# Off-box alerting for Rocket Pool nodes: pages you when a client hangs or the whole box is gone (open-source agent, looking for feedback)

**URL:** <https://dao.rocketpool.net/t/off-box-alerting-for-rocket-pool-nodes-pages-you-when-a-client-hangs-or-the-whole-box-is-gone-open-source-agent-looking-for-feedback/4067>\
**Category:** Node Operator Experience\
**Created:** [6 October 2026 21:51 UTC](https://dao.rocketpool.net/t/off-box-alerting-for-rocket-pool-nodes-pages-you-when-a-client-hangs-or-the-whole-box-is-gone-open-source-agent-looking-for-feedback/4067 "2026-10-06T21:51:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![hieu10x](https://dao.rocketpool.net/letter_avatar_proxy/v4/letter/h/278dde/32.png) [@hieu10x](https://dao.rocketpool.net/u/hieu10x)\
**Post date:** [6 October 2026 21:51 UTC](https://dao.rocketpool.net/t/off-box-alerting-for-rocket-pool-nodes-pages-you-when-a-client-hangs-or-the-whole-box-is-gone-open-source-agent-looking-for-feedback/4067/1 "2026-10-06T21:51:46Z")

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_Disclosure: I’m the developer. NodeBeat is a hosted alerting service  
with a free tier; the agent that runs on your node is open source  
(Apache-2.0)._

**Why another monitoring tool, when Smartnode has alerts?**

Smartnode’s built-in alerting is good, and I’d keep it. Its default rules  
cover clients not synced, low disk, low ETH balance, proposals, sync  
committees and updates. Two gaps remain:

1. **It runs on the node.** Alertmanager lives in the same Smartnode  
stack, so if the machine freezes, loses power or drops off the  
network, nothing is left to page you. You find out from beaconcha.in,  
after the misses.
2. **There’s no rule for a client that’s down or hung.** “Not synced for  
5 minutes” catches a node that falls behind, but not reliably an EL  
that stops answering or a beacon node that stops following the head.  
That’s the failure that quietly costs attestations.

NodeBeat covers those two gaps and is meant to run _alongside_ Smartnode.

**How it works**

- A small Go agent polls your beacon node (Beacon API) and execution  
client (JSON-RPC) every second. **Read-only:** no keys, no signing  
endpoints, no restarts, and it never touches your node wallet. It  
listens on loopback only and makes outbound connections only.
- **A client that’s dead or hung pages you in seconds.** In  
fault-injection runs on a test devnet, fault to page took 5.6–8.6s  
(9 runs). A client that still answers but stops advancing pages in  
about a minute.
- **Alerting runs off-box** , so a frozen, unplugged or offline node still  
pages you, via Telegram, Discord, Slack, email, PagerDuty, Opsgenie or  
webhook.
- Given your validator indices, it also alerts on missed attestations and  
proposals, effectiveness and slashing, plus disk, peers, sync and clock  
drift.
- Trust: signed releases (cosign), SBOM, a public  
[threat model](https://github.com/nodebeat/agent/blob/main/docs/THREAT_MODEL.md)  
and [alert rules](https://github.com/nodebeat/agent/tree/main/deploy/rules),  
one-command uninstall.

**What I’d like from Rocket Pool operators**

1. **Would you run this next to your node, and if not, why?** Criticism  
of the trust model is the most useful feedback.
2. **Which alerts would be noise for you** , and what’s missing?
3. **Testers:** the free tier covers 1 node. For operators with several  
machines, I’m giving a few people 3 months of the paid plan free (up  
to 5 nodes, no card) in exchange for a short weekly feedback note.  
Reply here or email [support@nodebeat.stream](mailto:support@nodebeat.stream).

**Setup on a Smartnode host:** Smartnode keeps the client APIs closed to  
the host by default, so set **Expose RPC Ports** (Execution Client) and  
**Expose API Port** (Consensus Client) to **Open to Localhost** in  
`rocketpool service config` first. They bind to 127.0.0.1 only. The  
install guide covers the rest (Smartnode’s P2P port, optional metrics).

Tested on Smartnode v1.24.3 with Geth + Lighthouse, and outside it with  
Geth, Reth, Lighthouse and Teku. Nethermind, Besu, Nimbus, Prysm and  
Lodestar are auto-detected but untested on my side, so if you run one of  
those, I especially want to hear from you.

Code: [GitHub - nodebeat/agent · GitHub](https://github.com/nodebeat/agent)  
Smartnode setup: [NodeBeat — Validator Monitoring That Pages in Under 10 Seconds | Ethereum & Cosmos](https://www.nodebeat.stream/docs#rocket-pool-smartnode-docker-mode)