For the WebArena result, we actually used a mixture of models checking each other's work and evaluating in real time. We found the verifications to be really effective in producing accurate results. Feel free to take a look at our architectural blog post to learn more in detail: https://blog.withmeka.com/introducing-meka-an-open-source-fr...

Unfortunately, we didn't try it out with open source models, but you are welcome to pull the repo and try with any model that has good visual grounding! (I heard UI-TARS and the latest Qwen visual model are quite good)