Agent skill · marketing growth · jeremylongshore
posthog-migration-deep-dive
Plan and execute a controlled historical migration into PostHog with identity mapping, timestamp validation, dual-write evidence, and rollback boundaries. Use when moving from another analytics platform or PostHog region. Trigger with "migrate to PostHog", "PostHog historical import", or "PostHog dual write".
Why this skill is useful
Provides detailed migration strategies and code samples for transitioning analytics data to PostHog, which the AI wouldn't reliably generate on its own.
What it needs
Requires npm installed locally. Requires posthog account access. About 4k tokens when loaded. Last updated 2026-08-07. 2,604 stars on the source repository.
What this skill does
PostHog Migration Deep Dive Overview Migrate from Google Analytics, Mixpanel, Amplitude, or Segment to PostHog using a dual-write strategy (send events to both old and new platforms) followed by gradual traffic shifting. PostHog's capture API accepts events in a format similar to Segment's track/identify calls, making migration straightforward. Prerequisites A paid product analytics plan and a dedicated target project are confirmed for historical imports. The event taxonomy, distinct-ID map, timestamp policy, and rollback owner are approved. A representative sample can be validated before full ingestion. Authentication Use the target project's public project token only for event capture. It is an ingestion identifier, not a secret or a credential for private APIs. Use a least-privilege personal API key or OAuth token for private project APIs, keep it in a secret manager, and never place it in browser code, logs, examples, or committed files. If server-side local feature-flag evaluation is required, use a feature flags secure API key through the SDK's personalApiKey option; do not reuse a broadly scoped personal API key. Select the matching US or EU host for the target project before any sample or bulk write. Migration Types Source Primary discovery risk Evidence required before import -------- ------------------------ --------------------------------- Google Analytics (GA4) Event and identity models differ Approved taxonomy and identity mapping Mixpanel Similar names can hide property or identity drift Sample export reconciliation Amplitude Cohort and user-property semantics can differ Property and timestamp comparison Segment Destination behavior can differ from direct SDK capture Dual-write sample and delivery logs Custom analytics Source semantics are implementation-specific Source contract, resumable export, and representative sample Instructions Tool discipline Use Read to inspect the relevant configuration and implementation before proposing changes. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills jeremylongshore/posthog-migration-deep-dive