node:diagnostics_channel

Node.js diagnostics_channel module, resolvable via both ESM import and CommonJS require. Implemented as a guest-JavaScript shim providing named publish/subscribe channels and tracing channels.

javascript

import diagnostics_channel from "node:diagnostics_channel";

const ch = diagnostics_channel.channel("my.app.request");
ch.subscribe((message, name) => console.log(name, message));
if (ch.hasSubscribers) ch.publish({ path: "/" });

Implemented surface

Export	Description
`channel(name)`	Get (or create) the named `Channel`.
`hasSubscribers(name)`	Whether the named channel has subscribers.
`subscribe(name, onMessage)`	Subscribe to a channel by name.
`unsubscribe(name, onMessage)`	Remove a subscription.
`tracingChannel(nameOrChannels)`	Create a `TracingChannel` with `traceSync`, `tracePromise`, and `traceCallback`.
`Channel`	The channel class (`subscribe`, `unsubscribe`, `publish`, `hasSubscribers`).

The default/namespace import also exposes a boundedChannel helper (it is not a named ESM export). TracingChannel supports store binding via bindStore / runStores.

Behaviour notes

The channel registry holds strong references to channels.
Store-flow through bindStore is best-effort.

node:diagnostics_channel

Implemented surface

Behaviour notes

See also