I would if I were you store the emails you need to send in a KV or any other temporary storage from

SSeekerdasbatatas not natively, but you could use a script for it: ```bash #!/bin/bash # Exit imm...

R

Rakhim•2/11/25, 4:18 PM

woah, thanks a lot!

F

Focux•2/11/25, 7:38 PM

What's the best way to implement "wait until signal" on userland? sleeping and pulling?

A

Ashley•2/11/25, 7:56 PM

Do you mean the user (browser) polling to check if the Workflow has finished, or the Workflow waiting for “something” to happen?

F

Focux•2/11/25, 8:10 PM

I mean something like this:

while (true) {
  const isDone = await checkIfSomethingIsDone()
  if (isDone) break;
  step.sleep('wait for event', '5 minutes');
}

while (true) {
  const isDone = await checkIfSomethingIsDone()
  if (isDone) break;
  step.sleep('wait for event', '5 minutes');
}

while (true) {
  const isDone = await checkIfSomethingIsDone()
  if (isDone) break;
  step.sleep('wait for event', '5 minutes');
}

while (true) {
  const isDone = await checkIfSomethingIsDone()
  if (isDone) break;
  step.sleep('wait for event', '5 minutes');
}

F

Focux•2/11/25, 8:11 PM

Figuring out the right interval would be tricky in my case. I have a workflow that has several steps, and one of those is sending an email. I want to wait for that email to be opened before continuing with the workflow execution.

A

Ashley•2/11/25, 8:39 PM

Yeah, there’s no native way to do this yet (maybe it will come later - it seems a no brainer to me) so I think a repeated sleep is the only way

F

Focux•2/11/25, 9:25 PM

Yeah, I think I read on Twitter that it's on the roadmap

F

Focux•2/11/25, 9:27 PM

I'm wondering if it's possible to

pause

pause

the workflow from within a workflow instance, like calling the workflow binding and then resuming the workflow from a webhook or something like that

A

Ashley•2/11/25, 10:06 PM

You could as the workflow ID is available inside the Workflow class, you’d then call resume I believe on it (using Workflow binding for example)

F

Focux•2/11/25, 10:54 PM

yeah, that's what i was thinking, i'll try that and see how it goes

币

币成•2/12/25, 3:16 AM

我用谷歌帐号登录的，验证邮箱时收不到验证码如何处理？

A

Ashley•2/12/25, 11:26 AM

For sleeping workflows, I think I saw that they don’t contribute to the concurrent count, but is there a “minimum” sleep before this is true? (e.g. if a Workflow sleeps for 10 seconds, will it still not be counted in the concurrent count - asking as I thought I saw something that suggested this was the case)

AAshley For sleeping workflows, I think I saw that they don’t contribute to the concurre...

S

Seekerdasbatatas•2/12/25, 2:08 PM

at the moment yes, but that's an implementation detail of Workflows so the "minimum" sleep might (and probably will) change over time

SSeekerdasbatatas at the moment yes, but that's an implementation detail of Workflows so the "mini...

A

Ashley•2/12/25, 2:11 PM

Is there a rough guide? Just trying to consider whether hacking around a “wait for event” is worthwhile as I wouldn’t want to have say a 5 second sleep that is effectively polling for something happening and it eat into my concurrency

AAshley Is there a rough guide? Just trying to consider whether hacking around a “wait f...

S

Seekerdasbatatas•2/12/25, 2:14 PM

the minimum sleep required atm to pass it to waiting is in the minutes range (and the transition happens after that time has passed) - so I don't know if it's worthwhile hacking around that. I've personally seen people pausing and resuming an instance to "emulate" events, but on a lighter note, we're working on native events :soontm:

A

Ashley•2/12/25, 2:22 PM

The use case is let’s say it takes 10-30 seconds for something to happen, I don’t want to sleep for say 45 (to be safe) or “poll” at 10 seconds or it would eat concurrency. I could set it to 5 mins, let’s say, but then there’s an unneccessary gap. I have a little solution using a DO (pause workflow -> call DO that sets alarm that effectively does the polling -> DO resumes workflow when event happens) and it works nicely until native events, but wondered if it was worthwhile (but if it’s minutes, I think so for now)

AAshley The use case is let’s say it takes 10-30 seconds for something to happen, I don’...

