2026 CMS (SaaS) release notes

Requests to the retired Preview3 CMS REST API now return the 410 Gone status code. Preview3 reached end-of-life on August 1, 2026. If an integration calls an endpoint with /preview3/ in the URL, move it to CMS REST API v1 with the migration guide. Integrations that already use v1 need no changes.

Added UI extensions, which bring custom tools and pages into the CMS (SaaS) interface. Editors can work with external data, run custom checks, or use richer input fields without leaving CMS. Each extension is part of an Optimizely Connect Platform (OCP) app that you install for your CMS instance. An extension displays in one of the following places:

Administrators assign property editors in a property's Editor setting and check installed extensions on the Extensions Diagnostics page.

Rich-text editors now have image and video buttons, so you can insert media from CMS (SaaS) or Optimizely Digital Asset Management (DAM)  without leaving the editor. The image button replaces the TinyMCE image button in every toolbar, and the Expanded toolbar preset also has a video button. Each button lets you browse CMS media, pick a DAM asset when DAM is configured, or upload an image to CMS (SaaS).

Visual Builder now shows the rows, columns, and elements of every section in the outline , so you can edit an experience and its sections in one view without opening each section separately. One view makes it easier to work across sections, such as when you copy content from one section to another.

Pickers that accept pages now list Browse page tree with Browse, so you can find a page by where it sits in your site structure. Use it when you add a link to a page  or select a page for a property. Browse page tree displays when the property allows every page type. Browse still opens the Content Manager picker, where you can search and pick content from sources such as DAM.

The Optimizely Graph full sync  now does less work for assets, so sites with many assets sync with less load. The job skips the assets of permanently deleted content before it loads them and checks each asset folder only once per run. Optimizely Graph now leaves out every asset of permanently deleted content, including blocks, not only images and other media.

CMS (SaaS) now uses version 4 of the ImageSharp library to resize, crop, and otherwise process your images, so image processing stays on a version that gets security fixes. Static images look the same as before. When you resize or crop an animated PNG, it now keeps its animation instead of showing only the first frame. You do not need to take any action.

Mark (Optimizely Agent Platform) now uploads images and other files to CMS (SaaS) even when your media types require properties, such as alt text. Add the media you need without leaving the conversation.

Include property values in your upload request, or let Mark fill in alt text from the file's display name or file name. If another required property is missing, Mark tells you which one, so you can provide it and try again.

Mark reads the requirements from the media types on your instance, so customized media types work too.

CMS (SaaS) now has clear limits on how deeply you can nest content. If you save content that goes past a limit, the message names the limit, such as Blocks cannot be nested more than 8 levels deep. Previously, deeply nested content could save in the CMS UI and then fail to update through the CMS (SaaS) REST API, with an error that did not explain why.

The limits apply in the CMS UI and through the REST API. You cannot save existing content that is nested deeper than a limit, even after an unrelated edit, until you reduce its nesting. A shared block counts as one level, and CMS (SaaS) checks the blocks inside it when you save the shared block.

Optimizely Graph no longer indexes fallback content for languages that are not available. Visitors cannot see those languages, so skipping their fallback content keeps your index smaller and each sync faster. Optimizely Graph still indexes content that exists in those languages, and fallback content for available languages does not change.

Subscribe a webhook to the Completed event in the Import category (import:preview1:completed) to know when a content import finishes. CMS (SaaS) sends the event once, after the whole import completes, so your systems can start follow-up work, such as re-indexing or warming a cache, at the right time. The event includes how many content items, content types, blueprints, and other entities the import brought in, and whether the import logged any errors. CMS (SaaS) does not send the event when an import is aborted.

Give each content type an icon, so editors can recognize it at a glance. Pick the icon from the Icon list on the Settings tab of the content type . To set icons in code, use the icon property in the CMS (SaaS) REST API. Visual Builder shows the icon next to sections and elements in the outline, which makes them easier to tell apart.

Name rows and columns in Visual Builder  after their content, as you can for sections. Descriptive names make it easier to find what you need in large and complex layouts. Rename is available in the context menu of each row and column.

Link, Link collection, and URL properties now open the Content Manager picker, so links can reach beyond CMS (SaaS) content. The picker lists DAM assets and content from other connected sources whose content types the property allows. Content Reference and Image properties already use this picker.

The Create Link dialog in the rich-text editor uses the same picker for its Page and Media options. Links you add in text now work the same way as link properties.

Mark can now create, change, and delete the rules that control how your forms respond to visitor answers. Describe the behavior you want in plain language , such as showing a field only for a certain answer, hiding a step, or jumping ahead to a later step. Finish a form you started building with Mark without leaving the conversation.

Before saving, Mark lists every rule on the form in plain language and asks you to confirm. Ask Mark to show the rules on an existing form, and nothing changes. If the form is published, Mark saves your changes to a draft, so the published version stays as it is. If CMS (SaaS) rejects a rule, Mark marks the rule that needs fixing and explains why. Rules are saved for one language version at a time.

Mark works with the same form rules  that you configure in the form builder, including rules you set up by hand.

A new agent is now available in the Agent Directory to help you find and fix accessibility issues in your CMS (SaaS) content.

When you pick an image or video from Optimizely DAM, you can choose one of its renditions, such as a crop or a smaller size, rather than the full original. The rendition you pick is stored on the property and delivered to your frontend through Optimizely Graph. The correct asset arrives ready to render, so a developer does not have to adjust it in frontend code.

Renditions are available in Content Manager and in the DAM asset picker. The detail pane has an Info tab and, for assets that have renditions, a Renditions tab with a size comparison that shows each rendition against the original. DAM usage tracking records the rendition you used, so asset lineage reflects the exact file on the page.

Rendition content sources are created for you, including on instances already connected to DAM, so no configuration is required.

When you select a content item in Content Manager, the detail pane now shows its categories as chips on the Info tab, alongside details such as status and language. You can check how content is categorized without opening it for editing. If an item has more categories than fit, you can expand the list to see the rest.

View on website in the publish menu now opens the published page in a new tab. Your draft stays open behind it, so you can pick up editing where you left off instead of navigating back. An arrow icon on the link shows that it opens a new tab.

Closed a gap that let an uploaded file bypass content sanitization by disguising its actual file type, such as SVG or HTML content saved with a mismatched file extension. CMS (SaaS) now inspects file content directly instead of relying on the file extension, so these files are sanitized like any other upload. No action is required.

Added support for granular, resource-based scopes on the CMS (SaaS) REST API, such as read-only access to content types, instead of only full administrator access. A compromised or misconfigured API client is limited to what its scope allows. Existing clients using full administrator access continue to work without changes.

Content indexing now generates and processes content references in parallel instead of one at a time, and retrieves version information without an extra lookup per item. Content-heavy instances sync to Optimizely Graph faster, with no configuration required.

@optimizely/[email protected] 

@optimizely/[email protected] 

Astro sample application 

Mark can now work with the blueprints your team already maintains. Ask Mark which blueprints exist, or whether you have one for a particular purpose. Mark lists what is on your instance and describes the structure and default values inside any of them.

You can then ask Mark to build from a blueprint instead of from scratch. Mark can create a content item seeded from a blueprint. It can also add a saved section blueprint to an experience you are already working on. Values you give in your request override the blueprint's defaults. You get your template's structure with your own content in it.

Mark can now set up and maintain the categories that organize your content. Ask Mark to list your existing categories or look up a specific one. Mark can also create, update, and remove categories, including nested categories that sit under a parent. You can organize content by describing what you want instead of setting up each category by hand.

Mark recognizes the words you already use, so requests phrased as categories, labels, or tags reach the category tools. These tools manage categories only, and do not set the separate Tags field on a content item.

Managing categories with Mark requires CMS administrator rights.

Visual Builder now includes Preview in the toolbar. Select it to see how an experience looks to a visitor without leaving the editor.

Preview renders the experience through your application's preview URL, so the page displays without property overlays or edit outlines. The Visual Builder canvas keeps those overlays because it is an editable preview. Previously, seeing the page without them meant switching to compare view first.

Preview displays only when a preview URL is configured for the content type.

An experience can now hold several independent layouts instead of a single canvas. Model a main content area and a sidebar as separate compositions . Then lay out each one in Visual Builder with its own sections, rows, columns, and elements. Previously, an experience had one linear canvas. Anything more complex meant using Content Area properties, which cannot use display templates or blueprints.

Content administrators can now add a composition property to an experience content type in Settings > Content Types. Set its Layout Type to Outline or Grid, and restrict the content types the composition accepts so content managers see only what belongs in that region. The built-in Composition layout stays on every experience and section, and you cannot remove it.

When an experience has more than one composition, Visual Builder lists Properties alongside each composition by name. Select one to edit that layout on its own.

Optimizely CMS (SaaS) supports webhooks, so another system can react the moment your content changes instead of polling for updates. Subscribe to content lifecycle events (such as a page being created, updated, published, or deleted), and CMS (SaaS) sends the event data to an endpoint you choose. Use webhooks to trigger a translation service, notify a downstream system, or start a Mark agent when content changes. Create and manage webhooks in Settings > Webhooks, or use the REST API.

You can now create and manage categories to classify content across Optimizely CMS (SaaS). Administrators can create, edit, organize, and localize hierarchical categories. Editors assign one or more categories to a content item in the Edit view, then filter content by category in Content Manager. Categories give you a consistent way to organize large content libraries and help editors find content by browsing the hierarchy instead of relying on search keywords.

Optimizely CMS (SaaS) indexes your categories into Optimizely Graph, so you can build category-based navigation, filtering, and faceted search in your front-end applications. Content carries its assigned categories on the _itemMetadata.categories field, and each category is available as a standalone _TaxonomyTerm type with its key, display name, and parent term. See Taxonomies in Optimizely Graph for the schema and query examples.

You can now open the Optimizely Graph Search Management portal directly inside Optimizely CMS (SaaS). A Graph Portal item in the CMS navigation bar frames the portal in the UI, so you manage your CMS and Graph settings side by side instead of switching to a separate application. The menu item displays only for users who have administrator access to Graph.

The CMS REST API OpenAPI specification is updated to OpenAPI 3.1. Fields that used strict enum definitions now list their standard values as examples instead, so the specification matches how the API already behaves. Generate an API client from the updated specification, and it accepts the full range of valid values, and it keeps working when Optimizely adds standard values later. The specification also includes richer field descriptions.

If you use an API client generated from an earlier version of the specification, regenerate it from the updated specification. A client built from the previous enum definitions can reject valid values, and later additions to the standard values can break a client that was not regenerated. The runtime behavior of the API does not change.

The CMS toolbar shows a size indicator for the content item you are editing, so you can tell when an item is approaching the 29 MB limit for syncing to Optimizely Graph. The indicator updates as you edit and uses color and a status—Within Graph limit, Approaching Graph limit, or Exceeds Graph limit—to warn you before an item becomes too large to sync. You catch oversized content while you edit, instead of finding out when a sync fails.

If you build and host your own frontend, Optimizely now supports Astro  in addition to NextJS. Pick the framework that fits your site. Astro supports static site generation (SSG) and server-side rendering (SSR). An Astro site uses the same code package and deployment workflow as a NextJS site. For SSR sites, add Incremental Static Regeneration (ISR) with a Redis cache and Optimizely Graph webhooks. Pages then refresh within seconds of publishing, without a redeploy. Astro requires Node.js 22.12.0 or later, and odd-numbered Node.js releases are not supported.

See System tools for Optimizely Graph for details.

You can now create a content item directly from an existing blueprint using the CMS REST API. Include the blueprint's key in your create request, and Optimizely copies the blueprint's composition and properties into the content for you.

Previously, you had to fetch the blueprint, copy its composition into your request by hand, and regenerate the identifiers yourself. Each item you create this way gets its own layout and node identifiers, so you can reuse the same blueprint as often as you want without collisions.

In a multi-step form, you can now build rules that show or hide an entire step, not just individual fields, based on a respondent's answers.

A rule's conditions can reference fields from any step, so a step can appear or stay hidden based on what someone entered earlier in the form. You build these rules in the same form rules dialog you already use for fields.

When a background request in the editing interface fails, the failure is now recorded with an accurate error in the logs, so administrators and developers can identify the real cause instead of a generic message.

Editors no longer see a vague system-error notice with no explanation, and their work is not interrupted.

@optimizely/cms-create-app

@optimizely/[email protected]

@optimizely/[email protected]

Action required: Migrate Preview3 API integrations to CMS REST API v1 before August 1, 2026

If your CMS (SaaS) applications use the Preview3 CMS REST API endpoints, migrate to CMS REST API v1 before August 1, 2026. On August 1, 2026, Optimizely retires the Preview3 endpoints and begins disabling access. Applications that rely on Preview3 after this date may experience failed requests and service interruptions.

Who is affected – This change affects CMS (SaaS) integrations that make requests to Preview3 endpoints (typically URLs containing /preview3/). If your applications already use CMS REST API v1, no action is required. Optimizely has maintained support for both versions since CMS REST API v1 was released in May 2026 and provides a migration guide to support the transition.

What is changing – With the general availability of CMS REST API v1 on May 5, 2026, the Preview3 APIs entered a deprecation phase and are now approaching end-of-life.

Breaking changes – The transition from Preview3 to v1 introduced some breaking changes. Before migrating, review the migration guide and the experimental APIs documentation for detailed guidance and the recommended migration approach.

Why Preview3 is being retired – Maintaining multiple API versions increases complexity for both customers and Optimizely. Because v1 has been generally available for several months and provides a stable, supported alternative, retiring Preview3 lets Optimizely focus on higher reliability, better performance, and faster innovation across the platform.

How to stay informed – For future API lifecycle and platform updates, subscribe to the following channels, which are typically the first to communicate deprecations, support timelines, and migration guidance:

If you have questions about your migration strategy or encounter challenges during the transition, contact Optimizely.

Narrow a large content list to exactly what you need by filtering on the properties that belong to your content source. The Content Manager filter panel now includes property-based filters, like file type, width, height, or date range, alongside the existing type, status, and language filters. Because each content source exposes different properties, the available filters update when you switch between sources, like CMS, DAM, and OCP, so you only see filters that apply to what you are viewing.

Form submissions now map more reliably to the correct storage columns. Each input element uses a unique submission field name behind the scenes to keep your collected data and exports consistent as forms grow more complex. This works automatically, with no change to how you build or manage forms.

Break a long form into smaller, more digestible steps instead of showing visitors every question at once. Add steps to a form, rename them, and edit each step on its own detail screen while an outline view shows the whole form at a glance. Rather than hitting visitors with 15 questions in one go, you walk them through the form step by step, which reduces friction, keeps them engaged, and boosts conversion rates.

Content sources that you connect from Graph now display in Content Manager under their own name, automatically. For example, connect Commercetools, and it displays as its own source in the Content Manager sidebar, streamlining content filtering. You can browse, filter, and select content from a connected source as soon as you add it in Settings > Content Types > Create New > Connect from Graph.

Set and retrieve a content item's global fallback locale through the Locales endpoints in the CMS REST API. The API now mirrors the fallback behavior already available in CMS (SaaS) and Optimizely Graph, so applications that manage languages programmatically stay consistent with what editors see in the UI.

@optimizely/[email protected] 

@optimizely/[email protected] 

Action required: Migrate Preview3 API integrations to CMS REST API v1 before August 1, 2026

If your CMS (SaaS) applications use the Preview3 CMS REST API endpoints, migrate to CMS REST API v1 before August 1, 2026. On August 1, 2026, Optimizely retires the Preview3 endpoints and begins disabling access. Applications that rely on Preview3 after this date may experience failed requests and service interruptions.

Who is affected – This change affects CMS (SaaS) integrations that make requests to Preview3 endpoints (typically URLs containing /preview3/). If your applications already use CMS REST API v1, no action is required. Optimizely has maintained support for both versions since CMS REST API v1 was released in May 2026 and provides a migration guide to support the transition.

What is changing – With the general availability of CMS REST API v1 on May 5, 2026, the Preview3 APIs entered a deprecation phase and are now approaching end-of-life.

Breaking changes – The transition from Preview3 to v1 introduced some breaking changes. Before migrating, review the migration guide and the experimental APIs documentation for detailed guidance and the recommended migration approach.

Why Preview3 is being retired – Maintaining multiple API versions increases complexity for both customers and Optimizely. Because v1 has been generally available for several months and provides a stable, supported alternative, retiring Preview3 lets Optimizely focus on higher reliability, better performance, and faster innovation across the platform.

How to stay informed – For future API lifecycle and platform updates, subscribe to the following channels, which are typically the first to communicate deprecations, support timelines, and migration guidance:

If you have questions about your migration strategy or encounter challenges during the transition, contact Optimizely.

Released the Agent Visibility Analytics dashboard in Optimizely Analytics, which shows how AI platforms interact with your website so you can refine your content strategy for AI optimization. It draws on content delivery network (CDN) log data and insights generated by Mark, letting you monitor AI traffic patterns, see which AI platforms visit most often, and identify which pages attract the most AI attention.

The Content Manager picker now supports multi-select when adding content to a Content Reference List property. Select as many items as you need in a single session, then confirm to add them all at once.

If a property has a configured item limit, the picker shows your running count and alerts you as you approach the minimum or maximum, keeping you informed without blocking your selection. Multi-select works across all content sources in the picker, including CMS content, DAM assets, and Commerce products.

The CMS (SaaS) MCP server is now available, letting developers use AI tools like Claude with full CMS context to accelerate front-end development and CMS-connected workflows. Generate components, model content, and run CMS operations using natural language grounded in your real CMS structure and data.

After you configure the MCP server, you can ask questions like What content types were updated in the last year? or Create a page using this design file and get real results from your CMS instance.

The MCP server lets you do the following:

CMS (SaaS) platform releases now roll out progressively through ring deployments, replacing the previous all-at-once global deployment approach. Each release advances through controlled groups of accounts, called rings, only after passing validation, limiting the impact of potential issues before they reach production.

