What is dt-obs-frontends?

A monitoring and investigation skill for web and mobile frontends, the parts of applications that users see and interact with. It uses real-user data to examine performance, sessions, actions, requests, crashes, and errors.

Use it to query web and mobile telemetry, track Core Web Vitals, inspect sessions and interactions, analyze frontend errors with backend traces, and investigate mobile startup and stability.

It helps connect reported slowness or failures with what users actually experienced. This makes it easier to find frontend performance problems and diagnose their causes.

How israel-salgado/dt-mcp-server configures Claude Code and Codex

Reuse

Borrowing it

Nothing to install: this file belongs to israel-salgado/dt-mcp-server. 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/israel-salgado/dt-mcp-server/main/.agents/skills/dt-obs-frontends/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/israel-salgado/dt-mcp-server

Made for: Claude Code, Codex.

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/israel-salgado/dt-mcp-server/dt-obs-frontends/github.svg)](https://agentmods.dev/skills/israel-salgado/dt-mcp-server/dt-obs-frontends)

Your own site

<a href="https://agentmods.dev/skills/israel-salgado/dt-mcp-server/dt-obs-frontends"><img src="https://agentmods.dev/badge/skills/israel-salgado/dt-mcp-server/dt-obs-frontends/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/skills/israel-salgado/dt-mcp-server/dt-obs-frontends"><img src="https://agentmods.dev/badge/skills/israel-salgado/dt-mcp-server/dt-obs-frontends.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 5,722 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.

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	$0.00040	$0.05722
Opus 5.5	$0.00016	$0.02289
Sonnet 5.5	$0.00008	$0.01144
Haiku 4.5	$0.00004	$0.00572

Measured 2mo ago against content hash e98fa38ad69d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

dt-obs-frontends 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 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.

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/dt-obs-frontends/SKILL.md · 610 lines

How it starts

The opening of the file, as written. The whole thing — 610 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Frontend Observability Skill

Monitor web and mobile frontends using Real User Monitoring (RUM) with DQL queries. This skill targets the new RUM experience only; do not use classic RUM data.

Overview

This skill helps you:

Monitor Core Web Vitals and frontend performance
Track user sessions, engagement, and behavior
Analyze errors and correlate with backend traces
Optimize mobile app startup and stability
Diagnose performance issues with detailed timing analysis

Data Sources:

Metrics: timeseries with dt.frontend.* (trends, alerting)
Events: fetch user.events (individual page views, requests, clicks, errors)
Sessions: fetch user.sessions (session-level aggregates: duration, bounce, counts)

Quick Reference

Common Metrics

dt.frontend.user_action.count - User action volume
dt.frontend.user_action.duration - User action duration
dt.frontend.request.count - Request volume
dt.frontend.request.duration - Request latency (ms)
dt.frontend.error.count - Error counts
dt.frontend.session.active.estimated_count - Active sessions
dt.frontend.user.active.estimated_count - Unique users
dt.frontend.web.page.cumulative_layout_shift - CLS metric
dt.frontend.web.navigation.dom_interactive - DOM interactive time
dt.frontend.web.page.first_input_delay - FID metric (legacy; prefer INP)
dt.frontend.web.page.largest_contentful_paint - LCP metric
dt.frontend.web.page.interaction_to_next_paint - INP metric
dt.frontend.web.navigation.load_event_end - Load event end
dt.frontend.web.navigation.time_to_first_byte - Time to first byte

Common Filters

frontend.name - Filter by frontend name (e.g. my-frontend)
dt.rum.user_type - Exclude synthetic monitoring
geo.country.iso_code - Geographic filtering
device.type - Mobile, desktop, tablet
browser.name - Browser filtering

Common Timeseries Dimensions

Use these for dt.frontend.* timeseries splits and breakdowns:

frontend.name - Frontend name
geo.country.iso_code
device.type
browser.name
os.name
user_type - real_user, synthetic, robot

Read the full file on GitHub · 610 lines

Files

What ships with it

24 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 610 lines · 40 tokens per session scan A e98fa38ad69d

Subscribe to this mod's changes

dt-obs-frontends is a skill published in the GitHub repository israel-salgado/dt-mcp-server (2 stars, last pushed 6mo ago), licensed MIT. It adds 40 tokens to every session and 5,722 once invoked, about $0.0002 per session on Opus 5.5. 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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dt-mcp-server: Skill for Claude Code