S

Seekerdasbatatas•2/12/25, 2:25 PM

Considering that you probably don't have stuff running parallel to the wait for event call, that seems to work nicely

A

Ashley•2/12/25, 2:28 PM

Yeah, what would have been super cool was if I could define the callback (well, the logic to determine if to continue) in the Workflow and pass it to the DO, but alas the “connection” doesn’t naturally survive hibernation

A

Ashley•2/12/25, 3:48 PM

https://github.com/apeacock1991/workflows-wait-for-action/ this was surprisingly easy (I wrote it at the weekend, hadn't had the time to check if it was useful until just then) for anyone that wants to pause/resume workflow using a DO and "protect" your concurrency limit

GitHub

GitHub - apeacock1991/workflows-wait-for-action

Contribute to apeacock1991/workflows-wait-for-action development by creating an account on GitHub.

W

wesbos•2/12/25, 6:15 PM

Hi folks - having some trouble with throwing errors inside a workflow.

First, it seems throwing a NonRetryableError, is retried as many times as specified

Second, I can't seem to find out where the throw error messages are being returned in the workflow status. The docs seem to say

const wf = await MY_WORKFLOW.get(id)

const wf = await MY_WORKFLOW.get(id)

and then

await wf.status()

await wf.status()

should return errors, but they are always empty.

here is the code I'm using to reproduce:

export class MyWorkflow extends WorkflowEntrypoint<Env, Params> {
    async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
        step.do('Step 1', async () => { return 'Step 1 finished!';  });

        step.do('Step 2', {
            retries: { limit: 2, delay: '1 second', backoff: 'linear', },
        }, async () => {
            console.log('Trying Step 2');
            throw new NonRetryableError('Step 3 failed. Non-retryable');
        });
    }
}

export class MyWorkflow extends WorkflowEntrypoint<Env, Params> {
    async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
        step.do('Step 1', async () => { return 'Step 1 finished!';  });

        step.do('Step 2', {
            retries: { limit: 2, delay: '1 second', backoff: 'linear', },
        }, async () => {
            console.log('Trying Step 2');
            throw new NonRetryableError('Step 3 failed. Non-retryable');
        });
    }
}

export class MyWorkflow extends WorkflowEntrypoint<Env, Params> {
    async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
        step.do('Step 1', async () => { return 'Step 1 finished!';  });

        step.do('Step 2', {
            retries: { limit: 2, delay: '1 second', backoff: 'linear', },
        }, async () => {
            console.log('Trying Step 2');
            throw new NonRetryableError('Step 3 failed. Non-retryable');
        });
    }
}

export class MyWorkflow extends WorkflowEntrypoint<Env, Params> {
    async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
        step.do('Step 1', async () => { return 'Step 1 finished!';  });

        step.do('Step 2', {
            retries: { limit: 2, delay: '1 second', backoff: 'linear', },
        }, async () => {
            console.log('Trying Step 2');
            throw new NonRetryableError('Step 3 failed. Non-retryable');
        });
    }
}

This logs "trying step 2" three times

Aadeola13.I would if I were you store the emails you need to send in a KV or any other tem...

J

JonasDoesThings•2/12/25, 6:59 PM

Yeah, that would def. work-out, but is not that elegant / simple again

Sticking with using upstash's queueing service for now, where I have 1 scheduled task that calls my api/tasks/generate-reports endpoint every day, which then queries my database and batch-enqueues one task for each report I want to generate & send out

N

Nathan Scheele•2/13/25, 10:41 PM

Hi all! I'm running into the following error when using Workflows:

An RPC stub was not disposed properly. You must call dispose() on all stubs in order to let the other side know that you are no longer using them. You cannot rely on the garbage collector for this because it may take arbitrarily long before actually collecting unreachable objects. As a shortcut, calling dispose() on the result of an RPC call disposes all stubs within it.

An RPC stub was not disposed properly. You must call dispose() on all stubs in order to let the other side know that you are no longer using them. You cannot rely on the garbage collector for this because it may take arbitrarily long before actually collecting unreachable objects. As a shortcut, calling dispose() on the result of an RPC call disposes all stubs within it.

