1# Authentication Events — .NET SDK Quick Reference
2 
3> Condensed from **microsoft-azure-webjobs-extensions-authentication-events-dotnet**.
4> Full patterns (attribute collection, OTP customization, external data enrichment)
5> in the source plugin skill if installed.
6 
7## Install
8dotnet add package Microsoft.Azure.WebJobs.Extensions.AuthenticationEvents
9 
10## Quick Start
11```csharp
12using Microsoft.Azure.WebJobs.Extensions.AuthenticationEvents;
13using Microsoft.Azure.WebJobs.Extensions.AuthenticationEvents.TokenIssuanceStart;
14 
15[FunctionName("OnTokenIssuanceStart")]
16public static WebJobsAuthenticationEventResponse Run(
17    [WebJobsAuthenticationEventsTrigger] WebJobsTokenIssuanceStartRequest request,
18    ILogger log)
19{
20    var response = new WebJobsTokenIssuanceStartResponse();
21    response.Actions.Add(new WebJobsProvideClaimsForToken
22    {
23        Claims = new Dictionary<string, string> { { "claim", "value" } }
24    });
25    return response;
26}
27```
28 
29## Best Practices
30- Validate all inputs — never trust request data; validate before processing
31- Handle errors gracefully — return appropriate error responses, don't throw
32- Log correlation IDs — use CorrelationId for troubleshooting
33- Keep functions fast — authentication events have timeout limits
34- Use managed identity — access Azure resources securely
35- Cache external data — avoid slow lookups on every request
36- Test locally — use Azure Functions Core Tools with sample payloads
37- Monitor with App Insights — track function execution and errors
38