PR number

Process

Phase 0: Execution Capability Precondition (BLOCKING)

Run this self-check FIRST, before any context gathering, analysis, or plan. Conflict resolution requires shell execution: worktree creation, git merge, staging, commit, and git push. Without those tools you can only describe steps, never resolve anything.

Step	Action	Verification
0.1	Confirm shell/Bash is available (git, worktree creation, git push)	A tool result in this run shows a shell command executed
0.2	If shell is unavailable: return immediately with status [BLOCKED], one-line reason, route execution back to the orchestrator, and STOP	No resolution plan, phase list, or report is produced

If shell execution is unavailable, do NOT produce a step-by-step resolution plan. A plan reads as completed work and is the exact failure this precondition prevents (issue #2646). Return BLOCKED and route execution back to the orchestrator.

Completion rule (applies to every execution phase below): mark a phase complete ONLY when a tool result in this run proves it ran. A plan is not a completion. Never report "create worktree", "merge", "push", or "run gates" as complete from instructions alone.

Phase 1: Context Gathering

Step	Action	Verification
1.1	Fetch PR metadata via gh pr view	PR metadata displayed
1.2	Checkout PR branch	git branch --show-current matches
1.3	Attempt merge with base (--no-commit)	Conflict markers created
1.4	List conflicted files	git diff --name-only --diff-filter=U output

Phase 2: Analysis and Resolution

Step	Action	Verification
2.1	Classify files (auto-resolvable vs manual)	Classification logged
2.2	Auto-resolve known patterns (accept --theirs)	Files staged cleanly
2.3	For manual files: run git blame, analyze intent	Commit messages captured
2.4	Apply manual resolutions per decision framework	Conflict markers removed
2.5	Stage all resolved files	git diff --check clean

Phase 3: Validation (BLOCKING)

Step	Action	Verification
3.1	Verify no remaining conflict markers and no unmerged files	python3 .claude/skills/merge-resolver/scripts/verify_no_conflict_markers.py exits 0
3.2	Run session protocol validator	validate_session_json.py exits 0
3.3	Run markdown lint	npx markdownlint-cli2 exits 0
3.4	Commit merge resolution	Commit SHA recorded
3.5	Push to remote	Remote ref updated

Intent Classification

Classify each side's changes to determine resolution priority.

Type	Indicators	Priority
Security	"security", "vuln", "CVE" in message	Highest (1)
Bugfix	"fix", "bug", "patch", "hotfix" in message	High (2)
Feature	"feat", "add", "implement"; new functionality	Medium (3)
Refactor	"refactor", "cleanup", "rename"; no behavior change	Medium (3)
Style	"style", "format", "lint"; whitespace only	Lowest (4)

Priority is a strict priority hierarchy: Security (1) > Bugfix (2) > Feature/Refactor (3) > Style (4). Intent priority is the PRIMARY sort key when two sides conflict. A Security change is NEVER dropped: if it cannot be cleanly combined with the other side, Security wins and the lower-priority change is reapplied around it. Recency and test coverage are tiebreakers ONLY between two changes in the same priority tier; they never let a lower-tier change beat a higher-tier one.

Decision Framework

Scenario	Resolution
Same intent, compatible changes	Merge both
Bugfix vs feature	Bugfix wins; integrate feature around it
Security vs anything else	Security wins and is preserved; reapply the other change around the security fix (never drop the security change)
Higher-priority vs lower-priority tier (e.g. Bugfix vs Refactor)	Higher-priority wins; integrate the lower-priority change around it
Same-tier conflict / Conflicting logic	Combine if possible; else break the tie by better-tested, then more recent
Style vs Style conflicts	Accept either; prefer consistency with surrounding code
Deletions vs modifications	Investigate why; deletion usually intentional

Session File Rules

CRITICAL: Session files from main are immutable audit records.

Action	Correct	Wrong
Session file conflict	Accept --theirs, rename ours to next number	Accept --ours (alters main's record)
Same-numbered session	Keep both with different numbers	Overwrite one version

See references/strategies.md for the full session file resolution workflow.

Auto-Resolvable Patterns

The script auto-resolves these by accepting the target branch version.

Pattern	Rationale
.agents/sessions/*.json	Session files from main are immutable audit records
.agents/*	Session artifacts, constantly changing
.serena/*	Serena memories, auto-generated
.claude/skills/*/*.md	Skill definitions, main is authoritative
.claude/commands/*	Command definitions, main is authoritative
.claude/agents/*	Agent definitions, main is authoritative
templates/*	Template files, main is authoritative
src/copilot-cli/*	Platform agent definitions
src/vs-code-agents/*	Platform agent definitions
src/claude/*	Platform agent definitions
.github/agents/*	GitHub agent configs
.github/prompts/*	GitHub prompts
package-lock.json, yarn.lock, pnpm-lock.yaml	Lock files; regenerate from main

Plugin Manifests (Special Rule)

*/.claude-plugin/plugin.json is NOT accept-theirs. Accepting main's copy makes head version equal to the merge-base and re-trips the plugin version-bump gate with not-bumped (issue #2543). When the two sides differ only in version, the script resolves to one patch bump above the higher side (for example ours 0.5.168 vs theirs 0.5.169 resolves to 0.5.170). Any other field difference, or a prerelease/build-metadata version, blocks auto-resolution and requires manual handling.

