libtelemetry

Structured logging and trace spans — observable operations so problems surface before they escalate.

Getting Started

import { createLogger, createObserver } from '@forwardimpact/libtelemetry';

const logger = createLogger('myservice');

Trace visualization

fit-visualize reads recorded spans from the trace index and renders them as Mermaid sequence diagrams. Pipe a JMESPath expression on stdin to select spans; scope with --trace or --resource:

echo "[?name=='ProcessStream']" | fit-visualize
echo "[]" | fit-visualize --trace 0f53069dbc62d
echo "[]" | fit-visualize --resource common.Conversation.abc123

The expression filters span fields (name, kind, attributes); the flags scope the query to one trace or resource. With --resource, matching traces combine into one diagram titled by resource ID; otherwise each trace renders separately. When nothing matches, the command prints No spans found matching the filter criteria.

Documentation

• Add Observability — structured logs and traces with no framework setup, including querying and visualizing recorded traces with fit-visualize.
• Manage Service Lifecycle from One Interface — the full lifecycle setup for services, from supervision to observability.