Promises/async/await in Meteor

There have been a number of forum posts recently around the topic of working with Promises in Meteor.

I’ve put together a short Medium article on server-side Promises and how they interact with Meteor’s classic Fiber-based coding, including mixing 3rd party Promises with Meteor Promises.

I’m not 100% sure that Medium is the best tool for technical articles, but here it is anyway. Feedback welcomed! :slight_smile:


Hey I think this is something that would be cool to have a post about on the official Medium blog - do you want to collaborate on a post there? We can go into some other ideas, such as Promise.await (a way to convert any promise into fiber code, without the await syntax), and I also think you can use Promise.resolve(otherPromise) to convert between promise libraries more easily!


Great article! I have myself encountered the issue a few days ago.

I would also add, if you don’t need to write in a Mongo collection the result of the promise and only return it to client, you can use promises without any trouble:

  myMethod: function () {
    return api.create({
    }).then((res) => {
      console.log('Promise resolved', res);
      return res;
    }).catch((e) => {
      console.log('Promise failed', e);
      throw new Meteor.Error(500, 'There was an error processing your request');

As @sashko mentionned, we can also use Promise.await() inside a try catch block to make the promise synchronous.

Anyways, an post on the official blog would be really helpful for other devs as this is a common issue.


Cool! Yes, I’d be happy to.

There was a lot of stuff I left out, because I felt there was more than one article’s worth.

Yes, I used that back in the day, but for some reason I’d got it into my head that it had been deprecated.

I’d also like to show why this.unblock() in methods can be a bad thing and how async/await gives you the same result without the pitfalls.

And then there’s using Promises in client code…


Great article! I would also love to have an official post talking about promises in depth including client side promises :slight_smile:

1 Like

Great article! And much needed. With some NPM packages, due to how the packages were created & interactions with Meteor, I had to nest a number of promises just to get them working, which is not only confusing but also led to very messy looking code.

This, in my opinion, is the weakest aspect of Meteor’s NPM support.

1 Like

Yeah there are so many possibilities here! Perhaps email me at and we can get a first post going?

@robfallows this was a great article and you must take @sashko on his offer because I was trying to solve an async/await problem for a friend this morning where

async function foo() { return await bar(); }

kept throwing errors about meteor code needing to be run within a fiber and whatever I did (wrapasync/bindenvironment et al) within bar() or foo() did not help.

And finally, I remembered this thread and did

function foo() { return Promise.await bar(); }   

and voila!

And then I tried to find some meteor documentation about async/await and that special promise but there was none I could find.

Furthermore, it seems there’s no documentation about things like webappinternals, mongointernals and httpinternals either. I’m sure there are other things that meteor has to offer yet undocumented. @sashko what can we do about such things?


Would getting rid of Fibers from Meteor solve a lot of the current difficulties of using NPM packages that use promises?

If you read the article there aren’t too many difficulties already. But yes we are moving towards using fibers as little as possible.

Alright! It’s up on the Meteor blog, thanks @robfallows!


Thank you for the opportunity to give something back :slight_smile: