availabilityuniversalweight 1adapter 1 of 17Availability.
The Availability adapter answers the most basic trust question: is this subject actually online and responding right now, and has it been online consistently? It probes the subject over a trailing window and normalizes uptime into the component every other score leans on.
What it measures.
Uptime ratio
Successful reachability probes over the trailing 30-day window.
Recency
How recently the subject was last seen responding.
Consistency
Uptime stability across the window, not just the raw average.
Component keys.
availability.uptimeNormalized 0–100 uptime component from the probe window.
When it counts.
Universal — applies to any subject with a reachable endpoint, regardless of registry or protocol.
When signals are missing.
If the subject cannot be probed at all, the component carries a timeout or missing status and the composite is computed without it.
How it contributes.
{
"component": "availability.*",
"scale": "0-100",
"mode": "universal",
"weight": 1,
"contribution": "component x 1 / total weight"
}The adapter’s components are averaged into the composite as a weighted mean: every contributing adapter’s component is multiplied by its weight, summed, and divided by the total weight of contributing adapters. The result is published as trustScores.total with a config version and timestamp so anyone can recompute it.
Questions about Availability.
What does the Availability adapter measure in HCS-25?
It probes the subject for reachability over a trailing 30-day window and normalizes the uptime ratio, recency, and consistency into the availability.uptime component on a 0–100 scale.
How much does Availability contribute to the HCS-25 composite score?
Availability is a universal adapter with a default weight of 1, so its component counts with standard weight for every subject that has a reachable endpoint.