A thread runs on a harness
When a thread does work, it runs on a harness: the agent engine that reasons over the request, calls tools, and produces output. The harness is the loop that turns a request into results. The thread sits above it and keeps the durable record of everything the harness did. Sidekick supports more than one harness, so the engine can change without changing the thread. Whatever runs the work, the thread stays the ledger of what happened.A harness runs inside a placement
Every harness runs inside a placement: the environment where the work executes. There are two.Cloud
A managed remote sandbox. This is the default placement and it is always available. Nothing extra is required to use it.
On your computer
An approved desktop device. This placement requires the desktop app and admin enablement before it can be used.
The thread stays the record, wherever it runs
Placement changes where work executes. It does not change where the work lives. The thread remains the durable record across both placements: the conversation, tool runs, approvals, files, and artifacts stay in one place.Work is never silently moved between placements. If a thread is set to run on your computer and that device is disconnected, the thread surfaces a failure. It does not quietly fall back to the cloud. You stay in control of where the work runs.
Where to go next
Running on your computer
How to install the desktop app and run a thread on your own device.
Local-execution policy
How admins enable and govern on-your-computer execution.
Cloud vs on your computer
How to decide which placement fits a piece of work.