Allow case-insensitive agents and clients resolution

Configuration-driven sections can change case when a subsequent provider overrides a section value but uses a different casing (since config is inherently case-insensitive). This means we may end up with a client ID with an unexpected casing at run-time.

In order to solve this, we register both clients and agents using an alternative ServiceKey object which performs a comparer-aware comparison (defaults to ordinal ignore case).

Users would need to look for this alternative key explicitly, since we don't want to pollute the container with additional string-only registrations. But to improve discoverability of this case-insensitive lookup, we provide GetChatClient and GetAIAgent extension methods for IServiceProvider.

Author: kzu

src/Agents/ConfigurableAIAgent.cs

@@ -91,7 +91,8 @@ public override IAsyncEnumerable<AgentRunResponseUpdate> RunStreamingAsync(IEnum
 
         var client = services.GetKeyedService<IChatClient>(options?.Client
             ?? throw new InvalidOperationException($"A client must be specified for agent '{name}' in configuration section '{section}'."))
-            ?? throw new InvalidOperationException($"Specified chat client '{options?.Client}' for agent '{name}' is not registered.");
+            ?? services.GetKeyedService<IChatClient>(new ServiceKey(options!.Client))
+            ?? throw new InvalidOperationException($"Specified chat client '{options!.Client}' for agent '{name}' is not registered.");
 
         var provider = client.GetService<ChatClientMetadata>()?.ProviderName;
         ChatOptions? chat = provider == "xai"

src/Agents/AddAIAgentsExtensions.cs …c/Agents/ConfigurableAgentsExtensions.cssrc/Agents/AddAIAgentsExtensions.cs renamed to src/Agents/ConfigurableAgentsExtensions.cs src/Agents/AddAIAgentsExtensions.cs renamed to src/Agents/ConfigurableAgentsExtensions.cs

@@ -1,18 +1,20 @@
 using System.ComponentModel;
+using Devlooped.Agents.AI;
 using Devlooped.Extensions.AI;
 using Microsoft.Agents.AI;
 using Microsoft.Agents.AI.Hosting;
+using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
 
-namespace Devlooped.Agents.AI;
+namespace Microsoft.Extensions.DependencyInjection;
 
 /// <summary>
 /// Adds configuration-driven agents to an application host.
 /// </summary>
 [EditorBrowsable(EditorBrowsableState.Never)]
-public static class AddAIAgentsExtensions
+public static class ConfigurableAgentsExtensions
 {
     /// <summary>
     /// Adds AI agents to the host application builder based on configuration.
@@ -52,8 +54,17 @@ public static TBuilder AddAIAgents<TBuilder>(this TBuilder builder, Action<strin
 
                 return agent;
             });
+
+            // Also register for case-insensitive lookup, but without duplicating the entry in 
+            // the AgentCatalog, since that will always resolve from above.
+            builder.Services.TryAdd(ServiceDescriptor.KeyedSingleton(new ServiceKey(name), (sp, key)
+                => sp.GetRequiredKeyedService<AIAgent>(name)));
         }
 
         return builder;
     }
+
+    /// <summary>Gets an AI agent by name (case-insensitive) from the service provider.</summary>
+    public static AIAgent? GetIAAgent(this IServiceProvider services, string name)
+        => services.GetKeyedService<AIAgent>(name) ?? services.GetKeyedService<AIAgent>(new ServiceKey(name));
 }

src/Extensions/ConfigurableChatClient.cs

@@ -1,5 +1,6 @@
 using System.ClientModel.Primitives;
 using System.ComponentModel;
+using System.Security.Cryptography;
 using Azure;
 using Azure.AI.Inference;
 using Azure.AI.OpenAI;
@@ -54,13 +55,24 @@ public ConfigurableChatClient(IConfiguration configuration, ILogger logger, stri
     /// <summary>Disposes the client and stops monitoring configuration changes.</summary>
     public void Dispose() => reloadToken?.Dispose();
 
+    /// <inheritdoc/>
+    public object? GetService(Type serviceType, object? serviceKey = null)
+    {
+        if (serviceType == typeof(ConfigurableChatClientMetadata) &&
+            innerClient.GetService(typeof(ChatClientMetadata)) is ChatClientMetadata innerMetadata)
+            return new ConfigurableChatClientMetadata(id, section, innerMetadata.ProviderName, innerMetadata.ProviderUri, innerMetadata.DefaultModelId);
+
+        var service = innerClient.GetService(serviceType, serviceKey);
+        if (service is ChatClientMetadata metadata)
+            return new ConfigurableChatClientMetadata(id, section, metadata.ProviderName, metadata.ProviderUri, metadata.DefaultModelId);
+
+        return service;
+    }
+
     /// <inheritdoc/>
     public Task<ChatResponse> GetResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default)
         => innerClient.GetResponseAsync(messages, options, cancellationToken);
     /// <inheritdoc/>
-    public object? GetService(Type serviceType, object? serviceKey = null)
-        => innerClient.GetService(serviceType, serviceKey);
-    /// <inheritdoc/>
     public IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default)
         => innerClient.GetStreamingResponseAsync(messages, options, cancellationToken);
 
@@ -160,3 +172,12 @@ internal class ConfigurableAzureOptions : AzureOpenAIClientOptions
         public string? ModelId { get; set; }
     }
 }
+
+/// <summary>Provides metadata about a configurable <see cref="IChatClient"/>.</summary>
+public class ConfigurableChatClientMetadata(string id, string section, string? providerName = null, Uri? providerUri = null, string? defaultModelId = null) : ChatClientMetadata(providerName, providerUri, defaultModelId)
+{
+    /// <summary>Gets the unique identifier for the client.</summary>
+    public string Id => id;
+    /// <summary>Gets the configuration section for the client.</summary>
+    public string Section => section;
+}

