Reference · Looking things up while working
Liveness probes
The five probe kinds, what is sent and what counts as an answer.
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A probe is the minimal harmless call that proves an interface is alive. The manifest names it per interface under interfaces[].probe with kind and expect; optionally target names a probe URL that differs from the endpoint.
kind | What is sent | expect |
|---|---|---|
sparql-ask | an ASK query against the endpoint | boolean |
http-get | a plain GET | ok (2xx) or response |
http-head | a HEAD | ok or response |
mcp-initialize | the initialize handshake, servers of the handshake era | response |
mcp-discover | server/discover as the first message, servers of the stateless era (revision 2026-07-28) | ok or response |
expect = response means: any HTTP answer proves liveness, even a 400 to a bare GET. Two MCP probes because MCP has two eras; the wrong probe yields an answer that proves nothing.
States of a check
Three, never more: never checked, passed, failed, each with instant, probe and the address actually probed. A measurement against a local instance says so. Nothing is shown as passed that was not measured.