Fetch changelog via WebFetch (try in order, stop on first hit):
- https://github.com/OWNER/REPO/releases
- https://github.com/OWNER/REPO/blob/main/CHANGELOG.md
- https://github.com/OWNER/REPO/blob/main/HISTORY.md
- https://github.com/OWNER/REPO/blob/main/NEWS.md
Extract changes between current → target. Flag:
- Major bumps (X.x → Y.x)
- Keywords: BREAKING, removed, renamed, changed behavior
- Migration guides
- Ruby/Rails version requirements
- Deprecations

Present analysis:

## Upgrade Analysis: GEM CURRENT → TARGET

### Version Jump: PATCH | MINOR | MAJOR
### Breaking Changes: [list]
### Migration Required: [steps]
### Deprecations: [list]
### New Features: [list]
### Compatibility: [Ruby/Rails reqs]

AskUserQuestion → options:
- Upgrade to latest minor (recommended) — safer, bug fixes
- Upgrade to latest (TARGET) — review breaking changes
- Upgrade to specific version — prompt for version
- Skip

Update Gemfile (Edit):

# latest
gem 'GEM', '~> MAJOR.MINOR'
# minor only
gem 'GEM', '~> CURRENT_MAJOR.CURRENT_MINOR'

Run update:
```
bundle update GEM --conservative
```
On failure → show conflicts, suggest dependent updates, offer rollback.

Run tests (auto-detect):

if [ -f spec/spec_helper.rb ]; then bundle exec rspec
elif [ -f test/test_helper.rb ]; then bundle exec rails test
fi

Pass → step 10
Fail → show failures, AskUserQuestion: Rollback | Investigate

Commit:

git add Gemfile Gemfile.lock
git commit -m "$(cat <<'EOF'
chore(deps): upgrade GEM from CURRENT to TARGET

Breaking changes:
- [list]

Migration notes:
- [steps taken]

Changelog: URL
EOF
)"

Workflow (--outdated batch mode)

bundle outdated --strict
Group by jump type:
- PATCH (X.Y.Z → X.Y.Z+1) — usually safe
- MINOR (X.Y → X.Y+1) — review recommended
- MAJOR (X → X+1) — careful review required
AskUserQuestion (multi-select) presenting all gems grouped by risk
For each selected gem → run single-gem workflow (steps 1-10)

Rollback

At any failure step:

git checkout -- Gemfile Gemfile.lock
bundle install

Safety Rules

Always show diff before applying
Create backup of Gemfile before edit (Edit tool preserves prior content via git)
Never commit if tests fail
Default to --conservative to avoid cascading updates
Flag major version jumps explicitly in analysis

gemfile-upgrade

Gemfile Upgrade

Input

Workflow (single gem)