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.
npx skills add PostHog/skills --skill error-tracking-nodegit clone --depth 1 https://github.com/PostHog/skillsWrote 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.
[](https://agentmods.dev/skills/posthog/skills/error-tracking-node)<a href="https://agentmods.dev/skills/posthog/skills/error-tracking-node"><img src="https://agentmods.dev/badge/skills/posthog/skills/error-tracking-node.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00013 | $0.00523 |
| Opus 5 | $0.00006 | $0.00262 |
| Sonnet 5 | $0.00003 | $0.00105 |
| Haiku 4.5 | $0.00001 | $0.00052 |
Grade A, and why
error-tracking-node 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.
How it starts
The opening of the file, as written. The whole thing — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PostHog error tracking for Node.js
This skill helps you add PostHog error tracking to Node.js applications.
Reference files
references/node.md- Node.js error tracking installation - docsreferences/fingerprints.md- Fingerprints - docsreferences/alerts.md- Send error tracking alerts - docsreferences/monitoring.md- Monitor and search issues - docsreferences/assigning-issues.md- Assign issues to teammates - docsreferences/upload-source-maps.md- Upload source maps - docs
Consult the documentation for API details and framework-specific patterns.
Key principles
- Environment variables: Always use environment variables for PostHog keys and host URLs. Never hardcode them.
- Minimal changes: Add error tracking alongside existing error handling. Don't replace or restructure existing error handling code.
- Autocapture first: Enable exception autocapture in the SDK initialization before adding manual captures.
- Source maps: Upload source maps so stack traces resolve to original source code, not minified bundles.
- Manual capture for boundaries: Use
captureException()at error boundaries and catch blocks for errors that don't propagate to the global handler.
Framework guidelines
- posthog-node is the Node.js server-side SDK package name – do NOT use posthog-js on the server
- Include enableExceptionAutocapture: true in the PostHog constructor options
- Add posthog.capture() calls in route handlers for meaningful user actions – every route that creates, updates, or deletes data should track an event with contextual properties
- Add posthog.captureException(err, distinctId) in the application's error handler (e.g., Express error middleware, Fastify setErrorHandler, Koa app.on('error'))
- In long-running servers, the SDK batches events automatically – do NOT set flushAt or flushInterval unless you have a specific reason to
- For short-lived processes (scripts, CLIs, serverless), set flushAt to 1 and flushInterval to 0 to send events immediately
- Reverse proxy is NOT needed for server-side Node.js – only client-side JavaScript needs a proxy to avoid ad blockers
- Remember that source code is available in the node_modules directory
- Check package.json for type checking or build scripts to validate changes
What ships with it
6 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.
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.
- 3d ago First seen · 43 lines · 13 tokens per session scan A f547d6bf3157
error-tracking-node is a skill published in the GitHub repository PostHog/skills (60 stars, last pushed yesterday), licensed MIT. It adds 13 tokens to every session and 523 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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