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/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/skills/cratis/ai/cratis-lens-browser-extension"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-lens-browser-extension.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 | $0.00102 | $0.03333 |
| Opus 5.5 | $0.00041 | $0.01333 |
| Sonnet 5.5 | $0.00020 | $0.00667 |
| Haiku 4.5 | $0.00010 | $0.00333 |
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 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.
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 — 269 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 | Purpose |
|---|---|
Cratis/Lens Source/ |
The extension itself; no newer release |
Cratis.Arc.Core |
The /.cratis/* endpoints, the forwarded-identity contract, and the tenancy header Lens depends on |
Arc evidence: ArcOptions.cs, MicrosoftIdentityPlatformAuthenticationHandler.cs, IntrospectionOptions.cs and DiscoveryExposure.cs.
⚠️ 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.
Safety
The manifest asks for storage, scripting, cookies, declarativeNetRequest,
declarativeNetRequestWithHostAccess and <all_urls>. That combination lets the
extension present a chosen identity to any origin, read and delete cookies, and
inject into any page.
- Keep it out of a browser profile used for anything but development.
- The user roster, including claims, is stored unencrypted in
chrome.storage.local. - An application reachable outside a developer's machine while trusting the forwarded headers is impersonatable by anyone who can set them. Lens does not create that exposure — it demonstrates it.
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.
- 10d ago Changed 019d0a86296f
- 11d ago Changed · +27 lines ec2038bb4844
- 15d ago Changed a1d8a3e795a8
- 1mo ago Changed · +2 lines d628a28de0d2
- 1mo ago 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 (4 stars, last pushed yesterday), licensed MIT. It adds 102 tokens to every session and 3,333 once invoked, about $0.0004 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 2026-09-06.
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