I hear that often but to me it does not feel like it. I built my own framework around pi.dev harness and run all kind of different LLMs with it. Sometimes also use the vendor harnesses and they don't feel better adapted.

I feel very strongly the first party harnesses don't make sense when essentially every month the Pareto frontier changes as new models get released

I want to use the same consistent working surface across models in the same way I want to use the same text editor across all different languages

One thing I found was tool calling in GLM 5.2 on github using Claude Code was mostly failing then fixing. But I didn't compare to z.ai's harness. (Nothing to do with Deepseek, sorry.)

I use OpenCode and I like knowing the direct token spend for doing tasks. A healthy repo can get a lot done with Luna + fresh context. Then I can spend $1-$2 a day when I'm doing development, and costwise honestly it beats a $200 / month plan.

I also just do a bit of hand-coding to guide the agent still.

I worry the $200 / month plans are loss-leaders encouraging you to maximize token usage to churn out slop, rather than thoughtfully use coding agents in a way that still engages your brain, and produces good software.

i've been using Cascade (a third party harness) since the 3 week period in 2023 when it was hot. I think it's called something else now. Devin? Things got confusing there for a second and I stopped paying attention.

Anyway very happy with it, I use it as a plugin to RubyMine and Webstorm.

One of the primary advantages is being able to choose your model - and it often has free deals for newer models that are running promotions. Whenever I switch to Claude Code it seems clunky. Would rather use Claude with Cascade.