OTel Data Flow — All Agents

OTel Data Flow — VS Code Copilot Chat Extension

Complete tracing architecture for foreground agent, CLI background agent, CLI terminal, and Claude Code

Provider A (Extension NodeOTelService)

Provider B (SDK BasicTracerProvider)

Bridge SpanProcessor

Debug Panel Consumer

External Exporter

Synthetic Spans (ext-created)

Overview (All Agents)

Foreground Agent

CLI Background

CLI Terminal

Claude Code

Provider A (NodeOTelService): Created at extension activation. Stores tracer ref. Serves foreground agent, CLI wrapper span, Claude synthetic spans.
Provider B (BasicTracerProvider): Created by SDK's OtelLifecycle.initializeOtelSdk(). Replaces A as global. Serves all SDK-native spans.
Provider A's stored this._tracer still works after override — OTel tracers are bound to their provider at creation time.

Extension root span → traceparent = 00-{traceId}-{spanId}-01
Passed to SDK via otelLifecycle.updateParentTraceContext(sessionId, traceparent)
SDK spans inherit the extension's traceId → same trace in Grafana
Bridge matches traceId → injects CHAT_SESSION_ID → debug panel buckets correctly

Foreground: tracer A → TrackedSpanHandle.end() → _onDidCompleteSpan.fire()
CLI background: tracer B → Bridge.onEnd() → injectCompletedSpan() → _onDidCompleteSpan.fire()
Claude: tracer A → TrackedSpanHandle.end() → _onDidCompleteSpan.fire() (same as foreground)
CLI terminal: N/A (separate process, no debug panel visibility)
Both consumers: OTelChatDebugLogProvider (trajectory) and ChatDebugFileLoggerService (file)

copilot-chat — Extension Provider A spans (foreground, CLI wrapper, Claude synthetic)
github-copilot — SDK Provider B spans (CLI native), CLI terminal
claude-code — Claude subprocess metrics/events

Grafana: Everything from all OTLP exporters (Provider A + B + terminal + Claude subprocess)
Debug Panel: Only spans that fire onDidCompleteSpan with copilot_chat.chat_session_id
File Logger: Same as debug panel (listens to same event)