Previously, a request to the Workers Create Route API always returned null for "script" and an empty string for "pattern" even if the request was successful.
The Workers and Workers for Platforms secrets APIs are now properly documented in the Cloudflare OpenAPI docs. Previously, these endpoints were not publicly documented, leaving users confused on how to directly manage their secrets via the API. Now, you can find the proper endpoints in our public documentation, as well as in our API Library SDKs such as cloudflare-typescript ↗︎ (>4.2.0) and cloudflare-python ↗︎ (>4.1.0).
Note the cloudflare_workers_secret and cloudflare_workers_for_platforms_script_secretTerraform resources ↗︎ are being removed in a future release. This resource is not recommended for managing secrets. Users should instead use the:
Secrets Store with the "Secrets Store Secret" binding on Workers and Workers for Platforms Script Upload
Pipelines let you ingest high volumes of real time data, without managing the underlying infrastructure. A single pipeline can ingest up to 100 MB of data per second, via HTTP or from a Worker. Ingested data is automatically batched, written to output files, and delivered to an R2 bucket in your account. You can use Pipelines to build a data lake of clickstream data, or to store events from a Worker.
Create your first pipeline with a single command:
Create a pipelinebash
$ npx wrangler@latest pipelines create my-clickstream-pipeline --r2-bucket my-bucket🌀 Authorizing R2 bucket "my-bucket"🌀 Creating pipeline named "my-clickstream-pipeline"✅ Successfully created pipeline my-clickstream-pipelineId: 0e00c5ff09b34d018152af98d06f5a1xvcName: my-clickstream-pipelineSources: HTTP: Endpoint: https://0e00c5ff09b34d018152af98d06f5a1xvc.pipelines.cloudflare.com/ Authentication: off Format: JSON Worker: Format: JSONDestination: Type: R2 Bucket: my-bucket Format: newline-delimited JSON Compression: GZIPBatch hints: Max bytes: 100 MB Max duration: 300 seconds Max records: 100,000🎉 You can now send data to your pipeline!Send data to your pipeline's HTTP endpoint:curl "https://0e00c5ff09b34d018152af98d06f5a1xvc.pipelines.cloudflare.com/" -d '[{ ...JSON_DATA... }]'To send data to your pipeline from a Worker, add the following configuration to your config file:{ "pipelines": [ { "pipeline": "my-clickstream-pipeline", "binding": "PIPELINE" } ]}
Head over to our getting started guide for an in-depth tutorial to building with Pipelines.
D1 read replication is available in public beta to help lower average latency and increase overall throughput for read-heavy applications like e-commerce websites or content management tools.
Workers can leverage read-only database copies, called read replicas, by using D1 Sessions API. A session encapsulates all the queries from one logical session for your application. For example, a session may correspond to all queries coming from a particular web browser session. With Sessions API, D1 queries in a session are guaranteed to be sequentially consistent to avoid data consistency pitfalls. D1 bookmarks can be used from a previous session to ensure logical consistency between sessions.
// retrieve bookmark from previous session stored in HTTP headerconst bookmark = request.headers.get("x-d1-bookmark") ?? "first-unconstrained";const session = env.DB.withSession(bookmark);const result = await session .prepare(`SELECT * FROM Customers WHERE CompanyName = 'Bs Beverages'`) .run();// store bookmark for a future sessionresponse.headers.set("x-d1-bookmark", session.getBookmark() ?? "");
Read replicas are automatically created by Cloudflare (currently one in each supported D1 region), are active/inactive based on query traffic, and are transparently routed to by Cloudflare at no additional cost.
To checkout D1 read replication, deploy the following Worker code using Sessions API, which will prompt you to create a D1 database and enable read replication on said database.
To learn more about how read replication was implemented, go to our blog post ↗︎.
The Overview tab shows logs from all your Workers in one place. The Invocations view groups logs together by invocation, which refers to the specific trigger that started the execution of the Worker (i.e. fetch). The Events view shows logs in the order they were produced, based on timestamp. Previously, you could only view logs for a single Worker.
