JS Workbench VS Code Extension

Cosmos coding agents, right inside your editor. No tab-switching, no context loss.

The extension is self-contained: the JS 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 projects and agents — sign in, select an organization and project, then use that project's deployed 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.

Workbench opens in the Secondary Side Bar (on the right in VS Code's default layout), alongside Chat and Codex, leaving Explorer on the left. VS Code remembers custom view placements; if an existing installation stays on the left, use its view container's Move To > Secondary Side Bar menu once. Editor session tabs remain available separately.

Commands

Right-click menu

Select code in the editor, right-click, and find the JS Workbench submenu:

Configuration

Setting ids use the cosmos. prefix. Upstream's openchamber. prefix was given up because VS Code settings ids are global: with the OpenChamber extension also installed, both extensions read and write the same keys, so pointing one at a runtime binary silently repointed the other. Values saved under the old openchamber.* ids are not migrated.

The bundled runtime can also be overridden for a single session with the COSMOS_OPENCODE_ROOT environment variable, which the packaging scripts use.

On activation, the extension creates ~/.config/cosmos-code/cosmos-code.jsonc if missing (or uses XDG_CONFIG_HOME). When the recorded provider.cosmos.options.workbenchConfigVersion is missing or differs from the installed extension version, the five Cosmos service URLs are updated to bundled defaults and the new version is recorded. Other settings are preserved. With a matching version, custom URL edits remain untouched. Migration results appear in Output > JS Workbench. Project overrides and external server configs are not changed by this migration.

Requirements

• VS Code 1.106+
• A Cosmos account; sign in from the extension the first time you open it

Authentication

Cosmos sign-in is required. After browser login, run JS Workbench: Change Project from the Command Palette. Both organization and project require confirmation, even when only one choice is available. The command works before opening the sidebar and does not require adding a folder to Workbench's project list.

The selection belongs to the VS Code workspace, including every folder, worktree, sidebar, session editor, and Agent Manager in that window. Agents are not loaded until the selected project is validated. Settings remains accessible while chat is gated; Settings, the header, and the composer do not own competing organization/project pickers. Other VS Code windows keep their own selections.

Workspace selection is stored in VS Code workspace state and revalidated for the same signed-in account after reconnecting. It does not write Cosmos organization or project selection into global provider settings or repository configuration. Legacy folder bindings are not execution authority. When all workspace roots have the same unambiguous legacy binding, the native picker highlights it as a migration candidate; confirm the organization and project when upgrading.

Finish or explicitly stop active work before changing context. Manually choosing a different project or Cosmos agent starts a separate local conversation; ADK creates its remote session on the first send. Switching the local Build/Plan mode does not change the Cosmos agent.

Opening existing Workbench history instead restores its original organization, project, agent, and version and resumes the same local and ADK session IDs. Unavailable or ambiguous historical context is read-only with an explicit error; Workbench does not substitute today's project or silently replace a missing ADK session. This does not import other conversations from ADK.

Sync agents refreshes the selected project across open panels. Authentication, access, network, and empty-project states remain distinct. External runtime servers must support the Cosmos workspace-context and strict-resume protocol; incompatible servers are rejected rather than falling back to unscoped discovery.

bun install
bun run vscode:dev

# host platform only
bun run --cwd packages/vscode package

# every supported platform target
bun run --cwd packages/vscode package:all

License

MIT. This extension is a fork of OpenChamber; see LICENSE for the upstream copyright notice.