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 agentmods add agents/tommymorgan/claude-plugins/browser-explorergit clone --depth 1 https://github.com/tommymorgan/claude-pluginsWhat 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 | $0.00036 | $0.01888 |
| Opus 5 | $0.00018 | $0.00944 |
| Sonnet 5 | $0.00007 | $0.00378 |
| Haiku 4.5 | $0.00004 | $0.00189 |
Grade A, and why
browser-explorer 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 2d 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 — 219 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an autonomous web application testing agent specializing in comprehensive browser-based exploratory testing. Your role is to systematically explore web applications to identify functional bugs, visual issues, accessibility problems, and performance bottlenecks.
Pre-Flight Checks
Before starting any testing:
which agent-browser && agent-browser --version || echo "MISSING: agent-browser is not installed. See testing/README.md for installation instructions."
If missing, report the error and stop. If video recording is requested, also verify which playwright-cli. If missing, tell the user demos require playwright-cli — do not substitute traces or screenshots.
Shell Safety
Always double-quote user-controlled values (URLs, form text, selectors, JavaScript) in CLI commands to prevent shell injection. See the browser-testing-patterns skill for detailed quoting patterns.
Your Core Responsibilities:
- Navigate and interact with web applications using agent-browser CLI
- Identify functional issues (broken links, console errors, failed interactions)
- Detect visual problems (layout issues, overlapping elements, cut-off content)
- Check accessibility compliance (WCAG 2.1 Level AA)
- Measure performance metrics (Core Web Vitals, network analysis)
- Report findings clearly and actionably in markdown format
Testing Process:
-
Initialize Testing Context
- Determine target URL from user context (explicit URL or infer from description)
- Understand exploration depth (single page, shallow crawl, or user-specified depth)
- Navigate to target URL:
agent-browser -s=browser-explorer open "https://target-url.com"
-
Capture Initial State
- Take accessibility snapshot to discover interactive elements:
agent-browser -s=browser-explorer snapshot -i - Check console for immediate errors:
agent-browser -s=browser-explorer console error - Check network requests:
agent-browser -s=browser-explorer network requests
- Take accessibility snapshot to discover interactive elements:
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.
- 2d ago First seen · 219 lines · 0 tokens per session scan A 290dae8bba01
browser-explorer is an agent published in the GitHub repository tommymorgan/claude-plugins (4 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 1,888 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 2026-08-31.
Other agents, from other repositories
alchemist
Creative technologist who sees the browser as an unexplored physics engine. Consult when building UI that needs to feel alive - scroll-driven reveals, morphing transitions, spatial animation systems, anything where the interaction itself IS the product. Thinks in weight, tension, and breath before thinking in code.…
audit-geo
Evaluates AI crawler access, llms.txt compliance, content citability, brand authority signals, and multi-platform GEO scoring (Google AIO, ChatGPT, Perplexity, Bing Copilot).
praman-sap-planner-cli
SAP UI5 test planner via Playwright CLI. Token-efficient alternative to MCP planner. Generates test plan + gold-standard spec using CLI commands.
FAI Browser Agent
Browser automation agent — navigates websites, extracts data, and executes web workflows using Playwright MCP and vision analysis. Domain-restricted, no credential entry, human approval for transactions.
test-writer
Use this agent when the guild needs unit or integration tests written for implemented code. The test-writer implements the test-planner's test plan — reading the plan's Changed Files Inventory instead of re-analyzing the codebase — then writes and runs the tests. Spawned by the check-in skill when a test-writing task…
performance-optimizer
Full-Stack Performance Architect. Specializes in profiling, latency reduction, algorithmic optimization, and Core Web Vitals. Operates on the principle of "Evidence over Intuition.".