What is gsd-browser AGENTS.md?

Instructions for gsd-browser, a command-line tool that controls Chrome or Chromium for browser automation. It can navigate pages, interact with elements, take snapshots, check results, extract data, mock network requests, emulate devices, store authentication details, and scan for prompt injection.

Opening websites, clicking and filling forms, collecting page data, checking visual changes, testing different devices, using saved logins, and inspecting page or network behavior.

They provide the commands and setup information an AI assistant needs to operate a real browser consistently. This avoids manually repeating the browser connection and interaction details.

How gsd-build/gsd-browser configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to gsd-build/gsd-browser. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/gsd-build/gsd-browser/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/gsd-build/gsd-browser

Made for: Codex, OpenCode.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/gsd-build/gsd-browser/agents-md/github.svg)](https://agentmods.dev/instructions/gsd-build/gsd-browser/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/gsd-build/gsd-browser/agents-md"><img src="https://agentmods.dev/badge/instructions/gsd-build/gsd-browser/agents-md/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/gsd-build/gsd-browser/agents-md"><img src="https://agentmods.dev/badge/instructions/gsd-build/gsd-browser/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 204 This file is loaded in full into every session.

When invoked 204 The same file — it is already loaded in full.

Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00204	$0.00204
Opus 5.5	$0.00082	$0.00082
Sonnet 5.5	$0.00041	$0.00041
Haiku 4.5	$0.00020	$0.00020

Measured 2mo ago against content hash 70508b1d2924, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

gsd-browser AGENTS.md scanned grade C with 2 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 2mo 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.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

curl -fsSL https://install.gsd.build/browser | bash

Makes network callslowCapability

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

curl -fsSL https://install.gsd.build/browser | bash

AGENTS.md · 29 lines

What it actually says

AGENTS.md

gsd-browser

Native Rust browser automation CLI for AI agents. Controls Chrome/Chromium via CDP with a persistent background daemon. Supports navigation, element interaction (click, type, fill), snapshots with versioned refs, assertions, form analysis, structured data extraction, visual regression testing, network mocking, device emulation, auth vault, and prompt injection scanning.

Quick Start

gsd-browser navigate https://example.com
gsd-browser snapshot
gsd-browser click-ref @v1:e1

Installation

curl -fsSL https://install.gsd.build/browser | bash

# or from a repo checkout
cargo install --path cli

Requires Chrome or Chromium. The installer reuses a system browser when present and downloads Chromium automatically where Chrome for Testing is available.

Full Reference

See SKILL.md for complete command reference (63 commands), workflow patterns, configuration, and examples.

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.

2mo ago First seen · 29 lines · 204 tokens per session scan C 70508b1d2924

Subscribe to this mod's changes

gsd-browser AGENTS.md is an instructions file published in the GitHub repository gsd-build/gsd-browser (269 stars, last pushed 6mo ago), licensed Apache-2.0. It adds 204 tokens to every session, about $0.0008 per session on Opus 5.5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Browser automation

gsd-browser AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
gsd-browser AGENTS.mdgsd-build/gsd-browser	Instructions file	269	6mo ago	Apache-2.0	C	204	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

gsd-browser: Instructions file for Codex