Follow this exact procedure when adding a NEW headless component to @llui/components (packages/components) — a behavior+state+a11y module in the family of dialog/tabs/ select/menu/tree-view/accordion, exposing init/update/connect (+ overlay for overlay components). Use it whenever you're building a new interactive widget inside the LLui components package: the connect() part-bag contract, the overlay engine, ARIA/id wiring, i18n via LocaleContext, value-based list identity, the shared utils to reuse, and the THREE export edits are all easy to get wrong. This is framework-internals work on the component library (NOT app code — that's llui-app-dev — and NOT a runtime primitive). Load it before writing the component.
Follow this exact procedure when adding a NEW compile-time lint rule to the LLui compiler (@llui/compiler, packages/compiler/src/signals/rules.ts). Use it whenever you want the build to reject an unsafe or non-idiomatic LLui authoring pattern — a new signal/view/reducer check that should fail compilation, not merely warn. This is framework-internals work. Critical doctrine it enforces: LLui framework rules are NON-BYPASSABLE compiler ERRORS, never ESLint rules (LLMs and humans ignore warnings), so the rule must be wired to halt the build and ship with BOTH positive and negative tests. Load it before writing the rule; getting the ScriptKind, the root-tracking, or the negative case wrong produces false positives that block valid builds.
Follow this exact procedure when adding a NEW publishable package to the LLui monorepo (a new packages/<name>/ shipping as @llui/<name>). Use it whenever you're creating a new workspace package in this repo: the package.json shape (exports map, files, scripts, sideEffects), the tsconfig chain, the CRITICAL @llui/dom-must-be-a-peer rule (a hard dependency causes the two-context provide() production bug), how build/publish order is derived, and the CLAUDE.md + site registry drift-gates you MUST update or CI fails. This is framework-internals / monorepo-plumbing work. Load it before scaffolding the package.
Follow this exact procedure when adding a NEW structural primitive to the LLui runtime (@llui/dom) — a scope-owning, region-reconciling helper in the family of show/branch/each/virtualEach/lazy/portal/foreign/unsafeHtml. Use it whenever you're working inside packages/dom and creating a primitive that builds live nodes lazily, owns a child scope, reconciles a region between anchors, or swaps arms/rows. This is framework-internals work (NOT app code and NOT a @llui/components component); the sequence is easy to get subtly wrong — miss the context snapshot, the draining/insert order, the teardown, or an export and you ship a leak or a stale-UI bug. Load it before writing the primitive, not after.
Use whenever a question involves app code built with LLui — anything importing @llui/dom, @llui/components, @llui/effects, @llui/router, @llui/vike, @llui/markdown, @llui/markdown-editor, @llui/a2ui, @llui/agent. Load it before answering, not after. Every shape of LLui question qualifies: write a feature, review a PR or diff, answer an API question, or debug a plain-English symptom — UI stuck at its initial value, stale reads, effects that never fire, lists that duplicate/throw/lag on reorder, SSR or hydration flashes, "what should State hold?", "is this idiomatic?". The framework name need not appear; an @llui/* import is enough. Why: LLui has no virtual DOM and view() runs exactly once, building bindings instead of re-rendering, so React/Vue/Solid/Elm reasoning yields fluent, confident, wrong diagnoses here — this skill carries the real rules and the failure-mode checklist. Not for other frameworks, nor for publishing/versioning the @llui packages themselves.
Find every project under a path that depends on @llui/* packages and migrate each to the latest llui versions. Use when asked to migrate, upgrade, or update consumer projects to the newest LLui libraries, audit consumers for outdated @llui deps, or replace hand-rolled code with what an llui library already provides (e.g. @llui/components, @llui/markdown). Also handles bugs found in llui itself by fixing them on a branch.