Portable Computer is a local-first AI agent platform that runs the agent harness, orchestrator, and post-trained models directly on NVIDIA DGX Spark hardware. It supports persistent state across sessions and connects to tools like Gmail, Slack, and GitHub through the local orchestrator. When a task requires frontier reasoning or web access, the orchestrator prompts the user before routing that step to one of 15 or more cloud models. Code and tool execution run in isolated sandboxes with controlled access to local files and connected apps.