PostHog Upgrade & Migration

Overview

Guide for upgrading PostHog SDK versions and handling breaking changes.

Prerequisites

Current PostHog SDK installed
Git for version control
Test suite available
Staging environment

Instructions

Step 1: Check Current Version

set -euo pipefail
npm list @posthog/sdk
npm view @posthog/sdk version

Step 2: Review Changelog

open https://github.com/posthog/sdk/releases

Step 3: Create Upgrade Branch

set -euo pipefail
git checkout -b upgrade/posthog-sdk-vX.Y.Z
npm install @posthog/sdk@latest
npm test

Step 4: Handle Breaking Changes

Update import statements, configuration, and method signatures as needed.

Output

Updated SDK version
Fixed breaking changes
Passing test suite
Documented rollback procedure

Error Handling

SDK Version	API Version	Node.js	Breaking Changes
3.x	2024-01	18+	Major refactor
2.x	2023-06	16+	Auth changes
1.x	2022-01	14+	Initial release

Examples

Import Changes

// Before (v1.x)
import { Client } from '@posthog/sdk';

// After (v2.x)
import { PostHogClient } from '@posthog/sdk';

Configuration Changes

// Before (v1.x)
const client = new Client({ key: 'xxx' });

// After (v2.x)
const client = new PostHogClient({
  apiKey: 'xxx',
});

Rollback Procedure

set -euo pipefail
npm install @posthog/sdk@1.x.x --save-exact

Deprecation Handling

// Monitor for deprecation warnings in development
if (process.env.NODE_ENV === 'development') {
  process.on('warning', (warning) => {
    if (warning.name === 'DeprecationWarning') {
      console.warn('[PostHog]', warning.message);
      // Log to tracking system for proactive updates
    }
  });
}

// Common deprecation patterns to watch for:
// - Renamed methods: client.oldMethod() -> client.newMethod()
// - Changed parameters: { key: 'x' } -> { apiKey: 'x' }
// - Removed features: Check release notes before upgrading

Resources

Next Steps

For CI integration during upgrades, see posthog-ci-integration.

posthog-upgrade-migration