What is calendarcn CLAUDE.md?

A set of coding instructions for CalendarCN, an open-source React calendar component. It documents the project structure, important files, technologies, and code rules.

Use it when working on CalendarCN features, interactions, styling, or supporting code. It helps locate calendar components, hooks, utilities, and application files.

Contributors otherwise need to spend time discovering how the repository is organised and which conventions to follow. The instructions give a coding agent the project context needed before making changes.

How vmnog/calendarcn configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to vmnog/calendarcn. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/vmnog/calendarcn/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/vmnog/calendarcn

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/vmnog/calendarcn/claude-md/github.svg)](https://agentmods.dev/instructions/vmnog/calendarcn/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/vmnog/calendarcn/claude-md"><img src="https://agentmods.dev/badge/instructions/vmnog/calendarcn/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/vmnog/calendarcn/claude-md"><img src="https://agentmods.dev/badge/instructions/vmnog/calendarcn/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 2,085 This file is loaded in full into every session.

When invoked 2,085 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.02085	$0.02085
Opus 5.5	$0.00834	$0.00834
Sonnet 5.5	$0.00417	$0.00417
Haiku 4.5	$0.00209	$0.00209

Measured 26d ago against content hash 7cb721ac3a58, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

calendarcn CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 26d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 193 lines

How it starts

The opening of the file, as written. The whole thing — 193 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CalendarCN — Claude Context

Purpose

CalendarCN is an open-source React calendar component inspired by Notion Calendar. It provides a weekly view with drag/resize interactions, multi-day events, dark mode, and keyboard shortcuts. Built with Next.js 16, React 19, Tailwind CSS 4, and shadcn/ui.

Live: https://calendarcn.vercel.app

Repo Map

src/
├── app/                  # Next.js App Router (page.tsx owns top-level state)
├── components/
│   ├── ui/               # shadcn/ui primitives (don't edit directly)
│   ├── week-view*.tsx     # Core calendar — grid, columns, time axis, all-day row
│   ├── calendar-event-*   # Event rendering & interactions
│   ├── event-*            # Context menu, detail panel, detail popover
│   ├── sidebar-*          # Left/right sidebars
│   ├── nav-*              # Navigation components
│   └── theme-*            # Dark mode provider & toggle
├── hooks/                # Custom hooks (drag, resize, all-day-resize, scroll)
└── lib/
    ├── event-utils.ts    # Event positioning & column assignment algorithms
    ├── mock-events.ts    # Sample data
    └── utils.ts          # cn() helper

Key files:

src/components/week-view-types.ts — canonical type source for all shared types
src/app/page.tsx — owns currentDate, events, selectedEventId state
src/lib/event-utils.ts — positioning math (column assignment, pixel calculations)
src/hooks/use-event-drag.ts — drag interaction (snapping, cross-day, auto-scroll)
src/hooks/use-event-resize.ts — resize interaction (anchor model, edge flipping)

Rules

Code Style

No any types — import or create correct types, always
Prefer early returns over if/else chains or nested ternaries
All shared types go in week-view-types.ts — single source of truth
Never assign ref.current during render — always use useEffect
Constants in ALL_CAPS with JSDoc comments explaining purpose
Exhaustive hook dependencies — use refs to break circular deps, never skip deps
Use cn() for class merging — never string concatenation for conditional classes
import type for type-only imports — keep runtime and type imports separate

Read the full file on GitHub · 193 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

26d ago Changed · +4 lines · +249 tokens per session 7cb721ac3a58
28d ago First seen · 189 lines · 1,836 tokens per session scan A 45385e4e39fc

Subscribe to this mod's changes

calendarcn CLAUDE.md is an instructions file published in the GitHub repository vmnog/calendarcn (139 stars, last pushed 27d ago), licensed MIT. It adds 2,085 tokens to every session, about $0.0083 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-02.

Frontend React calendar nextjs shadcn-ui tailwindcss

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 9,715 tokens

calendarcn: Instructions file for Claude Code

Borrowing it

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

CalendarCN — Claude Context

Purpose

Repo Map

Rules

Code Style

What this file has done since we first saw it

Other instructions, from other repositories

vscode buildNext.instructions.md

next.js AGENTS.md

vscode oss-third-party-notices.instructions.md

langchain AGENTS.md

vscode copilot-instructions.md

deno copilot-instructions.md