It doesn't seem to be. Their Chinese website talks about buying AI credits, their English website only has a waitlist but this looks more like a new closed commercial product than anything else.

Also, check the appendix in the paper, I think it's a bit concerning that the second author is responsible for the writebench benchmark they use to make their claims about the model. That is, the evaluation isn't independent from the authors.

I mean, I'm not saying they're not right, just that this is a yellow flag to investigate more.

Second flag is I don't see a journal this will/is published in. Arxiv is not peer reviewed.

A. Appendix A.1. Author Contributions Tiannan Wang is the core contributor of Weaver. Tiannan is responsible for continual pre-training, supervised fine-tuning, and preference optimization. Tiannan is also a main contributor for the data synthesis and the benchmark/evaluation process.

Jiamin Chen is a main contributor of Weaver. Jiamin is responsible for WriteBench and is also main contributor for data synthesis and model evaluation process