agent-browser

agent-browser is a skill for Claude Code, Codex from tashfeenahmed/circlechat. It costs 101 tokens per session (1,282 once invoked), scanned A, original, MIT.

A skill for controlling a real headless Chromium browser, a browser without a visible window, from the workspace. It can read JavaScript-rendered pages, fill forms, click controls, run JavaScript, and take screenshots.

In plain words
What is it for?
Use it to test interactive websites, inspect pages after JavaScript runs, submit forms, click through workflows, and capture screenshots.
Why use it?
It handles web pages that a simple HTTP request cannot fully load or interact with.

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/tashfeenahmed/circlechat/browser-skill
Any agent
npx skills add tashfeenahmed/circlechat --skill browser-skill
Clone the repo
git clone --depth 1 https://github.com/tashfeenahmed/circlechat

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 agent-browser

README.md
[![agentmods](https://agentmods.dev/badge/skills/tashfeenahmed/circlechat/browser-skill.svg)](https://agentmods.dev/skills/tashfeenahmed/circlechat/browser-skill)
Your own site
<a href="https://agentmods.dev/skills/tashfeenahmed/circlechat/browser-skill"><img src="https://agentmods.dev/badge/skills/tashfeenahmed/circlechat/browser-skill.svg" alt="Measured on agentmods" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,282 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
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 $0.00101 $0.01282
Opus 5 $0.00051 $0.00641
Sonnet 5 $0.00020 $0.00256
Haiku 4.5 $0.00010 $0.00128

Measured 4d ago against content hash 3d8f7253a821, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agent-browser 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 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.

Makes network callslowCapability

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

`curl`**. Use `python3` for every HTTP call below.
api/templates/browser-skill/SKILL.md · 141 lines

How it starts

The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.

agent-browser — browser automation over HTTP

Chromium runs as a shared daemon on the host (one browser across all agents). You drive it by POST'ing to /agent-api/browser with the CLI verb + args. Response is {exitCode, stdout, stderr} as JSON.

The shell you're in

Hermes agents (Nova, Ada, …): your container has python3 but not curl. Use python3 for every HTTP call below.

OpenClaw agents (Max, …): your container has both curl and python3. Either works; curl is shorter.

Python helper (works everywhere)

Paste this at the top of your terminal block, then call ab() repeatedly in the same turn:

import json, os, urllib.request
API = os.environ.get("CC_API_BASE", "http://localhost:3300/api")
TOKEN = os.environ["CC_BOT_TOKEN"]
def ab(cmd, args=None, stdin=None):
    body = json.dumps({"cmd": cmd, "args": args or [], "stdin": stdin}).encode()
    req = urllib.request.Request(
        f"{API}/agent-api/browser",
        data=body,
        headers={"Authorization": f"Bearer {TOKEN}", "Content-Type": "application/json"},
        method="POST",
    )
    with urllib.request.urlopen(req, timeout=50) as r:
        return json.loads(r.read())

Recipes

Read the visible text of a page (most common — research/citations):

ab("open", ["https://example.com"])
print(ab("get text", ["body"])["stdout"])
ab("close")

Accessibility snapshot with element refs (best for AI — gives you @e1, @e2, … handles to click/fill by):

print(ab("snapshot")["stdout"])

Click an element by ref from a snapshot:

ab("click", ["@e3"])

Find + act by semantic locator (resilient to page redesigns):

ab("find role", ["button", "click", "--name", "Submit"])
ab("find text", ["Sign In", "click"])
ab("find label", ["Email", "fill", "[email protected]"])

Evaluate JavaScript on the current page:

print(ab("eval", ["document.title"])["stdout"])

Open → snapshot → extract → close in one turn (preferred):

Read the full file on GitHub · 141 lines

Files

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.

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 · 141 lines · 101 tokens per session scan A 3d8f7253a821

Subscribe to this mod's changes

agent-browser is a skill published in the GitHub repository tashfeenahmed/circlechat (57 stars, last pushed 9d ago), licensed MIT. It adds 101 tokens to every session and 1,282 once invoked, about $0.0005 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 2026-08-30.