The Investigate tab presents a Query Builder, which helps you write structured queries to investigate and visualize your logs. The Query Builder can help answer questions such as:
Which paths are experiencing the most 5XX errors?
What is the wall time distribution by status code for my Worker?
What are the slowest requests, and where are they coming from?
Who are my top N users?
The Query Builder can use any field that you store in your logs as a key to visualize, filter, and group by. Use the Query Builder to quickly access your data, build visualizations, save queries, and share them with your team.
Workers Logs is now Generally Available
Workers Logs is now Generally Available. With a small change to your Wrangler configuration, Workers Logs ingests, indexes, and stores all logs emitted from your Workers for up to 7 days.
We've introduced a number of changes during our beta period, including:
Dashboard enhancements with customizable fields as columns in the Logs view and support for invocation-based grouping
Performance improvements to ensure no adverse impact
The API documents three endpoints: list the keys in the telemetry dataset, run a query, and list the unique values for a key. For more, visit our REST API documentation ↗︎.
Visit the docs to learn more about the capabilities and methods exposed by the Query Builder. Start using Workers Logs and the Query Builder today by enabling observability for your Workers:
For Workers Logpush, CPU and Wall time are surfaced at the top level of the Workers Trace Events object. All new jobs will have these new fields included by default. Existing jobs need to be updated to include CPU time and Wall time.
You can use a Workers Logs filter to search for logs where Wall time exceeds 100ms.
You can also use the Workers Observability Query Builder ↗︎ to find the median CPU time and median Wall time for all of your Workers.
You can now add a Deploy to Cloudflare button to the README of your Git repository containing a Workers application — making it simple for other developers to quickly set up and deploy your project!
The Deploy to Cloudflare button:
Creates a new Git repository on your GitHub/ GitLab account: Cloudflare will automatically clone and create a new repository on your account, so you can continue developing.
Automatically provisions resources the app needs: If your repository requires Cloudflare primitives like a Workers KV namespace, a D1 database, or an R2 bucket, Cloudflare will automatically provision them on your account and bind them to your Worker upon deployment.
Configures Workers Builds (CI/CD): Every new push to your production branch on your newly created repository will automatically build and deploy courtesy of Workers Builds.
To create a Deploy to Cloudflare button in your README, you can add the following snippet, including your Git repository URL:
[](https://deploy.workers.cloudflare.com/?url=<YOUR_GIT_REPO_URL>)
Check out our documentation for more information on how to set up a deploy button for your application and best practices to ensure a successful deployment for other developers.
When you use @cloudflare/vite-plugin, you can use Vite's local development server and build tooling, while ensuring that while developing, your code runs in workerd ↗︎, the open-source Workers runtime.
This lets you get the best of both worlds for a full-stack app — you can use Hot Module Replacement ↗︎ from Vite right alongside Durable Objects and other runtime APIs and bindings that are unique to Cloudflare Workers.
You can build any type of application with @cloudflare/vite-plugin, using any rendering mode, from single page applications (SPA) and static sites to server-side rendered (SSR) pages and API routes.
React Router v7 (Remix) is the first full-stack framework to provide full support for Cloudflare Vite plugin, allowing you to use all parts of Cloudflare's developer platform, without additional build steps.
You can also build complete full-stack apps on Workers without a framework — "just use Vite" ↗︎ and React together, and build a back-end API in the same Worker. Follow our React SPA with an API tutorial to learn how.
Configuration
If you're already using Vite ↗︎ in your build and development toolchain, you can start using our plugin with minimal changes to your vite.config.ts:
vite.config.tsts
import { defineConfig } from "vite";import { cloudflare } from "@cloudflare/vite-plugin";export default defineConfig({ plugins: [cloudflare()],});
The Agents SDK now includes built-in support for building remote MCP (Model Context Protocol) servers directly as part of your Agent. This allows you to easily create and manage MCP servers, without the need for additional infrastructure or configuration.
