CASC Score (Quality Score)
The CASC score (displayed in the UI as Quality Score) is a single number between 0 and 9.99 that summarizes how consistently a monitor or project has passed and how fast and steady its responses have been.
What the number means
| Range | Meaning |
|---|---|
| 8.00–9.99 | Healthy |
| 5.00–7.99 | Degraded: some failures, outliers, or latency spikes |
| 0–4.99 | Critical: significant failure rate or very slow responses |
Each project starts with a Quality score SLO of greater than 7.99 over a month. You can change it in Conformance Settings; see SLA Model for how SLOs are checked.
What feeds into the score
The score is calculated and aggregated across all locations. Four signals feed each location's score:
- Pass rate: the share of results that passed
- Outlier rate: the share of results flagged as outliers
- Mean latency: the average response time of passing results
- Latency spread: how much that response time varies from run to run (its standard deviation)
The exact weighting of these signals is proprietary and includes additional elements.
Conformance is not an input. Schema and security conformance results do not change the score. They are reported separately (see Conformance Explained), so turning on Skip Conformance Checks does not change a monitor's score. Your SLO targets are not inputs either: the score is calculated from results, and a Quality score SLO compares it to a target afterward.
Quality Score vs CASC Score
The CASC Score (Cloud API Service Consistency) is the technical name; the Quality Score is the name shown in the UI. They refer to the same value. Older documentation and API responses may use casc_score in JSON fields. For the full methodology and how CASC enables API quality benchmarking, see What is CASC? on the platform site.
Where to find it
- Project overview: aggregate score across all monitors in the project
- Individual monitor: score for that monitor's recent run history
- Quality Analytics: detailed breakdown of score drivers
See also
- SLA Model: how SLOs, including the Quality score SLO, are checked
- Conformance Explained: conformance results, reported separately from the score
- Quality Analytics guide: working with the score in practice