Bedrock for .NET

Jan 02, 2026
2 min read

AWS Bedrock is a managed service for programmatic access to generative AI and large language models. The service supports many models from numerous providers. SDKs exist for almost all major platforms.

Enabling Access

The below IAM policy allows invoking the AWS model “nova-micro-v1”. This policy is attached to a role used by an AWS AppRunner service.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "bedrock:InvokeModel",
                "bedrock:InvokeModelWithResponseStream"
            ],
            "Resource": "arn:aws:bedrock:*::foundation-model/amazon.nova-micro-v1:0"
        }
    ]
}

C# Sample

Step 1: Create a native request

The Bedrock SDK supports multiple models which each have their own parameters. The first step is to create a “native request” specific to the model being invoked. This request is for the AWS model Nova.

There a few useful parameters for Nova

max_new_tokens: Maximum tokens the model will output. Useful to limit how much content can be generated and establish guardrail against malicious use.
top_p & temperature: Supports values between 0 and 1. Values closer to 0 provides more consistent responses. Values closer to 1 provide more variability.

string prompt = "Create a poem about using Bedrock with C# in iambic pentameter";
var nativeRequest = System.Text.Json.JsonSerializer.Serialize(new
{
    messages = new[] { new { content = new[] { new { text = prompt } }, role = "user" } },
    inferenceConfig = new
    {
        max_new_tokens = 4096,
        top_p = 0,
        temperature = 0
    }
});

Step 2: Create Bedrock client

Be sure to specify a supported AWS region to use to invoke the model. Each model has certain regions it is supported. ModelIds can be found on the list of models.

var client = new AmazonBedrockRuntimeClient(RegionEndpoint.USEast1);
var request = new InvokeModelRequest
{
    ModelId = "amazon.nova-micro-v1:0",
    Body = new MemoryStream(Encoding.UTF8.GetBytes(nativeRequest))
};

Step 3: Invoke Model

The Bedrock SDKs don’t provide built-in objects to represent deserialized responses returned from invoking the models. The below NativeResponse and related classes are to simplify handling the JSON responses.

var response = await client.InvokeModelAsync(request);
var res = new StreamReader(response.Body).ReadToEnd();
var modelResponse = JsonConvert.DeserializeObject<NativeResponse>(res);
string responseText = modelResponse.output.message.content[0].text;

public record class NativeResponse(Output output, string stopReason, Usage usage);
public record class Output(Message message);
public record class Message(Content[] content, string role);
public record class Content(string text);