VCN #38: Glass Box — Trace Agents with OpenTelemetry

Build the observability layer for agents from OTel primitives. No SaaS. Agents fail quietly. Tool calls silently skip. The model returns a hallucination. The trace would have told you, but you didn't ship one, because LangSmith costs money and Braintrust costs money and Helicone costs money and you decided to "add observability later." Later is now. And later is free. VCN #38: Glass Box is a builder night where we wire OpenTelemetry into an agent stack from primitives. No managed dashboard until you can read a trace by hand. OpenInference is the de-facto plug-in layer (the OTel GenAI semantic conventions are still in development); we use it because Arize ships instrumentations for OpenAI, Claude Agent SDK, LangChain, DSPy, CrewAI, Bedrock, Anthropic, Google GenAI, LlamaIndex, and a dozen…