Connect to Azure AI Inference

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This page describes how consuming apps connect to an Azure AI Inference endpoint that’s already registered as a connection string in your AppHost. For instructions on registering the connection, see Get started with the Azure AI Inference integrations.

When you reference an Azure AI Inference connection from your AppHost, Aspire injects the connection string into the consuming app as an environment variable. Your app can either read the environment variable directly — the pattern works from any language — or, in C#, use the Aspire.Azure.AI.Inference client integration for automatic dependency injection, health checks, and telemetry.

Connection string

Aspire injects the full connection string into consuming apps:

• .NET apps: available via IConfiguration under the key ConnectionStrings:{resourcename}
• All other apps: available as the environment variable ConnectionStrings__{resourcename} (note the double underscore)

Connection string format:

Endpoint=https://{endpoint}/;Key={apikey};DeploymentId={deploymentName}

Component	Description
Endpoint	The Azure AI Inference service endpoint URL
Key	The API key for authentication
DeploymentId	The model deployment name

Example:

Endpoint=https://myresource.services.ai.azure.com/models;Key=abc123;DeploymentId=gpt-4o-mini

Connect from your app

Pick the language your consuming app is written in. Each example assumes your AppHost registers a connection string named ai-foundry and references it from the consuming app.

C#

For C# apps, the recommended approach is the Aspire Azure AI Inference client integration. It registers a ChatCompletionsClient through dependency injection and adds health checks and telemetry automatically. If you’d rather read the connection string directly, see the Read the connection string section at the end of this tab.

Install the client integration

Install the 📦 Aspire.Azure.AI.Inference NuGet package in the client-consuming project:

.NET CLI

.NET CLI — Add Aspire.Azure.AI.Inference package

dotnet add package Aspire.Azure.AI.Inference

Program.cs (C# file-based app)

Program.cs

#:package Aspire.Azure.AI.Inference@*

PackageReference (*.csproj)

XML — Add Aspire.Azure.AI.Inference package reference

<PackageReference Include="Aspire.Azure.AI.Inference" Version="*" />

Add a chat completions client

In Program.cs, call AddAzureChatCompletionsClient on your IHostApplicationBuilder to register a ChatCompletionsClient:

C# — Program.cs

builder.AddAzureChatCompletionsClient(connectionName: "ai-foundry");

Tip

The connectionName must match the connection string name used in the AppHost. For more information, see Get started with the Azure AI Inference integrations.

Resolve the client through dependency injection:

C# — ExampleService.cs

public class ExampleService(ChatCompletionsClient client)
{
    // Use client...
}

Register an IChatClient

Chain AddChatClient to also register an IChatClient from Microsoft.Extensions.AI:

C# — Program.cs

builder.AddAzureChatCompletionsClient(connectionName: "ai-foundry")
    .AddChatClient("gpt-4o-mini");

Resolve the IChatClient through dependency injection:

C# — ExampleService.cs

public class ExampleService(IChatClient chatClient)
{
    public async Task<string> GetResponseAsync(string userMessage)
    {
        var response = await chatClient.CompleteAsync(userMessage);
        return response.Message.Text ?? string.Empty;
    }
}

Add an embeddings client

Call AddAzureEmbeddingsClient to register an EmbeddingsClient:

C# — Program.cs

builder.AddAzureEmbeddingsClient(connectionName: "ai-foundry");

Add keyed clients

To register multiple clients with different connection names, use the keyed variants:

C# — Program.cs

builder.AddKeyedAzureChatCompletionsClient(name: "chat");
builder.AddKeyedAzureChatCompletionsClient(name: "code");

Then resolve each instance by key:

C# — ExampleService.cs

public class ExampleService(
    [FromKeyedServices("chat")] ChatCompletionsClient chatClient,
    [FromKeyedServices("code")] ChatCompletionsClient codeClient)
{
    // Use clients...
}

For more information, see Keyed services in .NET.

Configuration

The Aspire Azure AI Inference client integration offers multiple ways to provide configuration.

Connection strings. The integration reads the connection string from the ConnectionStrings configuration section automatically when you pass the connection name to AddAzureChatCompletionsClient:

JSON — appsettings.json

{
  "ConnectionStrings": {
    "ai-foundry": "Endpoint=https://{endpoint}/;Key={apikey};DeploymentId={deploymentName}"
  }
}

Configuration providers. The integration supports Microsoft.Extensions.Configuration. It loads ChatCompletionsClientSettings from configuration using the Aspire:Azure:AI:Inference key:

JSON — appsettings.json

{
  "Aspire": {
    "Azure": {
      "AI": {
        "Inference": {
          "DisableTracing": false,
          "EnableSensitiveTelemetryData": false
        }
      }
    }
  }
}

Inline delegates. Pass an Action<ChatCompletionsClientSettings> to configure settings inline:

C# — Program.cs

builder.AddAzureChatCompletionsClient(
    connectionName: "ai-foundry",
    configureSettings: static settings => settings.DisableTracing = true);

Client integration health checks

The Azure AI Inference client integration participates in Aspire health checks. The integration wires into the /health HTTP endpoint, where all registered health checks must pass before the app is considered ready to accept traffic.

