Borrowing it
Nothing to install: this file belongs to fixed-width/glass. 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/fixed-width/glass/master/CLAUDE.mdgit clone --depth 1 https://github.com/fixed-width/glassWrote 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/fixed-width/glass/claude-md)<a href="https://agentmods.dev/instructions/fixed-width/glass/claude-md"><img src="https://agentmods.dev/badge/instructions/fixed-width/glass/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/fixed-width/glass/claude-md"><img src="https://agentmods.dev/badge/instructions/fixed-width/glass/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 | $0.01237 | $0.01237 |
| Opus 5.5 | $0.00495 | $0.00495 |
| Sonnet 5.5 | $0.00247 | $0.00247 |
| Haiku 4.5 | $0.00124 | $0.00124 |
Grade A, and why
glass 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 27d 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.
This is a copy
89% identical to glass AGENTS.md — 22 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
Guidance for Claude Code working in the glass open-core Rust workspace.
This repository is PUBLIC. Keep internal business/strategy, licensing-strategy framing, planning and design specs, and the internal security threat model out of this repo — that material lives in the private
fixed-widthrepo. Document what the product does, never why it helps the business.
What glass is
A Rust MCP server giving an AI agent a closed build → see → interact → debug loop
over external native GUI apps: launch, capture (lossless WebP), inject mouse/keyboard,
read logs, diff against baselines, wait-until-stable, and read/drive the accessibility
tree — served over MCP (stdio, or serve --http). Backends behind a Platform seam: X11
and Wayland (headless sway) on Linux, Windows (WGC/SendInput), Android (native apps in an AVD
emulator over adb, host-OS-agnostic; clipboard + high-fidelity input via an optional
on-device companion agent), iOS (native apps in the Simulator over xcrun simctl; capture,
logs, clipboard, plus input and the accessibility tree via idb_companion, including a
two-finger pinch; other multi-touch gestures excepted), macOS (ScreenCaptureKit
capture, CGEvent input, AXUIElement
windows/logs, accessibility tree, clipboard (isolated + working under containment for
apps not built with hardened runtime, via a DYLD_INSERT_LIBRARIES swizzle shim;
hardened-runtime apps fall back to unsupported), sandboxing (Seatbelt)).
Layout
Cargo workspace at the repo root. Crates: glass-core (platform-agnostic heart — the
Platform/Accessibility seams, session, Frame, diff, stability, log buffer), the
backends (glass-x11, glass-wayland, glass-windows, glass-android, glass-ios (the iOS
Simulator backend over xcrun simctl), glass-macos), the a11y readers
(glass-a11y-linux, glass-a11y-windows, glass-a11y-macos; the Android uiautomator
reader lives in glass-android), glass-sandbox-linux, glass-sandbox-macos, the glass-mcp server binary, and the
glass-testapp fixture. glass-android also holds the host-side client + lifecycle for two
optional on-device companions — an app_process agent (clipboard + high-fidelity input) and an
AccessibilityService (Compose-rich a11y tree + high-fidelity set_value); both live in the
separate repo github.com/fixed-width/glass-android-agent, driven over adb forward.
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.
- 27d ago Changed · +3 lines · +54 tokens per session dd07ed6b126f
- 2mo ago Changed · +1 tokens per session 69c8b4b2dd47
- 2mo ago Changed · +9 lines · +130 tokens per session 18413176d818
- 2mo ago First seen · 71 lines · 1,052 tokens per session scan A b10ff6cd8e19
glass CLAUDE.md is an instructions file published in the GitHub repository fixed-width/glass (20 stars, last pushed 4d ago), licensed Apache-2.0. It adds 1,237 tokens to every session, about $0.0049 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 89% identical to glass AGENTS.md, differing in 22 lines, and is treated as a copy.
glass CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| glass CLAUDE.mdfixed-width/glass | Instructions file | 20 | 4d ago | Apache-2.0 | A | 1,237 | 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 | yesterday | 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 |