Observability overview

Three pillars, one entry point.

Pillar	Gives you	Reference
Events	The raw stream.	Events
Logging	Console line per event with configurable verbosity, plus pluggable sinks (NDJSON, your own).	Log sinks · Logger options
Tracing	A read-after-run object: spans, token usage, cost, retries, tool calls.	Tracing

The fluent setup

AgentContext exposes two fluent extensions that wire everything for you. Call one, both, or neither — they share the event bus.

var ctx = new AgentContext()
    .WithLogging(new LogicGridLoggerOptions { ShowLlmMessages = false })
    .WithTracing(out var trace);

var output = await admin.RunAsync(input);

Console.WriteLine($"\nLLM calls : {trace.TotalLlmCalls}");
Console.WriteLine($"Tokens    : {trace.TotalTokenUsage.TotalTokens}");
Console.WriteLine($"Cost      : ${trace.TotalCost.TotalCostUsd:0.0000}");
Console.WriteLine($"Retries   : {trace.TotalRetries}");

WithLogging(options, sinks…) defaults to a single ConsoleSink. Pass JsonSink(file) (or your own ILogSink) for structured logging.

WithTracing(out var trace) creates a fresh AgentRunTrace that adopts run identity from the first event it sees and populates as the run progresses. Read it after RunAsync completes.

Bring your own bus

If you already have an IAgentEventBus (e.g. you're forwarding events into another telemetry system), set it directly:

var ctx = new AgentContext { EventBus = myBus };
// .WithLogging() / .WithTracing() will reuse it instead of creating a new one

External run correlation

Pass your platform's request ID as runId and every log line + every span carries it:

var ctx = new AgentContext(
        originalTask: "summarise daily report",
        runId: HttpContext.TraceIdentifier)
    .WithLogging()
    .WithTracing(out var trace);

Where next

• Events — the full 22-event catalog.
• Log sinks — Console, NDJSON, custom (e.g. Serilog bridge).
• Logger options — every flag in LogicGridLoggerOptions.
• Tracing — AgentRunTrace shape and how to ship it to your APM.
• Cost & budget — MaxBudgetUsd, BudgetWarningEvent, BudgetExceededException.