Compose a complete, durable build-loop handoff document from the current run state, and optionally launch a fresh session with it injected. Use when crossing a context boundary (context limit, planned restart, worktree GC). Triggers: 'hand off', 'handoff', 'new session', 'context limit', 'restart', 'fresh session', '/build-loop:compose-handoff'.
Use when build-loop needs UI design direction, visual style selection, UI guidance inventory, a .build-loop/app-contract/ui.md design contract, or non-trivial web/mobile/native UI planning. Build-loop-owned design route for design-contract-specialist; selects from project tokens, recent structures, UI Guidance, IBR artifacts, Mockup Gallery, and research based on product/workflow/data/platform fit.
Generate accessible color systems and solve contrast, instead of guessing hex values. Use when picking or fixing colors for any UI, chart, diagram, doc, or artifact — "what colors should this use", "is this readable", "this text fails contrast", "make a dark theme", "pick an accent". Also use before shipping any palette, to PROVE contrast rather than assert it. NOT for choosing layout, typography, or component structure.
Use when a Build Loop run or Git worktree touches mutable non-Git state: SQLite or file-backed databases, PostgreSQL databases/schemas and migrations, generated search/vector indexes, Docker volumes or service projects, mutable file trees, caches that cannot be rebuilt safely, or external cloud/account namespaces. Inventories each surface, selects per-worktree, shared-readonly, shared-serialized, or external-namespaced isolation, registers it in the run data manifest, validates collisions before writes, and requires a terminal disposition at closeout.
Use when choosing a model tier or segment for a subagent, deciding a role descriptor (segment + tier) in frontmatter, or escalating mid-flow. Covers the two-axis taxonomy (work-role segment × 7-rung capability ladder) — Opus/Sonnet/Haiku are Anthropic-default mappings; selection is provider-portable and data-driven. NOT for benchmarking models head-to-head on a task — use `model-bakeoff`.
Orchestrated build loop for multi-step code work. TRIGGER on verb language ('build', 'implement', 'create', 'add', 'ship', 'wire up', 'integrate', 'refactor', 'migrate', 'rewrite', 'replace') OR symptom language ('fix', 'broken', 'doesn't work', 'isn't loading', 'not displaying', 'missing', 'should show', 'needs to', 'make it', 'show this differently') OR any task touching 2+ files, adding/removing an endpoint, crossing an architectural boundary, or attached screenshots of a bug. SKIP one-line edits, pure Q&A, conversational clarifications, status checks, and trivial typos/renames.
Use when the build needs to automate a macOS .app without touching the hardware cursor, or the user asks to "click through the app" or "test the UI headlessly". Drives running apps via Accessibility API; self-contained Swift binary — no IBR, Playwright, or Appium required.
Audit and evolve repository structure safely across the full maintenance lifecycle: repository topology and scope, application and build-system profiles, module and folder boundaries, canonical source-of-truth and monorepo decisions, sibling consolidation, generated/build artifact retention, worktree and branch hygiene, local-versus-remote state, verified closeout into local main, and preparing a repository for open-source or external distribution (personal-content and secret scrub, internal-artifact de-tracking, .git bloat and history-leak review, distribution signing/notarization). Use when asked how any kind of repo should be structured or maintained, what application/build profile it has, why it has duplicate source or many build directories, whether repositories or modules should split or merge, to clean generated artifacts or a polluted data store (a log, telemetry, cache, or dataset corrupted by test/non-production writes), to review open commits/worktrees/branches/stashes, to merge and close completed