# instrument-logs

Configures structured application log capture and OTLP export to PostHog across mobile, web, and backend stacks.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 454 installs · ★ 76
- 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/instrument-logs/SKILL.md
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/skills/instrument-logs

## What it does

This skill inspects project files, detects the package manager, and identifies existing log libraries like Winston, Pino, or Python logging. If PostHog export is missing, it installs the necessary OpenTelemetry SDK packages and sets up an OTLP exporter pointing to PostHog ingest endpoints. For Android, iOS, and React Native, it relies on native SDK capture rather than a standalone OTLP exporter.

The skill keeps existing log handlers intact and avoids restructuring files. New logs receive structured key-value attributes for PostHog search. If PostHog MCP is connected, it fetches the project token via `projects-get`; otherwise, it prompts you for the token and cloud region (US or EU) before writing endpoints to your environment files.

## Install

### Claude Code (native platform)

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

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

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill instrument-logs -a codex
```

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

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill instrument-logs -a cursor
```

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

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install PostHog/skills instrument-logs
```

2. **Manually: put the files in place**
- File: `.github/skills/instrument-logs/SKILL.md`

### Gemini CLI

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

2. **Platform CLI**
```bash
gemini skills install https://github.com/PostHog/skills --path skills/omnibus/instrument-logs
```

### Windsurf (Devin Desktop)

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

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add PostHog/skills --skill instrument-logs -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/instrument-logs/SKILL.md

## When to use it
- configure PostHog OTLP log export for new features
- attach structured key-value properties to application logs
- integrate OpenTelemetry SDK without altering current loggers
- set up PostHog US or EU cloud environment variables

## Example prompts
- Set up PostHog log capture for the newly created billing service
- Review this PR and add structured logs to all modified endpoints
- Configure an OTLP exporter to send our Winston logs to PostHog

## 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: 25fa76417c18d723.

BEGIN THIRD-PARTY FILE 25fa76417c18d723
```text
---
name: instrument-logs
description: >-
  Add PostHog log capture to track application logs. Use after implementing
  features or reviewing PRs to ensure meaningful log events are captured with
  structured properties. Also handles initial OTLP exporter setup if not yet
  configured.
metadata:
  author: PostHog
---

# Add PostHog log capture

Use this skill to add PostHog log capture for new or changed code. Use it after implementing features or reviewing PRs to ensure meaningful log events are captured with structured properties. If PostHog log export is not yet configured, this skill also covers initial OTLP exporter setup. Supports any platform or language.

Supported platforms: Next.js, Node.js, Python, Go, Java, Datadog, Android, React Native, iOS, and any language via OpenTelemetry.

## Instructions

Follow these steps IN ORDER:

STEP 1: Analyze the codebase and detect the platform.
  - Detect the language, framework, and existing logging setup.
  - Look for dependency files and project files (package.json, Podfile, Package.swift, requirements.txt, go.mod, pom.xml, etc.).
  - Look for log libraries (winston, pino, logging module, logrus, log4j, serilog, os_log, Logger, etc.).
  - Look for lockfiles (pnpm-lock.yaml, package-lock.json, yarn.lock, bun.lockb, go.sum, Podfile.lock, Package.resolved, etc.) to determine the package manager.
  - Check for existing PostHog log export setup. If the OTLP exporter is already configured, skip to STEP 5 to add log capture for new code.

STEP 2: Research log capture. (Skip if PostHog log export is already configured.)
  2.1. Find the reference file below that matches the detected platform — it is the source of truth for OTLP exporter configuration and integration with existing logging. Read it now.
  2.2. If no reference matches, use the "Other Languages" reference as a fallback — it covers the generic OpenTelemetry approach.

STEP 3: Install dependencies. (Skip if PostHog log export is already configured.)
  - Install the OpenTelemetry SDK and OTLP exporter packages for the detected platform.
  - Do not manually edit dependency files — use the package manager's install command.

STEP 4: Configure the OTLP exporter. (Skip if PostHog log export is already configured.)
  - PostHog logs use the OpenTelemetry protocol. Set up an OTLP exporter pointed at PostHog's ingest endpoint.
  - For SDK-native log support such as Android, React Native, and iOS, follow the platform reference instead of adding a separate OTLP exporter.
  - Follow the platform-specific reference for the exact configuration.

STEP 5: Integrate with existing logging.
  - Add the PostHog log exporter alongside existing logging. Don't replace existing log handlers or outputs.
  - Do not alter the fundamental architecture of existing files. Make additions minimal and targeted.
  - You must read a file immediately before attempting to write it.

STEP 6: Add structured properties.
  - Ensure logs include structured key-value properties for filtering and search in PostHog.
```
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