The SDK includes a new MCPAgent class that extends the Agent class and allows you to expose resources and tools over the MCP protocol, as well as authorization and authentication to enable remote MCP servers.
export class MyMCP extends McpAgent { server = new McpServer({ name: "Demo", version: "1.0.0", }); async init() { this.server.resource(`counter`, `mcp://resource/counter`, (uri) => { // ... }); this.server.tool( "add", "Add two numbers together", { a: z.number(), b: z.number() }, async ({ a, b }) => { // ... }, ); }}
export class MyMCP extends McpAgent<Env> { server = new McpServer({ name: "Demo", version: "1.0.0", }); async init() { this.server.resource(`counter`, `mcp://resource/counter`, (uri) => { // ... }); this.server.tool( "add", "Add two numbers together", { a: z.number(), b: z.number() }, async ({ a, b }) => { // ... }, ); }}
See the example ↗︎ for the full code and as the basis for building your own MCP servers, and the client example ↗︎ for how to build an Agent that acts as an MCP client.
We've made a number of improvements to the Agents SDK, including:
Support for building MCP servers with the new MCPAgent class.
The ability to export the current agent, request and WebSocket connection context using import { context } from "agents", allowing you to minimize or avoid direct dependency injection when calling tools.
Fixed a bug that prevented query parameters from being sent to the Agent server from the useAgent React hook.
Automatically converting the agent name in useAgent or useAgentChat to kebab-case to ensure it matches the naming convention expected by routeAgentRequest.
To install or update the Agents SDK, run npm i agents@latest in an existing project, or explore the agents-starter project:
Durable Objects can now be used with zero commitment on the Workers Free plan allowing you to build AI agents with Agents SDK, collaboration tools, and real-time applications like chat or multiplayer games.
Durable Objects let you build stateful, serverless applications with millions of tiny coordination instances that run your application code alongside (in the same thread!) your durable storage. Each Durable Object can access its own SQLite database through a Storage API. A Durable Object class is defined in a Worker script encapsulating the Durable Object's behavior when accessed from a Worker. To try the code below, click the button:
import { DurableObject } from "cloudflare:workers";// Durable Objectexport class MyDurableObject extends DurableObject { ... async sayHello(name) { return `Hello, ${name}!`; }}// Workerexport default { async fetch(request, env) { // Every unique ID refers to an individual instance of the Durable Object class const id = env.MY_DURABLE_OBJECT.idFromName("foo"); // A stub is a client used to invoke methods on the Durable Object const stub = env.MY_DURABLE_OBJECT.get(id); // Methods on the Durable Object are invoked via the stub const response = await stub.sayHello("world"); return response; },};
Free plan limits apply to Durable Objects compute and storage usage. Limits allow developers to build real-world applications, with every Worker request able to call a Durable Object on the free plan.
SQLite in Durable Objects is now generally available (GA) with 10GB SQLite database per Durable Object. Since the public beta ↗︎ in September 2024, we've added feature parity and robustness for the SQLite storage backend compared to the preexisting key-value (KV) storage backend for Durable Objects.
SQLite-backed Durable Objects are recommended for all new Durable Object classes, using new_sqlite_classesWrangler configuration. Only SQLite-backed Durable Objects have access to Storage API's SQL and point-in-time recovery methods, which provide relational data modeling, SQL querying, and better data management.
export class MyDurableObject extends DurableObject { sql: SqlStorage constructor(ctx: DurableObjectState, env: Env) { super(ctx, env); this.sql = ctx.storage.sql; } async sayHello() { let result = this.sql .exec("SELECT 'Hello, World!' AS greeting") .one(); return result.greeting; }}
KV-backed Durable Objects remain for backwards compatibility, and a migration path from key-value storage to SQL storage for existing Durable Object classes will be offered in the future.
You can now capture a maximum of 256 KB of log events per Workers invocation, helping you gain better visibility into application behavior.
All console.log() statements, exceptions, request metadata, and headers are automatically captured during the Worker invocation and emitted
as JSON object. Workers Logs deserializes
this object before indexing the fields and storing them. You can also capture, transform, and export the JSON object in a
Tail Worker.
