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

# September 2026 Release Notes

> Real email flows to remix, one library for every image, unsubscribe lists per domain, and a month of making silent failures say what went wrong.

<Note>
  **September 2026**
</Note>

<Note>
  **Historical note · September 2026** · Describes Brew as of September 2026.
  Each item links to the guide for current behavior.
</Note>

September's theme was quiet failures, and each one now stops and says why:

* A publish could let every fire fail.
* A send could be created for zero people.
* An import could read UK dates as American.

We also shipped flows, one library for every image, and unsubscribe lists per
domain.

## New

* **Organization keys.** One API key or agent connection can reach every
  brand in your organization. See
  [Organization Keys](/changelog/posts/organization-keys).
* **Brew University.** Eight short walkthroughs play from the Home page. See
  [Brew University](/changelog/posts/brew-university).
* **Flows.** Real signup and newsletter sequences from other brands, with the
  day each email landed. Remix one and Brew builds a draft automation with
  the same timing and emails written for your brand. See
  [Remix a Flow](/create-emails/templates#remix-a-flow).
* **One library for every image.** Assets holds your logos, the images from
  your site, your uploads, and everything Brew generated. Filter by kind,
  crop and adjust, or delete. See [Assets](/brand/assets).
* **Unsubscribe lists per domain.** Each marketing domain keeps its own list,
  on the API and MCP first. See
  [Unsubscribe Lists for Every Domain](/changelog/posts/domain-unsubscribe-lists).

## Agents & API

API, MCP, SDK, and CLI changes this month are in the [API Changelog](/changelog/api).

## Improvements

* **Publish refuses merge tags the trigger doesn't declare.** An automation
  using `{{ trigger.code }}` on a trigger without `code` used to publish, then
  fail on every fire without saying so. Now publish stops and names the tag.
  See [When a Tag Does Not Resolve](/create-emails/merge-tags#when-a-tag-does-not-resolve).
* **A send that would reach nobody is refused.** If every contact is
  unsubscribed, suppressed, or undeliverable, **Send now** stops and tells you
  why. A send that skips some contacts says how many and for what reason. See
  [Send Options](/create-emails/send-options).
* **Searching a whole address finds that contact.** It used to match every
  contact sharing a word, such as `gmail`.
* **Valid means a check ran.** A contact reads **Valid** only after a real
  deliverability check, never from the free format check alone.
* **Re-subscribing an opt-out is refused.** The API, MCP, and imports never
  re-subscribe anyone. A person on your team does it from the contact's page.
  See [Unsubscribes](/audience/manage-contacts#unsubscribes).
* **Imports can unsubscribe existing contacts.** A `subscribed` column set to
  false, or a status such as `unsubscribed` or `cleaned`, now applies to
  contacts you already have.

## Fixes

* **Day-first dates import in the right month.** A UK file's `03/04/2026` is
  now 3 April, not 4 March. Brew reads the whole column in one order. See
  [Custom Properties](/audience/manage-contacts#custom-properties).
* **The credit balance reads correctly past the plan cap.** Readouts counted
  bonus-credit spending twice. Charges were always right, so nothing is owed.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.