CAFE news

News from people who build with Cloudflare, Alchemy, Foldkit and Effect. A person reviews each entry before it appears.

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[thread]I built "foldkit for the backend" on top of Alchemy. I absolutely love this style of testing. (x.com)
Sam Goodwin shows alchemy/Fold tests: backend aggregates and stories tested in the same scene style as Foldkit.
2026-10-09 by sam-goodwin
13 replies · 15 people
Top replies
- @samgoodwin89: Playing with it over here"https://t.co/3ii6ERXjew 8 likes
- @Plague_FPS: @samgoodwin89 This is the most readable test I've seen that actually tests a complex user flow of extreme importance. The testing in Alchemy/Foldkit more than anything is what is absolutely blowing me away. 4 likes
- @just_be_dev: @samgoodwin89 Wait I need that 3 likes
[post]Alchemy 2.0.0-beta.83: the Cloudflare Birthday Week release (alchemy.run)
Adds DO containers, K2 streams, Basin and KV Instant. Needs Node 24.11.1+. One-way: once deployed, Durable Object stacks can't use older Alchemy.
2026-10-12 by alchemy-run
[thread]Very bullish on the CAFE stack (cloudflare, alchemy, foldkit, effect). Got my own template for it here: github.com/just-be-dev/ef… (x.com)
Justin Bennett names the CAFE stack and shares his template; replies ask about Foldkit and point to Effect-TS/cafe.
2026-10-08 by @just_be_dev
10 replies · 13 people
Top replies
- @cnakazawa: it should be CAFFE 5 likes
- @abbesm0hamed: @maxwellbrown has also been working on one https://github.com/Effect-TS/cafe 5 likes
- @just_be_dev: More analogous to react and it’s still early. I was a big fan of elm though and I’m a big effect fan so it’s like pb&j. 3 likes
[post]A Foldkit Scene test for the Foldkit UI Toast (x.com)
Devin Jameson walks through a Scene that swipes a toast a short way and checks it settles back instead of dismissing.
2026-10-10 by devinjameson
[thread]All of Effect v4 clicked with this example https://t.co/Kbu2ZIranW (x.com)
2026-10-07 by @peterpme
11 replies · 12 people
Top replies
- @rvcas: @peterpme I’m just joking! https://t.co/DU2xTncDQM 7 likes
- @count_slopula: @peterpme This code will give me nightmares for weeks. 1 likes
- @kevin_moechel: @peterpme const data = getMarketData().then().error() 1 likes
[launch]HumanLayer Channels (github.com)
Puts agents in Slack, GitHub and Linear without losing a message: durable, ordered webhook mailboxes on Effect 4, with Durable Objects storage through Alchemy.
2026-10-10 by humanlayer
[thread]Now that I'm codex-resets rich, I kinda ported pi-durable to @EffectTS_, but built on workflows and their AI module https://t.co/M8nWw6OyUT (x.com)
2026-10-08 by @JuliaScript
5 replies · 6 people
Top replies
- @catmanyau: @JuliaScript @EffectTS_ Porting pi-durable onto Effect workflows makes durable agent flows easier to express; the harder constraint becomes modeling retries and state transitions cleanly. 2 likes
- @JuliaScript: @sheherenow_ @EffectTS_ ngl I was a bit embarrassed to share that after this https://t.co/oX5ffmOjrP 2 likes
- @MrBye32: @JuliaScript @EffectTS_ thanks! 1 likes
[release]Alchemy 2.0.0-beta.81 (github.com)
Syncs Cloudflare OAuth scopes with the registered client.
2026-10-05 by alchemy-run
[thread]btw i made a wrapper for Foldkit (🪨: sick Elm Architecture frontend framework built on Effect) that renders natively with gpui v early but (x.com)
2026-10-09 by @sheherenow_
4 replies · 5 people
Top replies
- @sheherenow_: @JuliaScript maybe you can build a foldkit-native app to check your DMs and reply to me 👿😇 2 likes
- @devinjameson: @sheherenow_ Dark magic. 1 likes
- @codecology: @sheherenow_ Long-term perhaps peat can compile to platform-specific styles? :O 1 likes
[thread]Streaming today at 2:30 PM ET with @maxwellbrown of @EffectTS_ and @samgoodwin89 of @alchemy_run. We’ll be having some fun building with th (x.com)
2026-10-08 by @devinjameson
4 replies · 11 people
Top replies
- @thefubhy: @devinjameson @maxwellbrown @EffectTS_ @samgoodwin89 @alchemy_run C# + Angular + Firebase + Ember.js 13 likes
- @MichaelArnaldi: @thefubhy @devinjameson @maxwellbrown @EffectTS_ @samgoodwin89 @alchemy_run They did it not to have us in chat you know 5 likes
- @thefubhy: @devinjameson @maxwellbrown @EffectTS_ @samgoodwin89 @alchemy_run Hey better not do it any earlier than that or someone from Europe might join to watch. 5 likes
[thread]Foldkit Dials: a lil port of Dialkit to align with Foldkit/TEA (x.com)
Live tuning controls for Foldkit apps. Each dial is an Effect Schema and every edit is a Message.
2026-10-09 by jem-computer
4 replies · 6 people
Top replies
- @sheherenow_: 🎨 Pleat is a library for algebraic style composition https://t.co/eBwUIJIVbc 6 likes
- @sheherenow_: @_aierie @joshpuckett because functional programming is sick \m/ 2 likes
- @mattespapier: @sheherenow_ @joshpuckett damn that’s nice! and a music technology lab with effect! foldkit! 2 likes
[release]effect@4.0.3 released (github.com)
A patch on the Effect 4 line: fixes for cached re-entry, cluster shard handoffs and DurableDeferred, plus TestCrypto.layer.
2026-10-10 by github.com
[video]Effect 4.0 Just Got a Lot Harder to Ignore (www.youtube.com)
Better Stack video on Effect 4.0's rewritten runtime, smaller bundles and faster task throughput.
2026-10-06 by www.youtube.com
[thread]Turns out @EffectTS_ + XState is the best tech stack for agents The matter is settled 🤝 https://t.co/Gi7ZaGeJLd (x.com)
2026-10-08 by @SandroMaglione
3 replies · 3 people
Top replies
- @the_madcoder: @SandroMaglione @EffectTS_ XState is perfect for state management. I used to avoid it because it was too verbose and took too long to write, while Jotai and Zustand were much simpler. Now there is no 4 likes
- @buswe_com: @SandroMaglione @EffectTS_ XState actors map really well onto multi-agent handoffs: each agent its own machine, explicit transitions, and you can replay the whole run. 3 likes
- @SandroMaglione: Add in also some @alchemy_run and you stop worrying also about deployment 3 likes
[post]Foldkit 0.167.0 (foldkit.dev)
Foldkit 0.167.0 lets the server entry render the whole HTML page and adds a Node host adapter.
2026-10-07 by devinjameson
[thread]seeing Effect and Foldkit pick up mindshare / heartshare is so vindicating for those of us who were repeatedly told we were insane, idealist (x.com)
2026-10-07 by @sheherenow_
7 replies · 9 people
Top replies
- @sheherenow_: @arjunkmrm LITERALLY. it’s not just a nerdsnipe or a white whale or idealism, it’s actually A Better Choice 3 likes
- @sheherenow_: @joelhooks @willking damn we really such oldheads 2 likes
- @willking: @joelhooks @sheherenow_ The series that brought me to egghead. 2 likes
[post]alchemy/Fold proposes Foldkit-style domain modelling for the backend (github.com)
Open PR: aggregates, views, policies and stories over Effect RPC, hosted on Durable Objects with a transactional outbox.
2026-10-09 by sam-goodwin
[post]Workers Observability in custom dashboards (developers.cloudflare.com)
Custom Dashboards can chart Workers logs and traces next to analytics, which helps a CAFE builder check a Worker's health in one place.
2026-10-02 by developers.cloudflare.com
[post]This Week in Effect - 138 (effect.website)
Weekly Effect roundup; the index lists Effect v4 as stable this week.
2026-10-02 by effect.website
[thread]Looking for folks' best resources on recommendations for structuring effect codebases. @kitlangton, @samgoodwin89, @devinjameson, @arjunkmrm (x.com)
2026-10-05 by @just_be_dev
7 replies · 19 people
Top replies
- @kitlangton: @just_be_dev @samgoodwin89 @devinjameson @arjunkmrm @EffectTS_ 🫡 https://t.co/9UNS28PZec 170 likes
- @samgoodwin89: @just_be_dev @kitlangton @devinjameson @arjunkmrm @EffectTS_ One file, one Context.Service+Layer. One file, one entrypoint+Effect.provide One file, one API route (may be controversial opinion) src/{do 73 likes
- @kitlangton: @just_be_dev @samgoodwin89 @devinjameson @arjunkmrm @EffectTS_ (I'll have a real reply later!) 16 likes
[release]effect@4.0.2 released (github.com)
A patch on the Effect 4 line, so a CAFE app pinned to 4.0.0 should move to 4.0.2 once its lockfile is checked.
2026-10-07 by github.com
[post]Announcing @neon/effect (neon.com)
Neon ships @neon/effect, Effect 4 bindings for the Neon SDK with typed errors and Streams.
2026-10-01 by neon.com
[post]Foldkit 0.165.0 and 0.166.0 (foldkit.dev)
Foldkit 0.165 and 0.166 bring Effect 4 stable and an experimental Query module for remote data.
2026-10-04 by devinjameson
[thread]@alchemy_run v2 + @EffectTS_ v4 is an incredible combo for infra-as-code biggest shocker: new frameworks and tools can be sooo much better (x.com)
2026-10-07 by @esthor
3 replies · 5 people
Top replies
- @MichaelArnaldi: @esthor @alchemy_run @EffectTS_ Agents work well with high level declarative languages and symbolic reasoning with guardrails, they don’t work well with imperative logic filled with implementation det 16 likes
- @bjacobso: @MichaelArnaldi @esthor @alchemy_run @EffectTS_ I’ve been working on this https://t.co/ayCbVvzvSE 3 likes
- @itsmattchan: @esthor @EffectTS_ @alchemy_run It’s GOATED. Porting a frankenstein stack over to this on AWS and it’s such a more tightly integrated experience. 3 likes
[post]Cloudflare Containers, rebuilt to scale agent sandboxes (blog.cloudflare.com)
Containers can now pick their image and instance size from a Durable Object at runtime, with Sandbox SDK 1.0 on top, which matters to a CAFE builder running Worker-controlled sandboxes (beta).
2026-09-30 by blog.cloudflare.com
[post]Pending I/O operations allow Durable Objects to continue long-running work without a connected client (developers.cloudflare.com)
Durable Objects with a 2026-10-01 compatibility date keep running for pending service-binding and RPC calls for up to 15 minutes, which a CAFE builder running long jobs on Workers needs to know about.
2026-10-01 by developers.cloudflare.com
[video]Using Effect? Use Alchemy, too! (www.youtube.com)
Academind video pitching Alchemy as the infrastructure companion to Effect.
2026-10-01 by @maxedapps
[thread]Back to @EffectTS_ community work in Paris next Tuesday with the 7th edition! The edition will probably be the first one ever recorded in Pa (x.com)
2026-10-09 by @c9antoine
3 replies · 7 people
Top replies
- @devinjameson: @c9antoine @EffectTS_ @EvrygDotCom Ooo @mixeddev talk! 2 likes
- @devinjameson: @rodygosset @c9antoine @EffectTS_ @EvrygDotCom Looking forward to the recording! 1 likes
- @rodygosset: @devinjameson @c9antoine @EffectTS_ @EvrygDotCom Yeah ! Super excited to share my thoughts on the case for defaulting to Effect in most projects 1 likes
[post]2.0.0-beta.80 - GCP, Neon & Secret Providers (alchemy.run)
Alchemy beta.80 adds GCP, Neon and secret providers.
2026-09-29 by alchemy.run
[post]Effect 4.0 (effect.website)
Rebuilt from the ground up, with a dependency-free core and long-term support.
2026-09-30 by Effect-TS
[thread]Tardigrades survive space, boiling, and freezing. This one survives `ctx.abort()` Kill it N times while it works, and it comes back and sh (x.com)
2026-10-07 by @acoyfellow
3 replies · 5 people
Top replies
- @gingerhendrixai: @acoyfellow @pidotdev @EffectTS_ @foldkit @Cloudflare great name... but @arjunkmrm has you beat - you should also check his out https://t.co/rYPQmSwtE3 6 likes
- @trydotworks: @acoyfellow @pidotdev @EffectTS_ @foldkit @Cloudflare shout out to @arjunkmrm 3 likes
- @arjunkmrm: @acoyfellow @trydotworks @pidotdev @EffectTS_ @foldkit @Cloudflare It’s all cool! :D 1 likes
[post]Foldkit proposes Layer-backed effects and typed application assembly (github.com)
Open PR: Commands, Subscriptions and Queries get implementations from Layers, and the app graph is built once per runtime start.
2026-10-09 by devinjameson
[post]Effect TypeScript explained for beginners (2026) (robotostudio.com)
Plain-English intro to Effect covering typed errors, retries, timeouts and dependency injection.
2026-09-24 by robotostudio.com
[thread]How about SolidYield in @alchemy_run ? https://t.co/KsmM3zi0Qs https://t.co/cSepsYwwXX (x.com)
2026-10-07 by @samgoodwin89
2 replies · 2 people
Top replies
- @samgoodwin89: PR: https://t.co/5OdF48loX4 4 likes
- @devagrawal09: @samgoodwin89 @alchemy_run Holy shit that was quick This is awesome! 2 likes
[post]Foldkit 0.164.0 (foldkit.dev)
Foldkit 0.164.0 adds Meter and Progress UI primitives and simplifies DevTools MCP and server rendering setup.
2026-09-30 by devinjameson
[release]effect@4.0.0 released (Effect 4 stable) (github.com)
Effect 4 is now the stable, long-term-support line, so a CAFE builder can start new code on it and plan the v3 migration with MIGRATION.md.
2026-10-01 by github.com
[video]You MUST learn and use Effect now! (www.youtube.com)
Academind video arguing developers should adopt Effect, including for work with AI agents.
2026-09-24 by @maxedapps
[thread]This - every single contribution, regardless of how sloppy, is a signal we can use to continuously improve the @EffectTS_ ecosystem. Everyt (x.com)
2026-10-06 by @maxwellbrown
2 replies · 3 people
Top replies
- @tokatedev: @maxwellbrown @EffectTS_ We think there's a middle-ground between fully closed and fully open. The best of both worlds for AI-friendly projects is to allow contributions written by AI, but on the owne 3 likes
- @maxwellbrown: @bohdanbirdie @EffectTS_ And we appreciate it! 1 likes
- @bohdanbirdie: @maxwellbrown @EffectTS_ I did contribute a little to effect and to my surprise - thing got merged 🤑 1 likes
[post]Test every pull request in an isolated environment with Worker Previews (developers.cloudflare.com)
Each PR gets its own Worker URL with isolated Durable Objects and Containers, which a CAFE builder can use for per-PR tests against real infrastructure.
2026-09-22 by developers.cloudflare.com
[thread]Last night I was thinking it'd make a lot of sense for @EffectTS_ to take over KafkaJS project and integrate Kafka directly into Effect. T (x.com)
2026-10-06 by @JacobWolf
1 reply · 5 people
Top replies
- @MichaelArnaldi: @JacobWolf @EffectTS_ If the current maintainers and authors are happy with it we would gladly take over and integrate into effect core 23 likes
- @JacobWolf: @MichaelArnaldi @EffectTS_ I don’t know them, but here’s the post looking for maintainers: https://t.co/qMt8a0WRWS I’m also happy to be involved as a user of both in a pretty large scale production s 2 likes
- @thefubhy: @MichaelArnaldi @JacobWolf @EffectTS_ https://t.co/Nte8Cm4bRZ 1 likes
[thread]@EffectTS_ Boston meetup?!!?! Would love to make it happen. If you’re in Greater Boston and would come (or know of companies in Boston usi (x.com)
2026-10-07 by @devinjameson
8 replies · 9 people
Top replies
- @MKassabov: @devinjameson @EffectTS_ I'd go!! 2 likes
- @devinjameson: @texoport__ @EffectTS_ 😭 2 likes
- @michaelvessia: @devinjameson @EffectTS_ Decent chance I'd turn it into a family weekend in Boston depending on the timing 2 likes
[post]2.0.0-beta.78 - Git Hosting, Stripe & Worker Previews (alchemy.run)
Alchemy beta.78 adds git hosting, Stripe and Worker Previews support.
2026-09-17 by alchemy.run
[thread]Pleat: algebraic, typed styles for Foldkit and Effect v4 (x.com)
A new style composition library for Foldkit frontends. Early and in flux, with a Foldkit UI page of live components.
2026-10-09 by jem-computer
0 replies · 1 person
Top replies
[thread]Foldkit 0.167.0 is now available on everyone’s favorite JavaScript package registry! - SSR without HTML templates - New @foldkit/node adap (x.com)
2026-10-08 by @devinjameson
2 replies · 4 people
Top replies
- @thefubhy: @devinjameson @sheherenow_ https://t.co/nXUA3hIskG 2 likes
- @enspiration_eth: @filipfalcon @devinjameson I just remember reading that it wasn't a priority, but I guess that was a while ago 2 likes
- @filipfalcon: @enspiration_eth @devinjameson SSR is available for a while now. It's still experimental and matures every week. Give it a try and share feedback. 2 likes
[post]Foldkit 0.162.0 and 0.163.0 (foldkit.dev)
Adds swipe-to-dismiss on Toast, makes canonical URLs an application decision, and stops SSR builds publishing an unrendered HTML template.
2026-09-19 by devinjameson
[post]2.0.0-beta.77 - Profiles, CLI & Workers Tracing (alchemy.run)
Alchemy beta.77 adds profiles and sends Effect spans from Workers to Cloudflare Workers Observability.
2026-09-08 by alchemy.run
[post]Foldkit 0.159.0 (foldkit.dev)
Adds a portable fetch handler for server-rendered apps, so the same entry runs on Node or a custom Worker.
2026-09-12 by devinjameson
[post]We think this is it ... (effect.website)
Effect 4.0 release candidate, with a call for users to test and veto before stable.
2026-08-12 by effect.website

How this list is sorted

Each entry gets a score from the signals we already have:

X likes, replies and the number of people in a thread
GitHub stars, and the date of the last push
YouTube views
The number of independent crawlers that found the entry
The date of the entry

The score follows these rules:

Each signal adds its weight times log10(1 + signal). Views weigh 0.5. Every other signal weighs 1.
Age subtracts one point for every 72 hours since the entry date or the last push.
So 10 times the engagement is worth 72 hours of freshness.
A missing signal counts as zero.
After scoring, an entry loses 0.5 points for each higher entry by the same author or from the same site.
Equal scores go to the newer entry, then to the earlier URL.
Votes come in a later phase. A Wilson score suits up and down votes, so it waits until we have them.

Prior art: Reddit hot ranking, Hacker News gravity and penalties, Bear Blog ranking for a small site.

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