An RPC stub was not disposed properly. You must call dispose() on all stubs in order to let the other side know that you are no longer using them. You cannot rely on the garbage collector for this because it may take arbitrarily long before actually collecting unreachable objects. As a shortcut, calling dispose() on the result of an RPC call disposes all stubs within it.

An RPC stub was not disposed properly. You must call dispose() on all stubs in order to let the other side know that you are no longer using them. You cannot rely on the garbage collector for this because it may take arbitrarily long before actually collecting unreachable objects. As a shortcut, calling dispose() on the result of an RPC call disposes all stubs within it.

I see that

step.do

step.do

expects to return

Rpc.Serializable<unknown>

Rpc.Serializable<unknown>

, so I did a little bit of reading about the RPC lifecycle here and found that in the context of Worker Service Bindings, you should either use the experimental

using

using

syntax, or explicitly call

object[Symbol.dispose]()

object[Symbol.dispose]()

.

I'm a little confused because this error is only thrown after some calls to

step.do

step.do

, and not others. If someone could provide some insight as to what's going on, that would be great. Happy to provide more details also

Cloudflare Docs

Workers RPC — Lifecycle · Cloudflare Workers docs

Memory management, resource management, and the lifecycle of RPC stubs.

T

topmass•2/15/25, 4:17 PM

can anyone help me understand the cost difference of a workflow, while the workflow is running does this add all cpu time during the total run time or just during events that trigger CPU time effectively making the cost that same as using wokers native or roughly the same

I'm curious for scale if I implemented in two ways

Option 1. I send post req with a worker webhook url and then when the job is completed webhook is hit generating new worker instance to handle post job completion duties

Option 2. I create a workflow that for a particular "generation" or request tracks/handles everything, initial http post req as well as waiting for job completion

thank you in advance if anyone can help!

A

Ashley•2/15/25, 8:01 PM

https://blog.cloudflare.com/building-workflows-durable-execution-on-workers/#so-how-much-does-it-cost it’s exactly the same as Workers pricing

The Cloudflare Blog

Build durable applications on Cloudflare Workers: you write the Wor...

Cloudflare Workflows is now in open beta! Workflows allows you to build reliable, repeatable, long-lived multi-step applications that can automatically retry, persist state, and scale out. Read on to learn how Workflows works, how we built it on top of Durable Objects, and how you can deploy your first Workflows application.

A

Ashley•2/16/25, 9:53 PM

If I’m understanding correctly, that’s how Workflows are designed, you can just start a Workflow per file (as an example) and they will run in parallel (up to the max concurrency limit, which is current 100 Workflows at any one time - will likely be raised during beta)

F

Focux•2/17/25, 3:50 PM

When using

sleep

sleep

locally with a number value, it treats it like ms instead of seconds

F

Focux•2/17/25, 3:51 PM

I'm not sure if that's a local development issue or if the documentation is outdated, but it says in the doc that when passing a number value to

sleep

sleep

it's seconds not ms

FFocux I'm not sure if that's a local development issue or if the documentation is outd...

D

D Trombett•2/17/25, 3:58 PM

docs outdated (ref. https://canary.discord.com/channels/595317990191398933/1296923707792560189/1336055153945739456)

F

Focux•2/17/25, 4:01 PM

good to know, thank you

F

Focux•2/17/25, 5:06 PM

I see that there's been an open PR since november to fix the docs, it'd be good to get it merged so people don't get confused by the docs
https://github.com/cloudflare/cloudflare-docs/pull/18369

D

Dom•2/18/25, 1:51 AM

Hey!
I'm trying to use Workflows within an existing Workers project. The project is using vite to build a remix app.
But I'm getting this error if I try to add a workflows configuration into wrangler.jsonc:

