Cowork and Artifacts
A Cowork thread is a conversation surface where an agent works alongside you and hands back renderable artifacts, without provisioning a repository, branch, or diff.
A Cowork thread is a place to talk to an agent and get back things it can show you, rather than a checkout it commits to. Start from a question or an idea; whatever the agent produces appears beside the conversation as an artifact.
There is no repo to choose. With workspace delegation on, a thread can create coding workspaces and send agents into them. Use a workspace directly when the output should be code someone reviews and merges.
A Cowork thread starts the agent at its most permissive mode (Bypass for Claude, full-access for Codex), so it acts without per-command approval. There is no diff to check first, only the transcript and artifacts after.
Artifacts
An artifact is renderable content, shown in its real form in the artifact panel rather than as code in the transcript. Four kinds render:
- Markdown for formatted prose with links, lists, and inline code.
- HTML documents, rendered in their own nested frame.
- SVG vector graphics, sanitized before they render.
- React components, compiled at runtime and run in a sandboxed frame with a curated set of libraries.
Each artifact is one file, tracked by a manifest the agent's tools manage. PDFs, images, JSON, and other binaries do not render.
The panel
The panel lists every artifact in the thread. They belong to the thread, not to a turn, so an earlier one stays open-able after later ones arrive. That is what makes "show me three approaches" work.
The viewer
React and HTML artifacts run in a sandboxed iframe served by the runtime. If the preview runtime is unreachable the list still works, it just cannot render.
React artifacts run against React 19 with a fixed import list: Lucide, Recharts, D3, date-fns, lodash. Anything outside it fails with an error in the viewer rather than quietly reaching the internet.
Artifact code cannot make network requests: fetch, XHR, and WebSocket are blocked. The runtime loads libraries from a pinned allowlist, and an artifact cannot add to it. The one thing it can do outside its frame is ask to open a link, which you see and control.
The sandbox is an isolation boundary, not a full security boundary. Read the source before trusting an artifact that behaves oddly.
When to use which
| Cowork thread | Workspace | |
|---|---|---|
| You start from | a question, an idea, a plan | a repository |
| The output is | a conversation and artifacts | a branch, diff, and pull request |
| Best for | demos, diagrams, drafts, one-off answers | code changes you'll review and merge |
Starting one
Start one from the home composer. Threads sit in the sidebar next to your workspaces, and the toggle-cowork-threads shortcut opens the list.