cloudflare/workers-sdk miniflare@4.20260329.0

on GitHub

Minor Changes

• #13025 9eff028 Thanks @ruifigueira! - Add missing devtools endpoints to browser rendering local binding.

  The local browser rendering binding now implements the full set of devtools endpoints, matching the remote Browser Rendering API:

  • GET /v1/limits — returns local concurrency defaults
  • GET /v1/history — returns empty array (no persistence in local dev)
  • GET /v1/devtools/session - list and inspect active sessions
  • GET /v1/devtools/session/:id — list and inspect active session
  • GET /v1/devtools/browser/:id/json/version — Browser version metadata, includes webSocketDebuggerUrl
  • GET /v1/devtools/browser/:id/json/list — A list of all available websocket targets
  • GET /v1/devtools/browser/:id/json — Alias for GET /v1/devtools/browser/:id/json
  • GET /v1/devtools/browser/:id/json/protocol — The current devtools protocol, as JSON. Includes webSocketDebuggerUrl and devtoolsFrontendUrl
  • PUT /v1/devtools/browser/:id/json/new — Opens a new tab. Responds with the websocket target data for the new tab
  • GET /v1/devtools/browser/:id/json/activate/:target — Brings a page into the foreground (activate a tab)
  • GET /v1/devtools/browser/:id/json/close/:target — Closes the target page identified by targetId
  • GET /v1/devtools/browser/:id/page/:target — WebSocket connection to a page target
  • GET /v1/devtools/browser/:id — WebSocket connection to a previously acquired browser session
  • DELETE /v1/devtools/browser/:id — Closes a browser session
  • POST /v1/devtools/browser — Acquires a new session
  • GET /v1/devtools/browser — Acquire a new session and connect via WebSocket in one step, returning cf-browser-session-id header

• #13086 d4c6158 Thanks @pombosilva! - Add Workflows support to the local explorer UI.

  The local explorer (/cdn-cgi/explorer/) now includes a full Workflows dashboard for viewing and managing workflow instances during local development.

  UI features:

  • Workflow instance list with status badges, creation time, action buttons, and pagination
  • Status summary bar with instance counts per status
  • Status filter dropdown and search
  • Instance detail page with step history, params/output cards, error display, and expandable step details
  • Create instance dialog with optional ID and JSON params

Patch Changes

• #13111 f214760 Thanks @dependabot! - Update dependencies of "miniflare", "wrangler"

  The following dependency versions have been updated:

  Dependency	From	To
  workerd	1.20260317.1	1.20260329.1

• #13078 9282493 Thanks @penalosa! - Fix noisy EBUSY errors on Windows when disposing Miniflare instances

  On Windows, workerd may not release file handles immediately after disposal, causing EBUSY errors when Miniflare tries to remove its temporary directory during dispose(). Previously, this error propagated to the caller (e.g. vitest-pool-workers), producing repeated noisy error messages in test output. The cleanup is now best-effort — matching the existing exit hook behaviour — since the temporary directory lives in os.tmpdir() and will be cleaned up by the OS.

• #13090 a532eea Thanks @edmundhung! - Remove LOCAL_EXPLORER_BASE_PATH and LOCAL_EXPLORER_API_PATH constants in favor of CorePaths.EXPLORER

  These were redundant aliases introduced before CorePaths was centralized. All internal consumers now use CorePaths.EXPLORER directly.