Worker "workflows:workflow"'s binding "USER_WORKFLOW" refers to service "core:user:" with a named entrypoint "ExcelImportWorkflow", but "core:user:" has no such named entrypoint.
MiniflareCoreError [ERR_RUNTIME_FAILURE]: The Workers runtime failed to start. There is likely additional logging output above.
    at Miniflare2.#assembleAndUpdateConfig (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1403:10)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at Mutex.runWith (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/workers/shared/sync.ts:66:45)
    at Miniflare2.#waitForReady (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1485:3)
    at Miniflare2._getProxyClient (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1691:3)
    at Miniflare2.getBindings (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1714:23)
    at getPlatformProxy (/home/roboto/devel/portcity/cf-hono-remix/node_modules/wrangler/src/api/integrations/platform/index.ts:118:24)
    at configureServer (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/cloudflare-proxy-plugin.js:55:11)
    at _createServer (file:///home/roboto/devel/portcity/cf-hono-remix/node_modules/vite/dist/node/chunks/dep-CHZK6zbr.js:63230:20)
    at configResolved (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/plugin.js:768:27) {
  code: 'ERR_RUNTIME_FAILURE',
  cause: undefined

Worker "workflows:workflow"'s binding "USER_WORKFLOW" refers to service "core:user:" with a named entrypoint "ExcelImportWorkflow", but "core:user:" has no such named entrypoint.
MiniflareCoreError [ERR_RUNTIME_FAILURE]: The Workers runtime failed to start. There is likely additional logging output above.
    at Miniflare2.#assembleAndUpdateConfig (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1403:10)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at Mutex.runWith (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/workers/shared/sync.ts:66:45)
    at Miniflare2.#waitForReady (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1485:3)
    at Miniflare2._getProxyClient (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1691:3)
    at Miniflare2.getBindings (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1714:23)
    at getPlatformProxy (/home/roboto/devel/portcity/cf-hono-remix/node_modules/wrangler/src/api/integrations/platform/index.ts:118:24)
    at configureServer (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/cloudflare-proxy-plugin.js:55:11)
    at _createServer (file:///home/roboto/devel/portcity/cf-hono-remix/node_modules/vite/dist/node/chunks/dep-CHZK6zbr.js:63230:20)
    at configResolved (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/plugin.js:768:27) {
  code: 'ERR_RUNTIME_FAILURE',
  cause: undefined

Worker "workflows:workflow"'s binding "USER_WORKFLOW" refers to service "core:user:" with a named entrypoint "ExcelImportWorkflow", but "core:user:" has no such named entrypoint.
MiniflareCoreError [ERR_RUNTIME_FAILURE]: The Workers runtime failed to start. There is likely additional logging output above.
    at Miniflare2.#assembleAndUpdateConfig (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1403:10)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at Mutex.runWith (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/workers/shared/sync.ts:66:45)
    at Miniflare2.#waitForReady (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1485:3)
    at Miniflare2._getProxyClient (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1691:3)
    at Miniflare2.getBindings (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1714:23)
    at getPlatformProxy (/home/roboto/devel/portcity/cf-hono-remix/node_modules/wrangler/src/api/integrations/platform/index.ts:118:24)
    at configureServer (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/cloudflare-proxy-plugin.js:55:11)
    at _createServer (file:///home/roboto/devel/portcity/cf-hono-remix/node_modules/vite/dist/node/chunks/dep-CHZK6zbr.js:63230:20)
    at configResolved (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/plugin.js:768:27) {
  code: 'ERR_RUNTIME_FAILURE',
  cause: undefined

Worker "workflows:workflow"'s binding "USER_WORKFLOW" refers to service "core:user:" with a named entrypoint "ExcelImportWorkflow", but "core:user:" has no such named entrypoint.
MiniflareCoreError [ERR_RUNTIME_FAILURE]: The Workers runtime failed to start. There is likely additional logging output above.
    at Miniflare2.#assembleAndUpdateConfig (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1403:10)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at Mutex.runWith (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/workers/shared/sync.ts:66:45)
    at Miniflare2.#waitForReady (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1485:3)
    at Miniflare2._getProxyClient (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1691:3)
    at Miniflare2.getBindings (/home/roboto/devel/portcity/cf-hono-remix/node_modules/miniflare/src/index.ts:1714:23)
    at getPlatformProxy (/home/roboto/devel/portcity/cf-hono-remix/node_modules/wrangler/src/api/integrations/platform/index.ts:118:24)
    at configureServer (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/cloudflare-proxy-plugin.js:55:11)
    at _createServer (file:///home/roboto/devel/portcity/cf-hono-remix/node_modules/vite/dist/node/chunks/dep-CHZK6zbr.js:63230:20)
    at configResolved (/home/roboto/devel/portcity/cf-hono-remix/node_modules/@remix-run/dev/dist/vite/plugin.js:768:27) {
  code: 'ERR_RUNTIME_FAILURE',
  cause: undefined

