Testing through an agent needs agent version 1.7.0 or later. Older
agents keep working; only the test is unavailable through them.
Run a test
In the metric form, under the source settings, select Test check, then Run test. The test uses the agent chosen under Schedule. Test check is available for these sources: Prometheus, HTTP, TCP, DNS, ICMP, TLS certificate, gRPC, WebSocket, database, CloudWatch, Loki and Elasticsearch. It is not available for custom probes, OTLP, manual metrics or heartbeats. For an HTTP check with a JSON path, Test extraction runs the request once and shows the number the path extracts. It is enabled once the URL and the JSON path are set.What comes back
A test returns four things:
A test through an agent never returns query rows, response bodies,
headers, log lines or error messages. Error messages from drivers can
contain connection strings or tokens, so the agent sends only a reason
code. Secret references (
*_ref fields) are resolved on the agent host
and never leave it.
States
A test cannot go through the agent when:
- no agent is selected for the metric;
- the agent is offline: no heartbeat in the last 90 seconds;
- the agent has not connected yet;
- the agent’s key is revoked;
- the agent is outdated: it runs a version older than 1.7.0. Update the agent to test through it, or save the metric and watch its first sample.
Fallback for public HTTP URLs
When the agent cannot run the test, an HTTP check whose URL is public is tested once from Observer instead. The result says it ran from Observer’s servers, and it can differ from what your agent sees.- Only public addresses are reached. Private, internal and loopback addresses are refused, and every redirect is checked again. A private URL can only be tested through an online agent.
- Secret headers (
header_refs) are resolved by the agent from its environment variables, so they are not sent. The result names the headers that were left out. - Other source types have no fallback: they are tested only through the agent.
Limits
- Up to 30 tests per minute per organization through agents, and up to 20 waiting tests per agent.
- Up to 20 tests per minute per organization from Observer.

