Developer Platform Updates & Release Notes

TanStack Start ↗︎ apps can now prerender routes to static HTML at build time with access to build time environment variables and bindings, and serve them as static assets. To enable prerendering, configure the prerender option of the TanStack Start plugin in your Vite config:

vite.config.tsts

import { defineConfig } from "vite";
import { cloudflare } from "@cloudflare/vite-plugin";
import { tanstackStart } from "@tanstack/react-start/plugin/vite";

export default defineConfig({
  plugins: [
    cloudflare({ viteEnvironment: { name: "ssr" } }),
    tanstackStart({
      prerender: {
        enabled: true,
      },
    }),
  ],
});

This feature requires @tanstack/react-start v1.138.0 or later. See the TanStack Start framework guide for more details.

R2 Data Catalog now supports automatic snapshot expiration for Apache Iceberg tables.

In Apache Iceberg, a snapshot is metadata that represents the state of a table at a given point in time. Every mutation creates a new snapshot which enable powerful features like time travel queries and rollback capabilities but will accumulate over time.

Without regular cleanup, these accumulated snapshots can lead to:

• Metadata overhead
• Slower table operations
• Increased storage costs.

Snapshot expiration in R2 Data Catalog automatically removes old table snapshots based on your configured retention policy, improving performance and storage costs.

# Enable catalog-level snapshot expiration
# Expire snapshots older than 7 days, always retain at least 10 recent snapshots
npx wrangler r2 bucket catalog snapshot-expiration enable my-bucket \
  --older-than-days 7 \
  --retain-last 10

Snapshot expiration uses two parameters to determine which snapshots to remove:

• --older-than-days: age threshold in days
• --retain-last: minimum snapshot count to retain

Both conditions must be met before a snapshot is expired, ensuring you always retain recent snapshots even if they exceed the age threshold. …

Workers for Platforms lets you build multi-tenant platforms on Cloudflare Workers, allowing your end users to deploy and run their own code on your platform. It's designed for anyone building an AI vibe coding platform, e-commerce platform, website builder, or any product that needs to securely execute user-generated code at scale.

Previously, setting up Workers for Platforms required using the API. Now, the Workers for Platforms UI supports namespace creation, dispatch worker templates, and tag management, making it easier for Workers for Platforms customers to build and manage multi-tenant platforms directly from the Cloudflare dashboard.

Workers for Platforms Dashboard Improvements

Key improvements

• Namespace Management: You can now create and configure dispatch namespaces directly within the dashboard to start a new platform setup. …

We've published build image policies for Workers Builds and Cloudflare Pages, which establish:

• Minor version updates: We typically update preinstalled software to the latest available minor version without notice. For tools that don't follow semantic versioning (e.g., Bun or Hugo), we provide 3 months’ notice.
• Major version updates: Before preinstalled software reaches end-of-life, we update to the next stable LTS version with 3 months’ notice.
• Build image version deprecation (Pages only): We provide 6 months’ notice before deprecation. Projects on v1 or v2 will be automatically moved to v3 on their specified deprecation dates.

To prepare for updates, monitor the Cloudflare Changelog ↗︎, dashboard notifications, and email. You can also override default versions to maintain specific versions.

Wrangler now includes a new wrangler auth token command that retrieves your current authentication token or credentials for use with other tools and scripts.

wrangler auth token

The command returns whichever authentication method is currently configured, in priority order: API token from CLOUDFLARE_API_TOKEN, or OAuth token from wrangler login (automatically refreshed if expired).

Use the --json flag to get structured output including the token type:

wrangler auth token --json

The JSON output includes the authentication type:

// API token
{ "type": "api_token", "token": "..." }

// OAuth token
{ "type": "oauth", "token": "..." }

// API key/email (only available with --json)
{ "type": "api_key", "key": "...", "email": "..." }

API key/email credentials from CLOUDFLARE_API_KEY and CLOUDFLARE_EMAIL require the --json flag since this method uses two values instead of a single token.

Wrangler now includes a new wrangler auth token command that retrieves your current authentication token or credentials for use with other tools and scripts.

wrangler auth token

The command returns whichever authentication method is currently configured, in priority order: API token from CLOUDFLARE_API_TOKEN, or OAuth token from wrangler login (automatically refreshed if expired).