A

advanced•2/18/25, 10:18 AM

can someone confirms AsyncLocalStorage will not behave as expected in a step fn unless the callback is defined inline ?

async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
    await context.run({ id: "124" }, async () => {
    // loadFile will get undefined when calling content.getStore()  
    const txt = await step.do("load", loadFile);
    const txt2 = await step.do("load2", 
// this one will work
async()=>console.log(context.getStore().id));
    });
  }

async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
    await context.run({ id: "124" }, async () => {
    // loadFile will get undefined when calling content.getStore()  
    const txt = await step.do("load", loadFile);
    const txt2 = await step.do("load2", 
// this one will work
async()=>console.log(context.getStore().id));
    });
  }

async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
    await context.run({ id: "124" }, async () => {
    // loadFile will get undefined when calling content.getStore()  
    const txt = await step.do("load", loadFile);
    const txt2 = await step.do("load2", 
// this one will work
async()=>console.log(context.getStore().id));
    });
  }

async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
    await context.run({ id: "124" }, async () => {
    // loadFile will get undefined when calling content.getStore()  
    const txt = await step.do("load", loadFile);
    const txt2 = await step.do("load2", 
// this one will work
async()=>console.log(context.getStore().id));
    });
  }

Eeve0415 Is it possible to terminate the workflow between the steps? ```ts async run(eve...

T

tadhglewis•2/19/25, 8:36 AM

Can you just

return

return

return

return?

Eeve0415 Is it possible to terminate the workflow between the steps? ```ts async run(eve...

M

Matt Silverlock•2/19/25, 1:02 PM

Or throw a

NonRetryableError

NonRetryableError

NonRetryableError

NonRetryableError

https://developers.cloudflare.com/workflows/build/workers-api/#nonretryableerror

Cloudflare Docs

Workers API · Cloudflare Workflows docs

This guide details the Workflows API within Cloudflare Workers, including methods, types, and usage examples.

J

John Resig•2/20/25, 3:51 PM

Question: has anyone encountered problems doing image transforms in workflows? I'm encountering a strange issue where my image transformations aren't working at all.

I have a pretty basic request, fetching an image from an external domain. I can confirm that the

Cf-Resized

Cf-Resized

Cf-Resized

Cf-Resized header is

null

null

and the

Content-Type

Content-Type

Content-Type

Content-Type header is un-changed (

image/jpeg

image/jpeg

image/jpeg

image/jpeg).

    const image = await fetch(imageUrl, {
        cf: {
            image: {
                format: "webp",
            },
        },
    });

    console.log(
        "Image headers, post-transform",
        image.headers.get("Cf-Resized"),
        image.headers.get("Content-Type"),
    );

    const image = await fetch(imageUrl, {
        cf: {
            image: {
                format: "webp",
            },
        },
    });

    console.log(
        "Image headers, post-transform",
        image.headers.get("Cf-Resized"),
        image.headers.get("Content-Type"),
    );

    const image = await fetch(imageUrl, {
        cf: {
            image: {
                format: "webp",
            },
        },
    });

    console.log(
        "Image headers, post-transform",
        image.headers.get("Cf-Resized"),
        image.headers.get("Content-Type"),
    );

    const image = await fetch(imageUrl, {
        cf: {
            image: {
                format: "webp",
            },
        },
    });

    console.log(
        "Image headers, post-transform",
        image.headers.get("Cf-Resized"),
        image.headers.get("Content-Type"),
    );

I'm calling this from within a Workflow, in case that matters. I do have Image Transformation enabled for the zone in which the worker is running. I'm not running this on a

worker.dev

worker.dev

worker.dev

worker.dev domain, this is in the expected zone (but on a sub-domain). I have confirmed that Image Transformations are working with another worker within the same zone, so the only thing difference is the use of a Workflow. Is there something that I'm missing here? Thanks!

JJohn Resig Question: has anyone encountered problems doing image transforms in workflows? I...

U

Unsmart•2/20/25, 7:01 PM

It's not possible for a workflow to run on a custom zone it will always run as if in the "workers.dev" zone. So I don't think it's possible to use image transforms through workflows unless they made it possible to use transforms in workers regardless of zone since I last checked.,

UUnsmart It's not possible for a workflow to run on a custom zone it will always run as i...

