Ampersand v0.1 is a collaborator model built by humans& on Z.ai's GLM 5.3 backbone. According to the creator's model card, the underlying network is a mixture-of-experts transformer with 78 layers, 256 routed experts plus one shared expert, and eight routed experts active per token, totaling roughly 744B parameters with about 40B active. Rather than being a general chat assistant, its intended use is narrow and social: the model is dropped into a group conversation and, after each incoming message, either posts a single message or passes, so in practice it stays silent for most turns. The launch framing from humans& positions it as the first model trained specifically for people to achieve more together.
Qualitatively, the model is optimized for restraint and contribution rather than raw throughput. On humans&'s own collaboration simulation it added the most value of the models tested, but that same evaluation reported it annoyed users more when it coached them, a tension the team is actively probing through a dedicated sycophancy evaluation awareness section in the model card. Its coding performance sits slightly below its own base model, which is consistent with a system tuned for interpersonal judgment rather than code generation. The official card documents specifications, intended uses, inputs and outputs, training, evaluations, safety and security, limitations, access terms and a citation, giving an unusually complete record for such a young release and a clear basis for judging how the model behaves in multi-party chats.