microsoft/semantic-kernel · error · KernelException

An error occurred while initializing the {nameof(BedrockText

Error message

An error occurred while initializing the {nameof(BedrockTextGenerationService)}: {ex.Message}

What it means

Thrown by AddBedrockTextGeneration (classic Kernel service DI) when the BedrockTextGenerationService factory throws. Same structure as 309: the factory resolves IAmazonBedrockRuntime from the container (GetRequiredService) and constructs the service; failure is wrapped in a KernelException.

Source

Thrown at dotnet/src/Connectors/Connectors.Amazon/Bedrock/Extensions/BedrockServiceCollectionExtensions.cs:101

            services.TryAddAWSService<IAmazonBedrockRuntime>();
        }
        services.AddKeyedSingleton<ITextGenerationService>(serviceId, (serviceProvider, _) =>
        {
            try
            {
                IAmazonBedrockRuntime runtime = bedrockRuntime ?? serviceProvider.GetRequiredService<IAmazonBedrockRuntime>();
                var loggerFactory = serviceProvider.GetService<ILoggerFactory>();
                // Check if the runtime instance is a proxy object
                if (runtime.GetType().BaseType == typeof(AmazonServiceClient))
                {
                    // Cast to AmazonServiceClient and subscribe to the event
                    ((AmazonServiceClient)runtime).BeforeRequestEvent += BedrockClientUtilities.BedrockServiceClientRequestHandler;
                }
                return new BedrockTextGenerationService(modelId, runtime, loggerFactory);
            }
            catch (Exception ex)
            {
                throw new KernelException($"An error occurred while initializing the {nameof(BedrockTextGenerationService)}: {ex.Message}", ex);
            }
        });

        return services;
    }

    /// <summary>
    /// Add Amazon Bedrock Text Generation service to the <see cref="IServiceCollection" />.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="modelId">The model for text generation.</param>
    /// <param name="bedrockRuntime">The optional <see cref="IAmazonBedrockRuntime" /> to use. If not provided will be retrieved from the Service Collection.</param>
    /// <param name="serviceId">The optional service ID.</param>
    /// <returns>Returns back <see cref="IServiceCollection"/> with a configured service.</returns>
    [Obsolete("Use AddBedrockEmbeddingGenerator instead.")]
    public static IServiceCollection AddBedrockTextEmbeddingGenerationService(
        this IServiceCollection services,
        string modelId,

View on GitHub (pinned to c028a0c7dc)

Solutions

  1. Register the runtime first: services.AddAWSService<IAmazonBedrockRuntime>();.
  2. Use a supported text-generation modelId (e.g. 'amazon.titan-text-premier-v1:0', 'anthropic.claude-...').
  3. Inspect ex.InnerException for the root cause.
  4. Pass an explicit IAmazonBedrockRuntime if you manage it manually.

Example fix

// before
services.AddBedrockTextGeneration("stability.stable-image-core");
// wraps 'Unsupported model provider: stability'

// after
services.AddAWSService<IAmazonBedrockRuntime>();
services.AddBedrockTextGeneration("amazon.titan-text-premier-v1:0");
Defensive patterns

Strategy: validation

Validate before calling

static readonly string[] s_textProviders = { "ai21", "amazon", "anthropic", "cohere", "meta", "mistral" };
bool IsValidTextModelId(string id) => s_textProviders.Contains(id.Split('.')[0], StringComparer.OrdinalIgnoreCase);

Try / catch

try { services.AddBedrockTextGeneration(modelId); }
catch (KernelException ex) { throw new InvalidOperationException($"Bedrock text-gen init failed: {ex.InnerException?.Message ?? ex.Message}", ex); }

Prevention

When it happens

Trigger: services.AddBedrockTextGeneration(modelId) without a registered IAmazonBedrockRuntime, so GetRequiredService throws. Also an invalid/unsupported text modelId that fails inside the BedrockTextGenerationService constructor (which internally calls BedrockServiceFactory.CreateTextGenerationService).

Common situations: Missing services.AddAWSService<IAmazonBedrockRuntime>(). Passing an unsupported provider/model id (e.g. a provider not in AI21/AMAZON/ANTHROPIC/COHERE/META/MISTRAL).

Related errors

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/04f2810851d9c970. Report an issue: GitHub.