Scripts

resolve_pr_conflicts.py

Resolves PR merge conflicts with auto-resolution for known file patterns.

python3 .claude/skills/merge-resolver/scripts/resolve_pr_conflicts.py \
    --pr-number <number> --branch-name <name> [--target-branch <branch>] \
    [--worktree-base-path <path>] [--dry-run]

Exit codes:

Code	Meaning
0	Conflicts resolved successfully (and, if not --dry-run, pushed)
1	Non-auto-resolvable conflicts remain

When running with --dry-run, exit code 0 indicates that conflicts were fully auto-resolvable and the changes would have been pushed, but no changes were made because of dry-run mode.

Output format (JSON):

{
  "success": true,
  "message": "Successfully resolved conflicts for PR #123",
  "files_resolved": [".agents/HANDOFF.md"],
  "files_blocked": []
}

Security: Branch name validation prevents command injection. Worktree path validation prevents path traversal.

verify_no_conflict_markers.py

Verifies that resolution is complete: no still-unmerged (UU) files and no leftover conflict markers in any in-flight change. Replaces the broad git grep -n '<<<<<<<' -- check, which false-fails on intentional fenced examples in committed docs and Serena memories (issue #2424).

python3 .claude/skills/merge-resolver/scripts/verify_no_conflict_markers.py [--cwd PATH] [--json]

Uses git diff HEAD --check (catches leftover markers in working tree + index) plus git diff --name-only --diff-filter=U (catches files still unmerged). Both inspect in-flight changes only, so committed historical content is intentionally ignored.

Exit codes:

Code	Meaning
0	Clean: no unmerged files and no leftover conflict markers
1	Resolution incomplete: markers remain or unmerged files exist
2	Usage error: not inside a git working tree
3	External error: a git command failed unexpectedly

Anti-Patterns

Anti-Pattern	Why It Fails	Instead
Alter session files from main	Breaks audit trail (immutable records)	Accept --theirs, then rename our session file to the next available number
Push without session validation	CI blocks with MUST violations	Run validate_session_json.py first
Manual edit of generated files	Lost on regeneration	Edit template, run generator
Accept --ours for HANDOFF.md	Branch version often stale	Accept --theirs (main is canonical)
Merge lock files manually	JSON corruption, broken deps	Accept base, regenerate with npm install
Skip git blame analysis	Wrong intent inference	Always check commit messages
Resolve before fetching PR context	Missing context, wrong base	Always gh pr view first
Forget to stage .agents/	Dirty worktree CI failure	Include all .agents/ changes

Verification

Success Criteria

Criterion	Evidence
All conflicts resolved	git diff --check returns empty
No merge markers remain	python3 .claude/skills/merge-resolver/scripts/verify_no_conflict_markers.py exits 0 (uses git diff HEAD --check + git diff --diff-filter=U; ignores intentional fenced examples in committed docs -- issue #2424)
Session protocol valid	validate_session_json.py exits 0
Markdown lint passes	npx markdownlint-cli2 exits 0
Push successful	Remote ref updated

Completion Checklist

• All conflicted files staged (git add)
• No UU status in git status --porcelain
• Session log exists at .agents/sessions/
• Session end checklist completed
• Serena memory updated
• Merge commit created
• Branch pushed to origin

Extension Points

Custom Auto-Resolvable Patterns

Add patterns to AUTO_RESOLVABLE_PATTERNS in resolve_pr_conflicts.py.

Custom Resolution Strategies

Add entries in references/strategies.md for domain-specific conflicts.

CI/CD Integration

- name: Resolve conflicts
  env:
    PR_NUMBER: ${{ github.event.pull_request.number }}
    HEAD_REF: ${{ github.head_ref }}
    BASE_REF: ${{ github.base_ref }}
  run: |
    python3 .claude/skills/merge-resolver/scripts/resolve_pr_conflicts.py \
      --pr-number "$PR_NUMBER" \
      --branch-name "$HEAD_REF" \
      --target-branch "$BASE_REF"

Related

• Security: Branch name and path validation prevent injection and traversal
• SESSION-PROTOCOL.md: Session end requirements (blocking gate)
• strategies.md: Detailed resolution patterns for edge cases
• merge-resolver-session-protocol-gap: Memory documenting root cause analysis

Session Protocol Validation Details

Why This Matters

Session protocol validation is a CI blocking gate. Pushing without completing session requirements causes CI failures with "MUST requirement(s) not met" errors.

Validation Commands

# 1. Ensure session log exists
SESSION_LOG=$(ls -t -- .agents/sessions/*.json 2>/dev/null | head -1)
if [ -z "$SESSION_LOG" ]; then
    echo "ERROR: No session log found."
    exit 1
fi

# 2. Run session protocol validator
python3 scripts/validate_session_json.py "$SESSION_LOG"

Session End Checklist (REQUIRED)

Req	Step	Status
MUST	Complete session log (all sections filled)	[ ]
MUST	Update Serena memory (cross-session context)	[ ]
MUST	Run markdown lint	[ ]
MUST	Route to qa agent (feature implementation)	[ ]
MUST	Commit all changes (including .serena/memories)	[ ]
MUST NOT	Update .agents/HANDOFF.md directly	[ ]

Common Failures

Error	Cause	Fix
E_TEMPLATE_DRIFT	Session checklist outdated	Copy canonical checklist from SESSION-PROTOCOL.md
E_QA_EVIDENCE	QA row checked but no report path	Add QA report or use "SKIPPED: docs-only"
E_DIRTY_WORKTREE	Uncommitted changes	Stage and commit all files including .agents/