Collector

Optional. The two histograms now come from your app directly, so you do not need a collector to get metrics at all. This is for one narrower job your server genuinely cannot do for itself. It stops a program’s claim from turning into a metric that looks like a measured fact.

If you don’t attest crossing.target, the tool name on a call span is whatever the program said. A span-metrics connector doesn’t read provenance, so left alone it happily produces calls_total{gen_ai.tool.name="order_ship"} from a name the program picked, and a metric has nowhere to carry the doubt.

Your server can’t prevent that, because the connector runs downstream. A collector can, because it sits after every server and before every backend.

Config

On purpose. A custom collector component has to be compiled into a distribution, so everyone adopting it has to rebuild and redeploy their collector first. Everything here is stock opentelemetry-collector-contrib, so it works with the collector you already run.

Pipelines

Two passes over the same spans.

The trace pipeline keeps everything, claims included. A claim belongs in a trace, next to the label saying what it is, where a person reads it in context.

A second traces pipeline feeds the metrics connector and drops the claims first, so nothing unobserved ever gets counted.

Spans with no provenance label are left alone, so telemetry from the rest of your system passes through untouched.

There’s also an off-by-default transform processor that strips program-written payload values, for when you want the shape of a run in your backend but not the content. The capture note survives it, so you still see the size and hash of whatever got removed.

Checking

collector/check.mjs sends two calls through a real collector. One from a server that watched its own boundary, one from a server that didn’t.

Takes about a minute.

Gotcha

Since v0.104 the collector binds OTLP to localhost by default, so a collector in a container with the stock config receives nothing at all and says nothing about it. The config here sets explicit endpoints.