Lasso.TelemetryLogger; its event categories can be enabled or disabled through application configuration. Text remains the default console format. Set LOG_LEVEL=debug|info|warning|error to control the level and LOG_FORMAT=json for one JSON object per line.
JSON entries include UTC time, severity, message, and an allowlist of route and request identifiers. The formatter masks embedded upstream URL paths and queries and common labeled credential assignments. Do not put secrets in arbitrary freeform messages or provider identifiers. Protect the log drain at your deployment boundary.
rpc.request.completed log for every request, and it has no request-log sampling configuration. If you need a request-completion stream, attach a short handler to [:lasso, :rpc, :request, :stop]. Its duration measurement is in milliseconds; metadata includes chain, method, strategy, provider, transport, result, and failover count. This event describes routed completion, not every ingress request. Keep telemetry handlers nonblocking because they run in the emitting process.
For client correlation, opt into response metadata. Provider identifiers can appear in logs and metadata, so do not put secrets in them. Protect logs using your deployment’s normal access controls.
See the released observability reference for the event contract and TelemetryLogger source for its handlers.