Agent Tracing CLI Guide

@lobechat/agent-tracing is a zero-config local dev tool that records agent execution snapshots to disk and provides a CLI to inspect them.

How It Works

In NODE_ENV=development, AgentRuntimeService.executeStep() automatically records each step to .agent-tracing/ as partial snapshots. When the operation completes, the partial is finalized into a complete ExecutionSnapshot JSON file.

Data flow: executeStep loop -> build StepPresentationData -> write partial snapshot to disk -> on completion, finalize to .agent-tracing/{timestamp}_{traceId}.json

Context engine capture: In RuntimeExecutors.ts, the call_llm executor calls ctx.tracingContextEngine(input, output) after serverMessagesEngine() processes messages. AgentRuntimeService.executeStep buffers the call per step and forwards it to OperationTraceRecorder.appendStep as the typed contextEngine field. CE flows through this side channel rather than the events array so its heavy payload (agentDocuments, systemRole, …) never enters the Redis state pipeline (LOBE-9110).

Package Location