What is observability?

A set of tools for watching and debugging web applications. It follows requests across the browser and backend, records logs and errors, and reports page performance measurements.

Use it to inspect distributed traces, browser console messages, network requests, JavaScript errors, and Core Web Vitals. It is intended for diagnosing application behaviour across frontend and backend services.

It helps locate failures and slowdowns that may occur between the web page and the services it calls. This gives developers evidence about what happened during a request or user action.

observability — Skill for Claude Code and Codex by serkan-ozal: A set of tools for watching and debugging web…

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/serkan-ozal/browser-devtools-claude/observability

Any agent

npx skills add serkan-ozal/browser-devtools-claude --skill observability

Clone the repo

git clone --depth 1 https://github.com/serkan-ozal/browser-devtools-claude

Made for: Claude Code, Codex.

Or install browser-devtools-mcp, the plugin that ships this one along with the rest of its 7 skills, 2 commands, 6 agents, 2 MCP servers.

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/skills/serkan-ozal/browser-devtools-claude/observability.svg)](https://agentmods.dev/skills/serkan-ozal/browser-devtools-claude/observability)

Your own site

<a href="https://agentmods.dev/skills/serkan-ozal/browser-devtools-claude/observability"><img src="https://agentmods.dev/badge/skills/serkan-ozal/browser-devtools-claude/observability.svg" alt="Measured on agentmods" height="20"></a>

Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 978 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.

Model	Per session	Once invoked
Fable 5	$0.00037	$0.00978
Opus 5	$0.00018	$0.00489
Sonnet 5	$0.00007	$0.00196
Haiku 4.5	$0.00004	$0.00098

Measured 5d ago against content hash 3731941225e3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

observability 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 5d 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.

skills/observability/SKILL.md · 154 lines

How it starts

The opening of the file, as written. The whole thing — 154 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Observability Skill

Monitor and debug web applications using OpenTelemetry, console logs, network requests, and distributed tracing.

When to Use

This skill activates when:

User asks about distributed tracing
User wants to correlate frontend and backend requests
User mentions OpenTelemetry, Jaeger, Zipkin, or tracing
User needs to debug request flow across services
User wants to monitor application behavior

Capabilities

Distributed Tracing

Get current trace ID (o11y_get-trace-id)
Generate new trace ID (o11y_new-trace-id)
Set specific trace ID (o11y_set-trace-id)
Correlate browser actions with backend traces

Console Monitoring

Capture all console output (o11y_get-console-messages)
Filter by level (error, warn, info, debug)
Track JavaScript exceptions
Monitor application logs

Network Observability

Track HTTP requests (o11y_get-http-requests)
Monitor API call timing
Identify failed requests
Inspect request/response details

Performance Metrics

Core Web Vitals (o11y_get-web-vitals)
Page load timing
Resource timing
User interaction metrics

OpenTelemetry Integration

Trace Context

Browser DevTools MCP can inject and extract W3C Trace Context headers:

traceparent: Contains trace-id, span-id, and trace flags
tracestate: Vendor-specific trace information

When using Node platform (PLATFORM=node), tracepoint/logpoint snapshots include traceContext (traceId, spanId) when the Node process uses @opentelemetry/api, enabling correlation of backend traces with browser traces in Jaeger/Grafana.

Correlation Flow

Browser Session
    │
    ├─► trace-id: abc123
    │
    ▼
Frontend Request
    │
    ├─► Header: traceparent: 00-abc123-def456-01
    │
    ▼
Backend Service
    │
    ├─► Logs with trace-id: abc123
    │
    ▼
Observability Platform
    │
    └─► Full trace visualization

Debugging Workflow

1. Set Up Tracing

/trace new

Generate a fresh trace ID for the session.

Read the full file on GitHub · 154 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.

5d ago First seen · 154 lines · 37 tokens per session scan A 3731941225e3

Subscribe to this mod's changes

observability is a skill published in the GitHub repository serkan-ozal/browser-devtools-claude (8 stars, last pushed 5mo ago), licensed MIT. It adds 37 tokens to every session and 978 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.

Debugging

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

chronicle

Analyze Copilot session history for standup reports, usage tips, session search, and session reindexing. Use when the user asks for a standup, daily summary, usage tips, workflow recommendations, wants to search or find past sessions by keyword/file/PR, wants to reindex their session store, or asks about deleting…

microsoft/vscode · 72 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens