Workers SDK Updates & Release Notes

Minor Changes

#15609 1f070c8 Thanks @emily-shen! - Build Containers when emitting experimental Build Output

Wrangler and the Cloudflare Vite plugin now build Dockerfile-backed Container images when experimental Build Output is enabled. Container configs are emitted under .cloudflare/output/v0/containers with local image references, while existing registry references pass through unchanged.

#15329 c4c9b75 Thanks @akshitsinha! - Evaluate Flagship flags locally during development

Flagship bindings now use the local Miniflare store by default in Wrangler and the Vite plugin, keeping development offline and isolated from production flags. Set remote: true on a binding to continue using its remote app.

Use wrangler flagship flags pull <APP_ID> to seed the store from a remote app. Flag management commands also accept --local to read and update the local store directly.

#15701 643e5cc Thanks @WillTaylorDev! - Pass Preview intent to defineWorker and upload its resolved configuration

Preview builds now evaluate programmatic Worker configuration with ctx.isPreview set to true and record that intent in Build Output. The shared Preview uploader deploys the resolved bindings and settings while preserving configured Preview base values when it creates a Preview.

Patch Changes

#15705 a0485d5 Thanks @dependabot! - Update dependencies of "miniflare", "wrangler"

The following dependency versions have been updated:

Dependency
From
To
@cloudflare/workers-types
^5.20260917.1
^5.20260918.1
workerd
1.20260917.1
1.20260918.1

#15587 629ddef Thanks @Kuldeeep18! - Fix duration calculation for running workflow instances, steps, and attempts in wrangler workflows instances describe

wrangler workflows instances describe previously distorted the elapsed duration of in-progress instances, steps, and attempts across non-UTC timezones by stripping " GMT" from toUTCString(), causing new Date(...) to parse the timestamp in the local client timezone. The duration is now correctly computed against the current time.

Updated dependencies [a0485d5]:
[email protected]

Patch Changes

#15329 c4c9b75 Thanks @akshitsinha! - Evaluate Flagship flags locally during development

Flagship bindings now use the local Miniflare store by default in Wrangler and the Vite plugin, keeping development offline and isolated from production flags. Set remote: true on a binding to continue using its remote app.

Use wrangler flagship flags pull <APP_ID> to seed the store from a remote app. Flag management commands also accept --local to read and update the local store directly.

Minor Changes

• #15609 1f070c8 Thanks @emily-shen! - Build Containers when emitting experimental Build Output

Wrangler and the Cloudflare Vite plugin now build Dockerfile-backed Container images when experimental Build Output is enabled. Container configs are emitted under .cloudflare/output/v0/containers with local image references, while existing registry references pass through unchanged.

• #15329 c4c9b75 Thanks @akshitsinha! - Evaluate Flagship flags locally during development

Flagship bindings now use the local Miniflare store by default in Wrangler and the Vite plugin, keeping development offline and isolated from production flags. Set remote: true on a binding to continue using its remote app.

Use wrangler flagship flags pull <APP_ID> to seed the store from a remote app. Flag management commands also accept --local to read and update the local store directly.

• #15701 643e5cc Thanks @WillTaylorDev! - Pass Preview intent to defineWorker and upload its resolved configuration

Preview builds now evaluate programmatic Worker configuration with ctx.isPreview set to true and record that intent in Build Output. The shared Preview uploader deploys the resolved bindings and settings while preserving configured Preview base values when it creates a Preview.

Patch Changes

Updated dependencies [1f070c8, a0485d5, 629ddef, c4c9b75, 643e5cc]:

[email protected]

[email protected]

Minor Changes

• #15701 643e5cc Thanks @WillTaylorDev! - Pass Preview intent to defineWorker and upload its resolved configuration
• Preview builds now evaluate programmatic Worker configuration with ctx.isPreview set to true and record that intent in Build Output. The shared Preview uploader deploys the resolved bindings and settings while preserving configured Preview base values when it creates a Preview.

Patch Changes

• Updated dependencies [1f070c8, 1f070c8, a0485d5, c4c9b75, 643e5cc]:
• @cloudflare/[email protected]
• @cloudflare/[email protected]
• [email protected]
• @cloudflare/[email protected]
• @cloudflare/[email protected]

Minor Changes

• #15684 6874aa9 Thanks @Ankcorn! - Add support for configuring real-time Issues with observability.issues.enabled

Wrangler now validates and uploads the Issues setting alongside the existing logs and traces observability options. The experimental configuration format supports the equivalent observability.issues.enabled option.

• #15681 d96b319 Thanks @podonnell-dev! - Mark wrangler preview commands as open beta

Wrangler now labels Preview commands as open beta in help output and command warnings, matching the feature's public availability.

• #15673 2b39fc2 Thanks @ghostwriternr! - Support explicit named Container image selection in Wrangler local development

Wrangler builds or pulls named images configured through Wrangler JSON or TOML and exposes their local tags through ctx.container.images. Pass one of those references to ctx.container.start({ image }) to select the image.

This extends the experimental Durable Object-managed Containers interface. Named images are opt-in and do not become the Container's default image. A Container without a default image must supply an image or full Container snapshot when starting.

Patch Changes

• #15689 876eea1 Thanks @dependabot! - Update dependencies of "miniflare", "wrangler"

The following dependency versions have been updated:

Dependency
From
To
@cloudflare/workers-types
^5.20260916.1
^5.20260917.1
workerd
1.20260916.1
1.20260917.1

Updated dependencies [2298cf1, 876eea1]:
[email protected]

Minor Changes

• #15672 2298cf1 Thanks @ghostwriternr! - Support named images or no default image for Durable Object-managed Containers

Miniflare now accepts named image references for Durable Object-managed Containers and preserves an omitted default image (imageName). A Container without a default image must supply an image or full Container snapshot when starting.

This extends Miniflare's experimental Durable Object-managed Containers interface.

Patch Changes

• #15689 876eea1 Thanks @dependabot! - Update dependencies of "miniflare", "wrangler"

The following dependency versions have been updated:

Dependency

From

To

@cloudflare/workers-types

^5.20260916.1

^5.20260917.1

workerd

1.20260916.1

1.20260917.1

Minor Changes

• #15674 a939a6c Thanks @ghostwriternr! - Support explicit named Container image selection in local development

The Vite plugin builds or pulls named images from Wrangler configuration and exposes their local tags through ctx.container.images. Pass one of those references to ctx.container.start({ image }) to select the image.

This extends the experimental Durable Object-managed Containers interface.

Patch Changes

Updated dependencies [6874aa9, 2298cf1, d96b319, 876eea1, 2b39fc2]:

• [email protected]
• [email protected]