Configuration

A merged configuration tree answers what is this setting now. The question that actually brings you here is why is it not what I wrote — and that needs the layer as well as the value.

Column	Meaning
key	Full dotted path, e.g. actor-ts.cluster.seed-nodes
value	The effective value, after the merge
from	Which layer won: reference.conf, application.conf, or code

Hover a row for the whole story: the layer, whether it displaced a lower one, and whether the value was truncated for the wire.

Changed from defaults only hides everything still at its bundled value, which is usually all but a handful of keys. If that leaves the table empty, the panel says so — nothing overriding the defaults is a worthwhile answer in itself, and a different one from “no key matches that filter”.

The three layers

Precedence, highest first:

1. code — what you passed as ActorSystemOptions.config.
2. application.conf — resolved from configFile, then ACTOR_TS_CONFIG, then ./application.conf.
3. reference.conf — bundled with the package.

The panel names where application.conf was read from, or says none was found. That distinction matters more than it looks: my file is being ignored and my file says something else are different problems, and the path is what separates them.

Code options are not HOCON

Per-consumer options — MqttOptions.create().withQos(1), and every other XOptions builder — override HOCON at the call site and never pass through the configuration tree. So a key shown here may still be overridden by an explicit option in your code, and this panel cannot see that. What it shows is the HOCON resolution, exactly.

Secrets

A value whose key names a secret — anything matching pass, secret, token, key, credential or auth — is replaced with <redacted> before it leaves the process. By key rather than by value, because a password that happens to look ordinary is still a password and the key is what names it.

That is a blunt instrument on purpose. A configuration tree still says a great deal about a deployment even redacted — hosts, ports, seed nodes, storage paths — so switch the panel off where that matters:

const devtoolsOptions = DevToolsOptions.create()
  .withPanels({ config: false });