On your computer
Local tasks use the selected harness’s native MCP configuration. Configure servers through that harness, just as you would outside Twill. The available servers, login state, and command support depend on your local setup. Twill adds run-scoped tools for cloud handoff and environment setup to project chats. These don’t replace your saved harness configuration. Connecting an integration to a cloud workspace doesn’t automatically make it available locally.In a cloud workspace
Cloud agents receive tools configured for their workspace:
Use Settings → Integrations for supported services and Settings → Environment for the variables your project needs.
Custom MCP configuration is harness-specific. A configuration file for one agent isn’t a portable configuration for all three; check the chosen harness’s supported setup before depending on a custom server in a cloud task. Native configuration and credentials on your laptop don’t travel with a handoff.