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G-Labs Setup

The Generation Runner and the PatchWork web app both need a G-Labs backend running. G-Labs is the local service that proxies generation API calls to NanoBanana 2 and Veo 3.1. This page walks through getting it running on your machine.

PatchWork Settings panel

PatchWork's Settings panel. Where the G-Labs Server URL gets pasted (after you start the cloudflared tunnel) and where auto-retry behavior is configured.

The architecture

flowchart LR
    A[PatchWork Web App<br/>patchwork-33m.pages.dev] --> B[cloudflared tunnel<br/>public HTTPS URL]
    C[workflow-runner.js<br/>headless] --> B
    B --> D[G-Labs<br/>http://localhost:8765]
    D --> E[NanoBanana 2 API]
    D --> F[Veo 3.1 API]

G-Labs sits between PatchWork and the actual model APIs. It runs locally on http://localhost:8765. For PatchWork (which lives on a public domain) to reach it, you expose your local port through a cloudflared tunnel — covered in detail on its own page.

Quick start

Two services need to be running before any generation work:

  1. G-Labs on http://localhost:8765 (see "Installing G-Labs" below)
  2. A cloudflared tunnel pointing at G-Labs (see Cloudflared Tunnel Setup)

The Manager auto-starts the tunnel for you when you trigger a generation pass. You still need G-Labs running yourself.

Installing G-Labs

(One-time setup. Skip if G-Labs is already installed.)

G-Labs is internal tooling — installation instructions are kept in the internal docs separate from this wiki. Once installed, you start it the same way every session:

  1. Open a terminal in the G-Labs directory.
  2. Run the start command (typically npm start or similar — see the G-Labs README).
  3. Confirm it's serving on http://localhost:8765 by hitting http://localhost:8765/health in a browser. You should see a 200 OK response.

Connecting PatchWork to G-Labs

PatchWork can't talk to http://localhost:8765 directly. You point it at the tunnel URL instead:

  1. Open PatchWork → Settings (left sidebar → SYSTEM → Settings).
  2. In the API section, paste your tunnel URL into G-Labs Server URL.
  3. Save.

The URL gets cached in your browser's local storage. With a quick tunnel you'll update this every session (since the URL changes); with a named tunnel you set it once and forget it. See Cloudflared Tunnel Setup for the two approaches.

Connecting the headless Generation Runner

The Generation Runner takes the tunnel URL as a CLI flag:

node workflow-runner.js workflow.nbflow \
  --server "https://your-tunnel-url" \
  --api-key "..." \
  --concurrency 3

The Manager invokes the runner with the current tunnel URL automatically — you don't pass this by hand in normal operation.

Common issues

"Connection refused" from the runner or PatchWork
G-Labs isn't running on localhost:8765, or it crashed. Hit http://localhost:8765/health in a browser — if that fails, restart G-Labs.
"522 Connection timed out" or "1033 error" from cloudflared
The tunnel is up but G-Labs isn't responding on the target port. Same diagnosis as above — check G-Labs is running.
"API key invalid" from generations
The --api-key value the runner has doesn't match what G-Labs expects. Double-check the key is current. (API key is separate from the tunnel URL — the tunnel URL changes per session for quick tunnels; the API key stays the same until rotated.)
PatchWork shows "no backend configured"
You haven't set the G-Labs server URL in PatchWork's settings, or you set the wrong URL. Open settings, paste the current tunnel URL, save.

For tunnel-specific failures (tunnel won't start, named tunnel returns 502, DNS not resolving), see Common issues on the Cloudflared Tunnel Setup page.

Session checklist

Every session before running a workflow:

  1. Start G-Labs (port 8765). Confirm health endpoint returns 200.
  2. Start a tunnel (quick or named). Copy or confirm the URL.
  3. If using the headless runner: pass the URL as --server.
  4. If using PatchWork web app: paste the URL into settings (only if it changed since last session).
  5. Run the workflow.

When you're ready

→ Next: Cloudflared Tunnel Setup — the dedicated page for setting up the tunnel itself, covering both the quick-tunnel and named-tunnel paths.