Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add Cratis/AI --skill cratis-lens-browser-extensiongit clone --depth 1 https://github.com/Cratis/AIWrote 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/skills/cratis/ai/cratis-lens-browser-extension)<a href="https://agentmods.dev/skills/cratis/ai/cratis-lens-browser-extension"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-lens-browser-extension.svg" alt="Measured on agentmods" 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 | $0.00102 | $0.02836 |
| Opus 5 | $0.00051 | $0.01418 |
| Sonnet 5 | $0.00020 | $0.00567 |
| Haiku 4.5 | $0.00010 | $0.00284 |
Grade A, and why
cratis-lens-browser-extension 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 yesterday.
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 — 240 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Use Lens against a running Arc application
Lens is a Manifest V3 browser extension that impersonates a user and a tenant against an Arc application you are developing, and executes that application's commands and queries from a popup. It changes nothing in the application: it rewrites request headers at the network boundary and reads Arc's own introspection endpoints.
⚠️ Lens is a development tool that can present any identity to any origin the developer points it at. Nothing in it is production tooling.
Verified product sources
| Source | Version | Purpose |
|---|---|---|
Cratis/Lens Source/ |
manifest 1.0.0, repository revision 3d0df87 |
The extension itself |
Cratis.Arc.Core |
22.10.4 |
The /.cratis/* endpoints, the forwarded-identity contract, and the tenancy header Lens depends on |
⚠️ There is no published store listing. Nothing in the Lens repository links a Chrome Web Store, Edge Add-ons, AMO, or App Store entry — the only store URLs present are developer-console links inside its own publishing guide. Building from source and loading unpacked is the only install path that exists.
Install
cd Source
yarn install
yarn build # writes the unpacked extension to Source/dist/
Then open chrome://extensions, enable Developer mode, choose Load
unpacked, and select Source/dist. Chrome lists it as Cratis Lens — the
name in manifest.json; the repository's own tutorial calls it "Lens - Cratis
Developer Tools", which is stale.
yarn dev is vite build --watch; the extension still has to be reloaded in
Chrome after each rebuild. yarn ci runs typecheck, test and build — the
same three the pull-request workflow runs. There is no lint script.
The code uses the chrome.* namespace throughout with no polyfill. The release
workflow also packages for Edge, Firefox and Safari, but no cross-browser
behavior is tested; treat Chromium as the supported target.
What the Arc application must already provide
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- yesterday First seen · 240 lines · 102 tokens per session scan A 83cdd6356442
cratis-lens-browser-extension is a skill published in the GitHub repository Cratis/AI (2 stars, last pushed yesterday), licensed MIT. It adds 102 tokens to every session and 2,836 once invoked, about $0.0005 per session on Opus 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 2026-09-06.
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