Instrument Logs

PostHogOfficialCreated by PostHog

Skill
Tool integration
Data and AI
MIT
Low risk

From the author

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.

— the description by PostHog

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

This skill guides the integration of PostHog log capture into various application stacks. It automates the setup of OTLP exporters and provides instructions for adding structured logging alongside existing application logs. The skill ensures that log events are captured with meaningful properties, facilitating better observability and debugging within the PostHog platform.

What it does

Detects the application platform and existing logging infrastructure.
Configures the OpenTelemetry (OTLP) exporter for PostHog ingestion.
Integrates PostHog log capture without replacing existing logging handlers.
Ensures logs are captured with structured key-value properties.
Manages environment variable configuration for API tokens and host URLs.
Provides platform-specific guidance for SDK-native log capture.

When to use it

After implementing new features that require observability.
During code reviews when you identify a need for better log coverage.
When setting up initial log export for a new project.
When migrating from standard logging to structured, centralized log management.

Advantages

Maintains existing logging architecture without disruptive changes.
Supports a wide range of languages and frameworks via OpenTelemetry.
Enables structured logging for improved search and filtering in PostHog.
Automates the configuration of environment variables and ingestion endpoints.

Usage examples

“Add PostHog log capture to my Node.js application.”: The agent will analyze your package.json, install necessary OpenTelemetry dependencies, configure the OTLP exporter, and guide you through adding PostHog logging calls to your code.
“I need to start tracking logs in my Android app using PostHog.”: The agent will verify your Android SDK setup, configure the PostHogAndroidConfig for logs, and show you how to use PostHog.logger to capture structured events.

Install

Download the skill as a ZIP:
https://autogineer.com/agent-skills/posthog/instrument-logs/download

Unzip it into the cross-client skills folder of your project:

mkdir -p .agents/skills && unzip instrument-logs.zip -d .agents/skills

Documentation by 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.
Prefer structured log formats with key-value properties over plain text messages.

STEP 7: Set up environment variables.

Check if the project already has PostHog environment variables configured (e.g. in .env, .env.local, or framework-specific env files). If valid values already exist, skip this step.
If the PostHog project token is missing, use the PostHog MCP server's projects-get tool to retrieve the project's api_token. If multiple projects are returned, ask the user which project to use. If the MCP server is not connected or not authenticated, ask the user for their PostHog project token instead.
For the PostHog host URL: check the projects-get MCP response for a region field — US maps to https://us.i.posthog.com, EU maps to https://eu.i.posthog.com. If the region is not available from the MCP response or from existing project configuration, ask the user: "Are you on PostHog US Cloud or EU Cloud?" Do not assume US Cloud.
For the OpenTelemetry endpoint, use https://us.i.posthog.com/v1 (US) or https://eu.i.posthog.com/v1 (EU), matching the region determined above.
Write these values to the appropriate env file using the framework's naming convention.
Reference these environment variables in code instead of hardcoding them.

Reference files

references/nextjs.md - Next.js logs installation
references/nodejs.md - Node.js logs installation
references/python.md - Python logs installation
references/go.md - Go logs installation
references/java.md - Java logs installation
references/datadog.md - Datadog logs installation
references/android.md - Android logs installation
references/react-native.md - React native logs installation
references/ios.md - Ios logs installation
references/flutter.md - Flutter logs installation
references/other.md - Other languages logs installation
references/start-here.md - Getting started with logs
references/search.md - Search logs
references/best-practices.md - Logging best practices
references/troubleshooting.md - Logs troubleshooting
references/link-session-replay.md - Link session replay
references/mcp.md - Use logs over PostHog mcp
references/COMMANDMENTS.md - Framework-specific rules the integration must follow

Each platform reference contains specific OTLP configuration, SDK setup, and integration patterns. Find the one matching the user's stack.

Key principles

Environment variables: Always use environment variables for PostHog keys and OpenTelemetry endpoints. Never hardcode them.
Minimal changes: Add log export alongside existing logging. Don't replace or restructure existing logging code.
OpenTelemetry: PostHog logs use the OpenTelemetry protocol. Configure an OTLP exporter pointed at PostHog's ingest endpoint unless the platform SDK provides native log capture.
SDK-native logs: For Android, React Native, and iOS, use the SDK logger/capture APIs from the platform reference instead of adding a separate OTLP exporter.
Structured logging: Prefer structured log formats with key-value properties over plain text messages.

Files

ATTRIBUTION.mdAdded by AutoGineer931 B
LICENSELicence file added by AutoGineer1.0 KiB
SKILL.md6.1 KiB
references/COMMANDMENTS.md1.5 KiB
references/android.md9.2 KiB
references/best-practices.md25.2 KiB
references/datadog.md3.8 KiB
references/flutter.md20.4 KiB
references/go.md4.9 KiB
references/ios.md11.1 KiB
references/java.md4.7 KiB
references/link-session-replay.md6.4 KiB
references/mcp.md4.1 KiB
references/nextjs.md6.9 KiB
references/nodejs.md4.8 KiB
references/other.md3.5 KiB
references/python.md4.7 KiB
references/react-native.md10.8 KiB
references/search.md8.0 KiB
references/start-here.md10.2 KiB
references/troubleshooting.md6.5 KiB

references/link-session-replay.md

AI agents: this is one page from PostHog's docs. Full index of Markdown docs for LLMs: https://posthog.com/llms.txt

Link session replay

Canonical URL: https://posthog.com/docs/logs/link-session-replay

Cloud region: This page uses US Cloud hosts. For an EU Cloud project, use https://eu.posthog.com instead of https://app.posthog.com (app host for links).