Assign different projects or environments to different rings to match your team's needs. For example, keep production in the Main ring for maximum stability, and move staging to the Early Adopter ring for advance access to new features and early validation.

Contact Optimizely support  to change your ring assignment.

(Beta) Released the Optimizely Graph Search Management Portal, a dedicated UI that lets content editors and marketers configure search behavior directly, without developer involvement for day-to-day tasks. Find the portal in the Optimizely global navigation bar. The portal includes:

Access requires Opti ID and Admin Center permissions for your Graph tenant. Pinned Results and Synonyms also require a one-time developer configuration. Use the in-portal feedback link to share feedback during the beta.

Define a default fallback language at the instance level so visitors always see content in a supported language, even when a translation is not yet available. Global fallback languages are now available in the CMS UI under Settings > Languages.

Smooth rebuild is now enabled for CMS (SaaS). Use Settings > Smooth Rebuild to build a new Graph index in the background while the current one stays live. When the rebuild is complete, review the new index, then promote it or revert to the previous state.

This follows a blue-green deployment strategy: a new slot receives a full content sync in the background while the current slot continues serving queries. After verifying the new slot, accept it to swap instantly or abandon it to keep the current data unchanged.

Content type binding property mappings are now more flexible. Property types with fewer capabilities automatically map to types with more capabilities, reducing the need to modify existing content types when working with external content or content type bindings.

The expanded mappings include:

These rules also apply to list versions of each property type.

The DAM integration is now generally available.

The Applications endpoints in the CMS REST API are now generally available. Manage applications (websites) programmatically through the CMS REST API with confidence in CMS (SaaS) environments. The experimental attribute has been removed from the Applications endpoints.

When you reference DAM assets through LinkItem properties, Optimizely Graph now indexes the actual external DAM URL instead of the internal representation. Queries return the correct public URL in the url.default and url.hierarchical fields.

Use the new CMS (SaaS) Mark tools to list, view, create, and update styles for rows, columns, sections, and content types, all directly through Mark chat. Combined with Mark's existing ability to create and manage CMS content, you can now handle the full content creation and editing experience without leaving Mark.

Build content-driven experiences faster with the JavaScript SDK , now generally available. Developers can model, fetch, and render CMS content using a modern, React-ready SDK that reduces manual overhead.

The CMP Library picker is now available as a full asset selection option directly within the CMS editor. Alongside the existing Content Manager picker, you can browse and select CMP DAM assets without leaving the CMS editor, giving you more flexibility in how you find and manage assets across both systems, all in one place.

Access the CMP Library picker by clicking Browse DAM from supported content types in the CMS editor.

Assets are validated against Optimizely Graph before being applied. Renditions are not supported. The Browse action now fulfils the role previously held by the legacy Replace command.

You can now access open-source license agreements for third-party packages directly from the Help menu in edit mode (go to Help > License Agreement). This gives you visibility into the licenses behind the software delivered to your browser, without needing to look elsewhere.

The impersonation option is no longer available when creating or managing API keys. This aligns the UI with the deprecation of this feature at the API level.

URL paths for the following CMS modules now align with the Optimizely brand, delivering a cleaner navigation experience. These changes affect URL segments only. Underlying package, assembly, and class names remain unchanged, so no compatibility issues or breaking changes are introduced.

The following updates are formatted as module – new URL segment.

Content import now enforces the AllowedFileExtensions allow list. Any file with an extension not on the allowlist is blocked, while all other valid files continue to import as normal. A message identifies any blocked files so you know exactly what to address.

CMS now validates values provided for select list and dropdown list choice properties, including those submitted through the API, against their predefined selectable options. This prevents invalid values from being applied to content instances and keeps your content data consistent.

The preview2 version of the CMS REST API reached end-of-life on December 1, 2025, and is no longer available. Update any integrations still using preview2 endpoints to avoid service disruption. See the July 3, 2025 enhancements for guidance on migrating to a supported version.

Contracts now let you define shared interfaces that enforce common properties across multiple content types, keeping your editing experience and metadata consistent at scale. Contracts also integrate directly with Optimizely Graph, automatically generating GraphQL schemas so developers can query all implementing content types through a single unified query. This reduces complexity, improves code reusability, and decouples frontend development from specific content type implementations.

The JavaScript SDK  is now generally available, giving developers a modern, React-ready toolkit for modeling, fetching, and rendering CMS content. It reduces manual overhead and accelerates the creation and maintenance of content-driven experiences.