| name | apex-tier2 |
| description | Execute complex tasks with periodic human checkpoints. Background work with steering — the agent works autonomously but pauses at defined decision points for human input. Use for medium-complexity tasks like feature implementation, refactoring, or multi-file changes. Triggers on keywords like guided task, checkpoint, background with review, implement feature, refactor module. |
APEX Tier 2 — Guided Execution
Work autonomously on a complex task but pause at predefined checkpoints for human steering. The agent does the heavy lifting; the human makes the judgment calls.
When to Use
Use Tier 2 when:
- The task involves multiple files or modules
- Some decisions require human judgment (naming, architecture choices)
- The work takes more than one focused session
- You want to review progress before the agent goes further
Escalate to Tier 3 when:
- Every step requires discussion
- The architecture is being designed from scratch
- The task is exploratory with no clear end state
Workflow
- Plan the work and define checkpoints
- Execute until the next checkpoint
- Present checkpoint summary for human review
- Incorporate feedback and continue
- Final validation and PR
Step 1: Plan and Define Checkpoints
Break the task into phases. Each phase ends with a checkpoint:
## Execution Plan
### Phase 1: Data layer changes
- Modify schema for new fields
- Update migrations
- **CHECKPOINT: Review schema changes before proceeding**
### Phase 2: Business logic
- Implement service methods
- Add validation rules
- **CHECKPOINT: Review logic before wiring to API**
### Phase 3: API layer
- Add/modify endpoints
- Update request/response types
- **CHECKPOINT: Review API contract before tests**
### Phase 4: Tests and cleanup
- Write unit and integration tests
- Update documentation
- Final validation
Present this plan to the user. Get approval before starting.
Step 2: Execute Until Checkpoint
Work through the current phase. Follow the same implementation rules as Tier 1: one file at a time, match specs, preserve edge cases.
Run the self-correcting loop after each phase:
Linux/Mac:
bash "${CLAUDE_SKILL_DIR}/scripts/validate.sh" <target-dir>
Windows:
powershell -File "${CLAUDE_SKILL_DIR}/scripts/validate.ps1" <target-dir>
Step 3: Checkpoint Summary
When reaching a checkpoint, present a structured summary:
## Checkpoint: {Phase Name}
### Completed
- [x] Item 1
- [x] Item 2
### Decisions Made
| Decision | Choice | Reasoning |
|----------|--------|-----------|
| Field naming | `created_at` | Matches existing convention |
### Questions for You
1. Should X use pattern A or pattern B?
2. Is the error message "..." appropriate for this context?
### Next Phase Preview
Phase 2 will implement [brief description]. Estimated scope: N files.
Wait for human response before continuing. Do not proceed past a checkpoint without explicit approval.
Step 4: Incorporate Feedback
Apply the human's feedback. If feedback contradicts a previous decision, update the relevant code AND update AGENTS.md if the feedback reveals a recurring preference (two-strike rule).
Step 5: Final Validation and PR
After all phases complete, run full validation and open a PR with the complete execution log:
gh pr create --draft --title "apex: {task description}" --body-file /tmp/apex-pr-body.md
Output
A draft PR with a complete audit trail of checkpoints, decisions, and human feedback incorporated at each stage.
Example PR body with checkpoint log:
## apex: Refactor payment module to Stripe v3
### Execution Log
#### Phase 1: Data Layer ✅
- Updated PaymentIntent schema
- Added new webhook event types
- **Human feedback:** "Use camelCase for new fields" → Applied
#### Phase 2: Business Logic ✅
- Migrated to PaymentIntents API
- Added idempotency keys
- **Human feedback:** "Add retry logic for network errors" → Applied
#### Phase 3: API Layer ✅
- Updated `/payments/create` endpoint
- Added `/payments/confirm` endpoint
- **Human feedback:** None needed
#### Phase 4: Tests ✅
- 23 new tests, 0 failing
- Updated 8 existing tests
### Validation: ✅ All checks pass
