---
name: klaviyo-upgrade-migration
description: 'Upgrade Klaviyo SDK versions and migrate between API revisions.

  Use when upgrading the klaviyo-api package, migrating from v1/v2 legacy APIs

  to the current REST API, or handling breaking changes between revisions.

  Trigger with phrases like "upgrade klaviyo", "klaviyo migration",

  "klaviyo breaking changes", "update klaviyo SDK", "klaviyo API revision".

  '
allowed-tools: Read, Write, Edit, Bash(npm:*), Bash(git:*)
version: 1.0.0
license: MIT
author: Jeremy Longshore <jeremy@intentsolutions.io>
tags:
- saas
- klaviyo
- email-marketing
- cdp
compatibility: Designed for Claude Code
---
# Klaviyo Upgrade & Migration

## Overview

Guide for upgrading the `klaviyo-api` SDK, migrating from legacy v1/v2 APIs, and handling breaking changes between Klaviyo API revisions.

## Prerequisites

- Current Klaviyo SDK installed
- Git for version control
- Test suite available

## Klaviyo API Revision Timeline

Each revision is supported for **2 years** after release. Connect to the latest every 12-18 months.

| Revision | Released | Deprecated | Key Changes |
|----------|----------|------------|-------------|
| `2024-10-15` | Oct 2024 | Oct 2026 | Reporting API, campaign message updates |
| `2024-07-15` | Jul 2024 | Jul 2026 | Custom objects, tracking settings |
| `2024-02-15` | Feb 2024 | Feb 2026 | Bulk operations, segments V2 |
| `2023-12-15` | Dec 2023 | Dec 2025 | Profile subscription changes |
| `2023-07-15` | Jul 2023 | Jul 2025 | Relationship endpoint restructuring |

## Instructions

### Step 1: Assess Current State

```bash
# Check current SDK version
npm list klaviyo-api
# e.g., klaviyo-api@15.0.0

# Check latest available
npm view klaviyo-api version
# e.g., 21.0.0

# See all available versions
npm view klaviyo-api versions --json | tail -10
```

### Step 2: Review Breaking Changes

```bash
# View changelog
# https://github.com/klaviyo/klaviyo-api-node/releases

# Find your usage patterns that may be affected
grep -rn "from 'klaviyo-api'" src/
grep -rn "ApiKeySession\|ProfilesApi\|EventsApi" src/
```

### Step 3: Common Migration Patterns

#### Legacy v1/v2 to Current API

```typescript
// BEFORE: Legacy v1/v2 endpoints (DEPRECATED)
// POST https://a.klaviyo.com/api/v2/list/LIST_ID/subscribe
// POST https://a.klaviyo.com/api/track

// AFTER: Current REST API (2024-10-15)
import { ApiKeySession, ProfilesApi, EventsApi, ProfileEnum } from 'klaviyo-api';

const session = new ApiKeySession(process.env.KLAVIYO_PRIVATE_KEY!);

// v2 Track → Create Event
const eventsApi = new EventsApi(session);
await eventsApi.createEvent({
  data: {
    type: 'event',
    attributes: {
      metric: { data: { type: 'metric', attributes: { name: 'Placed Order' } } },
      profile: { data: { type: 'profile', attributes: { email: 'user@example.com' } } },
      properties: { orderId: '123' },
      time: new Date().toISOString(),
      value: 99.99,
    },
  },
});

// v2 Identify → Create or Update Profile
const profilesApi = new ProfilesApi(session);
await profilesApi.createOrUpdateProfile({
  data: {
    type: ProfileEnum.Profile,
    attributes: {
      email: 'user@example.com',
      firstName: 'Jane',
      properties: { plan: 'pro' },
    },
  },
});
```

#### SDK Version Upgrade (e.g., v15 to v21)

```typescript
// BEFORE (older SDK versions): ConfigWrapper pattern
// import { ConfigWrapper, Profiles } from 'klaviyo-api';
// ConfigWrapper('pk_***');
// const profiles = await Profiles.getProfiles();

// AFTER (v21+): ApiKeySession pattern
import { ApiKeySession, ProfilesApi } from 'klaviyo-api';
const session = new ApiKeySession('pk_***');
const profilesApi = new ProfilesApi(session);
const profiles = await profilesApi.getProfiles();
```

#### Property Casing Changes

```typescript
// BEFORE: Some older versions used snake_case
// { first_name: 'Jane', phone_number: '+1555...' }

// AFTER: SDK v21+ uses camelCase everywhere
{ firstName: 'Jane', phoneNumber: '+15551234567' }
```

### Step 4: Upgrade Procedure

```bash
# 1. Create upgrade branch
git checkout -b upgrade/klaviyo-api-v21

# 2. Install new version
npm install klaviyo-api@21.0.0 --save-exact

# 3. Run TypeScript compiler to find breaking changes
npx tsc --noEmit 2>&1 | grep -i "klaviyo\|error TS"

# 4. Fix all type errors, then run tests
npm test

# 5. Run integration tests against staging
KLAVIYO_TEST=1 npm run test:integration

# 6. Commit and deploy to staging first
git add package.json package-lock.json src/
git commit -m "upgrade: klaviyo-api to v21.0.0"
```

### Step 5: Rollback Procedure

```bash
# If issues found after upgrade
npm install klaviyo-api@15.0.0 --save-exact
npm test
git add package.json package-lock.json
git commit -m "revert: rollback klaviyo-api to v15.0.0"
```

## Migration Checklist

- [ ] Backup current `package-lock.json`
- [ ] Read SDK changelog for target version
- [ ] Update `ApiKeySession` import (if changed)
- [ ] Fix property casing (camelCase in v21+)
- [ ] Update response access pattern (`response.body.data`)
- [ ] Verify all filter syntax still works
- [ ] Run full test suite
- [ ] Deploy to staging first
- [ ] Monitor error rates for 24 hours after production deploy

## Error Handling

| Issue | Cause | Solution |
|-------|-------|----------|
| `TypeError: ConfigWrapper is not a function` | Old SDK pattern | Switch to `ApiKeySession` pattern |
| `Property 'first_name' does not exist` | Casing change | Use `firstName` (camelCase) |
| `response.data is undefined` | Access pattern change | Use `response.body.data` |
| `revision not supported` | Deprecated revision | Update `revision` header value |

## Resources

- [API Versioning & Deprecation Policy](https://developers.klaviyo.com/en/docs/api_versioning_and_deprecation_policy)
- [v1/v2 Migration Guide](https://developers.klaviyo.com/en/v2024-10-15/docs/best_practices_v1v2_migration)
- [Relationship Migration](https://developers.klaviyo.com/en/v2024-10-15/docs/migrate_to_2023_07_15_relationships)
- [klaviyo-api-node Releases](https://github.com/klaviyo/klaviyo-api-node/releases)

## Next Steps

For CI integration during upgrades, see `klaviyo-ci-integration`.