256 KB is a 2x increase from the previous 128 KB limit. After you exceed this limit, further context associated with the request will not be
recorded in your logs.
This limit is automatically applied to all Workers.
Workflows is now Generally Available (or "GA"): in short, it's ready for production workloads. Alongside marking Workflows as GA, we've introduced a number of changes during the beta period, including:
A new waitForEvent API that allows a Workflow to wait for an event to occur before continuing execution.
Improved observability, including new CPU time metrics that allow you to better understand which Workflow instances are consuming the most resources and/or contributing to your bill.
Support for vitest for testing Workflows locally and in CI/CD pipelines.
Workflows also supports the new increased CPU limits that apply to Workers, allowing you to run more CPU-intensive tasks (up to 5 minutes of CPU time per instance), not including the time spent waiting on network calls, AI models, or other I/O bound tasks.
Human-in-the-loop
The new step.waitForEvent API allows a Workflow instance to wait on events and data, enabling human-in-the-the-loop interactions, such as approving or rejecting a request, directly handling webhooks from other systems, or pushing event data to a Workflow while it's running.
Because Workflows are just code, you can conditionally execute code based on the result of a waitForEvent call, and/or call waitForEvent multiple times in a single Workflow based on what the Workflow needs.
For example, if you wanted to implement a human-in-the-loop approval process, you could use waitForEvent to wait for a user to approve or reject a request, and then conditionally execute code based on the result.
import { WorkflowEntrypoint, WorkflowStep, WorkflowEvent,} from "cloudflare:workers";export class MyWorkflow extends WorkflowEntrypoint { async run(event, step) { // Other steps in your Workflow let stripeEvent = await step.waitForEvent( "receive invoice paid webhook from Stripe", { type: "stripe-webhook", timeout: "1 hour" }, ); // Rest of your Workflow }}
import { WorkflowEntrypoint, WorkflowStep, WorkflowEvent } from "cloudflare:workers";export class MyWorkflow extends WorkflowEntrypoint<Env, Params> { async run(event: WorkflowEvent<Params>, step: WorkflowStep) { // Other steps in your Workflow let stripeEvent = await step.waitForEvent<IncomingStripeWebhook>("receive invoice paid webhook from Stripe", { type: "stripe-webhook", timeout: "1 hour" }) // Rest of your Workflow }}
You can then send a Workflow an event from an external service via HTTP or from within a Worker using the Workers API for Workflows:
export default { async fetch(req, env) { const instanceId = new URL(req.url).searchParams.get("instanceId"); const webhookPayload = await req.json(); let instance = await env.MY_WORKFLOW.get(instanceId); // Send our event, with `type` matching the event type defined in // our step.waitForEvent call await instance.sendEvent({ type: "stripe-webhook", payload: webhookPayload, }); return Response.json({ status: await instance.status(), }); },};
export default { async fetch(req: Request, env: Env) { const instanceId = new URL(req.url).searchParams.get("instanceId") const webhookPayload = await req.json<Payload>() let instance = await env.MY_WORKFLOW.get(instanceId); // Send our event, with `type` matching the event type defined in // our step.waitForEvent call await instance.sendEvent({type: "stripe-webhook", payload: webhookPayload}) return Response.json({ status: await instance.status(), }); },};
Read the GA announcement blog ↗︎ to learn more about what landed as part of the Workflows GA.
You can now run a Worker for up to 5 minutes of CPU time for each request.
Previously, each Workers request ran for a maximum of 30 seconds of CPU time — that is the time that a Worker is actually performing a task (we still allowed unlimited wall-clock time, in case you were waiting on slow resources). This
meant that some compute-intensive tasks were impossible to do with a Worker. For instance,
you might want to take the cryptographic hash of a large file from R2. If
this computation ran for over 30 seconds, the Worker request would have timed out.
By default, Workers are still limited to 30 seconds of CPU time. This protects developers
from incurring accidental cost due to buggy code.
