---
layout: docs
page_title: v0.4.0 release notes
description: >-
  Learn more about the features included in the Boundary 0.4.0 release and discover what has changed.
---

# Boundary v0.4.0

The release notes below contain information about new functionality available in Boundary v0.4.0. To see a granular record of when each item was merged into the Boundary project, please refer to the [Changelog](https://github.com/hashicorp/boundary/blob/main/CHANGELOG.md). To learn about what Boundary consists of, we highly recommend you start at the [Getting Started Page](/boundary/docs/getting-started).

Lastly, for instructions on how to upgrade an existing Boundary deployment to v0.4.0, please review Boundary’s [general upgrade guide](/boundary/tutorials/oss-configuration/upgrade-version).

## Boundary v0.4.0 highlights

**Session Credential Brokering:** Boundary 0.4, adds a Vault integration for the brokering of [Vault](https://www.vaultproject.io/) secrets to Boundary clients (both command line and desktop clients) for use
in Boundary sessions. Brokering of Vault secrets is the foundation of Boundary’s larger credential-management story for seamless single sign-on to infrastructure targets. This feature introduces new Boundary resources - [credential stores](/boundary/docs/domain-model/credential-stores), [credential libraries](/boundary/docs/domain-model/credential-libraries), and [credentials](/boundary/docs/domain-model/credentials) -
to support binding credentials with user sessions, as well as surfacing those credentials during session initialization on the command line and in Boundary Desktop.

**`boundary connect` Credential Brokering Integration:** Additionally, we have started integration into the [boundary connect helpers](/boundary/docs/getting-started/connect-to-target), starting in this release with the Postgres helper; if the credential contains a username/password and boundary connect postgres is the helper being used, the command will automatically pass the credentials to the psql process.

**Session Security Improvements:** Boundary workers will now close any existing proxy connections they're handling when they cannot make a status request to the worker. The timeout for this behavior is currenly 15 seconds.

## What's changed

For more detailed information of all changes since 0.3.0, please refer to the [Changelog](https://github.com/hashicorp/boundary/blob/main/CHANGELOG.md)