Tether Releases QVAC BotPsy, an 800M-Parameter Open-Source On-Device AI Agent Model

November 11: According to an official Tether announcement, its AI research division has launched QVAC BotPsy, an open-weight model with 800 million parameters. Built on Alibaba's open-source Qwen3.5 architecture, it can run locally on personal devices such as phones, converting user requests into tool calls to help users handle everyday tasks such as schedules and messages. Tether says that in the six agentic benchmarks it tested, BotPsy outperformed all tested models with no more than 1.2 billion parameters; in four core tests—BFCL v4, ACEBench, τ-bench and ToolSandbox—it beat Qwen3.5-2B-Think, which has roughly 2.5 times its parameter count, with tool-calling scores about twice those of its base model. The model weights are now available on Hugging Face.