cloudflare/workers-sdk miniflare@5.20260828.0-alpha

on GitHub

Minor Changes

• #15337 b23de74 Thanks @tpmmorris! - Add email inspection and testing to Local Explorer

  Add an Email group with Routing and Sending views for inspecting messages received by a Worker's email() handler and messages sent through its send_email bindings. Detail views show message content, metadata, attachments, and handler activity including forwarding, replies, rejection, and unhandled messages.

  Add a test-email composer that delivers custom text, HTML, headers, and attachments directly to the selected Worker's email() handler during local development.

• #15305 015550a Thanks @Monark-Arkmon! - Support env.IMAGES.hosted.createDirectUpload() in local development. Creates a draft image and returns an uploadURL served by a new local endpoint that accepts the completed upload as multipart/form-data (field name file). Matches production's validation (expiresIn bounds of 120–21600 seconds, rejecting UUID custom IDs) and single-use/expiry semantics: completing an unknown or already-used upload link returns 404/409, and an expired link returns 410.

• #15305 015550a Thanks @Monark-Arkmon! - Support the filter.metadata option on env.IMAGES.hosted.list() in local development, matching the metadata filtering behaviour of the production Images binding. Filters support the eq (implicit for bare values), in, gt, gte, lt, and lte operators, dot-notation nested field paths, and AND logic across multiple fields.

• #15305 015550a Thanks @Monark-Arkmon! - Support env.IMAGES.hosted.image(id).signedUrl() in local development. A fixed local-dev signing secret is used to generate and verify signed delivery URLs, so images uploaded with requireSignedURLs: true can only be fetched from the local image delivery endpoint with a valid, unexpired signature — matching the production Images binding's signed URL behaviour end-to-end.

• #15373 3650d29 Thanks @jamesopstad! - Rename Worker target fields from workerName to worker

  The experimental @cloudflare/config and Miniflare configuration APIs now use worker consistently for Worker, Durable Object, Workflow, dispatch namespace, and tail consumer targets.

Patch Changes

• #15383 eb01850 Thanks @dependabot! - Update dependencies of "miniflare", "wrangler"

  The following dependency versions have been updated:

  Dependency	From	To
  @cloudflare/workers-types	^5.20260826.1	^5.20260827.1
  workerd	1.20260826.1	1.20260827.1

• #15393 e1df91a Thanks @dependabot! - Update dependencies of "miniflare", "wrangler"

  The following dependency versions have been updated:

  Dependency	From	To
  @cloudflare/workers-types	^5.20260827.1	^5.20260828.1
  workerd	1.20260827.1	1.20260828.1

• #15337 b23de74 Thanks @tpmmorris! - Validate custom headers sent through the Local Explorer test-email endpoint

  Reject header names and values that cannot be safely encoded. Multiline values remain supported and are folded into valid MIME continuation lines.