Jumpstart Workbench VS Code Extension
Cosmos coding agents, right inside your editor. No tab-switching, no context loss.
The extension is self-contained: the Jumpstart Workbench runtime binary ships inside the
.vsix, so there is nothing to install, no PATH lookup and no download on first run.
What you get
- Chat beside your code — responsive layout that adapts to narrow and wide panels
- Cosmos organizations and agents — pick an organization, then one of its agents; no third-party provider keys
- Agent Manager — run the same prompt across multiple agents in parallel, compare results side by side
- Right-click actions — add context, explain selections, and improve code in-place
- Click-to-open — file paths in tool output open directly in your editor; edit-style results land in a focused diff view
- Session editor panel — keep chat sessions open alongside files
- Theme-aware — adapts to your VS Code light, dark, and high-contrast themes
Plus the branchable timeline, tool UIs, voice mode and Git workflows from the shared UI.
Commands
| Command |
Description |
Jumpstart Workbench: Focus Chat |
Focus the chat panel |
Jumpstart Workbench: New Session |
Start a new chat session |
Jumpstart Workbench: Open Sidebar |
Open the Jumpstart Workbench sidebar |
Jumpstart Workbench: Open Agent Manager |
Launch parallel multi-agent runs |
Jumpstart Workbench: Open Session in Editor |
Open current or new session in an editor tab |
Jumpstart Workbench: Settings |
Open extension settings |
Jumpstart Workbench: Restart API Connection |
Restart the runtime process |
Jumpstart Workbench: Show Runtime Status |
Debug info for development or bug reports |
Select code in the editor, right-click, and find the Jumpstart Workbench submenu:
| Action |
Description |
| Add to Context |
Attach selection to your next prompt |
| Explain |
Ask the agent to explain the selected code |
| Improve Code |
Ask the agent to improve the selection in-place |
Configuration
Setting ids keep the upstream openchamber. prefix so existing workspace settings
and upstream rebases keep working.
| Setting |
Default |
Description |
openchamber.apiUrl |
(empty) |
URL of an external Jumpstart Workbench runtime server. Leave empty to auto-start the bundled runtime. |
openchamber.opencodeBinary |
(empty) |
Absolute path to a runtime binary that replaces the bundled one. Requires window reload to apply. |
The bundled runtime can also be overridden for a single session with the
COSMOS_OPENCODE_ROOT environment variable, which the packaging scripts use.
Requirements
- VS Code 1.85+
- A Cosmos account; sign in from the extension the first time you open it
Authentication
Models are supplied by the Cosmos platform. The extension shows your Cosmos
organizations and their agents; there are no per-vendor API keys, provider
connections or subscription usage panels.
Development
bun install
bun run vscode:dev
bun run vscode:dev starts watchers and opens an Extension Development Host.
Webview UI changes use Vite HMR.
Packaging (Vite requires Node >= 22.12):
# host platform only
bun run --cwd packages/vscode package
# every supported platform target
bun run --cwd packages/vscode package:all
Both commands stage the matching runtime binary into
packages/vscode/resources/opencode-cli/ and write the .vsix files to
packages/vscode/dist-vsix/. bun run --cwd packages/vscode verify:opencode-cli
re-checks a staged runtime against its sha256 manifest.
Install locally: code --install-extension packages/vscode/dist-vsix/cosmos-workbench-*.vsix
License
MIT. This extension is a fork of OpenChamber;
see LICENSE for the upstream copyright notice.
