spp

spp is a Claude Code plugin that brackets the superpowers planning/execution pipeline for features too large for one session. It ships three skills:

• /spp:chop — splits a spec into vertical-slice plans plus a progress.md tracking file. It's invoke-only (never auto-triggers): the human's decision to run it is the size judgment. If the work actually fits one session, chop says so and points at superpowers:writing-plans instead.
• /spp:cook — implements exactly one pending slice per session via superpowers:subagent-driven-development, updates progress.md, opens a draft slice PR into the feature branch, and hands off to a fresh session for the next slice.
• /spp:review-slices — verifies a chopped slice-plan set (seam signatures, spec coverage) and generates a visual review.html; read-only against the spec, plans, and progress.md, and re-runnable anytime to refresh slice statuses.

brainstorming → spec ──one-session work──→ writing-plans (1 plan) → SDD directly
                  │
                  └──human invokes /spp:chop──→ writing-plans ×N slice plans + progress.md
                                                     │
                                                     ▼
                                       /spp:cook (×N fresh sessions, one slice each)
                                                     │ each slice → draft PR → human reviews & merges into feature branch
                                                     │ all slices done
                                                     ▼
                                       superpowers:finishing-a-development-branch (once)

Requires

The superpowers plugin. Install it from the official marketplace:

claude plugin install superpowers@claude-plugins-official

Try it locally

From this repo, run Claude Code with the plugin loaded for the session only:

claude --plugin-dir /path/to/this/repo

/spp:chop, /spp:cook, and /spp:review-slices will be available.

Install

npx @v11g/spp-vertical-slices install
npx @v11g/spp-vertical-slices uninstall

The installer copies .claude-plugin/ and skills/ into ~/.claude/skills/spp/, which Claude Code auto-loads in future sessions, and checks whether superpowers is installed — offering to install it if not (or printing the install command when not interactive).

Alternative: marketplace-style install straight from this repo:

claude plugin marketplace add <this repo>
claude plugin install spp

Maintenance

spp steers superpowers via instructions, not code, so a superpowers update can silently break its assumptions. After every superpowers update, re-run the suites in evals/ before relying on spp for real work. Each SKILL.md carries an "Assumptions ledger" at the bottom listing exactly what it depends on from superpowers — start debugging any post-update misbehavior there.