Prometheus Alerting Rule Generator
Generate a valid Prometheus alerting_rules.yaml from a PromQL expression, severity, for: duration and annotation templates — with correct YAML structure and quoting every time.
Input
How often Prometheus evaluates this group, e.g. 30s, 1m. Leave blank to use the global default.
Alert rule
How long the condition must hold before firing — a number + unit (ms, s, m, h, d, w, y). Leave blank to fire immediately.
One more rule per line, pipe-delimited: AlertName | expr | for | severity | summary | description — only the name and expression are required; the rest fall back to the primary rule's severity or are omitted.
Output
Guides
What it does
The Prometheus Alerting Rule Generator turns a PromQL expression, a for: duration, a severity level and a pair of annotation templates into a ready-to-use alerting_rules.yaml file — the exact groups: → rules: → expr/for/labels/annotations shape promtool check rules expects.
Prometheus alert-rule YAML is strict about indentation, and PromQL expressions routinely contain characters — {, }, :, quotes — that break a hand-typed YAML scalar if they aren't quoted correctly. This tool builds the rule as structured data and lets a real YAML serializer handle the quoting, so the output is always valid regardless of what punctuation your expression or annotation text contains.
How to use it
- Set a rule group name (and an optional evaluation interval, e.g.
1m). - Fill in the alert: name, PromQL expression, for: duration (how long the condition must hold before firing), severity, and the
summary/descriptionannotation templates — both support Go template variables like{{ $labels.instance }}. - Copy or download the generated
alerting_rules.yaml.
Adding more rules to the same group
Real rule files almost always group several alerts together. Add one more per line under Additional rules, pipe-delimited:
AlertName | PromQL expression | for | severity | summary | description
Only the name and expression are required — a line that omits for/severity/summary/description falls back to the primary rule's severity (or omits that field entirely). Lines starting with # are treated as comments and skipped.
What's a valid for: duration?
A number followed by a unit: ms, s, m, h, d, w, or y — e.g. 30s, 5m, 2h. Leave it blank to fire the alert immediately once the expression is true, with no waiting period.
Does this validate my PromQL expression?
No — it emits your expression into a correctly-quoted YAML scalar, but doesn't parse or check the query itself. To format or sanity-check a PromQL expression before pasting it in, use the PromQL Formatter.
What if I need to generate a ConfigMap to mount this file into a pod?
Use the Kubernetes ConfigMap / Secret Generator to wrap the generated YAML into a mountable ConfigMap.
Privacy
Everything runs in your browser — the group name, PromQL expressions and annotation text you enter are never sent anywhere.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/prometheus-alerting-rule-generator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"groupName": "example-alerts",
"interval": "1m",
"alertName": "HighCpuUsage",
"expr": "avg(rate(node_cpu_seconds_total{mode=\"idle\"}[5m]…",
"forDuration": "5m",
"severity": "critical",
"summary": "{{ $labels.instance }}: high CPU usage",
"description": "CPU idle time has been below 10% for more than 5…",
"additionalRules": ""
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `prometheus-alerting-rule-generator` tool (Prometheus Alerting Rule Generator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.