vellum-browser-use

vellum-browser-use is a skill for Claude Code, Codex from vellum-ai/vellum-assistant. It costs 15 tokens per session (2,284 once invoked), scanned A, original, MIT.

A browser-automation skill that controls web pages through Vellum's browser command-line tools.

In plain words
What is it for?
Use it to navigate websites, take snapshots or screenshots, click, type, select options, scroll, extract text, handle downloads, and fill stored credentials.
Why use it?
It provides a defined way to navigate pages, inspect their controls, enter information, and wait for results.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to navigate websites, take snapshots or screenshots, click, type, select options, scroll, extract text, handle downloads, and fill stored credentials.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/vellum-ai/vellum-assistant/vellum-browser-use
About the project

Vellum Assistant is a personal AI assistant that remembers information about users, learns their preferences, and takes actions across connected apps. It is intended for people who want an assistant that can manage conversations, unfinished work, and proactive notifications over time. The catalogue skills, hooks, instruction, and setting configure or extend how the assistant works.

vellum-ai/vellum-assistant · 1,225 stars · on GitHub · vellum.ai

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.

Any agent
npx skills add vellum-ai/vellum-assistant --skill vellum-browser-use
Clone the repo
git clone --depth 1 https://github.com/vellum-ai/vellum-assistant

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 vellum-browser-use

README.md
[![agentmods](https://agentmods.dev/badge/skills/vellum-ai/vellum-assistant/vellum-browser-use/github.svg)](https://agentmods.dev/skills/vellum-ai/vellum-assistant/vellum-browser-use)
Your own site
<a href="https://agentmods.dev/skills/vellum-ai/vellum-assistant/vellum-browser-use"><img src="https://agentmods.dev/badge/skills/vellum-ai/vellum-assistant/vellum-browser-use/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.

agentmods 80×15 button for vellum-browser-use

Your own site · 80×15
<a href="https://agentmods.dev/skills/vellum-ai/vellum-assistant/vellum-browser-use"><img src="https://agentmods.dev/badge/skills/vellum-ai/vellum-assistant/vellum-browser-use.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 15 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,284 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original 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 5.1 $0.00015 $0.02284
Opus 5 $0.00008 $0.01142
Sonnet 5 $0.00003 $0.00457
Haiku 4.5 $0.00002 $0.00228

Measured today against content hash 156d8f14b2d3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

vellum-browser-use scanned grade A with 1 finding 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 today.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

If navigate, curl, or any fetch times out, hits an auth wall, or cannot reach a host (VPN, company login, internal dashboard):
skills/vellum-browser-use/SKILL.md · 207 lines

How it starts

The opening of the file, as written. The whole thing — 207 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Use this skill to browse the web. All browser operations are executed through the assistant browser CLI, invoked via bash or host_bash. Each operation is a subcommand:

Command Description
assistant browser navigate Navigate to a URL
assistant browser snapshot List interactive elements on the current page
assistant browser screenshot Take a visual screenshot
assistant browser click Click an element
assistant browser type Type text into an input
assistant browser press-key Press a keyboard key
assistant browser scroll Scroll the page or a specific element
assistant browser select-option Select an option from a native <select> element
assistant browser hover Hover over an element to reveal menus/tooltips
assistant browser wait-for Wait for a condition
assistant browser extract Extract page text content
assistant browser wait-for-download Wait for a file download to complete
assistant browser fill-credential Fill a stored credential into a form field
assistant browser attach Attach the Chrome debugger to the active tab
assistant browser detach Detach the Chrome debugger from the active tab
assistant browser close Close the browser page
assistant browser status Diagnose browser backend readiness and setup steps

Getting Started — Check Browser Readiness

Before using any browser commands, run assistant browser --json status first to check which browser backends are available. The status command returns JSON with readiness information for each backend mode:

assistant browser --json status

The response includes:

  • recommendedMode — the best available backend (use this)
  • modes[] — per-mode status with available, summary, and userActions (remediation steps)

Read the full file on GitHub · 207 lines

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. today Changed 156d8f14b2d3
  2. 2d ago Changed · +11 lines c16d22b49590
  3. 7d ago First seen · 196 lines · 15 tokens per session scan A 7ed38008bb89

Subscribe to this mod's changes

vellum-browser-use is a skill published in the GitHub repository vellum-ai/vellum-assistant (1,225 stars, last pushed today), licensed MIT. It adds 15 tokens to every session and 2,284 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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