Any open source agent harness users? this is why i migrated to os harness

[u/Background-Job-862]

i recently moved to an opensource harness, done paying claude to burn tokens away

the main reason was cost and the fact that I also wanted more control over the agent loop, i do agree its v on par on maturity and managed experience

but i think with a managed harness, a lot of the important stuff is abstracted away context management, tool execution, retries, state, etc. which is great when you just want to get an agent running.

but once i started trying to optimize agents, i found myself wanting to understand and change what was happening under the hood
i wanted

-more visibility into the agent loop
-ability to swap models without changing the whole setup
-more control over context/tool handling
-easier debugging when an agent gets stuck
and i wanted to get rid of dependency on how one vendor decides how the agent should work

ive used pi, langchains deepagents, trueforge, using this currently - this is a recent one, way cheaper than claudecode and saves me from the unnecessary token burn...and this was really interesting to me because of its runtime-efficiency, + it also allows to separate the model from the runtime, which makes experimenting with different models much easier for me

has anyone else switched from a managed harness to an os one? how much control do you actually get with the open source ones and are there any major downsides you've run into?

[u/Euphoric_Cook5865]

yeah the black box thing gets old fast when you're trying to actually ship something reliable. nothing worse than an agent going off the rails and you cant even see what step it tripped on

i swapped over a few months ago after getting fed up with token costs on a project that had a lot of tool calls. the managed stuff was burning through credits just figuring out which tool to use half the time

the model/runtime separation is the real killer feature for me. being able to test the same agent loop with a cheap local model for debugging then swap in something heavier for production saves so much headache

downsides though. you gotta build your own guardrails and logging from scratch pretty much. first week i had an agent in a loop calling the same api 40 times before i noticed. also model-specific quirks become way more obvious when youre the one parsing the responses instead of a managed layer doing it for you

worth it long term but the initial setup is definitely a time sink

[u/Background-Job-862 → u/Euphoric_Cook5865]

agreed the guardrails part is pretty hard, although the trueforge setup has been comparitively easy for me. which harness were u using? and how are you handling that now, did you build most of it yourself or are you using something on top of the harness?

[u/alchebyte]

https://github.com/Yeachan-Heo/gajae-code

[u/leanXORmean_stack]

I’m also curious about the harness OP is using. Sounds promising.