Editorial take
Why it stands out
Finance sees zero Prometheus line item until remote storage or hosted Grafana shows up—model both.
Tool profile
Open source metrics and alerting system built for time series collection, queries, and rule based alerts.
Kubernetes SLO and workload metrics
Prometheus is a CNCF graduated metrics and alerting toolkit: scrape targets, PromQL, local TSDB, and Alertmanager routing.
prometheus.io distributes code under Apache License 2.0 at $0. Production cost is VMs or Kubernetes for Prometheus (and Alertmanager) replicas, network for scrapes, disk for retention, and optional remote write to Cortex, Mimir, Thanos, or vendor backends. Grafana visualization may be self-hosted or Grafana Cloud—that is a separate bill.
There is no per-metric vendor fee from Prometheus itself—cardinality and HA design choices drive your cloud invoice.
Quick fit
Editorial take
Finance sees zero Prometheus line item until remote storage or hosted Grafana shows up—model both.
What it does well
Primary use cases
Fit notes
Pricing snapshot
Prometheus is Apache 2.0-licensed open-source software with no license fee. The software cost is $0, and actual spend comes from compute, storage, networking, remote-write backends, and any hosted services you pair with it.

Arcjet
Free planApplication runtime security
Runtime security toolkit for modern applications and AI systems that helps teams enforce quotas, block bots, prevent prompt abuse, and ship app-level protections in code.
Closer to application-runtime security and abuse-prevention tooling than to classic perimeter appliances.