`c2-list-item` is a selectable row: on its own a click, Enter or Space toggles `selected`; inside a `c2-list` (or a `c2-select`) the list drives the selected state and the keyboard.

Progress built with Lit: a linear bar, indeterminate by default or filling to a value, with an optional label and count.

Skeleton built with Lit: a placeholder block standing in for content that has not arrived, in three shapes and three animations.

`c2-button` is a themeable button with slots for the label text, a prefix icon, a suffix icon and a running (busy) icon.

`c2-menu` is a menu of commands: a trigger plus a popover of `c2-menu-item` rows, positioned by `c2-overlay` on the browser's top layer.

Creates a temporary folder inside cwd, cds inside the folder, runs a function, and removes the folder. Especially useful for testing.

`<c2-autocomplete>` is a keyboard-accessible combobox composed from `c2-overlay`, `c2-list` and `c2-list-item`.

`c2-link-button` is a text-styled control for link and navigation actions.

Slider built with Lit on a native `<input type="range">`: the browser handles dragging, keyboard steps, RTL and the `slider` role; the component draws a themeable track, fill, thumb, step ticks and a value bubble.

Line, area, bar, sparkline, pie, gauge, scatter and candlestick charts as custom elements, from one package.

A composable Lit component for empty states, operation outcomes, recoverable errors and unavailable content.

File and image attachments with metadata, upload progress, failure states, actions, and responsive grouping.

Switch built with Lit: an on/off toggle on a native `<input type="checkbox" role="switch">`, with label, description and optional icons inside the thumb.

DevRites: a disciplined senior-engineer workflow pack for Claude Code, Codex, omp, pi, and Devin CLI

Design tokens (--c2-theme--*) and a generated base theme that maps every @c2n component CSS variable onto them

Anchored popup built on the browser Popover API and positioned with floating-ui, built with Lit.

`c2-table` is a virtualized data grid: one CSS grid whose header and body rows are `subgrid` items, so columns stay aligned with no scroll syncing and pinned columns are sticky cells rather than separate containers. Columns are declared as `c2-table-colum

Unified route builder for Next.js App Router APIs with x402, MPP, SIWX, and API key auth

Filter Cypress tests using title or tags

`c2-side-nav` is an app-shell layout with a navigation drawer beside the page content. It pushes the content on large screens (`side` mode) and slides over it with a backdrop on small ones (`over` mode), switching automatically at 600px and 960px.