Building TypeScript-Native Observability: Async Context and Execution Flow

A useful agent trace is not a list of timestamps. It is a causal tree. When a TypeScript agent retrieves documents in parallel, calls a model, retries a tool, and falls back to cached data, each operation needs a trace ID, its own span ID, and the correct parent span. Without those relationships, completion order is easily mistaken for execution structure. This article builds a small Node.js tracer to demonstrate the core mechanics: immutable async context, parent-child spans, reliable…