Why should you care?

Support teams debug failed copilot calls without reproducing customer prompts verbatim in logs.

See it live — copy this example

Paste into an ASP.NET Core 8+ / AgentNest project, then run with dotnet run (set your API keys in user-secrets).

// AgentNest.Telemetry/AiLogExtensions.cs
public static partial class AiLogs
{
    [LoggerMessage(EventId = 4001, Level = LogLevel.Information,
        Message = "AI completion tenant={TenantId} agent={Agent} tokens={Tokens} ms={ElapsedMs}")]
    public static partial void Completion(ILogger log, string tenantId, string agent, int tokens, long elapsedMs);
}

What happened?

• LoggerMessage source generators emit high-performance structured logs with tenant, agent, token count, and duration — no raw prompt text.
• Follow the steps below — typing the code yourself is the fastest way to learn.

Practice next

1. Add AiLogs partial class with LoggerMessage attributes.
2. Call AiLogs.Completion from AgentBase finally block.
3. Configure Application Insights to index TenantId custom dimension.
4. Add EventId 4002 for tool invocation logs.
5. Sample debug logs at 1% in production.

Remember

Use structured LoggerMessage for AI completions. Log metrics and IDs, not full prompts. Index tenant and agent dimensions in App Insights.

Copilot outage triage

CRM copilot slow for one tenant after Azure incident.

Outcome: Structured logs filter TenantId and show p95 latency spike on gpt-4o deployment.