J

John Resig•2/20/25, 7:03 PM

Oh interesting - that's very helpful, thank you! This makes me wonder if I could make another worker in the right zone and use service bindings to talk with it?

UUnsmart It's not possible for a workflow to run on a custom zone it will always run as i...

J

John Resig•2/20/25, 7:04 PM

This does make me wonder - is it not possible to have more than 50 subrequests from a workflow, if it's in the workers.dev zone? https://developers.cloudflare.com/workers/platform/limits/

JJohn Resig This does make me wonder - is it not possible to have more than 50 subrequests f...

U

Unsmart•2/20/25, 7:06 PM

Subrequests goes by your account subscription. As long as you pay $5/mo for workers subscription all the workers limits will go by the workers paid plan.

Image transforms are just tied to zones still and not account so for something like a worker running a workflow it wont work.

UUnsmart Subrequests goes by your account subscription. As long as you pay $5/mo for work...

J

John Resig•2/20/25, 7:08 PM

Gotcha - ok, thank you! I'll do some experimentation later today to see if I can get it to work with another worker w/ service bindings - and if not, probably another worker doing a normal

fetch()

fetch()

.

T

Tuna•2/20/25, 7:23 PM

Hey Everyone!

Building a Cloudflare-Powered File Sharing App – Seeking Feedback on Architecture

I’m working on a file-sharing application where users can upload files and get a shareable link for others to download or upload additional files. My goal is to make it efficient, scalable, and cost-effective using Cloudflare’s ecosystem.

High-Level Architecture:
Cloudflare R2 stores uploaded files.
Event notifications send messages to a Cloudflare Queue when a file is uploaded.
A Cloudflare Worker consumes these messages and triggers a Cloudflare Workflow to handle file transfers.
The workflow:
Initiates a multipart upload to a cheaper storage bucket.
Reads the R2 object as a stream and uploads it in chunks.
Processes parts in bulk, each bulk handled in a separate step.
Sends a complete command if successful or an abort command if any step fails.
Questions I’d Love Feedback On:

How many workflows can run in parallel?

I trigger the workflow from a worker bound to a queue—how long can a workflow run?

What’s the best approach for handling uploads from the client?

whats counts for sub-requests in a workflow ?

Option 1: Upload to a worker endpoint (via Cloudflare Access) and trigger a workflow to handle multipart upload. Is this possible?
Option 2: Upload directly to R2 using se a PUT request for file under 50 MIB, for larger files use multipart upload:
(a) Temporary credentials (Access Key/Secret Key) scoped to the user's prefix (username).
(b) Pre-signed URLs (short expiration) for uploads/downloads.
(c) Worker with access for authenticated user with zero trust.

Would love to hear your thoughts! Looking forward to the discussion.

TTuna Hey Everyone! 👋 Building a Cloudflare-Powered File Sharing App – Seeking Feedba...

V

Victor•2/20/25, 8:40 PM

1 & 2 https://developers.cloudflare.com/workflows/reference/limits/
4 https://developers.cloudflare.com/workers/platform/limits/#subrequests

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Tuna•2/21/25, 8:44 AM

is a step in a workflow can be think of a single worker? does every step have it's own limitation of sub-request and open connection, cpu time, or the quota limitation is for the entire workflow ? its very unclear from the documentation.

TTuna is a step in a workflow can be think of a single worker? does every step have it...

S

Seekerdasbatatas•2/21/25, 11:20 AM

Sub-request and open connection limits are per workflow instance. We automatically retry when you reach CPU time and memory limits, but it's not really in a per-step basis (because you can have steps in parallel)

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Tuna•2/21/25, 2:04 PM

@Luís Duarte

and what is an instance of a workflow ?

TTuna @Luís Duarte 🧑🍳 and what is an instance of a workflow ?

I

Isaac McFadyen•2/21/25, 2:05 PM

A single run of the workflow.

I

Isaac McFadyen•2/21/25, 2:06 PM

I.e. you run the workflow, that's 1 instance, you run it again, that's 2 instances.

I would if I were you store the emails you need to send in a KV or any other temporary storage from

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