xvfb

xvfb is a skill for Claude Code, Codex from gpdir16/tabyAgent. It costs 32 tokens per session (606 once invoked), scanned A, original, AGPL-3.0.

A skill for running Linux graphical applications on a virtual X display, which provides a screen without requiring a physical monitor.

In plain words
What is it for?
It helps launch graphical Linux apps, capture screenshots, and interact with them using pixel coordinates.
Why use it?
It allows GUI programs to run inside Docker or another headless Linux environment, where there is normally no display for screenshots or mouse interaction.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/gpdir16/tabyagent/xvfb
Any agent
npx skills add gpdir16/tabyAgent --skill xvfb
Clone the repo
git clone --depth 1 https://github.com/gpdir16/tabyAgent

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for xvfb

README.md
[![agentmods](https://agentmods.dev/badge/skills/gpdir16/tabyagent/xvfb.svg)](https://agentmods.dev/skills/gpdir16/tabyagent/xvfb)
Your own site
<a href="https://agentmods.dev/skills/gpdir16/tabyagent/xvfb"><img src="https://agentmods.dev/badge/skills/gpdir16/tabyagent/xvfb.svg" alt="Measured on agentmods" height="20"></a>
Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 606 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00032 $0.00606
Opus 5 $0.00016 $0.00303
Sonnet 5 $0.00006 $0.00121
Haiku 4.5 $0.00003 $0.00061

Measured 4d ago against content hash 52074e5d7dd8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

xvfb 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 4d 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.

codes/skills/xvfb/SKILL.md · 65 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

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.

  1. 4d ago First seen · 65 lines · 32 tokens per session scan A 52074e5d7dd8

Subscribe to this mod's changes

xvfb is a skill published in the GitHub repository gpdir16/tabyAgent (18 stars, last pushed 3d ago), licensed AGPL-3.0. It adds 32 tokens to every session and 606 once invoked, about $0.0002 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 2026-08-30.

Related

Other skills, from other repositories

write-spec

Break large features into independently verifiable, human-reviewable slices under specs/ /. Use for risky or multi-step feature work that needs upfront questioning, API seams, browser-playable checkpoints, HTML visualizations, screenshot gates, staged implementation plans, recursive fog-of-war reslicing, or proactive…

dzhng/duet-agent · 175 tokens

dingtalk_channel_connect

Use a headed browser to automatically complete DingTalk channel integration for QwenPaw. Applicable when the user mentions DingTalk, developer console, Client ID, Client Secret, bot, Stream mode, binding or configuring a channel. Supports pausing when a login page is detected and resuming after the user logs in.

agentscope-ai/QwenPaw · 69 tokens

browser_cdp

当用户明确希望连接到已运行的 Chrome 浏览器、扫描本地 CDP 端口、显式指定 cdpport,或让多个 agent / 工具共享同一个浏览器时,使用本 skill。browser 默认不开放调试端口;仅当用户明确希望其他本地工具附加时才显式传入 cdpport。.

agentscope-ai/QwenPaw · 85 tokens

browser_visible

当用户需要控制 browser 的浏览器启动方式时,使用本 skill。browser 默认由 Playwright 直接管理、不开放调试端口(需让其他本地工具附加时显式传 cdpport);headed 控制是否显示窗口,privatemode 保留用于兼容、不再改变默认行为,browserargs 传入额外的 Chromium 启动参数,executablepath 指定自定义浏览器可执行文件路径。.

agentscope-ai/QwenPaw · 108 tokens

browser_visible

Use this skill when the user needs to control the browser launch mode for browser. By default browser is managed by Playwright and opens no debugging port (pass an explicit cdpport to let another local tool attach); headed controls whether the window is visible, and privatemode is kept for backward compatibility and…

agentscope-ai/QwenPaw · 75 tokens

browser

Drive a live browser with async Python against QwenPaw's builtin Browser SDK. The full reference is below; re-load this browser skill after context compaction.

agentscope-ai/QwenPaw · 35 tokens