By changing the cpu_ms value in your Wrangler configuration, you can opt in to
any value up to 300,000 (5 minutes).
{ // ...rest of your configuration... "limits": { "cpu_ms": 300000, }, // ...rest of your configuration...}
Source maps are now Generally Available (GA). You can now be uploaded with a maximum gzipped size of 15 MB.
Previously, the maximum size limit was 15 MB uncompressed.
Source maps help map between the original source code and the transformed/minified code that gets deployed
to production. By uploading your source map, you allow Cloudflare to map the stack trace from exceptions
onto the original source code making it easier to debug.
With no source maps uploaded: notice how all the Javascript has been minified to one file, so the stack trace is missing information on file name, shows incorrect line numbers, and incorrectly references js instead of ts.
With source maps uploaded: all methods reference the correct files and line numbers.
Uploading source maps and stack trace remapping happens out of band from the Worker execution,
so source maps do not affect upload speed, bundle size, or cold starts. The remapped stack
traces are accessible through Tail Workers, Workers Logs, and Workers Logpush.
To enable source maps, add the following to your
Pages Function's or Worker's wrangler configuration:
Update: Mon Mar 24th, 11PM UTC: Next.js has made further changes to address a smaller vulnerability introduced in the patches made to its middleware handling. Users should upgrade to Next.js versions 15.2.4, 14.2.26, 13.5.10 or 12.3.6. If you are unable to immediately upgrade or are running an older version of Next.js, you can enable the WAF rule described in this changelog as a mitigation.
Update: Mon Mar 24th, 8PM UTC: Next.js has now backported the patch for this vulnerability ↗︎ to cover Next.js v12 and v13. Users on those versions will need to patch to 13.5.9 and 12.3.5 (respectively) to mitigate the vulnerability.
Update: Sat Mar 22nd, 4PM UTC: We have changed this WAF rule to opt-in only, as sites that use auth middleware with third-party auth vendors were observing failing requests.
We strongly recommend updating your version of Next.js (if eligible) to the patched versions, as your app will otherwise be vulnerable to an authentication bypass attack regardless of auth provider.
Enable the Managed Rule (strongly recommended)
This rule is opt-in only for sites on the Pro plan or above in the WAF managed ruleset.
To enable the rule:
Head to Security > WAF > Managed rules in the Cloudflare dashboard for the zone (website) you want to protect.
Click the three dots next to Cloudflare Managed Ruleset and choose Edit
Scroll down and choose Browse Rules
Search for CVE-2025-29927 (ruleId: 34583778093748cc83ff7b38f472013e)
Change the Status to Enabled and the Action to Block. You can optionally set the rule to Log, to validate potential impact before enabling it. Log will not block requests.
Click Next
Scroll down and choose Save
This will enable the WAF rule and block requests with the x-middleware-subrequest header regardless of Next.js version.
Create a WAF rule (manual)
For users on the Free plan, or who want to define a more specific rule, you can create a Custom WAF rule to block requests with the x-middleware-subrequest header regardless of Next.js version.
To create a custom rule:
Head to Security > WAF > Custom rules in the Cloudflare dashboard for the zone (website) you want to protect.
Give the rule a name - e.g. next-js-CVE-2025-29927
Set the matching parameters for the rule match any request where the x-middleware-subrequest header exists per the rule expression below.
Set the action to 'block'. If you want to observe the impact before blocking requests, set the action to 'log' (and edit the rule later).
Deploy the rule.
Next.js CVE-2025-29927
We've made a WAF (Web Application Firewall) rule available to all sites on Cloudflare to protect against the Next.js authentication bypass vulnerability ↗︎ (CVE-2025-29927) published on March 21st, 2025.
Note: This rule is not enabled by default as it blocked requests across sites for specific authentication middleware.
This managed rule protects sites using Next.js on Workers and Pages, as well as sites using Cloudflare to protect Next.js applications hosted elsewhere.
This rule has been made available (but not enabled by default) to all sites as part of our WAF Managed Ruleset and blocks requests that attempt to bypass authentication in Next.js applications.
