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 Undertone0809/rudder --skill browsergit clone --depth 1 https://github.com/Undertone0809/rudderWrote 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/undertone0809/rudder/browser)<a href="https://agentmods.dev/skills/undertone0809/rudder/browser"><img src="https://agentmods.dev/badge/skills/undertone0809/rudder/browser/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/undertone0809/rudder/browser"><img src="https://agentmods.dev/badge/skills/undertone0809/rudder/browser.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00142 | $0.02232 |
| Opus 5.5 | $0.00057 | $0.00893 |
| Sonnet 5.5 | $0.00028 | $0.00446 |
| Haiku 4.5 | $0.00014 | $0.00223 |
Grade A, and why
browser 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 1mo 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 — 188 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Browser
Use Rudder's built-in Browser only when the user explicitly names or selects
that surface, for example by saying Rudder Browser, Rudder's built-in Browser, or $browser, or by referring to a page or tab already open there.
The request must identify the Rudder Browser as the intended surface; a generic
request to browse the web, visit a URL, research a site, test localhost, take a
screenshot, or interact with a page is not enough to invoke this skill.
When explicitly selected, the Browser may share signed-in website state from the local Rudder Browser profile. If the user does not explicitly select it, do not open, inspect, or interact with Rudder's Browser on the skill's behalf.
The Browser is a separate optional integration named rudder-browser. Do not
look for Browser tools inside rudder-tools, launch another browser,
or inspect Browser profile files to work around it.
Start With The Right State
- Call
rudder_browser_tabsonce. Reuse a run-owned tab when it already has useful in-progress state. - Call
rudder_browser_user_tabsonly when the task refers to a page the user already has open in Rudder. It returns privacy-safe hostname and origin summaries, never the real title, path, query, fragment, or credentials. Results are read-only context; opaque ids cannot be passed to interaction tools. Open the returned origin only when it is sufficient. Otherwise ask the user for the exact URL instead of guessing a path. - Open a new run-owned tab with
rudder_browser_openwhen no existing run tab fits. Navigate an existing tab only when replacing its current page is intentional. - Keep Browser work hidden by default. Use
rudder_browser_visibilitywhen the user asks to see the page or watching the interaction is useful.
If the Browser server is disabled or unavailable, follow Availability And Recovery. Do not silently substitute another browser surface.
Observe, Decide, Act
Before each interaction, understand the current visible state with the cheapest observation that answers the next question:
What ships with it
5 files 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.
- 1mo ago First seen · 188 lines · 142 tokens per session scan A 85e5e32d7c53
browser is a skill published in the GitHub repository Undertone0809/rudder (292 stars, last pushed today), licensed Apache-2.0. It adds 142 tokens to every session and 2,232 once invoked, about $0.0006 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.
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