Pantheon release notes

As of today, an increasing percentage of newly created sites on Pantheon will use a filesystem backed by Cloud Storage FUSE for their uploaded files (wp-content/uploads for WordPress and sites/default/files for Drupal). This filesystem replaces the "Valhalla" system Pantheon pioneered for sharing files across horizontally scalable PHP containers.

Existing sites will migrate to this new filesystem over the remainder of 2026 starting on 09/01/26.

With this change, we can create and restore backups faster and more reliably.

Background

Both WordPress and Drupal were originally architected in the early 2000s for systems where developer-controlled application files (.php, .css, .js, etc.) and files uploaded by CMS users (images, PDFs, etc.) would live on the same server. By default, both CMSes will write uploaded files to the local file system. Those defaults break down when the application files are horizontally scaled across multiple servers or containers which need to share access to an ever-changing set of uploaded files. To solve this challenge at Pantheon's founding we created a scalable filesystem (Valhalla) that mounted across containers which allows sites to behave as though they are writing to a local disc while those files are actually shared across containers. Additionally, this approach allows for the wide variance in the amount of files uploaded to WordPress or Drupal, with some sites writing millions of files.

While Valhalla was an innovative solution at Pantheon's founding, it has since been surpassed in performance by solutions like Cloud Storage FUSE. Thanks to our partnership with Google Cloud, we can deprecate Valhalla in favor of a more robust filesystem.

Rollout Timeline

New Sites: New sites will begin to be provisioned using the new filesystem on 8/3, ramping up to 100% of new sites being provisioned using the new filesystem by 8/17. There is no additional action you need to take.

Existing Sites: Existing site migrations will begin 9/1/2026. Rollout timeline:

• Free sites: September 1, 2026
• Basic sites: October 5, 2026
• Performance sites: November 16, 2026
• Elite sites: November 30, 2026

How to determine which Filesystem your site is using

In Site details, there is a Filesystem Generation field. Sites that are on the new filesystem will have a “2” in this field.

For more information, see our documentation. Should you have any questions or concerns, please reach out to our customer support team via chat or email us at the Pantheon Helpdesk.

After a successful Beta phase, Pantheon's next-generation Global CDN (GCDN) is now generally available. Built on Cloudflare, the new GCDN delivers built-in bot protection, expanded site eligibility, and the same self-serve migration experience customers have been using in the Beta — now production-ready for the majority of sites on the platform.

What's included

• Built-in bot protection — Incoming traffic is automatically scored, with managed challenges issued to suspicious requests and verified bots (such as search engine crawlers) allowed through.
• Multizone Failover support — Sites with Multizone Failover enabled can migrate to GCDN and continue to benefit from automated regional failover.
• Custom Certificates support — Sites using customer-provided TLS certificates are now supported on GCDN. Migration for these sites is owned by our Professional Services team and coordinated through support — open a support ticket to get started.
• Platform vanity domain support — Organization-owned vanity hostnames (e.g., live-mysite.example-agency.com) are fully supported. Migration for these sites is owned by our Professional Services team and coordinated through support — open a support ticket to get started.

Action Required

Eligible sites will display a GCDN banner in the Pantheon dashboard. To migrate:

1. Locate the GCDN banner on an eligible site.
2. Click it and complete the guided process.
3. Point your DNS records to the new GCDN infrastructure.

Domain verification supports DNS-01 TXT record validation, requiring TXT records added at your DNS provider.

Eligibility

GCDN is available to all sites on the platform except those currently using Advanced Global CDN (AGCDN). AGCDN customers will be migrated in a future phase — no action is required from them at this time.

More information

For full details on GCDN, refer to the Global CDN guide on the Pantheon docs site.

Sites can now compile frontend assets (themes, design systems, and other Node.js-based tooling) automatically as part of the build process.

When enabled, Pantheon installs your Node.js dependencies and runs your build script for each configured path on every code push, so compiled assets no longer need to be committed to your repository. Frontend builds work on any site, whether or not you use Integrated Composer.

Enable frontend builds

Add a frontend_build block to your pantheon.yml file:

Pantheon selects a package manager automatically based on the lock file present in each build path. Supported package managers include bun, pnpm, yarn, and npm.

For full configuration details and examples, see the frontend asset builds documentation.

Elasticsearch is now available as an add-on for WordPress sites on Pantheon for all Performance sites and above. This new capability is powered by ElasticPress, the leading Elasticsearch solution for WordPress.

What's included?