The vulnerability affects almost all Next.js versions, and has been fully patched in Next.js 14.2.26 and 15.2.4. Earlier, interim releases did not fully patch this vulnerability.
Users on older versions of Next.js (11.1.4 to 13.5.6) did not originally have a patch available, but this the patch for this vulnerability and a subsequent additional patch have been backported to Next.js versions 12.3.6 and 13.5.10 as of Monday, March 24th. Users on Next.js v11 will need to deploy the stated workaround or enable the WAF rule.
The managed WAF rule mitigates this by blocking external user requests with the x-middleware-subrequest header regardless of Next.js version, but we recommend users using Next.js 14 and 15 upgrade to the patched versions of Next.js as an additional mitigation.
Smart Placement is a unique Cloudflare feature that can make decisions to move your Worker to run in a more optimal location (such as closer to a database). Instead of always running in the default location (the one closest to where the request is received), Smart Placement uses certain “heuristics” (rules and thresholds) to decide if a different location might be faster or more efficient.
Previously, if these heuristics weren't consistently met, your Worker would revert to running in the default location—even after it had been optimally placed. This meant that if your Worker received minimal traffic for a period of time, the system would reset to the default location, rather than remaining in the optimal one.
Now, once Smart Placement has identified and assigned an optimal location, temporarily dropping below the heuristic thresholds will not force a return to default locations. For example in the previous algorithm, a drop in requests for a few days might return to default locations and heuristics would have to be met again. This was problematic for workloads that made requests to a geographically located resource every few days or longer. In this scenario, your Worker would never get placed optimally. This is no longer the case.
If you've already been building with the Agents SDK, you can update your dependencies to use the new package name, and replace references to agents-sdk with agents:
# Install the new packagenpm i agents
# Remove the old (deprecated) packagenpm uninstall agents-sdk# Find instances of the old package name in your codebasegrep -r 'agents-sdk' .# Replace instances of the old package name with the new one# (or use find-replace in your editor)sed -i 's/agents-sdk/agents/g' $(grep -rl 'agents-sdk' .)
All future updates will be pushed to the new agents package, and the older package has been marked as deprecated.
Agents SDK updates New
We've added a number of big new features to the Agents SDK over the past few weeks, including:
You can now set cors: true when using routeAgentRequest to return permissive default CORS headers to Agent responses.
The regular client now syncs state on the agent (just like the React version).
useAgentChat bug fixes for passing headers/credentials, including properly clearing cache on unmount.
Experimental /schedule module with a prompt/schema for adding scheduling to your app (with evals!).
Changed the internal zod schema to be compatible with the limitations of Google's Gemini models by removing the discriminated union, allowing you to use Gemini models with the scheduling API.
We've also fixed a number of bugs with state synchronization and the React hooks.
// via https://github.com/cloudflare/agents/tree/main/examples/cross-domainexport default { async fetch(request, env) { return ( // Set { cors: true } to enable CORS headers. (await routeAgentRequest(request, env, { cors: true })) || new Response("Not found", { status: 404 }) ); },};
// via https://github.com/cloudflare/agents/tree/main/examples/cross-domainexport default { async fetch(request: Request, env: Env) { return ( // Set { cors: true } to enable CORS headers. (await routeAgentRequest(request, env, { cors: true })) || new Response("Not found", { status: 404 }) ); },} satisfies ExportedHandler<Env>;
Call Agent methods from your client code New
We've added a new @unstable_callable() decorator for defining methods that can be called directly from clients. This allows you call methods from within your client code: you can call methods (with arguments) and get native JavaScript objects back.
