integration-javascript_web

integration-javascript_web is a skill for Claude Code from PostHog/skills. It costs 20 tokens per session (762 once invoked), scanned A, original, MIT.

A guide for adding PostHog, a tool that records how people use a website, to a browser-based JavaScript app.

In plain words
What is it for?
Use it to add PostHog to a web app, identify users, and track product usage from the browser.
Why use it?
It gives you a documented setup process and keeps the PostHog key out of your source code by using environment variables.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the posthog-all plugin — 62 skills, 1 hook shipped together

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.

agentmods
npx agentmods add skills/posthog/skills/integration-javascript_web
Any agent
npx skills add PostHog/skills --skill integration-javascript_web
Clone the repo
git clone --depth 1 https://github.com/PostHog/skills

Made for: Claude Code.

Or install posthog-all, the plugin that ships this one along with the rest of its 62 skills, 1 hook.

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 integration-javascript_web

README.md
[![agentmods](https://agentmods.dev/badge/skills/posthog/skills/integration-javascript_web.svg)](https://agentmods.dev/skills/posthog/skills/integration-javascript_web)
Your own site
<a href="https://agentmods.dev/skills/posthog/skills/integration-javascript_web"><img src="https://agentmods.dev/badge/skills/posthog/skills/integration-javascript_web.svg" alt="Measured on agentmods" height="20"></a>
Per session 20 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 762 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00020 $0.00762
Opus 5 $0.00010 $0.00381
Sonnet 5 $0.00004 $0.00152
Haiku 4.5 $0.00002 $0.00076

Measured 3d ago against content hash f69dff7a81f4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

integration-javascript_web 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 3d 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/posthog/all/skills/integration-javascript_web/SKILL.md · 63 lines

How it starts

The opening of the file, as written. The whole thing — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.

PostHog integration for JavaScript Web

This skill helps you add PostHog analytics to JavaScript Web applications.

Workflow

Follow these steps in order to complete the integration:

  1. basic-integration-1.0-begin.md - PostHog Setup - Begin ← Start here
  2. basic-integration-1.1-edit.md - PostHog Setup - Edit
  3. basic-integration-1.2-revise.md - PostHog Setup - Revise
  4. basic-integration-1.3-conclude.md - PostHog Setup - Conclusion

Reference files

  • references/js.md - JavaScript web - docs
  • references/posthog-js.md - PostHog JavaScript web SDK
  • references/identify-users.md - Identify users - docs
  • references/basic-integration-1.0-begin.md - PostHog setup - begin
  • references/basic-integration-1.1-edit.md - PostHog setup - edit
  • references/basic-integration-1.2-revise.md - PostHog setup - revise
  • references/basic-integration-1.3-conclude.md - PostHog setup - conclusion

The example project shows the target implementation pattern. Consult the documentation for API details.

Key principles

  • Environment variables: Always use environment variables for PostHog keys. Never hardcode them.
  • Minimal changes: Add PostHog code alongside existing integrations. Don't replace or restructure existing code.
  • Match the example: Your implementation should follow the example project's patterns as closely as possible.

Framework guidelines

  • Remember that source code is available in the node_modules directory
  • Check package.json for type checking or build scripts to validate changes
  • posthog-js is the JavaScript SDK package name
  • posthog.init() MUST be called before any other PostHog methods (capture, identify, etc.)
  • posthog-js is browser-only — do NOT import it in Node.js or server-side contexts (use posthog-node instead)
  • Autocapture is ON by default with posthog-js (tracks clicks, form submissions, pageviews). Do NOT disable autocapture unless the user explicitly requests it.
  • NEVER send PII in posthog.capture() event properties — no emails, full names, phone numbers, physical addresses, IP addresses, or user-generated content
  • PII belongs in posthog.identify() person properties (email, name, role), NOT in capture() event properties
  • Call posthog.identify(userId, { email, name, role }) on login AND on page refresh if the user is already logged in
  • Call posthog.reset() on logout to unlink future events from the current user
  • For SPAs without a framework router, capture pageviews with posthog.capture($pageview) or use the capture_pageview history_change option in init for History API routing

Read the full file on GitHub · 63 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago First seen · 63 lines · 20 tokens per session scan A f69dff7a81f4

Subscribe to this mod's changes

integration-javascript_web is a skill published in the GitHub repository PostHog/skills (60 stars, last pushed yesterday), licensed MIT. It adds 20 tokens to every session and 762 once invoked, about $0.0001 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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