Live data from Hacker News

Components of a Coding Agent

magazine.sebastianraschka.com

51–60 of 120 posts

Re: Components of a Coding Agent

#51
> This is speculative, but I suspect that if we dropped one of the latest, most capable open-weight LLMs, such as GLM-5, into a similar harness, it could likely perform on par with GPT-5.4 in Codex or Claude Opus 4.6 in Claude Code.

People have been doing that for over a year already? GLM officially recommends plugging into Claude Code https://docs.z.ai/devpack/tool/claude and any model can be plugged into Codex CLI (it's open source and can be set via config file).

Re: Components of a Coding Agent

#52
post #50

Earlier quoted context omitted.

If you saw the Claude Code leak, you’d know the harness is anything but simple. It’s a sprawling, labyrinthine mess, but it’s required to make LLMs somewhat deterministic and useful as tools.

It's pretty easy to get determinism with a simple harness for a well-defined set of tasks with the recent models that are post-trained for tool use. CC probably gets some bloat because it tries to do a LOT more; and some bloat because it's grown organically.

>It's pretty easy to get determinism with a simple harness for a well-defined set of tasks with the recent models that are post-trained for tool use.

Do you have a source? Claude Code is the only genetic system that seems to really work well enough to be useful, and it’s equipped with an absolutely absurd amount of testing and redundancy to make it useful.

Re: Components of a Coding Agent

#53
post #3

I still find it incredible at the power that was unleashed by surrounding an LLM with a simple state machine, and giving it access to bash

At it's heart it's prompt/context engineering. The model has a lot of knowledge baked into it, but how do you get it out (and make it actionable for a semi-autonomous agent)? ... you craft the context to guide generation and maintain state (still interacting with a stateless LLM), and provide (as part of context) skills/tools to "narrow" model output into tool calls to inspect and modify the code base. I suspect that…

[dead]

Re: Components of a Coding Agent

#54

> This is speculative, but I suspect that if we dropped one of the latest, most capable open-weight LLMs, such as GLM-5, into a similar harness, it could likely perform on par with GPT-5.4 in Codex or Claude Opus 4.6 in Claude Code. People have been doing that for over a year already? GLM officially recommends plugging into Claude Code https://docs.z.ai/devpack/tool/claude and any model can be plugged into Codex CLI…

And while it’s not Opus level, it is incredibly good. I use it basically exclusively (and qwen3.5-plus) on my personal projects.

Re: Components of a Coding Agent

#55
post #3

I still find it incredible at the power that was unleashed by surrounding an LLM with a simple state machine, and giving it access to bash

If you saw the Claude Code leak, you’d know the harness is anything but simple. It’s a sprawling, labyrinthine mess, but it’s required to make LLMs somewhat deterministic and useful as tools.

That’s also because of how Claude Code was written. It doesn’t have to be that way per se.

Re: Components of a Coding Agent

#56

Earlier quoted context omitted.

unfortunately all the agent cli makers have decided that simply giving it access to bash is not enough. instead we need to jam every possible functionality we can imagine into a javascript “TUI”.

If all you want is a program that calls the model in a loop and offers a bash tool, then ask Claude Code to build that. You won't like it though! For a preview of what it'd be like, just tell your AI chat app that you'll run bash commands for it, and please change the app in your "current directory" to "sort the output before printing it", or some such request.

> If all you want is a program that calls the model in a loop and offers a bash tool, then ask Claude Code to build that. You won't like it though!

Okay sure it’s technically more than just bash, but my own for-fun coding agent and pi-coding-agent work this way. The latter is quite useful. You can get surprisingly far with it.

Re: Components of a Coding Agent

#57
post #40

Earlier quoted context omitted.

Yes, Claude Code has a Bash tool, and Claude in some cases uses the CLI sed utility (via the Bash tool) for file changes (although it has built-in file update), at least on my Linux machine.

Interesting - thanks. I just asked Claude, and apparently CC makes it's bash tool available on all platforms it runs on (Linux, macOS, Windows WSL, Git for Windows), and doesn't do platform-specifc filtering of bash commands, which would seem to make for some interesting incompatibilities - GNU utils (sed, grep, find) on Linux and Windows, but BSD variants on macOS.

Claude code will semi-regularly try to use GNU utils on my Mac
Post reply on HN