Flue is a TypeScript framework for building the next generation of agents

21 hours ago (flueframework.com)

Vibe coding aside [1], it's very interesting software projects these days don't really care about adding a single test [2].

[1]: https://github.com/withastro/flue/blob/8fdf8e0e9df5bd33c3120...

[2]: https://github.com/search?q=repo%3Awithastro%2Fflue+test+pat...

  • I find this impressive: in my experience, codex-rs loves to add tests even when not prompted. Of course, it’s a bit of a crap shoot as to whether the test tests useful behavior.

    (My favorite so far: it created an empty file in /home/whatever and added a test to verify that some code it wrote would indeed fail when tested on this empty input and that it would fail with the correct error message. Never mind that this covered approximately none of the desired behavior and that the test would, of course, fail on any other system.

  • That would be really interesting. I doubt it's the case, actually probably the opposite? The harnesses seem very happy to write extensive test suits, without me having to ask much.

Ok, real question. What products are people actually building with agent frameworks? I get the utility of AI coding tools and generic chat apps, but that is the extent of utility that I've been able to get from AI. I'm looking for examples that are real businesses, not toys.

  • We're building https://brooked.io/. In the same way that Cursor provides a lot of features on top of the base agents, we want to do the same for spreadsheets. There are many workflows that benefit from having an agent available - resolving cell values from a prompt, writing functions, sheet insights, alerting, debugging.

What is the problem this solves? Why would I use this instead of telling claude to vomit out the underlying boilerplate.

Why TS? The npm ecosystem is insane and insecure. Not a chance we are running this in our machines.

Go/Rust way better choices. Besides, if it’s all vibe coded, it shouldn’t matter for the author

  • I think the TypeScript ecosystem is more suitable for this.

    I do not think Rust is a bad language. But the agent ecosystem changes very quickly, and in Rust, assembling and reshaping agent workflows is difficult.

    Many people prefer Rust, and I understand why. It is a genuinely excellent language, and “Rust is a great language” is a strong message that attracts many developers. But as long as lifetimes exist, I think it will remain difficult.

    The lifetime system assumes, in some sense, that humans can fully predict the lifecycle of values and resources. I am not sure that is truly possible in all domains. I am also not sure whether that model is linguistically suitable for the agent ecosystem.

    In agent systems, requirements change constantly. Tools change, workflows change, providers change, schemas change, and failure policies change. In that kind of environment, I am not sure Rust is the right fit.

    I like Rust a lot, and it is a language I genuinely want to learn. But I am not sure that applying Rust to everything is really the right answer.

    I think Rust makes a lot of sense in relatively stable infrastructure ecosystems: operating systems, runtimes, sandboxes, and core low-level layers. But agent code usually requires high-level abstraction and rapid workflow composition. Doing that in Rust takes a tremendous amount of time.

  • I am using TS sandboxed in deno for all our agent code generated from a UI builder (inspired by OpenAI's own agent builder, and spits out the same code output)

As other comments have said, it would be great to add what this does that existing solutions can't. I see the project has been active since Feb, and has < 150 commits. I'd assume this is still pretty immature. So why use this? I think more explanation is needed.

What I wonder is, why do we still need code etc? Shouldn’t all code be just a promt? This way it becomes language and platform agnostic.

  • How would that actually work? Eventually the specification for the CPU has to be clear. For now, that means machine code.

  • Natural language is too vague, ambiguous, and inefficient.

    That’s why we have _programming_ languages.

    And once you specify everything you need, the “prompt” becomes a program.

    Anything else is to lossy

If only there were great backend languages

Go, C#, what have you.

Nah, thank god we have javascript

  • Anders Hejlsberg, who designed C#, is now leading Typescript development. Why would I not join him at the frontiers of his creative and intellectual energies?

    Go is a nice language, but it's not expressive the way typescript can be. I'm not convinced, either, that coroutines are all that snazzy an abstraction at the application level.

  • Not mentioning Java means we are already on the same wavelength.

    I love C# too.

  • You're welcome to port anything over to those languages. LLMs can do it in a couple of days at most.

    • Tell me next time Codex app would be rewritten to native stack scross all platforms: swiftui, winui, etc.

      Should be easy, yeah?

  • ADK comes in Go, Java, Python, and TS

    Same framework, multiple languages, let people decide their preference while having consistency and interoperability