// server.tsimport { unstable_callable, Agent } from "agents";export class Rpc extends Agent { // Use the decorator to define a callable method @unstable_callable({ description: "rpc test", }) async getHistory() { return this.sql`SELECT * FROM history ORDER BY created_at DESC LIMIT 10`; }}
// server.tsimport { unstable_callable, Agent, type StreamingResponse } from "agents";import type { Env } from "../server";export class Rpc extends Agent<Env> { // Use the decorator to define a callable method @unstable_callable({ description: "rpc test", }) async getHistory() { return this.sql`SELECT * FROM history ORDER BY created_at DESC LIMIT 10`; }}
We've fixed a number of small bugs in the agents-starter ↗︎ project — a real-time, chat-based example application with tool-calling & human-in-the-loop built using the Agents SDK. The starter has also been upgraded to use the latest wrangler v4 release.
If you're new to Agents, you can install and run the agents-starter project in two commands:
# Install it$ npm create cloudflare@latest agents-starter -- --template="cloudflare/agents-starter"# Run it$ npm run start
You can use the starter as a template for your own Agents projects: open up src/server.ts and src/client.tsx to see how the Agents SDK is used.
More documentation Updated
We've heard your feedback on the Agents SDK documentation, and we're shipping more API reference material and usage examples, including:
Expanded API reference documentation, covering the methods and properties exposed by the Agents SDK, as well as more usage examples.
More Client API documentation that documents useAgent, useAgentChat and the new @unstable_callable RPC decorator exposed by the SDK.
New documentation on how to route requests to agents and (optionally) authenticate clients before they connect to your Agents.
Note that the Agents SDK is continually growing: the type definitions included in the SDK will always include the latest APIs exposed by the agents package.
You can now access bindings
from anywhere in your Worker by importing the env object from cloudflare:workers.
Previously, env could only be accessed during a request. This meant that
bindings could not be used in the top-level context of a Worker.
Now, you can import env and access bindings such as secrets
or environment variables in the
initial setup for your Worker:
import { env } from "cloudflare:workers";import ApiClient from "example-api-client";// API_KEY and LOG_LEVEL now usable in top-level scopeconst apiClient = ApiClient.new({ apiKey: env.API_KEY });const LOG_LEVEL = env.LOG_LEVEL || "info";export default { fetch(req) { // you can use apiClient or LOG_LEVEL, configured before any request is handled },};
Additionally, env was normally accessed as a argument to a Worker's entrypoint handler,
such as fetch.
This meant that if you needed to access a binding from a deeply nested function,
you had to pass env as an argument through many functions to get it to the
right spot. This could be cumbersome in complex codebases.
Now, you can access the bindings from anywhere in your codebase
without passing env as an argument:
// helpers.jsimport { env } from "cloudflare:workers";// env is *not* an argument to this functionexport async function getValue(key) { let prefix = env.KV_PREFIX; return await env.KV.get(`${prefix}-${key}`);}
You can now retry your Cloudflare Pages and Workers builds directly from GitHub. No need to switch to the Cloudflare Dashboard for a simple retry!
Let\u2019s say you push a commit, but your build fails due to a spurious error like a network timeout. Instead of going to the Cloudflare Dashboard to manually retry, you can now rerun the build with just a few clicks inside GitHub, keeping you inside your workflow.
For Pages and Workers projects connected to a GitHub repository:
When a build fails, go to your GitHub repository or pull request
Select the failed Check Run for the build
Select "Details" on the Check Run
Select "Rerun" to trigger a retry build for that commit
We've released the next major version of Wrangler, the CLI for Cloudflare Workers — wrangler@4.0.0. Wrangler v4 is a major release focused on updates to underlying systems and dependencies, along with improvements to keep Wrangler commands consistent and clear.
You can run the following command to install it in your projects:
npm i wrangler@latest
yarn add wrangler@latest
pnpm add wrangler@latest
bun add wrangler@latest
Unlike previous major versions of Wrangler, which were foundational rewrites ↗︎ and rearchitectures ↗︎ — Version 4 of Wrangler includes a much smaller set of changes. If you use Wrangler today, your workflow is very unlikely to change.
Going forward, we'll continue supporting Wrangler v3 with bug fixes and security updates until Q1 2026, and with critical security updates until Q1 2027, at which point it will be out of support.
You can now debug your Workers tests with our Vitest integration by running the following command:
vitest --inspect --no-file-parallelism
Attach a debugger to the port 9229 and you can start stepping through your Workers tests. This is available with @cloudflare/vitest-pool-workers v0.7.5 or later.
In Node.js, environment variables are exposed via the global process.env object. Some libraries
assume that this object will be populated, and many developers may be used to accessing variables
in this way.
Previously, the process.env object was always empty unless written to in Worker code. This could
cause unexpected errors or friction when developing Workers using code previously written for Node.js.
To opt-in to the new process.env behaviour now, add the nodejs_compat_populate_process_env compatibility flag to your
wrangler.json configuration:
{ // Rest of your configuration // Add "nodejs_compat_populate_process_env" to your compatibility_flags array "compatibility_flags": ["nodejs_compat", "nodejs_compat_populate_process_env"], // Rest of your configuration
After April 1, 2025, populating process.env will become the default behavior when both nodejs_compat is enabled and
your Worker's compatibility_date is after "2025-04-01".
We've released a release candidate of the next major version of Wrangler, the CLI for Cloudflare Workers — wrangler@4.0.0-rc.0.
You can run the following command to install it and be one of the first to try it out:
npm i wrangler@v4-rc
yarn add wrangler@v4-rc
pnpm add wrangler@v4-rc
bun add wrangler@v4-rc
Unlike previous major versions of Wrangler, which were foundational rewrites ↗︎ and rearchitectures ↗︎ — Version 4 of Wrangler includes a much smaller set of changes. If you use Wrangler today, your workflow is very unlikely to change. Before we release Wrangler v4 and advance past the release candidate stage, we'll share a detailed migration guide in the Workers developer docs. But for the vast majority of cases, you won't need to do anything to migrate — things will just work as they do today. We are sharing this release candidate in advance of the official release of v4, so that you can try it out early and share feedback.
New JavaScript language features that you can now use with Wrangler v4
Version 4 of Wrangler updates the version of esbuild ↗︎ that Wrangler uses internally, allowing you to use modern JavaScript language features, including:
The using keyword from Explicit Resource Management
function sendEmail(id, message) { using user = await env.USER_SERVICE.findUser(id); await user.sendEmail(message); // user[Symbol.dispose]() is implicitly called at the end of the scope.}
Import attributes
Import attributes ↗︎ allow you to denote the type or other attributes of the module that your code imports. For example, you can import a JSON module, using the following syntax:
import data from "./data.json" with { type: "json" };
Other changes
--local is now the default for all CLI commands
All commands that access resources (for example, wrangler kv, wrangler r2, wrangler d1) now access local datastores by default, ensuring consistent behavior.
Clearer policy for the minimum required version of Node.js required to run Wrangler
Moving forward, the active, maintenance, and current versions of Node.js ↗︎ will be officially supported by Wrangler. This means the minimum officially supported version of Node.js you must have installed for Wrangler v4 will be Node.js v18 or later. This policy mirrors how many other packages and CLIs support older versions of Node.js, and ensures that as long as you are using a version of Node.js that the Node.js project itself supports, this will be supported by Wrangler as well.
Features previously deprecated in Wrangler v3 are now removed in Wrangler v4
All previously deprecated features in Wrangler v2 ↗︎ and in Wrangler v3 ↗︎ have now been removed. Additionally, the following features that were deprecated during the Wrangler v3 release have been removed:
Legacy Assets (using wrangler dev/deploy --legacy-assets or the legacy_assets config file property). Instead, we recommend you migrate to Workers assets ↗︎.
Legacy Node.js compatibility (using wrangler dev/deploy --node-compat or the node_compat config file property). Instead, use the nodejs_compat compatibility flag ↗︎. This includes the functionality from legacy node_compat polyfills and natively implemented Node.js APIs.
wrangler version. Instead, use wrangler --version to check the current version of Wrangler.
getBindingsProxy() (via import { getBindingsProxy } from "wrangler"). Instead, use the getPlatformProxy() API ↗︎, which takes exactly the same arguments.