Use the --json flag to get structured output including the token type:

wrangler auth token --json

The JSON output includes the authentication type:

// API token
{ "type": "api_token", "token": "..." }

// OAuth token
{ "type": "oauth", "token": "..." }

// API key/email (only available with --json)
{ "type": "api_key", "key": "...", "email": "..." }

API key/email credentials from CLOUDFLARE_API_KEY and CLOUDFLARE_EMAIL require the --json flag since this method uses two values instead of a single token.

The @cloudflare/vitest-pool-workers package now supports the ctx.exports API, allowing you to access your Worker's top-level exports during tests.

You can access ctx.exports in unit tests by calling createExecutionContext():

import { createExecutionContext } from "cloudflare:test";
import { it, expect } from "vitest";

it("can access ctx.exports", async () => {
  const ctx = createExecutionContext();
  const result = await ctx.exports.MyEntryPoint.myMethod();
  expect(result).toBe("expected value");
});

Alternatively, you can import exports directly from cloudflare:workers:

import { exports } from "cloudflare:workers";
import { it, expect } from "vitest";

it("can access imported exports", async () => {
  const result = await exports.MyEntryPoint.myMethod();
  expect(result).toBe("expected value");
});

See the context-exports fixture ↗︎ for a complete example.

Wrangler now supports automatic configuration for popular web frameworks in experimental mode, making it even easier to deploy to Cloudflare Workers.

Previously, if you wanted to deploy an application using a popular web framework like Next.js or Astro, you had to follow tutorials to set up your application for deployment to Cloudflare Workers. This usually involved creating a Wrangler file, installing adapters, or changing configuration options.

Now wrangler deploy does this for you. Starting with Wrangler 4.55, you can use npx wrangler deploy --x-autoconfig in the directory of any web application using one of the supported frameworks. Wrangler will then proceed to configure and deploy it to your Cloudflare account.

You can also configure your application without deploying it by using the new npx wrangler setup command. This enables you to easily review what changes we are making so your application is ready for Cloudflare Workers.

The following application frameworks are supported starting today:

• Next.js
• Astro
• Nuxt
• TanStack Start
• SolidStart
• React Router
• SvelteKit
• Docusaurus
• Qwik
• Analog

Automatic configuration also supports static sites by detecting the assets directory and build command. From a single index.html file to the output of a generator like Jekyll or Hugo, you can just run npx wrangler deploy --x-autoconfig to upload to Cloudflare. …

A new Rules of Durable Objects guide is now available, providing opinionated best practices for building effective Durable Objects applications. This guide covers design patterns, storage strategies, concurrency, and common anti-patterns to avoid.

Key guidance includes:

• Design around your "atom" of coordination — Create one Durable Object per logical unit (chat room, game session, user) instead of a global singleton that becomes a bottleneck.
• Use SQLite storage with RPC methods — SQLite-backed Durable Objects with typed RPC methods provide the best developer experience and performance.
• Understand input and output gates — Learn how Cloudflare's runtime prevents data races by default, how write coalescing works, and when to use blockConcurrencyWhile().
• Leverage Hibernatable WebSockets — Reduce costs for real-time applications by allowing Durable Objects to sleep while maintaining WebSocket connections.

The testing documentation has also been updated with modern patterns using @cloudflare/vitest-pool-workers, including examples for testing SQLite storage, alarms, and direct instance access:

test/counter.test.jsjs

import { env, runDurableObjectAlarm } from "cloudflare:test";
import { it, expect } from "vitest"; …

R2 SQL now supports aggregation functions, GROUP BY, HAVING, along with schema discovery commands to make it easy to explore your data catalog.

Aggregation Functions

You can now perform aggregations on Apache Iceberg tables in R2 Data Catalog using standard SQL functions including COUNT(*), SUM(), AVG(), MIN(), and MAX(). Combine these with GROUP BY to analyze data across dimensions, and use HAVING to filter aggregated results.

-- Calculate average transaction amounts by department
SELECT department, COUNT(*), AVG(total_amount)
FROM my_namespace.sales_data
WHERE region = 'North'
GROUP BY department
HAVING COUNT(*) > 50
ORDER BY AVG(total_amount) DESC

-- Find high-value departments
SELECT department, SUM(total_amount)
FROM my_namespace.sales_data
GROUP BY department
HAVING SUM(total_amount) > 50000

Schema Discovery

New metadata commands make it easy to explore your data catalog and understand table structures:

• SHOW DATABASES or SHOW NAMESPACES - List all available namespaces
• SHOW TABLES IN namespace_name - List tables within a namespace
• DESCRIBE namespace_name.table_name - View table schema and column types

❯ npx wrangler r2 sql query "{ACCOUNT_ID}_{BUCKET_NAME}" "DESCRIBE default.sales_data;"

 ⛅️ wrangler 4.54.0
───────────────────────────────────────────── …

Storage billing for SQLite-backed Durable Objects will be enabled in January 2026, with a target date of January 7, 2026 (no earlier).