ElasticPress improves the overall search experience and performance of your WordPress sites, as well as allowing for better WP_Query performance and reduced load on your application server. Capabilities include:

• Full-text search — Fuzzy matching, synonyms, and weighted fields for more relevant search results.
• Instant Search — Real-time search-as-you-type results without full page reloads.
• WP_Query integration — ElasticPress allows you to offload WP_Query requests to Elasticsearch, reducing database load and improving page load times.
• Faceted filtering — Narrow results by category, tag, custom taxonomy, and other attributes.
• WooCommerce support — Product search and filtering for WooCommerce storefronts.
• Related content — Surface related posts and pages automatically.
• Custom content indexing — Index posts, pages, custom post types, and custom fields.

Who has access?

Elasticsearch is available to WordPress sites on Performance Small plans and above.

How to enable it

Review the Setup and Configuration documentation for detailed instructions on setting up Elasticsearch and ElasticPress.

More information

For additional guidance and a walkthrough of these features, see the Elasticsearch on Pantheon documentation.

Pantheon Search now supports Apache Solr 9.10.1 for Drupal 7, 10, and 11 sites, with improved security defaults, the unified highlighter, and performance enhancements. See the major changes in Solr 9 for details.

How to get Solr 9

Drupal 10 and 11

Solr 9 support is available through Search API Pantheon version 8.5.0.

For detailed setup instructions, see the Solr for Drupal 10/11 guide.

Drupal 7

Solr 9 support is available through the Pantheon Drupal 7 upstream version 7.105.1.

For detailed setup instructions, see the Solr for Drupal 7 guide.

Solr 3 and Solr 8 removal timeline

The previously announced removal schedule still holds:

• Solr 3 will be removed on February 9, 2027. Drupal sites using Solr 3 must migrate to Solr 9 before this date. WordPress sites using Solr 3 through the Solr Power plugin should consider switching to Elasticsearch.
• Solr 8 will be removed on July 11, 2027. Drupal 10 and 11 sites using Solr 8 should migrate to Solr 9 before this date.

Feedback

Report issues or provide feedback in the drupal.org issue queue for Drupal 10/11, or through Pantheon Support for Drupal 7.

Pantheon's external repository integration now supports GitLab in addition to GitHub. You can connect a GitLab repository to a Pantheon site via Terminus using --vcs-provider=gitlab, with support for both GitLab.com and self-hosted GitLab instances.

What's new

• GitLab repository support — Create Pantheon sites connected to GitLab repositories using terminus site:create --vcs-provider=gitlab
• Self-hosted GitLab — Connect sites to self-hosted GitLab instances using the --vcs-host=<your-gitlab-domain> flag
• Token-based authentication — GitLab uses legacy personal access tokens or group access tokens rather than OAuth. Tokens require api and write_repository scopes. Group access tokens also require a Maintainer role or higher to create repositories and manage webhooks.

For full setup instructions, see the external repositories documentation.

The Security tab is now available for Next.js sites in the Site Dashboard. You can password protect any environment with basic authentication, the same way you can for Drupal and WordPress sites. When an environment is locked, visitors are prompted for a username and password before the site is served.

To lock an environment, select the environment, open the Security tab, choose Locked, provide a username and password, and save. To make it public again, choose Public. For step-by-step instructions, see Lock Environments with the Dashboard Security Tool.

Run a new build after changing lock status

On Next.js sites, locking or unlocking an environment does not take effect until a new build is deployed to that environment. After you change the lock or unlock status in the Security tab, trigger a new build using the Rebuild option (available in the Site Dashboard and through Terminus) or by pushing a new commit to the connected branch, so the change is applied to the running site.

For more details about Next.js on Pantheon, see our Next.js documentation.

Pantheon now supports Bun as a package manager for Next.js sites, alongside npm, yarn, and pnpm. We've also added support for Node.js 26 (LTS).

Bun support

To use Bun, add a bun.lock file to your repository. Pantheon automatically detects the lock file and uses Bun to install your dependencies during the build process.

You can specify a Bun version in the engines.bun or packageManager field of your package.json. If no version is specified, Pantheon defaults to the latest stable release.

Node.js 26 support

Node.js 26 is now available as an LTS runtime for Next.js sites. Set the engines.node field in your package.json to use it:

Node.js 20 removed

Node.js 20 has reached end of life and is no longer available as a runtime. Sites using Node.js 20 must upgrade to Node.js 22 or later.

For more details about Next.js on Pantheon, see our Next.js documentation.