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You should write an agent

fly.io

31–40 of 409 posts

Re: You should write an agent

#31
This work predates agents as we know them now and was intended for building chat bots (as in irc chat bots) but when auto-gpt I realized I could formalize it super nicely with this library:

https://blog.cofree.coffee/2025-03-05-chat-bots-revisited/

I did some light integration experiments with the OpenAI API but I never got around to building a full agent. Alas..

Re: You should write an agent

#32
post #21

I've found it much more useful to create an MCP server, and this is where Claude really shines. You would just say to Claude on web, mobile or CLI that it should "describe our connectivity to google" either via one of the three interfaces, or via `claude -p "describe our connectivity to google"`, and it will just use your tool without you needing to do anything special. It's like custom-added intelligence to Claude.

Honest question, as your comment confuses me.

Did you get to the part where he said MCP is pointless and are saying he's wrong?

Or did you just read the start of the article and not get to that bit?

Re: You should write an agent

#33
> It’s Incredibly Easy

    client = OpenAI()
    context_good, context_bad = [{
        "role": "system", "content": "you're Alph and you only tell the truth"
    }], [{
        "role": "system", "content": "you're Ralph and you only tell lies"
    }]
    ...

And this will work great until next week's update when Ralph responses will consist of "I'm sorry, it would be unethical for me to respond with lies, unless you pay for the Premium-Super-Deluxe subscription, only available to state actors and firms with a six-figure contract."

You're building on quicksand.

You're delegating everything important to someone who has no responsibility to you.

Re: You should write an agent

#34

> Another thing to notice: we didn’t need MCP at all. That’s because MCP isn’t a fundamental enabling technology. The amount of coverage it gets is frustrating. It’s barely a technology at all. MCP is just a plugin interface for Claude Code and Cursor, a way of getting your own tools into code you don’t control. Write your own agent. Be a programmer. Deal in APIs, not plugins. Hold up. These are all the right concern…

I think my thing about MCP, besides the outsized press coverage it gets, is the implicit presumption it smuggles in that agents will be built around the context architecture of Claude Code --- that is to say, a single context window (maybe with sub-agents) with a single set of tools. That straitjacket is really most of the subtext of this post.

I get that you can use MCP with any agent architecture. I debated whether I wanted to hedge and point out that, even if you build your own agent, you might want to do an MCP tool-call feature just so you can use tool definitions other people have built (though: if you build your own, you'd probably be better off just implementing Claude Code's "skill" pattern).

But I decided to keep the thrust of that section clearer. My argument is: MCP is a sideshow.

Re: You should write an agent

#35
I agree with the sentiment but I also recommend you build a local only agent. Something that runs on llama.cpp or vllm, whatever... This way you can better grasp the more fundamental nature of what LLM's really are and how they work under the hood. That experience will also make you realize how much control you are giving up when using cloud based api providers like OpenAI and why so mane engineers feel that LLM's are a "black box". Well duh buddy you been working with apis this whole time, of course you wont understand much working just with that.

Re: You should write an agent

#36
> Imagine what it’ll do if you give it bash. You could find out in less than 10 minutes. Spoiler: you’d be surprisingly close to having a working coding agent.

Okay, but what if I'd prefer not to have to trust a remote service not to send me

    { "output": [ { "type": "function_call", "command": "rm -rf / --no-preserve-root" } ] }

?

Re: You should write an agent

#37
post #21

I've found it much more useful to create an MCP server, and this is where Claude really shines. You would just say to Claude on web, mobile or CLI that it should "describe our connectivity to google" either via one of the three interfaces, or via `claude -p "describe our connectivity to google"`, and it will just use your tool without you needing to do anything special. It's like custom-added intelligence to Claude.

Honest question, as your comment confuses me. Did you get to the part where he said MCP is pointless and are saying he's wrong? Or did you just read the start of the article and not get to that bit?

I'd second the article on this, but also add to it that the biggest reason MCP servers don't really matter much any more is that the models are so capable of working with APIs, that most of the time you can just point them at an API and give them a spec instead. And the times that doesn't work, just give them a CLI tool with a good --help option.

Now you have a CLI tool you can use yourself, and the agent has a tool to use.

Anthropic itself have made MCP server increasingly pointless: With agents + skills you have a more composeable model that can use the model capabilities to do all an MCP server can with or without CLI tools to augment them.

Re: You should write an agent

#38
I realize now what I need in Cursor: A button for "fork context".

I believe that would be a powerful tool solving many things there are now separate techniques for.

Re: You should write an agent

#39
post #26

Earlier quoted context omitted.

You could even imagine a world in which we create an entire suite of deterministic, limited-purpose tools and then expose it directly to humans!

I wonder if we could develop a language with well-defined semantics to interact with and wire up those tools.

> language with well-defined semantics

That would certainly be nice! That's why we have been overhauling shell with https://oils.pub , because shell can't be described as that right now

It's in extremely poor shape

e.g. some things found from building several thousand packages with OSH recently (decades of accumulated shell scripts)

- bugs caused by the differing behavior of 'echo hi | read x; echo x=$x' in shells, i.e. shopt -s lastpipe in bash.

- 'set -' is an archaic shortcut for 'set +v +x'

- Almquist shell is technically a separate dialact of shell -- namely it supports 'chdir /tmp' as well as cd /tmp. So bash and other shells can't run any Alpine builds.

I used to maintain this page, but there are so many problems with shell that I haven't kept up ...

https://github.com/oils-for-unix/oils/wiki/Shell-WTFs

OSH is the most bash-compatible shell, and it's also now Almquist shell compatible: https://pages.oils.pub/spec-compat/2025-11-02/renamed-tmp/sp...

It's more POSIX-compatible than the default /bin/sh on Debian, which is dash

The bigger issue is not just bugs, but lack of understanding among people who write foundational shell programs. e.g. the lastpipe issue, using () as grouping instead of {}, etc.

---

It is often treated like an "unknowable" language

Any reasonable person would use LLMs to write shell/bash, and I think that is a problem. You should be able to know the language, and read shell programs that others have written

Re: You should write an agent

#40
post #26

Earlier quoted context omitted.

You could even imagine a world in which we create an entire suite of deterministic, limited-purpose tools and then expose it directly to humans!

I wonder if we could develop a language with well-defined semantics to interact with and wire up those tools.

As it happens, I have a prototype for this, but the syntax is honestly rather unwieldy. Maybe there's a way to make it more like natural human language....
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