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Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

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21–30 of 318 posts

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#21

Great work, but concurrency is lost. With search-replace you could work on separate part of a file independently with the LLM. Not to mention with each edit all lines below are shifted so you now need to provide LLM with the whole content. Have you tested followup edits on the same files?

(not the author) it works fine most of the time been using it alongside an active agent and haven't ran into too many noticable problems. The token savings alone are worth it.

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#22

I feel the baseline comparison should be relative to the intuitive and simple "line-numbers only" schema. It's less token heavy than the proposed hash approach, and I don't think frontier LLMs hallucinate line numbers if each line in the context is prefixed with them.

it starts writing to the wrong part of the file after multiple edits.

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#23
post #15
post #13

What was the point of Claude code or Gemini banning the OP? Why would they care about how IDEs use the underlying API?

I assume he was using Gemini the same way as he was Claude when I make the following statement. I don’t believe it’s exceptionally unique or new that companies will revoke access if you are using an unpublished API that the apps use. I don’t see anything wrong with it myself. If you want, pay for normal token use on the published APIs. There is no expectation that you can use APIs for an application, even if you are…

Indeed, that's why Anthropic, OpenAI and other LLM providers are known to adhere to published APIs to gather the world's data, obeying licensing and ROBOTS.txt.

It's truly disgusting.

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#25

I feel like cursors solution is still the best answer. Let the model suggest edits in whatever format it prefers using as few "extra" tokens as possible and have a small model figure it out. I don't use cursor anymore but when I did it was impressive how consistently it worked, I think there was a single time it failed. 70b might be overkill though...

Someone should try prompting the same LLM in use, to suggest an edit as a subagent.

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#26
post #13

What was the point of Claude code or Gemini banning the OP? Why would they care about how IDEs use the underlying API?

He wasn't using the regular paid api (ie per token pricing). He was using the endpoints for their subscribed customers (ie paid per month and heavily subsidized).

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#27
post #13

What was the point of Claude code or Gemini banning the OP? Why would they care about how IDEs use the underlying API?

Why does Google/Facebook et al arbitrarily enforce one human per account?

It’s because they want to study you.

They want the data!

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#28
post #17

Great article, recommend reading all of it. > Why bother, you ask? Opus may be a great model, but Claude Code to this day leaks raw JSONL from sub-agent outputs, wasting hundreds of thousands of tokens. I get to say, “fuck it, subagents output structured data now”. This is why I find the banning of using Claude subscriptions in other harnesses is so heinous. Their harness that they're forcing onto everyone has tons o…

I mean they want to make money right? CC is a cool tool, but obviously they want you to use the api eventually if you’re even remotely a power user, 200/month for all you can eat tokens (well, until some arbitrary limit of the day kicks in) just doesn’t make sense when compared to api prices. In other words, CC should be seen as a software subscription.

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#29
I agree with this article completely, nice to see it presented quantitatively.

>re "only" the harness changed

In our experience, AI's are like amnesiacs who can barely remember what they did three minutes ago (their last autonomous actions might still be in their context if you're lucky), with no chance at remembering what they did three days ago. As such, the "harness" determines their entire memory and is the single most important determinant of their outcome.

The best harness is a single self-contained, well-commented, obvious, and tiny code file followed by a plain explanation of what it does and what it's supposed to do, the change request, how you want it to do it (you have to say it with so much force and confidence that the AI is afraid of getting yelled at if they do anything else) and a large amount of text devoted to asking the AI not to break what is already working. Followed by a request to write a test that passes. Followed by asking for its judgment about whether it broke what was already working on or not. All in one tiny crisp prompt.

With such a harness, it's able to not break the code one time in twenty. If you use reverse psychology and ask it to do the opposite of what you want, it rises to fifty-fifty odds you'll get what you're trying to do.

Don't believe me? You can watch the livestream (see my previous comments).

Baby steps toward Utopia.

Re: Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed

#30
Shows how much room for improvement there is on the harness level.

Agents waste a lot of tokens on editing, sandboxes, passing info back and forth from tool calls and subagents.

Love the pragmatic mix of content based addressing + line numbers. Beautiful.

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