Observability and telemetry

The Aspire Azure AI Inference client integration automatically configures logging, tracing, and metrics through OpenTelemetry.

Logging categories:

• Azure.Core
• Azure.Identity

Tracing activities:

• Experimental.Microsoft.Extensions.AI

Note

Telemetry is only recorded by default when using the IChatClient interface from Microsoft.Extensions.AI. Raw ChatCompletionsClient calls do not automatically generate telemetry.

Read the connection string in C#

If you prefer not to use the Aspire client integration, install the 📦 Azure.AI.Inference NuGet package and read the connection string from IConfiguration directly:

C# — Program.cs

using Azure;
using Azure.AI.Inference;

var connectionString = builder.Configuration.GetConnectionString("ai-foundry")!;
var parts = connectionString.Split(';')
    .Select(p => p.Split('=', 2))
    .Where(p => p.Length == 2)
    .ToDictionary(p => p[0].Trim(), p => p[1].Trim());

var endpoint = new Uri(parts["Endpoint"]);
var apiKey = parts["Key"];
var deploymentId = parts["DeploymentId"];

var client = new ChatCompletionsClient(endpoint, new AzureKeyCredential(apiKey));

Go

Use the Go standard library to call the Azure AI Inference REST API directly. Read and parse the Aspire-injected connection string:

Go — main.go

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "net/http"
    "os"
    "strings"
)

// parseConnStr parses a semicolon-delimited key=value connection string.
func parseConnStr(connStr string) map[string]string {
    parts := make(map[string]string)
    for _, part := range strings.Split(connStr, ";") {
        if idx := strings.IndexByte(part, '='); idx > 0 {
            parts[strings.TrimSpace(part[:idx])] = strings.TrimSpace(part[idx+1:])
        }
    }
    return parts
}

func main() {
    // Read the Aspire-injected connection string
    connStr := os.Getenv("ConnectionStrings__ai-foundry")
    parts := parseConnStr(connStr)

    endpoint := strings.TrimRight(parts["Endpoint"], "/")
    apiKey := parts["Key"]
    deploymentID := parts["DeploymentId"]

    // Build the request URL for chat completions
    url := fmt.Sprintf("%s/%s/chat/completions?api-version=2024-05-01-preview",
        endpoint, deploymentID)

    body, _ := json.Marshal(map[string]any{
        "messages": []map[string]string{
            {"role": "user", "content": "Hello!"},
        },
    })

    req, _ := http.NewRequest(http.MethodPost, url, bytes.NewReader(body))
    req.Header.Set("Content-Type", "application/json")
    req.Header.Set("api-key", apiKey)

    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    result, _ := io.ReadAll(resp.Body)
    fmt.Println(string(result))
}

Python

Install the Azure AI Inference SDK for Python:

Terminal

pip install azure-ai-inference

Read the Aspire-injected connection string and connect:

Python — app.py

import os
from azure.ai.inference import ChatCompletionsClient
from azure.core.credentials import AzureKeyCredential

# Read and parse the Aspire-injected connection string
conn_str = os.environ.get("ConnectionStrings__ai-foundry", "")
parts = dict(
    part.split("=", 1)
    for part in conn_str.split(";")
    if "=" in part
)

endpoint = parts["Endpoint"]
api_key = parts["Key"]
deployment_id = parts["DeploymentId"]

client = ChatCompletionsClient(
    endpoint=endpoint,
    credential=AzureKeyCredential(api_key),
)

response = client.complete(
    model=deployment_id,
    messages=[{"role": "user", "content": "Hello!"}],
)

print(response.choices[0].message.content)

TypeScript

Install the Azure AI Inference SDK for JavaScript:

Terminal

npm install @azure-rest/ai-inference

Read the Aspire-injected connection string and connect:

TypeScript — index.ts

import ModelClient, { isUnexpected } from '@azure-rest/ai-inference';
import { AzureKeyCredential } from '@azure/core-auth';

// Read and parse the Aspire-injected connection string
const connStr = process.env["ConnectionStrings__ai-foundry"] ?? "";
const parts = Object.fromEntries(
    connStr.split(";")
        .filter(p => p.includes("="))
        .map(p => p.split("=", 2) as [string, string])
);

const endpoint = parts["Endpoint"];
const apiKey = parts["Key"];
const deploymentId = parts["DeploymentId"];

const client = ModelClient(endpoint, new AzureKeyCredential(apiKey));

const response = await client.path("/chat/completions").post({
    body: {
        model: deploymentId,
        messages: [{ role: "user", content: "Hello!" }],
    },
});

if (isUnexpected(response)) {
    throw new Error(response.body.error?.message);
}

console.log(response.body.choices[0].message.content);

See also

• Get started with the Azure AI Inference integrations
• Azure AI Inference documentation
• Aspire.Azure.AI.Inference on NuGet