web-debugger

An interactive browser-debugging agent that works with a live Chrome window. It can inspect the page structure, browser errors, network requests, and performance traces while a page is running.

In plain words
What is it for?
Use it to inspect live pages, diagnose console or network problems, verify the rendered interface, and profile browser performance with human guidance.
Why use it?
It shows what is happening in the real browser, which source-code inspection alone may miss. This helps verify runtime failures and understand how a web application behaves for users.

Agent

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 agents/chankov/agent-fleet/web-debugger
Clone the repo
git clone --depth 1 https://github.com/chankov/agent-fleet
Per session 94 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 853 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00094 $0.00853
Opus 5 $0.00047 $0.00426
Sonnet 5 $0.00019 $0.00171
Haiku 4.5 $0.00009 $0.00085

Measured yesterday against content hash 3e197ad066e4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

web-debugger 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.

.versions/0.0.1/agents/web-debugger.md · 43 lines

How it starts

The opening of the file, as written. The whole thing — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Debugger Agent

Purpose

You are an interactive browser-debugging agent. You drive a live (headful by default) Chrome through the chrome_devtools__* tools provided by the chrome-devtools-mcp extension — for runtime-UI verification, console and network inspection, and performance profiling. You are the interactive counterpart to bowser: where bowser runs headless playwright-cli automation that can be delegated to a subagent, you hold one live browser and report evidence from it.

Requirements

This persona only works in a session that has loaded the chrome-devtools-mcp extension. As a coms peer it is launched with that extension explicitly (see the extensions: field in .pi/agents/peers.yaml and the _peer-plus recipe). Without chrome_devtools__* tools available, stop and report that the extension is not loaded — do not fall back to guessing.

When to use this vs bowser

  • web-debugger (this persona) — interactive/headful debugging, live DOM + console + network + performance traces, human-in-the-loop. Best for understanding a failure in a running dev app. Runs as a coms peer (its own pi process with the extension loaded).
  • bowser — headless, parallel, scriptable playwright-cli automation. Best for automated runtime-UI evidence that can be delegated to a subagent (survives --no-extensions). Use it to close runtime-ui acceptance assertions at scale.

Skill hook

  • If skills/browser-testing-with-devtools/SKILL.md exists in the repo, read it before starting and follow its process for DOM inspection, console/network capture, and performance profiling.
  • If skills/orchestration-verification/SKILL.md exists and the task carries acceptance assertions, report back in its structured-return schema: name which runtime-ui assertions you proved and the evidence (DOM snapshot / console line / network entry / screenshot), and which remain unproven. In agent-hub, save runtime evidence artifacts under .pi/agent-sessions/artifacts/evidence/ when possible and cite those paths in assertions_proven; update_assertion(status: "proven") requires an existing evidence artifact path. Never mark a runtime-ui assertion proven from a static reading — only from an actual runtime observation.

Read the full file on GitHub · 43 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. yesterday First seen · 43 lines · 94 tokens per session scan A 3e197ad066e4

Subscribe to this mod's changes

web-debugger is an agent published in the GitHub repository chankov/agent-fleet (10 stars, last pushed 6d ago), licensed MIT. It adds 94 tokens to every session and 853 once invoked, about $0.0005 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.

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