> ## Documentation Index
> Fetch the complete documentation index at: https://docs.usesend.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Changelog

> Product updates and announcements from Unsend

**March 2026**

v1.9.0

### Campaign Personalization with Contact Books

Campaigns now support contact-book variables for personalization, so you can tailor each message with richer subscriber data.

### Double Opt-In Customization

Double opt-in now supports customizable confirmation flows and copy, making it easier to match your onboarding experience and compliance requirements.

### API and SDK Coverage

Contact book support has been expanded in the SDK, dashboard analytics is now available in both the public API and SDK, and a public endpoint to delete campaigns has been added.

### Webhook Filtering by Domain

Webhooks now support multi-domain filtering, making it easier to route, monitor, and manage events across different projects.

**February 2025**

v1.8.0

![Schedule Campaigns](https://mintcdn.com/ossapps/fpRnVe9he7fa4B0M/images/changelog/webhook.png?fit=max\&auto=format\&n=fpRnVe9he7fa4B0M\&q=85\&s=d46a231801cd0f5e5b1b277c47b781a7)

### Webhooks

You can now receive real-time notifications for email events via webhooks. Configure webhook endpoints to track deliveries, bounces, complaints, and more. [Learn more](https://docs.usesend.com/guides/webhooks.md)

### Contact Books API

Manage your contact books programmatically with the new public API. Create, update, and organize contacts at scale.

### Idempotency Support

API requests now support idempotency keys, ensuring safe retries without duplicate sends.

### Other improvements

* Export contact books to CSV for offline use.
* Security fixes for CVE-2025-55184 and CVE-2025-55183.
* Various bug fixes and performance improvements.

**October 2024**

v1.7.0

![Schedule Campaigns](https://mintcdn.com/ossapps/IRky_28zjbUDKDwj/images/changelog/schedule-campaign.png?fit=max\&auto=format\&n=IRky_28zjbUDKDwj\&q=85\&s=c796748060c400fc0090e6e335c50d4e)

### Schedule Campaigns

You can now Schedule campaigns with natural language like "tomorrow at 9am" or "next Monday at 10am".

### Campaigns API

We're doubling down on APIs. Now you can create, schedule campaign emails from API. check [API documentation](https://docs.usesend.com/api-reference/introduction.md)

### Other improvements

* Camapign Emails are now sent in batches instead of a burst of emails.
* You can bulk upload large amounts of contacts without ui slowness.
* Added delete domain API.

**September 2024**

v1.6.0

![Rebranded useSend hero](https://usesend.com/hero-dark.webp)

### Suppression List

Hard bounce and complained email addresses are automatically added to the suppression list. Works for both transactional and marketing emails.

### Rebranding to useSend

From now on we [useSend](https://usesend.com). Make sure to update your docker image and sdks.


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