debug-browser

debug-browser is a skill for Claude Code from blockmatic/basilic. It costs 24 tokens per session (241 once invoked), scanned A, original, MIT.

A browser-debugging tool that uses instrumentation and browser tools to investigate and improve the current task. Instrumentation means adding temporary checks or measurements to see what the software is doing.

In plain words
What is it for?
Use it to reproduce and investigate problems in a web page or browser-based application while making changes.
Why use it?
It reduces the need for manual testing by helping trace browser behavior during an iterative debugging process.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it to reproduce and investigate problems in a web page or browser-based application while making changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/blockmatic/basilic/debug-browser
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 blockmatic/basilic --skill debug-browser
Clone the repo
git clone --depth 1 https://github.com/blockmatic/basilic

Made for: Claude Code.

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 debug-browser

README.md
[![agentmods](https://agentmods.dev/badge/skills/blockmatic/basilic/debug-browser.svg)](https://agentmods.dev/skills/blockmatic/basilic/debug-browser)
Your own site
<a href="https://agentmods.dev/skills/blockmatic/basilic/debug-browser"><img src="https://agentmods.dev/badge/skills/blockmatic/basilic/debug-browser.svg" alt="Measured on agentmods" height="20"></a>
Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 241 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 24
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 $0.00024 $0.00241
Opus 5 $0.00012 $0.00120
Sonnet 5 $0.00005 $0.00048
Haiku 4.5 $0.00002 $0.00024

Measured yesterday against content hash 75692c53768a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

debug-browser 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 yesterday.

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.

.agents/skills/workflow/debug-browser/SKILL.md · 25 lines

What it actually says

Purpose and inputs

Use the affected URL, expected interaction, and available browser tools. Inspect the app's README and browser-testing conventions first.

Steps

  1. Reproduce the interaction and collect relevant DOM, network, and console evidence before adding instrumentation.
  2. Trace the failure to its owning client or server boundary. Use the repository logger for necessary temporary traces; avoid secrets in captured output.
  3. Apply the smallest authorized fix, then replay the same interaction and relevant failure or empty states.
  4. Run affected automated checks and remove temporary traces introduced here. If tools or credentials block reproduction, report the exact limitation rather than looping without new evidence.

Verification and handoff

  • Original interaction succeeds in the browser after the fix.
  • Relevant failures, loading states, and console/network errors were inspected.
  • Reported runtime evidence and automated results are distinguished.

Return the cause, changed behavior, and evidence. Do not ask the user to test something the available tools can verify.

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. yesterday Changed · +11 lines · -8 tokens per session 75692c53768a
  2. 4d ago First seen · 14 lines · 32 tokens per session scan A a92c270844c9

Subscribe to this mod's changes

debug-browser is a skill published in the GitHub repository blockmatic/basilic (89 stars, last pushed yesterday), licensed MIT. It adds 24 tokens to every session and 241 once invoked, about $0.0001 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 2026-09-03.

Related

Other skills, from other repositories

chrome-devtools-cli

Use this skill to write shell scripts or run shell commands to automate tasks in the browser or otherwise use Chrome DevTools via CLI.

ChromeDevTools/chrome-devtools-mcp · 31 tokens

a11y-debugging

Uses Chrome DevTools MCP for accessibility (a11y) debugging and auditing based on web.dev guidelines. Use when testing semantic HTML, ARIA labels, focus states, keyboard navigation, tap targets, and color contrast.

ChromeDevTools/chrome-devtools-mcp · 50 tokens

chrome-devtools

Uses Chrome DevTools via MCP for efficient debugging, troubleshooting and browser automation. Use when debugging web pages, automating browser interactions, analyzing performance, or inspecting network requests. This skill does not apply to --slim mode (MCP configuration).

ChromeDevTools/chrome-devtools-mcp · 55 tokens

chrome-performance-optimizer

Autonomous multi-agent performance optimization loop for Chromium and V8. Supports profile-seeded mode (analyzing Speedometer 3 / JetStream profiles via pprof or Sagacity MCP) and pattern-driven discovery mode (fan-out exploration of Blink and V8 macro-patterns grounded in historical wins and past rejected CLs).…

chromium/chromium · 119 tokens

nullaway

Guide for resolving NullAway static analysis errors. Best practices for: Passing ObservableSupplier/Supplier Dereferencing potentially @Nullable values Adding @NullMarked to Java code.

chromium/chromium · 43 tokens

bisect

Bisect regressions or broken builds in the Chromium repository using deterministic binary search, checking out midpoint commits, syncing dependencies with gclient sync, compiling the target with autoninja, and querying the user for test results until the culprit commit is isolated.

chromium/chromium · 52 tokens