posthog-foss: Skill for Claude Code

.agents/skills/placing-product-frontend-code/SKILL.md

placing-product-frontend-code is a skill for Claude Code, Codex from PostHog/posthog-foss. It costs 142 tokens per session (1,067 once invoked), scanned A, original, MIT.

A guide for choosing between two locations for frontend code: a product’s own folder or a shared scenes folder.

In plain words
What is it for?
Use it when adding or moving a screen, component, or other frontend logic in a product with both folder structures.
Why use it?
It helps avoid putting new files in the wrong part of a codebase, especially when older and newer locations both exist.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents); mentions AGENTS.md.

This is PostHog/posthog-foss's own configuration. It tells Claude Code and Codex how to work on posthog-foss itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything posthog-foss configures →

Reuse

Borrowing it

Nothing to install: this file belongs to PostHog/posthog-foss. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/PostHog/posthog-foss/master/.agents/skills/placing-product-frontend-code/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/PostHog/posthog-foss

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 placing-product-frontend-code

README.md
[![agentmods](https://agentmods.dev/badge/skills/posthog/posthog-foss/placing-product-frontend-code.svg)](https://agentmods.dev/skills/posthog/posthog-foss/placing-product-frontend-code)
Your own site
<a href="https://agentmods.dev/skills/posthog/posthog-foss/placing-product-frontend-code"><img src="https://agentmods.dev/badge/skills/posthog/posthog-foss/placing-product-frontend-code.svg" alt="Measured on agentmods" height="20"></a>
Per session 142 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,067 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Prompt Injection · line 31
    Large whitespace padding was detected (a block of blank lines or a long run of spaces). This can push injected instructions below or to the right of the visible area so a human reviewer never sees them while the agent still reads them. Manual review of the hidden content is recommended.
    Fix: Remove the large whitespace padding (blank-line blocks or long space runs) and review any content hidden below or to the right of it. Keep skill files compact and reviewable so no instructions can be
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 $0.00142 $0.01067
Opus 5 $0.00071 $0.00534
Sonnet 5 $0.00028 $0.00213
Haiku 4.5 $0.00014 $0.00107

Measured 8d ago against content hash 30968c0cfacb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

placing-product-frontend-code 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 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/scene_product_split.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.agents/skills/placing-product-frontend-code/SKILL.md · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Placing product frontend code

A product's UI belongs in products/<name>/frontend/, not frontend/src/scenes/<name>/.

About 18 products still have UI in both trees, so "there's already a folder in scenes/" is not evidence that a new file belongs there. Check before you add.

# Where does one directory stand?
python3 .agents/skills/placing-product-frontend-code/scripts/scene_product_split.py data-warehouse

# Every scene dir with a product counterpart, most migrated first
python3 .agents/skills/placing-product-frontend-code/scripts/scene_product_split.py

The script is advisory and read-only — no baseline, no exit code to satisfy. It counts hand-written .ts/.tsx on each side, skipping generated/ (orval writes those, so they are not migration progress).

Deciding where a file goes

Situation Where it goes
products/<name>/frontend/ holds as much or more than scenes/<name>/ products/<name>/frontend/ — the scenes copy is a remnant
The move is under way but early products/<name>/frontend/, and move the files the new code touches if that is cheap
products/<name>/ exists, no scenes/<name>/ yet products/<name>/frontend/ — never create the scenes directory
No product directory at all, and the feature is product-shaped Bootstrap the product: bin/hogli product:bootstrap <name>, see products/README.md
App-level scene — settings, onboarding, billing, max, error-tracking shells frontend/src/scenes/ is correct; these have nowhere else to go

Read the full file on GitHub · 61 lines

Files

What ships with it

1 file 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. 8d ago First seen · 61 lines · 142 tokens per session scan A 30968c0cfacb

Subscribe to this mod's changes

placing-product-frontend-code is a skill published in the GitHub repository PostHog/posthog-foss (714 stars, last pushed today), licensed MIT. It adds 142 tokens to every session and 1,067 once invoked, about $0.0007 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 2026-08-30.

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