LangFuse Glance

A minimal, always-current VS Code sidebar view of your recent LangFuse traces. No backend, no other vendor, no floating window — one list of recent calls (model and cost inline), one summary strip, and click-to-expand details for each call, with an optional link to LangFuse's own UI for deep debugging.

See docs/adr/ for the architecture decision records.

Setup

npm install
npm run build

Press F5 in VS Code (or the Extension Development Host launch config) to run the extension. Use the command LangFuse Glance: Configure Connection to set your LangFuse base URL, public key, and secret key (stored in SecretStorage).

Security: what happens to your keys

• Your public and secret keys are stored in your OS keychain via VS Code's SecretStorage, never in settings.json or any file that could be committed.
• They are only sent to the LangFuse base URL you enter. There is no backend, relay, or third party; the extension talks directly to your own LangFuse host.
• The sidebar UI (webview) never receives the keys. All network calls happen in the extension host (src/data/langfuseClient.ts is the only file that makes requests).
• Tip: create a dedicated API key pair for this extension in LangFuse (Project Settings → API Keys). You can revoke it at any time without touching the keys your app uses.

Development

• npm run watch: rebuild on change
• npm test: unit tests (Vitest, no vscode dependency)
• npm run typecheck: strict TypeScript check
• npm run lint: ESLint