…c/Extensions/AddChatClientsExtensions.cs …ions/ConfigurableChatClientExtensions.cssrc/Extensions/AddChatClientsExtensions.cs renamed to src/Extensions/ConfigurableChatClientExtensions.cs src/Extensions/AddChatClientsExtensions.cs renamed to src/Extensions/ConfigurableChatClientExtensions.cs

@@ -14,7 +14,7 @@ namespace Devlooped.Extensions.AI;
 /// Adds configuration-driven chat clients to an application host or service collection.
 /// </summary>
 [EditorBrowsable(EditorBrowsableState.Never)]
-public static class AddChatClientsExtensions
+public static class ConfigurableChatClientExtensions
 {
     /// <summary>
     /// Adds configuration-driven chat clients to the host application builder.
@@ -69,11 +69,19 @@ public static IServiceCollection AddChatClients(this IServiceCollection services
                     return client;
                 },
                 options?.Lifetime ?? ServiceLifetime.Singleton));
+
+            services.TryAdd(new ServiceDescriptor(typeof(IChatClient), new ServiceKey(id),
+                factory: (sp, _) => sp.GetRequiredKeyedService<IChatClient>(id),
+                options?.Lifetime ?? ServiceLifetime.Singleton));
         }
 
         return services;
     }
 
+    /// <summary>Gets a chat client by id (case-insensitive) from the service provider.</summary>
+    public static IChatClient? GetChatClient(this IServiceProvider services, string id)
+        => services.GetKeyedService<IChatClient>(id) ?? services.GetKeyedService<IChatClient>(new ServiceKey(id));
+
     internal class ChatClientOptions : OpenAIClientOptions
     {
         public string? ApiKey { get; set; }

src/Extensions/ServiceKey.cs

@@ -0,0 +1,34 @@
+namespace Devlooped.Extensions.AI;
+
+/// <summary>
+/// An alternative service key that provides more flexible key comparison (case insensitive by default).
+/// </summary>
+/// <param name="key">The service key for use in the dependency injection container.</param>
+/// <param name="comparer">The comparer used for equality comparisons, defaulting to <see cref="StringComparer.OrdinalIgnoreCase"/> if not specified.</param>
+public readonly struct ServiceKey(string key, IEqualityComparer<string?>? comparer = default) : IEquatable<ServiceKey>
+{
+    readonly IEqualityComparer<string?> comparer = comparer ?? StringComparer.OrdinalIgnoreCase;
+
+    /// <summary>
+    /// Gets the original value of the service key.
+    /// </summary>
+    public string Value => key;
+
+    /// <inheritdoc/>
+    public bool Equals(ServiceKey other) => comparer.Equals(Value, other.Value);
+
+    /// <inheritdoc/>
+    public override bool Equals(object? obj) => obj is ServiceKey k && Equals(k);
+
+    /// <inheritdoc/>
+    public override int GetHashCode() => comparer.GetHashCode(Value);
+
+    /// <inheritdoc/>
+    public override string ToString() => Value;
+
+    /// <summary>Compares both keys for equality.</summary>
+    public static bool operator ==(ServiceKey left, ServiceKey right) => left.Equals(right);
+
+    /// <summary>Compares both keys for inequality.</summary>
+    public static bool operator !=(ServiceKey left, ServiceKey right) => !(left == right);
+}

src/Tests/ConfigurableAgentTests.cs

@@ -38,6 +38,29 @@ public void CanConfigureAgent()
         Assert.Equal("Helpful chat agent", agent.Description);
     }
 
+    [Fact]
+    public void CanGetFromAlternativeKey()
+    {
+        var builder = new HostApplicationBuilder();
+
+        builder.Configuration.AddInMemoryCollection(new Dictionary<string, string?>
+        {
+            ["ai:clients:Chat:modelid"] = "gpt-4.1-nano",
+            ["ai:clients:Chat:apikey"] = "sk-asdfasdf",
+            // NOTE: mismatched case in client id
+            ["ai:agents:bot:client"] = "chat",
+        });
+
+        builder.AddAIAgents();
+
+        var app = builder.Build();
+
+        var agent = app.Services.GetRequiredKeyedService<AIAgent>(new ServiceKey("Bot"));
+
+        Assert.Equal("bot", agent.Name);
+        Assert.Same(agent, app.Services.GetIAAgent("Bot"));
+    }
+
     [Fact]
     public void DedentsDescriptionAndInstructions()
     {

src/Tests/ConfigurableClientTests.cs

@@ -33,6 +33,29 @@ public void CanConfigureClients()
         Assert.Equal("xai", grok.GetRequiredService<ChatClientMetadata>().ProviderName);
     }
 
+    [Fact]
+    public void CanGetFromAlternativeKey()
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["ai:clients:Grok:modelid"] = "grok-4-fast",
+                ["ai:clients:Grok:ApiKey"] = "xai-asdfasdf",
+                ["ai:clients:Grok:endpoint"] = "https://api.x.ai",
+            })
+            .Build();
+
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(configuration)
+            .AddChatClients(configuration)
+            .BuildServiceProvider();
+
+        var grok = services.GetRequiredKeyedService<IChatClient>(new ServiceKey("grok"));
+
+        Assert.Equal("xai", grok.GetRequiredService<ChatClientMetadata>().ProviderName);
+        Assert.Same(grok, services.GetChatClient("grok"));
+    }
+
     [Fact]
     public void CanOverrideClientId()
     {