retellai-upgrade-migration

# Retell AI Upgrade & Migration

## Overview
Guide for upgrading Retell AI SDK versions and handling breaking changes.

## Prerequisites
- Current Retell AI SDK installed
- Git for version control
- Test suite available
- Staging environment

## Instructions

### Step 1: Check Current Version
```bash
npm list @retellai/sdk
npm view @retellai/sdk version
```

### Step 2: Review Changelog
```bash
open https://github.com/retellai/sdk/releases
```

### Step 3: Create Upgrade Branch
```bash
git checkout -b upgrade/retellai-sdk-vX.Y.Z
npm install @retellai/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
```typescript
// Before (v1.x)
import { Client } from '@retellai/sdk';

// After (v2.x)
import { RetellAIClient } from '@retellai/sdk';
```

### Configuration Changes
```typescript
// Before (v1.x)
const client = new Client({ key: 'xxx' });

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

### Rollback Procedure
```bash
npm install @retellai/sdk@1.x.x --save-exact
```

### Deprecation Handling
```typescript
// Monitor for deprecation warnings in development
if (process.env.NODE_ENV === 'development') {
  process.on('warning', (warning) => {
    if (warning.name === 'DeprecationWarning') {
      console.warn('[Retell AI]', 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: