host-onboard-diagnose

host-onboard-diagnose is a skill for Claude Code, Codex from ccfos/nightingale. It costs 217 tokens per session (2,275 once invoked), scanned A, original, Apache-2.0.

A troubleshooting guide for machines that are newly added to Nightingale but do not appear correctly in its host list. Categraf is the agent that sends the machine's monitoring data to Nightingale.

In plain words
What is it for?
Use it to investigate missing hosts, unknown operating-system or CPU details, hosts deployed with Helm, Windows registration failures, and problems after a hostname change.
Why use it?
It checks the full onboarding path instead of assuming that an installed and running agent has successfully registered or sent usable metrics.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to investigate missing hosts, unknown operating-system or CPU details, hosts deployed with Helm, Windows registration failures, and problems after a hostname change.

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Install with agentmods
npx agentmods add skills/ccfos/nightingale/host-onboard-diagnose
About the project

Nightingale is an open-source monitoring and alerting system that connects to stored metrics and log data, evaluates alert rules, and distributes notifications. Operations teams use it to manage alarms and explore observability data alongside existing data sources and collectors. Catalogue add-ons provide skills for operating Nightingale.

ccfos/nightingale · 13,282 stars · on GitHub · n9e.github.io

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 ccfos/nightingale --skill host-onboard-diagnose
Clone the repo
git clone --depth 1 https://github.com/ccfos/nightingale

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.

agentmods badge for host-onboard-diagnose

README.md
[![agentmods](https://agentmods.dev/badge/skills/ccfos/nightingale/host-onboard-diagnose/github.svg)](https://agentmods.dev/skills/ccfos/nightingale/host-onboard-diagnose)
Your own site
<a href="https://agentmods.dev/skills/ccfos/nightingale/host-onboard-diagnose"><img src="https://agentmods.dev/badge/skills/ccfos/nightingale/host-onboard-diagnose/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 host-onboard-diagnose

Your own site · 80×15
<a href="https://agentmods.dev/skills/ccfos/nightingale/host-onboard-diagnose"><img src="https://agentmods.dev/badge/skills/ccfos/nightingale/host-onboard-diagnose.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 217 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,275 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00217 $0.02275
Opus 5 $0.00109 $0.01137
Sonnet 5 $0.00043 $0.00455
Haiku 4.5 $0.00022 $0.00228

Measured 10d ago against content hash 2dc016fe2745, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

host-onboard-diagnose scanned grade A with 1 finding 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 10d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- `curl -s http://<n9e>:17000/api/n9e/self-metrics | grep <ident>`>
aiagent/skill/embedded/builtin/host-onboard-diagnose/SKILL.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Host Onboarding Failure Diagnosis (host-onboard-diagnose)

Scope

Enter this skill:

  • "My newly installed categraf host doesn't show up in Nightingale"
  • "The agent is installed and running, but the host doesn't appear in the host list"
  • "For this host in the list, the OS / CPU / version are all unknown"
  • "I deployed 3 categraf hosts via Helm, but the platform only sees 1"
  • "I installed the agent on Windows but it won't register"
  • "The host disappeared right after I changed its hostname" (if categraf is still running)

Do NOT enter this skill:

  • Was visible before, recently lost contact → host-health-diagnose
  • ident duplicate / want to clean up residue after renaming → host-ident-cleanup (to be built)
  • Want to change alert rules / mutes → creation / create-alert-rule
  • Looking into why an alert didn't fire → alert-rule-troubleshoot

One-Sentence Principle

A missing host ≠ a single cause. The onboarding pipeline has 5 segments, and each segment getting stuck looks different. Looking at just one segment and telling the user to change config is a common pitfall. Gather evidence first, then localize segment by segment, and finally give fix commands.

The 5 Segments of the Onboarding Pipeline

[1] categraf local process    Is it present / is the config correct / is heartbeat.enable on
        │
[2] heartbeat report HTTP      Can it reach /v1/n9e/heartbeat (network / TLS / BasicAuth)
        │
[3] server / edge receive      token / version compatibility / hostname duplicate check
        │
[4] target table persistence   Is this ident in the DB, is the meta in redis
        │
[5] Redis + metric stream       Can the time-series store find samples for this ident

First Action: Call probe_target_onboard_status

This is the only diagnostic entry tool in this skill; it returns the footprint of all 5 segments in one shot. Always call it first, then decide the next step.

Key fields returned:

  • in_target_db + target.os + target.agent_version → evidence for segments 3/4
  • in_redis_beat + redis_meta.hostname + redis_meta.remote_addr → evidence for segment 4
  • in_prom_target_up + target_up_last + prom_metrics_hit → evidence for segment 5
  • likely_segment + likely_causesdiagnosis already aggregated at the tool layer; do not bypass it and re-derive it yourself

Read the full file on GitHub · 142 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. 10d ago First seen · 142 lines · 217 tokens per session scan A 2dc016fe2745

Subscribe to this mod's changes

host-onboard-diagnose is a skill published in the GitHub repository ccfos/nightingale (13,282 stars, last pushed yesterday), licensed Apache-2.0. It adds 217 tokens to every session and 2,275 once invoked, about $0.0011 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.