To view your SQLite storage usage, go to the Durable Objects page

Go to Durable Objects ↗

If you do not want to incur costs, please take action such as optimizing queries or deleting unnecessary stored data in order to reduce your SQLite storage usage ahead of the January 7th target. Only usage on and after the billing target date will incur charges.

Developers on the Workers Paid plan with Durable Object's SQLite storage usage beyond included limits will incur charges according to SQLite storage pricing announced in September 2024 with the public beta ↗︎. Developers on the Workers Free plan will not be charged.

Compute billing for SQLite-backed Durable Objects has been enabled since the initial public beta. SQLite-backed Durable Objects currently incur charges for requests and duration, and no changes are being made to compute billing. …

Python Workers now feature improved cold start performance, reducing initialization time for new Worker instances. This improvement is particularly noticeable for Workers with larger dependency sets or complex initialization logic.

Every time you deploy a Python Worker, a memory snapshot is captured after the top level of the Worker is executed. This snapshot captures all imports, including package imports that are often costly to load. The memory snapshot is loaded when the Worker is first started, avoiding the need to reload the Python runtime and all dependencies on each cold start.

We set up a benchmark that imports common packages (httpx ↗︎, fastapi ↗︎ and pydantic ↗︎) to see how Python Workers stack up against other platforms:

Platform

Mean Cold Start (ms)

Cloudflare Python Workers

1027

AWS Lambda

2502

Google Cloud Run

3069

These benchmarks run continuously. You can view the results and the methodology on our benchmark page ↗︎.

In additional testing, we have found that without any memory snapshot, the cold start for this benchmark takes around 10 seconds, so this change improves cold start performance by roughly a factor of 10.

To get started with Python Workers, check out our Python Workers overview.

We are introducing a brand new tool called Pywrangler, which simplifies package management in Python Workers by automatically installing Workers-compatible Python packages into your project.

With Pywrangler, you specify your Worker's Python dependencies in your pyproject.toml file:

[project]
name = "python-beautifulsoup-worker"
version = "0.1.0"
description = "A simple Worker using beautifulsoup4"
requires-python = ">=3.12"
dependencies = [
    "beautifulsoup4"
]

[dependency-groups]
dev = [
  "workers-py",
  "workers-runtime-sdk"
]

You can then develop and deploy your Worker using the following commands:

uv run pywrangler dev
uv run pywrangler deploy

Pywrangler automatically downloads and vendors the necessary packages for your Worker, and these packages are bundled with the Worker when you deploy.

Consult the Python packages documentation for full details on Pywrangler and Python package management in Workers.

When using the Cloudflare Vite plugin to build and deploy Workers, a Wrangler configuration file is now optional for assets-only (static) sites. If no wrangler.toml, wrangler.json, or wrangler.jsonc file is found, the plugin generates sensible defaults for an assets-only site. The name is based on the package.json or the project directory name, and the compatibility_date uses the latest date supported by your installed Miniflare version.

This allows easier setup for static sites using Vite. Note that SPAs will still need to set assets.not_found_handling to single-page-application ↗︎ in order to function correctly.

The Cloudflare Vite plugin now supports programmatic configuration of Workers without a Wrangler configuration file. You can use the config option to define Worker settings directly in your Vite configuration, or to modify existing configuration loaded from a Wrangler config file. This is particularly useful when integrating with other build tools or frameworks, as it allows them to control Worker configuration without needing users to manage a separate config file.

The config option

The Vite plugin's new config option accepts either a partial configuration object or a function that receives the current configuration and returns overrides. This option is applied after any config file is loaded, allowing the plugin to override specific values or define Worker configuration entirely in code.

Example usage

Setting config to an object to provide configuration values that merge with defaults and config file settings:

vite.config.tsts

import { defineConfig } from "vite";
import { cloudflare } from "@cloudflare/vite-plugin";

export default defineConfig({
	plugins: [
		cloudflare({
			config: {
				name: "my-worker",
				compatibility_flags: ["nodejs_compat"],
				send_email: [
					{
						name: "EMAIL",
					},
				],
			},
		}),
	],
});

Use a function to modify the existing configuration:

vite.config.tsts

You can now connect directly to remote databases and databases requiring TLS with wrangler dev. This lets you run your Worker code locally while connecting to remote databases, without needing to use wrangler dev --remote.

