Clojurians Log v2

Reagent needs significant work to be able to function reliably and backwards-compatibly in React 19 Concurrent Mode. Juho Teperi from Metosin has been maintaining Reagent for 8 years. He has been working on updating Reagent to work with React 19 part-time, but there is still a lot of work to do. To keep the work sustainable, and to be able to finish it, Juho needs to be able to concentrate on it full-time, so Metosin is now looking for sponsors. The aim is to have a new release of Reagent that is a drop-in replacement and works with React 19. Juho is currently working through the Reagent test suite and updating it to be compatible with the Concurrent Mode. With two sponsors each paying 8k€ we can get Juho to work on this full-time for one month. There is no guarantee that the work will finish in one month, but Juho is hopeful. In any case, we’ll know a lot more after one month of discovery. The sponsors will be mentioned in Metosin’s blog posts about this project and in the Reagent README. Juho’s work can be followed live on Github and we’ll write a detailed report at the end of the month. If you’re interested in sponsoring, contact me on slack! FAQ Why not fund this work via Clojurists Together? Juho wants to work on this as part of his job at Metosin, and companies can’t apply for Clojurists Together funding. Why can’t Metosin pay for the work? Metosin has already sponsored Reagent development over the years with over a thousand hours of Juho’s work time. We need the external funding to be able to give Juho the break from consulting needed to finish this work. Metosin will continue to cover the costs of other people helping Juho with the work. What about UIx and other newer React wrappers? UIx is compatible with React 19 and Juho recommends it for new projects. However, many old projects are stuck with Reagent and can’t afford the rewrite to another library. React 19 compatibility will also help projects that are using both Reagent and UIx when migrating. What if Juho finishes the work really quickly? If there is time left over, Juho intends to use it for quality-of-life improvements such as nicer React Hook use and potentially eliminating the need for the :f> magic.

Discussion welcome in this thread as well.

That’s great news! I wonder if it makes sense to allow donations from individuals in the community, if that’s possible

That's a good question, I need to figure out how the financial/tax side works. Sending invoices to companies is simple, we do it every day 😅

Finnish money collection law (Rahankeräyslaki) can also be complex, if not problematic. Taking donations requires a permit etc.

As an example, Wikipedia:

We've now managed to sign 20k€ worth of sponsorship deals for the Reagent - React 19 work, surpassing our goal of 16k€. That means the work will start! We'll post about the progress publicly. Stay tuned...

I will pass this request on to the people who can decide on this 💰

Very cool, thank you. Two questions: 1. Is this still the state of the art in UIx?

;; Reagent
[:div#id.class {:on-click f}
  [:div]]

;; UIx
($ :div#id.class {:on-click f}
  ($ :div))

https://www.metosin.fi/blog/2025-04-24-reagent-and-react-19-support

@hhausman 1. Yes, I guess? Not sure what the question is. 2. I can't say. I've made progress with getting the test suite running with concurrent mode or React 19 over last few months, but it is slow when I don't have time to focus on it for more than a few days at a time. I'm not sure if I would say this is "additional funding" because there hasn't been funding previously.

Makes sense. Thanks! 🙇

We at IPRally are potentially interested to sponsor.

Good to hear! Potentially – what does it depend on?

Us thinking about it a bit more and me convincing the CFO.

Sounds good. Good luck!

we have many reagent apps as well

do you have some URL that could be more easily shared?

this slack thread was my alpha test, we'll have a public blog post next week and I'll link it here 😇

Let's see if we can find more people named Tarvainen to support this.