Version Migration Assistant

Systematically plans and executes Frappe/ERPNext version migrations by analyzing breaking changes, scanning custom code for compatibility issues, and generating migration plans.

Purpose: Prevent failed migrations by detecting every breaking change BEFORE upgrading.

When to Use This Agent

MIGRATION TRIGGER
|
+-- Planning a version upgrade
|   "We need to go from v14 to v15"
|   --> USE THIS AGENT
|
+-- Post-upgrade errors
|   "Everything broke after bench update"
|   --> USE THIS AGENT (Step 2-5 for diagnosis)
|
+-- Checking custom app compatibility
|   "Will our custom app work on v16?"
|   --> USE THIS AGENT (Step 3 for code scan)
|
+-- Already mid-migration with issues
|   "bench migrate fails with errors"
|   --> USE THIS AGENT + frappe-agent-debugger

Migration Workflow

STEP 1: IDENTIFY MIGRATION PATH
  Source version → Target version (NEVER skip major versions)

STEP 2: CHECK BREAKING CHANGES
  Apply breaking changes database for each version jump

STEP 3: SCAN CUSTOM CODE
  Grep for deprecated patterns in all custom apps

STEP 4: GENERATE MIGRATION PLAN
  Backup → Staging → Test → Production sequence

STEP 5: GENERATE PATCH LIST
  Specific code changes needed per custom app

See references/workflow.md for detailed steps.

Step 1: Migration Path Rules

NEVER skip major versions. ALWAYS migrate sequentially:

Version Identification

# Check current versions
bench version
# Output shows: frappe X.Y.Z, erpnext X.Y.Z

# Check available versions
cd apps/frappe && git tag | grep "^v1[456]" | tail -5

Step 2: Breaking Changes Summary

v14 → v15 Breaking Changes

scheduler_events

job_id

frappe.enqueue()

Module Def

mysql --version

python3 --version

frappe.client.get_list

frappe.client.get_list

allow_guest=True

bench build

boot_session

boot_session

autoname

v15 → v16 Breaking Changes

extend_doctype_class

doc_events

doc_events

uuid

autoname

python3 --version

node --version

redis-server --version

See references/breaking-changes.md for complete details.

Step 3: Deprecated Pattern Detection

ALWAYS scan custom app code for these patterns:

v14 → v15 Deprecated Patterns

# Run these grep commands in apps/{your_app}/ directory:

# 1. Old-style module page references
grep -rn "Module Def" --include="*.py" --include="*.json"

# 2. Old scheduler API
grep -rn "frappe.utils.scheduler" --include="*.py"

# 3. Deprecated client API
grep -rn "frappe.set_route\|cur_page\|page_container" --include="*.js"

# 4. Old-style print format
grep -rn "frappe.get_print\|standard_format" --include="*.py"

# 5. Deprecated database methods
grep -rn "frappe.db.sql_list\|frappe.db.sql_ddl" --include="*.py"

v15 → v16 Deprecated Patterns

# Run these grep commands in apps/{your_app}/ directory:

# 1. doc_events that should use extend_doctype_class
grep -rn "doc_events" hooks.py

# 2. Old-style controller override
grep -rn "override_doctype_class" --include="*.py"

# 3. Deprecated frappe.utils methods
grep -rn "frappe.utils.now_datetime\b" --include="*.py"

# 4. Old print format API
grep -rn "frappe.utils.pdf\|get_pdf" --include="*.py"

# 5. Removed API calls
grep -rn "frappe.get_hooks\b.*boot_session" --include="*.py"

# 6. Missing type annotations (warning, not error)
grep -rn "def .*whitelist" --include="*.py"

Step 4: Migration Plan Template

ALWAYS generate a migration plan in this format:

## Migration Plan: v{source} → v{target}

### Prerequisites
- [ ] Python version: {required}
- [ ] Node.js version: {required}
- [ ] MariaDB version: {required}
- [ ] Redis version: {required}
- [ ] Disk space: minimum 2x current DB size

### Phase 1: Preparation (Day 1)
1. Full backup: `bench --site {site} backup --with-files`
2. Document current state: `bench version > pre-migration-versions.txt`
3. List all custom apps: `bench --site {site} list-apps`
4. Run deprecated pattern scan (Step 3)
5. Fix all detected issues in custom apps

### Phase 2: Staging (Day 2-3)
1. Clone production to staging environment
2. Restore backup on staging: `bench --site staging restore {backup}`
3. Switch branch: `bench switch-to-branch version-{target} frappe erpnext`
4. Run migration: `bench --site staging migrate`
5. Run full test suite on staging

### Phase 3: Testing (Day 4-5)
- [ ] All DocTypes load correctly
- [ ] All print formats render correctly
- [ ] All workflows transition correctly
- [ ] All scheduled jobs execute correctly
- [ ] All custom reports generate correctly
- [ ] All API endpoints respond correctly
- [ ] All user permissions work correctly
- [ ] Performance is acceptable (page load < 3s)

### Phase 4: Production (Day 6)
1. Schedule maintenance window
2. Enable maintenance mode: `bench --site {site} set-maintenance-mode on`
3. Final backup: `bench --site {site} backup --with-files`
4. Switch branch: `bench switch-to-branch version-{target} frappe erpnext`
5. Run migration: `bench --site {site} migrate`
6. Run `bench build --production`
7. Restart: `bench restart` (or `sudo supervisorctl restart all`)
8. Disable maintenance mode: `bench --site {site} set-maintenance-mode off`
9. Verify (Phase 3 checklist again)

### Rollback Plan
1. Stop all services: `sudo supervisorctl stop all`
2. Restore backup: `bench --site {site} restore {backup_path}`
3. Switch back: `bench switch-to-branch version-{source} frappe erpnext`
4. Run migration: `bench --site {site} migrate`
5. Rebuild: `bench build --production`
6. Restart: `sudo supervisorctl restart all`

Step 5: Custom App Patch List

For each deprecated pattern found in Step 3, generate a specific fix:

{file}

{line}

{old_pattern}

{new_pattern}

Common Patches (v14 → v15)

frappe.db.sql_list(...)

frappe.db.get_all(..., pluck="name")

Module Def

cur_page

frappe.router

Common Patches (v15 → v16)

doc_events

extend_doctype_class

super()

super().method()

frappe.utils.pdf.get_pdf()

Agent Output Format

ALWAYS produce migration output in this format:

## Migration Assessment

### Version Path
{source} → {target} (via {intermediate versions if any})

### Prerequisites Status
| Requirement | Current | Required | Status |
|-------------|---------|----------|--------|
| Python | {ver} | {ver} | OK/FAIL |
| Node.js | {ver} | {ver} | OK/FAIL |
| MariaDB | {ver} | {ver} | OK/FAIL |

### Breaking Changes Found: {count}
[List from Step 2]

### Custom Code Issues Found: {count}
[Table from Step 3 scan]

### Migration Plan
[From Step 4]

### Patch List
[From Step 5]

### Risk Assessment
| Risk | Likelihood | Impact | Mitigation |
|------|-----------|--------|------------|

### Estimated Timeline
Preparation: {days} | Staging: {days} | Testing: {days} | Production: {hours}

### Referenced Skills
- `frappe-ops-upgrades`: Version upgrade procedures
- `frappe-ops-backup`: Backup and restore
- `frappe-agent-debugger`: For post-migration error diagnosis

See references/checklists.md for complete migration checklists. See references/breaking-changes.md for full breaking changes database.