The localConnectionString field and CLOUDFLARE_HYPERDRIVE_LOCAL_CONNECTION_STRING_<BINDING_NAME> environment variable can be used to configure the connection string used by wrangler dev.

{
  "hyperdrive": [
    {
      "binding": "HYPERDRIVE",
      "id": "your-hyperdrive-id",
      "localConnectionString": "postgres://user:password@remote-host.example.com:5432/database?sslmode=require"
    }
  ]
}

Learn more about local development with Hyperdrive.

Workers applications now use reusable Cloudflare Access policies to reduce duplication and simplify access management across multiple Workers.

Previously, enabling Cloudflare Access on a Worker created per-application policies, unique to each application. Now, we create reusable policies that can be shared across applications:

• Preview URLs: All Workers preview URLs share a single "Cloudflare Workers Preview URLs" policy across your account. This policy is automatically created the first time you enable Access on any preview URL. By sharing a single policy across all preview URLs, you can configure access rules once and have them apply company-wide to all Workers which protect preview URLs. This makes it much easier to manage who can access preview environments without having to update individual policies for each Worker. …

The latest release of @cloudflare/agents ↗︎ brings resumable streaming, significant MCP client improvements, and critical fixes for schedules and Durable Object lifecycle management.

Resumable streaming

AIChatAgent now supports resumable streaming, allowing clients to reconnect and continue receiving streamed responses without losing data. This is useful for:

• Long-running AI responses
• Users on unreliable networks
• Users switching between devices mid-conversation
• Background tasks where users navigate away and return
• Real-time collaboration where multiple clients need to stay in sync

Streams are maintained across page refreshes, broken connections, and syncing across open tabs and devices.

Other improvements

• Default JSON schema validator added to MCP client
• Schedules ↗︎ can now safely destroy the agent

MCP client API improvements

The MCPClientManager API has been redesigned for better clarity and control:

• New registerServer() method: Register MCP servers without immediately connecting
• New connectToServer() method: Establish connections to registered servers
• Improved reconnect logic: restoreConnectionsFromStorage() now properly handles failed connections

// Register a server to Agent …

We've partnered with Black Forest Labs (BFL) to bring their latest FLUX.2 [dev] model to Workers AI! This model excels in generating high-fidelity images with physical world grounding, multi-language support, and digital asset creation. You can also create specific super images with granular controls like JSON prompting.

Read the BFL blog ↗︎ to learn more about the model itself. Read our Cloudflare blog ↗︎ to see the model in action, or try it out yourself on our multi modal playground ↗︎.

Pricing documentation is available on the model page or pricing page. Note, we expect to drop pricing in the next few days after iterating on the model performance.

Workers AI Platform specifics

The model hosted on Workers AI is able to support up to 4 image inputs (512x512 per input image). Note, this image model is one of the most powerful in the catalog and is expected to be slower than the other image models we currently support. One catch to look out for is that this model takes multipart form data inputs, even if you just have a prompt.

With the REST API, the multipart form data input looks like this:

curl --request POST \ …

Containers now support mounting R2 buckets as FUSE (Filesystem in Userspace) volumes, allowing applications to interact with R2 using standard filesystem operations.

Common use cases include:

• Bootstrapping containers with datasets, models, or dependencies for sandboxes and agent environments
• Persisting user configuration or application state without managing downloads
• Accessing large static files without bloating container images or downloading at startup

FUSE adapters like tigrisfs ↗︎, s3fs ↗︎, and gcsfuse ↗︎ can be installed in your container image and configured to mount buckets at startup.

FROM alpine:3.20

# Install FUSE and dependencies
RUN apk update && \
    apk add --no-cache ca-certificates fuse curl bash

# Install tigrisfs
RUN ARCH=$(uname -m) && \
    if [ "$ARCH" = "x86_64" ]; then ARCH="amd64"; fi && \
    if [ "$ARCH" = "aarch64" ]; then ARCH="arm64"; fi && \
    VERSION=$(curl -s https://api.github.com/repos/tigrisdata/tigrisfs/releases/latest | grep -o '"tag_name": "[^"]*' | cut -d'"' -f4) && \ …