| name | posthog-local-dev-loop |
|---|---|
| description | Configure PostHog local development with hot reload and testing. Use when setting up a development environment, configuring test workflows, or establishing a fast iteration cycle with PostHog. Trigger with phrases like "posthog dev setup", "posthog local development", "posthog dev environment", "develop with posthog". |
| allowed-tools | Read, Write, Edit, Bash(npm:*), Bash(pnpm:*), Grep |
| version | 1.0.0 |
| license | MIT |
| author | Jeremy Longshore <[email protected]> |
PostHog Local Dev Loop
Overview
Set up a fast, reproducible local development workflow for PostHog.
Prerequisites
- Completed
posthog-install-authsetup - Node.js 18+ with npm/pnpm
- Code editor with TypeScript support
- Git for version control
Instructions
Step 1: Create Project Structure
my-posthog-project/
├── src/
│ ├── posthog/
│ │ ├── client.ts # PostHog client wrapper
│ │ ├── config.ts # Configuration management
│ │ └── utils.ts # Helper functions
│ └── index.ts
├── tests/
│ └── posthog.test.ts
├── .env.local # Local secrets (git-ignored)
├── .env.example # Template for team
└── package.json
Step 2: Configure Environment
# Copy environment template
cp .env.example .env.local
# Install dependencies
npm install
# Start development server
npm run dev
Step 3: Setup Hot Reload
{
"scripts": {
"dev": "tsx watch src/index.ts",
"test": "vitest",
"test:watch": "vitest --watch"
}
}
Step 4: Configure Testing
import { describe, it, expect, vi } from 'vitest';
import { PostHogClient } from '../src/posthog/client';
describe('PostHog Client', () => {
it('should initialize with API key', () => {
const client = new PostHogClient({ apiKey: 'test-key' });
expect(client).toBeDefined();
});
});
Output
- Working development environment with hot reload
- Configured test suite with mocking
- Environment variable management
- Fast iteration cycle for PostHog development
Error Handling
| Error | Cause | Solution |
|---|---|---|
| Module not found | Missing dependency | Run npm install |
| Port in use | Another process | Kill process or change port |
| Env not loaded | Missing .env.local | Copy from .env.example |
| Test timeout | Slow network | Increase test timeout |
Examples
Mock PostHog Responses
vi.mock('@posthog/sdk', () => ({
PostHogClient: vi.fn().mockImplementation(() => ({
// Mock methods here
})),
}));
Debug Mode
# Enable verbose logging
DEBUG=POSTHOG=* npm run dev
Resources
Next Steps
See posthog-sdk-patterns for production-ready code patterns.