Check Implementation

Verify plan checkboxes against the codebase. Unmark items that don't hold up ([x] → [ ]).

Interactive prompts: present options as a numbered list and wait for the user's choice.

Input

The argument (if provided) is: $ARGUMENTS

Use the argument as <slug> if given. Accepts slug or @file reference.

If no argument is provided, list available plans as numbered options and wait for the user's choice.

Progress Algorithm

Count - [x] and - [ ] lines under each ## Phase N heading. Per-phase: Phase N — title: checked/total. Sum → Total: checked/total.

Workflow

1. Load the plan

Read .specs/plans/<slug>.md. If missing, list plans as numbered options and wait for the user's choice.

2. Fast-path: check if implementation exists

If primary module file(s) from Phase 1 don't exist, skip subagent — report 0/N — not yet started, list Phase 1 done-when items.

3. Launch read-only review

Use a general-purpose subagent (not code-review). The subagent must be read-only (no file writes, no edits). It should:

1. Read every section of the plan — architectural decisions, each phase, done-when checkboxes
2. For each phase, check every - [ ] / - [x] item against the codebase
3. Run the project's test suite and include pass/fail results
4. For each checkbox, determine whether it should be checked ([x]) or unchecked ([ ])

Collect findings into two categories:

• BLOCKERS — checked items that don't hold up, failing tests, broken contracts
• SUGGESTIONS — improvements, minor gaps, style issues

4. Update checkboxes

Using the subagent's report, update each checkbox in .specs/plans/<slug>.md:

• Items that pass verification → [x]
• Items that fail verification → [ ] (unmark)

5. Report

Count progress per phase (Progress Algorithm), then print:

## Verification: <slug>

### Progress

  Phase 1 — title: checked/total
> Phase 2 — title: checked/total
  Total: checked/total

The > marks the first incomplete phase (cursor).

### BLOCKERS

- (list or "None")

### SUGGESTIONS

- (list or "None")

If all items verified (total checked = total):

All phases complete — implementation verified.

6. Next steps

If blockers exist, list items to fix, then re-run /hb:check <slug>.

If all items verified, suggest creating a PR or shipping.

Rules

• The review subagent must be read-only — it must not create, edit, or delete any files
• The only file writes this skill makes are: checkbox updates in the plan
• Never modify implementation code — only observe and report