Gully Sentry · Operators

Run a sentry

The watcher reads Gully Chain assertions on Arbitrum Sepolia, compares them with Gully Chain itself, and signs a heartbeat for each key every 10 minutes. About 100 MB of memory, no funds needed.

Operator key
Delegate
Start
Check

Download the watcher: one JavaScript file for Windows, macOS and Linux (Node.js 20 or newer, or Docker). Check its SHA-256 before you run it.

Download gully-sentry.mjs SHA-256

SHA-256: see gully-sentry.mjs.sha256

# macOS / Linux
curl -fsSLO https://sentry.gullychain.xyz/downloads/gully-sentry.mjs
curl -fsSL https://sentry.gullychain.xyz/downloads/gully-sentry.mjs.sha256 | sha256sum -c -
# Windows PowerShell: compare with the SHA-256 above
(Get-FileHash .\gully-sentry.mjs -Algorithm SHA256).Hash.ToLower()

Then create the watcher's own hot key. It only signs heartbeats; your Sentry Key never leaves your wallet.

# in the folder that holds gully-sentry.mjs
docker run --rm -v gully-sentry:/data -v "$PWD/gully-sentry.mjs:/app/gully-sentry.mjs:ro" \
  -e SENTRY_KEY_FILE=/data/operator.key node:22-alpine node /app/gully-sentry.mjs init

node gully-sentry.mjs init

Copy the operator address it prints. The watcher is built from the Gully Sentry source by Gully Labs and served only from this site; there is no public image to pull.

Start the watcher with your key number. Your own Gully RPC URL gives the best results; the public endpoint works too.

What the watcher checks

Every assertion that the Gully Chain validator posts to the rollup contract on Arbitrum Sepolia names an L3 block hash and a send root.
The watcher asks your Gully Chain RPC for that block. A missing block or a different send root is a mismatch: it alerts (webhook or Telegram) and reports it.
No new assertion for 2 hours is reported as stale. Heartbeats carry the block you saw, so the collector can tell a real watcher from a copy.