Turnstone

Knowledge workers juggle multiple tasks like scheduling, outreach, writing in their own voice, tracking signups and fixing small engineering bugs, and currently have to do this manually or by switching between separate AI tools tied to a single model. People who already pay for ChatGPT, Claude, Grok or Cursor can't easily turn those subscriptions into persistent assistants that remember context, learn their writing style, or hand off work to each other. Existing agent products often lock users into one model, require a new paid plan or credits, or need a server and technical setup. This leaves people re-explaining context to AI repeatedly and manually assembling information from scattered apps like Gmail, Slack, and Calendar.

Turnstone is a free Mac app that lets users create persistent AI Agents, starting with a Chief of Staff that can spin up additional Agents for specific jobs like outreach, launch writing, signup tracking or engineering fixes. Each Agent can run on a different model (OpenAI, Claude, Gemini, Grok, Cursor or OpenRouter, or a local Ollama model) using the subscription or API key the user already has, and users can switch models mid-conversation without losing the Agent's memory or task. Agents read connected apps on a schedule to stay current on what changed, draft messages in the user's learned writing style, keep schedules that recur and report back in chat, and use their own browser tab (the Turnstone Browser) to open sites and fill forms. Everything, including chats and memory, is stored locally on the user's Mac in an accessible folder, with an optional paid Turnstone Cloud add-on to keep Agents running when the Mac is off and accessible from a phone.