# authoring-log-alerts

Walks an agent through picking services, baselining them over a week and drafting thresholds that fire 0–3 times per week in a PostHog project.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 356 installs · ★ 75
- Author: PostHog
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/PostHog/skills/tree/HEAD/skills/omnibus/authoring-log-alerts/SKILL.md
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/skills/authoring-log-alerts

## What it does

The skill treats alert authoring as a measurement problem. Step one calls `posthog:logs-services` for the last 24 hours and keeps services with non-trivial volume and a non-zero `error_rate`, or any service the user names outright.

From there the agent can narrow the filter with `posthog:logs-attributes-list` and `posthog:logs-attribute-values-list`, then baseline the candidate with `posthog:logs-count-ranges` over `-7d`. The response goes through `scripts/baseline_stats.py`, which returns a `suggested_threshold_count` plus health flags — `sparse`, `empty`, `spiky`, `flat`. A draft is replayed against history with `posthog:logs-alerts-simulate-create` before it is persisted and wired to Slack, a webhook or Microsoft Teams.

One rule is easy to trip over: `posthog:query-logs` is off-limits while authoring, because you need distributions rather than rows. Tuning an alert that already exists is a separate job — reach for `posthog:logs-alerts-events-list` and `posthog:logs-alerts-partial-update` instead.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill authoring-log-alerts -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/authoring-log-alerts/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/authoring-log-alerts/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill authoring-log-alerts -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/authoring-log-alerts/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill authoring-log-alerts -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/authoring-log-alerts/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install PostHog/skills authoring-log-alerts
```

2. **Manually: put the files in place**
- File: `.github/skills/authoring-log-alerts/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill authoring-log-alerts -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/PostHog/skills --path skills/omnibus/authoring-log-alerts
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/authoring-log-alerts/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill authoring-log-alerts -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/PostHog/skills/tree/HEAD/skills/omnibus/authoring-log-alerts/SKILL.md

## When to use it
- set a log alert threshold that does not page you every hour
- decide whether a service produces alertable signal at all
- get a starter set of alerts right after enabling log alerting
- narrow a filter by `http.status_code` or `error.type` instead of alerting on every error
- replay a draft alert against a week of history before shipping it

## Example prompts
- Set up log alerts for my PostHog project
- Look at the last 24h of services and suggest which ones deserve an alert
- Back-test this alert draft with simulate over `-7d`

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: fecc6098da4c8bdb.

BEGIN THIRD-PARTY FILE fecc6098da4c8bdb
```text
---
name: authoring-log-alerts
description: >
  Author useful, low-noise log alerts on services in a PostHog project. Use when the user asks to set up
  alerts for their logs, suggest alerts they should add, or evaluate whether a service is worth monitoring.
  Covers service triage, baseline characterisation, threshold drafting, back-testing via simulate, and
  shipping with a notification destination.
---

# Authoring log alerts

Authoring an alert is a _measurement_ problem, not a guessing problem. You are not trying to be exhaustive — you
are trying to land thresholds that fire 0–3 times per week on real production patterns, on services that matter.

## When to use this skill

- The user asks to "set up alerts" / "suggest alerts" for their project.
- The user wants to evaluate whether a service is producing alertable signal.
- The user has just enabled log alerting and wants a starter set.

## When _not_ to use this skill

- Tuning an alert that already exists — that's a different job (use `posthog:logs-alerts-events-list` to inspect
  fire/resolve cadence and `posthog:logs-alerts-partial-update` to adjust).
- Investigating an active incident — pull rows with `posthog:query-logs`, don't author an alert mid-incident.

## Tools

| Tool                                                                  | Job                                                                           | Where it fits      |
| --------------------------------------------------------------------- | ----------------------------------------------------------------------------- | ------------------ |
| `posthog:logs-services`                                               | Top-25 services in window with log_count, error_count, error_rate, sparkline. | Step 1 — triage.   |
| `posthog:logs-attributes-list` / `posthog:logs-attribute-values-list` | Discover keys/values for narrower filters.                                    | Step 2, optional.  |
| `posthog:logs-count-ranges`                                           | Adaptive time-bucketed counts for a filter.                                   | Step 3 — baseline. |
| `posthog:logs-alerts-simulate-create`                                 | Replay a draft config against `-7d` history with full state machine.          | Step 4 — validate. |
| `posthog:logs-alerts-create`                                          | Persist the alert.                                                            | Step 5 — ship.     |
```
END THIRD-PARTY FILE fecc6098da4c8bdb

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First 2490 of 12218 bytes. © PostHog · MIT · https://github.com/PostHog/skills/tree/HEAD/skills/omnibus/authoring-log-alerts/SKILL.md

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