Yesterday-AI

Root-cause debugging in four phases: investigate, analyze, hypothesize, implement. Iron Law -- no fixes without root cause. Thin ytstack wrapper around the vendored superpowers systematic-debugging procedure, routing findings into KNOWLEDGE.md / DECISIONS.md. Use when hitting a bug, test failure, or unexpected behavior.

User-triggered session handoff. Writes a detailed HANDOFF.md with current state, open items, pending decisions, and recommended resume prompt. Use before switching machines, before long breaks, or when you need to clear context intentionally. Parallel to the automatic pre-compact hook.

Challenge premise, scope, and ambition via four modes: SCOPE EXPANSION, SELECTIVE EXPANSION, HOLD SCOPE, SCOPE REDUCTION. Auto-detects mode: concept-mode reviews a pitch (OFFICE-HOURS.md) before any scaffolding exists; milestone-mode reviews a committed milestone (M###-CONTEXT.md + M###-ROADMAP.md) before slicing. Use concept-mode right after office-hours to stress-test the pitch; use milestone-mo

After a slice completes, review whether the milestone roadmap still fits reality. Reads recent summaries, surfaces deviations, prompts for roadmap changes (add/split/reorder/remove slices). Run at slice boundaries, not mid-slice.

Dispatch the current milestone's slices to a Claude Code Agent Team. Each teammate works on a slice in parallel with its own 200k context (replaces GSD's fresh-subprocess-per-task pattern). Requires CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1 and v2.1.32+. Run after slice-milestone + plan-eng-review.

Scaffold a ytstack project's `.ytstack/` directory with the 6 core artifacts (PROJECT.md, DECISIONS.md, KNOWLEDGE.md, RUNTIME.md, STATE.md, PREFERENCES.md). Use AFTER a pitch has been validated via office-hours (and optionally plan-ceo-review / plan-eng-review in concept-mode) -- init-project reads OFFICE-HOURS.md frontmatter to populate PROJECT.md name + one-liner. Do NOT use as the greenfield en

Flesh out a single task within the current slice. Reads M###-S##-PLAN.md, picks the next unplanned task, writes M###-S##-T##-PLAN.md with exact file paths + verification steps. Enforces fits-one-context-window rule. Run after slice-milestone, before executing the task.

Review execution approach for feasibility, architecture, data flow, edge cases, test coverage, performance, and security risks. Auto-detects mode: concept-mode reviews a pitch (OFFICE-HOURS.md) for technical feasibility before any scaffolding; milestone-mode reviews slice-plans (M###-S##-PLAN.md) before plan-task. Use concept-mode optionally after plan-ceo-review to sanity-check the pitched approa

Run verification commands and confirm output before claiming work is complete. Evidence before assertions. Thin ytstack wrapper around the vendored superpowers verification-before-completion procedure, injecting the current task's verification command. Use before commit, before PR, before summarize-task, before any 'done' claim.

Use as the first step when a new project, feature, or initiative has not yet been validated, or whenever the premise needs a forcing-question test. Six forcing questions expose demand reality, status quo, desperate specificity, narrowest wedge, observation, and future-fit. Produces OFFICE-HOURS.md pitch artifact with name + one-liner frontmatter that downstream skills (plan-ceo-review concept-mode

Clean code, robust architecture, no test slop. Foundational skill for high-quality software engineering, code structure, and reviews.

Use when picking software for EU customers, GDPR-driven replacements, digital-sovereignty contexts, or when user asks for the European / open-source version of a US product (Google Drive, Dropbox, Slack, …). Biases tech choices toward the 289 community-curated alternatives at european-alternatives.cloud. Fetches live data. Complements deutschland-stack-api (community-curated vs. government-graduat