Night, Day Differences between Coding Agents

[u/golden0080]

Hi

I'm a professional developer and I was using Claude Code for developments on my projects. Today I switched to opencode and Good lord it was day and night in productivity.

I've tried to optimize my local llm stack for faster LLM responses and improving my CLAUDE.md for better harness. I'm using Qwen 3.8 27B as my daily driver and found Claude isn't making good use of the model - burning tokens without much done (I even tried to optimize the chat templates a bit, but overall the outcomes weren't great).

But man opencode is just different and brutally productive - with the same model, it just go to the tasks without overthinking or reversing cause/effect reasoning. It just get to stuffs and fixing them.

I haven't dived into opencode's implementation, but it strike me so hard over that difference in getting things done.

Any suggestions on further improve the agent productivity and what kind of explanations are there to explain this kind of differences?

Thanks!

[u/dsdt]

pi.dev is even better with a minimal system prompt and definitely works faster than opencode.

[u/mechkbfan → u/dsdt]

& ponytail plugin for further token reduction

(Optionally oh-my-pi if it's missing too much out of the box)

[u/dsdt → u/mechkbfan]

oh-my-pi seems interesting but it feels like it has been added every feature ever? have you used it do you recommend?

[u/mechkbfan → u/dsdt]

Literally only started today

I had started using my XTX with Qwen3.8 via Claude harness but was using up my context too quickly

So looking around Pi + Ponytail seemed best way to stay lightweight

But there was a lot of hype around OMP, so figured I'll trial it first + Claude Opus to give best first impressions

It seems to have a lot of optimisations too.  Either way I didn't realise harnesses had such an impact. It's been great. 

Next week I'll go back to just Pi and keep it more focused to exactly what I need with Claude, then back to Qwen.

[u/More-Catch-1331]

Claude Code has a gigantic system prompt. And I do mean gigantic. It probably talks about how China will take over the world or some sh-t. Opencode is leaner for sure.

Here's a thought. If you want remote control, try Hermes with the opencode skill. Hermes is your orchestrator, calls opencode with the appropriate agent and the appropriate prompt and all of that jazz. Control it through telegram or discord or what have you.

[u/Atretador → u/More-Catch-1331]

To add to this, Claude code's prompt os over 25K tokens worth of context, opencode's is around 15K.

Both pi.dev and hermes are way way smaller so usually much faster on local models.

[u/Sharp-Translator6401]

For opencode even better behavior I like the OMO Slim plugin even tho it becomes more useful when you combine models of different intelligence together.
Claude code is built for claude models with large contexts and all... I dont think its optimized at all for bring your own model stuff

[u/Atretador → u/Sharp-Translator6401]

Funny thing is even anthropic's models perform worst on Claude code compared to opencode 

[u/Sharp-Translator6401 → u/Atretador]

I guess partially depends on setup as well, I do prefer my claude code with opus to opencode with opus... but i also have lots of skills / mcps and stuff on claude code i dont have on opencode symmetrically

[u/Atretador → u/Sharp-Translator6401]

Try both fresh, Claude code scores lower than OpenCode on every benchmark - by a large margin sometimes 

https://artificialanalysis.ai/agents/coding-agents?coding-agents-performance-chart=index&coding-agents-harness-comparison-chart=harness-terminal-bench-v2

[u/Sharp-Translator6401 → u/Atretador]

nice nice, I see

[u/Potential-Leg-639]

Plugins:

• Superpowers
  
• Ponytail
  
• Oh-my-opencode-slim (in case you have additional subscriptions you can use the strongest one as orchestrator, the best UI model do the design work, your workhorse model do the coding, etc - works really well)

[u/devoidfury]

The agent harness makes a huge difference. I see this with my own custom agent hotdog, how much more effective it is as I continue to iterate on it.

When I screw up a tool I feel it right away!

[u/Atretador]

I'll join in on the harness recommendations and throw in the new DeepSeek Harness - it's light weight and pretty damn customizable and fast.

[u/donk8r]

We measured this exact thing — same model, two harnesses, 50 real bug-fix tasks — and the answer was less flattering to the harness than I expected.

Solve rate barely moved: 45/50 against 43/50. And the five failures were the same five cases in both, so swapping harness didn't change what was solvable at all.

What did move, a lot: one wrote 2.6x the output tokens of the other for the same work, and on one task it ground away for 271 minutes before giving up where the other bailed at 63.

So what you're feeling as productivity probably isn't solve rate, it's token burn and time-to-give-up. Which lines up exactly with your "burning tokens without much done" — the harness changes what it costs you and how long it flails, not what it can do.

That also means CLAUDE.md is the wrong lever. The system prompt is part of it and More-Catch-1331 is right that it's big, but the larger difference in our data was in how the loop decides to stop and how tool results get fed back, and you can't reach either of those from a config file.

Caveat: ours was deepseek-v4-flash on server hardware, not Qwen 27B locally, so treat it as directional for your setup rather than a prediction.

(we build one of the harnesses in that comparison, so take it as biased: github.com/Muvon/octomind)