Why link to session replay?

By including session IDs and user identity in your logs, you can:

See the full user journey: Navigate from a log entry directly to the session replay to see what the user was doing
Debug issues faster: Quickly find and watch the exact session where an error or issue occurred
Correlate logs with user actions: Match backend log events with actual user experience
View related errors: See Error Tracking issues that occurred during the same session directly in the log details

Prerequisites

A logging client installed on your backend
The PostHog JavaScript SDK on your web frontend, or the React Native SDK in your mobile app
Session replay enabled if you want to link to replays (you can still pass posthogDistinctId without session replay to link logs to a user profile)

Logs captured client-side: When you call posthog.captureLog / posthog.logger.* directly from the JavaScript web SDK or React Native SDK, the current distinct_id and session_id are attached to every log record automatically. You only need the manual setup below when your backend emits the logs.

Implementation

To link logs to session replays, you need to pass the session ID and user identity from your frontend to your backend, then include them as log attributes.

Frontend: Get the session ID

In your frontend code, retrieve the current session ID and send it with your API requests:

JavaScript

import posthog from 'posthog-js'

// Get the current session ID
const sessionId = posthog.get_session_id()

// Send it with your API request
const response = await fetch('/api/chat', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    message: userInput,
    sessionId: sessionId  // Include session ID
  })
})

"React

import { posthog } from './posthog'

// Get the current session ID
const sessionId = posthog.get_session_id()

// Send it with your API request
const response = await fetch('https://api.example.com/chat', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    message: userInput,
    sessionId,  // Include session ID
  }),
})

Backend: Include session ID and user identity in logs

Once you have the session ID, include it along with the user's identity using the sessionId and posthogDistinctId attributes. These examples assume you've already set up a logging client for your language.

JavaScript

import { logs } from '@opentelemetry/api-logs'

const logger = logs.getLogger('my-app')

app.post('/api/chat', async (req, res) => {
  const { message, sessionId } = req.body
  const userId = req.userId // ... get your user ID

  logger.emit({
    severityText: 'info',
    body: 'Chat request received',
    attributes: {
      posthogDistinctId: userId,       // Links to PostHog user
      sessionId: sessionId,            // Links to session replay
      endpoint: '/api/chat',
    },
  })

  // ... handle the request

  res.json({ success: true })
})

Python

import logging

logger = logging.getLogger(__name__)

@app.route('/api/chat', methods=['POST'])
def chat():
    data = request.json
    message = data['message']
    session_id = data.get('sessionId')
    user_id = current_user.id

    logger.info(
        "Chat request received",
        extra={
            "posthogDistinctId": user_id,     # Links to PostHog user
            "sessionId": session_id,           # Links to session replay
            "endpoint": "/api/chat",
        }
    )

    # ... handle the request

    return jsonify({"success": True})

Note: If you don't include posthogDistinctId, logs won't be linked to a user. If you don't include sessionId, logs won't be linked to a session replay. You can use either or both independently.

Viewing linked replays

Once you've set up session linking, you can navigate from logs to their corresponding session replays:

From the logs list:

Hover over a log entry in the logs view
Click the View recording button in the floating action menu to open the session replay at the log timestamp

From log details:

Click on a log entry to open log details
Click the View recording button to open the session replay

The recording button only appears for log entries that have an associated session ID.

When you click on a log entry that has a session ID, you can view related errors in the Related errors tab. This tab shows Error Tracking issues that occurred within the same session (within ±6 hours of the log timestamp).

This helps you debug issues by showing errors that happened around the same time as your log entry, giving you a more complete picture of what went wrong.

If no session ID is found in the log entry, the tab displays a message prompting you to link your logs to sessions.

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Needs: Needs an MCP server, Needs Python, Needs Node.js

Security

What our scanner noticed· Low risk

Instructions that use the network

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Created by

PostHog

Publisher

PostHog (Official)

Source

PostHog/skills · skills/omnibus/instrument-logs · commit a5d30e7

Licence

MIT License (redistribution allowed)

LICENSE (added by AutoGineer from LICENSE)
ATTRIBUTION.md (written by AutoGineer)

Synced

2026-11-09

AutoGineer is not affiliated with or endorsed by PostHog or PostHog.

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download instrument-logs.zip

Instrument Logs

From the author

AutoGineer summary

What it does

When to use it

Advantages

Usage examples

Install

Documentation by PostHog

Add PostHog log capture

Instructions

Reference files

Key principles

Files

references/link-session-replay.md

Link session replay

On this page

Why link to session replay?

Prerequisites

Implementation

Frontend: Get the session ID

JavaScript

"React

Backend: Include session ID and user identity in logs

JavaScript

Python

Viewing linked replays

See also

Requirements and compatibility

Security

Attribution and licence

Download ZIP

From the author

AutoGineer summary

What it does

When to use it

Advantages

Usage examples

Install

Documentation by PostHog

Add PostHog log capture

Instructions

Reference files

Key principles

Files

references/link-session-replay.md

Link session replay

On this page

Why link to session replay?

Prerequisites

Implementation

Frontend: Get the session ID

JavaScript

"React

Backend: Include session ID and user identity in logs

JavaScript

Python

Viewing linked replays

View related errors

See also

Requirements and compatibility

Security

Attribution and licence

Related skills

Claude API

Transformers

Open Notebook

Vision Sft

LLM Evaluation

Lora Qlora Recipes

Download ZIP