observability-baseline

observability-baseline is a skill for Claude Code from avelikiy/great_cto. It costs 100 tokens per session (783 once invoked), scanned A, original, MIT.

A production-observability setup added during scaffolding. It adds Sentry error capture, request-based JSON logs, and health endpoints that show whether the app and its dependencies are working.

In plain words
What is it for?
It helps set up error reporting, structured request logging, source-map uploads, and liveness and readiness checks for deployed web applications.
Why use it?
It prevents production failures from being invisible and gives support teams the request details needed to investigate them.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the great-cto plugin — 40 skills, 44 commands, 70 agents shipped together

Good fit It helps set up error reporting, structured request logging, source-map uploads, and liveness and readiness checks for deployed web applications.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/avelikiy/great_cto/observability-baseline
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 avelikiy/great_cto --skill observability-baseline
Clone the repo
git clone --depth 1 https://github.com/avelikiy/great_cto

Made for: Claude Code.

Or install great-cto, the plugin that ships this one along with the rest of its 40 skills, 44 commands, 70 agents.

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 observability-baseline

README.md
[![agentmods](https://agentmods.dev/badge/skills/avelikiy/great_cto/observability-baseline/github.svg)](https://agentmods.dev/skills/avelikiy/great_cto/observability-baseline)
Your own site
<a href="https://agentmods.dev/skills/avelikiy/great_cto/observability-baseline"><img src="https://agentmods.dev/badge/skills/avelikiy/great_cto/observability-baseline/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.

agentmods 80×15 button for observability-baseline

Your own site · 80×15
<a href="https://agentmods.dev/skills/avelikiy/great_cto/observability-baseline"><img src="https://agentmods.dev/badge/skills/avelikiy/great_cto/observability-baseline.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 100 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 783 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 pass 7 Sept 2026
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 $0.00100 $0.00783
Opus 5 $0.00050 $0.00392
Sonnet 5 $0.00020 $0.00157
Haiku 4.5 $0.00010 $0.00078

Measured 7d ago against content hash 916b24904603, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

observability-baseline 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 7d 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-baseline/SKILL.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

observability-baseline

stack-baseline names Sentry and wires it nowhere — so every shipped product's first prod incident is invisible, and l3-support triages blind. This skill makes three things exist at scaffold time. Defaults baked in; no founder question.

1. Error capture (Sentry)

  • instrumentation.ts (Next.js) / SDK init at process start; DSN from SENTRY_DSN env (never hardcoded).
  • CI uploads source maps on release so stack traces are readable (release = git sha).
  • Capture unhandled rejections + a global error boundary on the client.

2. Request-id structured logging

  • A logger that emits JSON (not console.log prose) with a per-request request_id (generate at the edge, propagate via header/async-local-storage).
  • Levels: error / warn / info / debug — diagnostics go to stderr, never mixed into user-facing stdout. (Same discipline as the CLI logging gap, DEEPEN d94.)
  • One log line per request with: request_id, method, path, status, latency_ms.

3. Health endpoints

  • GET /healthz — liveness (process up). GET /readyz — readiness (deps reachable: db, cache). Cheap, unauthenticated, no PII.
  • These are what infra-provisioner probes and what a load balancer checks.

Wiring (a skill is shelfware unless a consumer loads it)

Consumer What it does with this skill
app-scaffolder bakes instrumentation.ts + the JSON logger + /healthz+/readyz into the generated app; adds SENTRY_DSN to .env.example
infra-provisioner sets SENTRY_DSN in the prod env list; points the platform health probe at /readyz; records the Sentry project in PROVISION
l3-support first triage step reads Sentry + the request-id logs (a trace now exists to read)
devops deploy gate fails if /readyz doesn't return 200 post-deploy

Output

A scaffolded app where the first prod error is captured, every request is traceable by id, and the platform can health-check it. Record the Sentry project + endpoints in docs/infra/PROVISION-{slug}.md. Done = the three pieces exist AND are wired into the prod env, not just present in code.

Read the full file on GitHub · 62 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. 7d ago First seen · 62 lines · 100 tokens per session scan A 916b24904603

Subscribe to this mod's changes

observability-baseline is a skill published in the GitHub repository avelikiy/great_cto (92 stars, last pushed today), licensed MIT. It adds 100 tokens to every session and 783 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 2026-09-03.

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