Rishikesh Ranjan — rishikeshranjan.com

// open source & systems

productgrowth-logdrain

A Vercel log-drain receiver that verifies HMAC-SHA1 signatures in constant time, filters AI-crawler user agents, and forwards anonymized events to PostHog.

Creator2026TypeScriptNext.jsVercelPostHog

Vercel log drains are a firehose — useful signal buried in noise, and unsafe to trust without verifying the sender. productgrowth-logdrain is a small, hardened receiver that turns that firehose into clean, anonymized analytics.

What it does

  • Constant-time verification. Verifies HMAC-SHA1 signatures in constant time, so it can't be timing-attacked into trusting forged logs.
  • AI-crawler filtering. Filters AI-crawler user agents out of the stream before they pollute the metrics.
  • Anonymized forwarding. Forwards clean, anonymized events to PostHog for downstream analysis.