---
key: review-and-replay-signals
title: Review and replay signals
audience: staff
section: critical-alerts
routes: ["/critical-alerts/signals"]
permissions: ["critical_alerts.view"]
features: ["critical_alerts.core"]
since: 0.0.1
updated: 0.0.1
status: published
summary: See every signal that reached a source, check whether a rule matched it, and run it through the rules again after you fix a rule.
keywords: [did the alarm arrive, signal log, no incident, unmatched, replay, test again, incoming events, event history]
related: [critical-alerts-04-sources-and-incoming-webhooks, create-a-critical-alert-rule, acknowledge-and-resolve-an-incident]
---

In the sidebar, open **Critical Alerts**, then **Signals**. The page address is `/critical-alerts/signals`.

A signal is one message that reached a source. This list is the first place to look when a device fired but nobody was called: it shows whether the signal arrived at all, and whether any rule matched it.

## Before you start

- Your admin has to give your role permission to view critical alerts. Replaying a signal needs the separate replay permission.

## Steps

1. Use the **Filters** button to narrow by **Signal type** (**Open**, **Clear**, **Heartbeat** or synthetic test signals) and **Status** (accepted, unmatched, ignored, resolved, grouped, suppressed or dead lettered).
2. Type in the search box to match a title, summary or source.
3. Press **Open** on a row to see **Signal detail**: everything Nova recorded for that signal, including the details the outside system sent.
4. Fix the rule that should have matched and publish it, then come back and press **Replay** on the signal. Nova runs it through the rules again as if it had just arrived.

## What you see

- Each row shows the signal's title, where it came from, its summary, when it occurred, when Nova processed it, and two badges: its status and its type.
- **Replay** confirms with "Signal replayed." A match opens an incident exactly as a live signal would.
- The list is paged; the count at the bottom is the true total, not only the rows on screen.

## If something looks different

- The signal is not in the list at all: it never reached Nova. Check the address in the outside system; see [[critical-alerts-04-sources-and-incoming-webhooks]].
- Status is unmatched: no published rule matched it. Compare the signal's event name and type with the rule's match fields.
- Status is suppressed: a suppression window covered it. See [[end-or-archive-a-suppression-window]].
- **Signal detail** looks like raw code: that is how it shows today, every recorded field, unformatted. Scroll for `event_name`, `severity` and `title`.

[[route:/critical-alerts/signals|Open Signals]]