OpenPencil is an open-source vector design tool where users describe interfaces in natural language and edit them on a live canvas with AI. Designers and developers use it for UI creation, design iteration, and coordinating multiple AI agents on different parts of a page. The catalogue entries provide instructions for working with OpenPencil.
Borrowing it
Nothing to install: this file belongs to ZSeven-W/openpencil. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/ZSeven-W/openpencil/main/CLAUDE.mdgit clone --depth 1 https://github.com/ZSeven-W/openpencilWrote 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.
[](https://agentmods.dev/instructions/zseven-w/openpencil/claude-md)<a href="https://agentmods.dev/instructions/zseven-w/openpencil/claude-md"><img src="https://agentmods.dev/badge/instructions/zseven-w/openpencil/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.
<a href="https://agentmods.dev/instructions/zseven-w/openpencil/claude-md"><img src="https://agentmods.dev/badge/instructions/zseven-w/openpencil/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.01425 | $0.01425 |
| Opus 5.5 | $0.00570 | $0.00570 |
| Sonnet 5.5 | $0.00285 | $0.00285 |
| Haiku 4.5 | $0.00143 | $0.00143 |
Grade A, and why
openpencil 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
The TypeScript OpenPencil has been retired.
apps/web,apps/desktop,apps/cli, and thepen-*packages (pen-types/core/engine/renderer/figma/mcp/ai-skills/sdk/react/acp) are gone. The product is now implemented in Rust (crates/) with a thin wasm-backed web SDK (packages/op-web-sdk*). Historical// ported from pen-*comments in the Rust sources name the retired TS as their origin — that code no longer exists in-tree; consult git history (last TS tagv0.7.5) if you need it.
Detailed module docs load automatically in subdirectories:
crates/CLAUDE.md— Rust shell: crate layout, editor core, widgets, hosts (native/web/desktop), MCP, AI, orchestrator, codegen. The canonical architecture doc.packages/CLAUDE.md— Remaining packages (op-web-sdk web viewer SDK family).
Commands
Tooling is Cargo (Rust — the product). The root has no package.json; the JS/Bun tooling for the web SDK lives under packages/ — run SDK/JS scripts from there.
- Web dev server (Rust):
bash scripts/start-web-rust.sh - Build (Rust):
cargo build --workspace --release - Run all tests (Rust):
cargo test --workspace; single crate:cargo test -p <crate> - Type check:
cargo check --workspace; wasm:cargo check --target wasm32-unknown-unknown -p op-host-web --no-default-features --features web - Lint / format (Rust):
cargo clippy --workspace --all-targets -- -D warnings/cargo fmt --all - Lint / format (remaining TS SDK): from
packages/:bun run lint(oxlint) /bun run format(oxfmt) - Desktop app:
cargo build -p op-host-desktop→ binaryopenpencil-desktop(live MCP on127.0.0.1:<port>/mcp) - CLI:
cargo build -p op-cli→ binaryop - MCP server: built into the desktop/web host (
--mcp <path>); crateop-mcp - Iconify catalog (Rust assets): from
packages/:bun run generate-iconify-catalog - Sync all managed versions:
scripts/sync-version.shreads the canonical version from rootCargo.toml; verify without writing viatools/check-version-sync.sh
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.
- 2mo ago First seen · 77 lines · 1,425 tokens per session scan A 1220aceffcb8
openpencil CLAUDE.md is an instructions file published in the GitHub repository ZSeven-W/openpencil (7,082 stars, last pushed yesterday), licensed MIT. It adds 1,425 tokens to every session, about $0.0057 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 2026-08-30.
openpencil CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| openpencil CLAUDE.mdZSeven-W/openpencil | Instructions file | 7.1k | yesterday | MIT | A | 1,425 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |