excalidraw-zephy: Instructions file for Claude Code

CLAUDE.md

excalidraw-zephy CLAUDE.md is an instructions file for Claude Code from valeriyproklov/excalidraw-zephy. It costs 5,171 tokens per session, scanned A, original, MIT.

A project-specific instruction file for Claude Code, explaining how the Excalidraw-Zephy codebase is structured and differs from its upstream project.

In plain words
What is it for?
Use it when working on the Excalidraw-Zephy server, deployment, APIs, dashboards, or its changes from upstream.
Why use it?
It gives the coding agent the repository context needed to make changes without guessing where components live or which local patches must be preserved.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions Claude Code; mentions Codex.

This is valeriyproklov/excalidraw-zephy's own configuration. It tells Claude Code how to work on excalidraw-zephy itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything excalidraw-zephy configures →

Not installable: its command points at a path on the author’s own machine, so it runs nowhere else. The line is /home/val/excalidraw-zephy.

Reuse

Borrowing it

Nothing to install: this file belongs to valeriyproklov/excalidraw-zephy. 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/valeriyproklov/excalidraw-zephy/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/valeriyproklov/excalidraw-zephy

Made for: Claude Code.

Wrote this? Show the measurements

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Per session 5,171 This file is loaded in full into every session.
When invoked 5,171 The same file — it is already loaded in full.
Security scan A 1 finding. 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.05171 $0.05171
Opus 5 $0.02586 $0.02586
Sonnet 5 $0.01034 $0.01034
Haiku 4.5 $0.00517 $0.00517

Measured 10d ago against content hash 518da3e2bc39, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

excalidraw-zephy CLAUDE.md scanned grade A with 1 finding 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 10d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s -H "X-Admin-Key: $KEY" -H "Content-Type: application/json" \
CLAUDE.md · 313 lines

How it starts

The opening of the file, as written. The whole thing — 313 lines — stays where its author put it; the contents beside it link to each section on GitHub.

excalidraw-zephy — self-hosted multi-room Excalidraw

A fork of yctimlin/mcp_excalidraw patched for multi-room support, file-based persistence, an admin API, a private dashboard, and Cloudflare-Tunnel public exposure. Designed to give one user (and friends with share links) the collaborative parts of Excalidraw+ without paying for it, plus an MCP server so a Claude Code agent can drive any board.

Lives on Zephy (Ubuntu 24.04 home server, 100.121.176.61 over Tailscale). Public URL: https://draw.proklov.dev via Cloudflare Tunnel.

Where things are

Path / URL
Local repo (Mac dev) ~/Documents/projects/excalidraw-zephy
Zephy deploy /home/val/excalidraw-zephy
Public canvas https://draw.proklov.dev/r/<room-id>
Public MCP endpoint https://draw.proklov.dev/mcp (bearer-token auth from dashboard's /api/tokens UI)
Admin dashboard https://draw-admin.proklov.dev/ — behind Cloudflare Access (Google IdP, val's Gmail only). LAN fallback: http://zephy:5000/.
Canvas REST API https://draw.proklov.dev/api/r/<room-id>/...
Canvas WebSocket wss://draw.proklov.dev/ws/r/<room-id>
Admin API (tailnet only) http://zephy:3000/api/admin/rooms (X-Admin-Key required)
Admin key .env on Zephy at ~/excalidraw-zephy/.env (mode 0600)
Persistent state docker named volume excalidraw-zephy_canvas-data/app/data/<room-id>.json
Tunnel config /home/val/.cloudflared/config.yml + /etc/systemd/system/cloudflared.service
CF Access apps draw-admin.proklov.dev (Google IdP, allow [email protected], 72h session). The Access app on draw.proklov.dev was retired so /r/<id> and /mcp stay public.

One GitHub repo (as of 2026-07 — the repos were merged):

  • Val4evr/excalidraw-zephy — canvas server + dashboard
    • the MCP server (src/index.ts, shared by the stdio npx install and the HTTP /mcp endpoint)
    • the headless renderer sidecar (renderer/).
  • Val4evr/excalidraw-mcpDEPRECATED, folded into this repo. Install the MCP with npx -y --package=github:Val4evr/excalidraw-zephy excalidraw-mcp.

Read the full file on GitHub · 313 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.

  1. 10d ago First seen · 313 lines · 5,171 tokens per session scan A 518da3e2bc39

Subscribe to this mod's changes

excalidraw-zephy CLAUDE.md is an instructions file published in the GitHub repository valeriyproklov/excalidraw-zephy (0 stars, last pushed 2mo ago), licensed MIT. It adds 5,171 tokens to every session, about $0.0259 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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