dotnet add package Azure.ResourceManager.ApiManagement
dotnet add package Azure.Identity

AZURE_SUBSCRIPTION_ID=<your-subscription-id>
# For service principal auth (optional)
AZURE_TENANT_ID=<tenant-id>
AZURE_CLIENT_ID=<client-id>
AZURE_CLIENT_SECRET=<client-secret>

using Azure.Identity;
using Azure.ResourceManager;
using Azure.ResourceManager.ApiManagement;

// Always use DefaultAzureCredential
var credential = new DefaultAzureCredential();
var armClient = new ArmClient(credential);

// Get subscription
var subscriptionId = Environment.GetEnvironmentVariable("AZURE_SUBSCRIPTION_ID");
var subscription = armClient.GetSubscriptionResource(
    new ResourceIdentifier($"/subscriptions/{subscriptionId}"));

ArmClient
└── SubscriptionResource
    └── ResourceGroupResource
        └── ApiManagementServiceResource
            ├── ApiResource
            │   ├── ApiOperationResource
            │   │   └── ApiOperationPolicyResource
            │   ├── ApiPolicyResource
            │   ├── ApiSchemaResource
            │   └── ApiDiagnosticResource
            ├── ApiManagementProductResource
            │   ├── ProductApiResource
            │   ├── ProductGroupResource
            │   └── ProductPolicyResource
            ├── ApiManagementSubscriptionResource
            ├── ApiManagementPolicyResource
            ├── ApiManagementUserResource
            ├── ApiManagementGroupResource
            ├── ApiManagementBackendResource
            ├── ApiManagementGatewayResource
            ├── ApiManagementCertificateResource
            ├── ApiManagementNamedValueResource
            └── ApiManagementLoggerResource

using Azure.ResourceManager.ApiManagement;
using Azure.ResourceManager.ApiManagement.Models;

// Get resource group
var resourceGroup = await subscription
    .GetResourceGroupAsync("my-resource-group");

// Define service
var serviceData = new ApiManagementServiceData(
    location: AzureLocation.EastUS,
    sku: new ApiManagementServiceSkuProperties(
        ApiManagementServiceSkuType.Developer, 
        capacity: 1),
    publisherEmail: "admin@contoso.com",
    publisherName: "Contoso");

// Create service (long-running operation - can take 30+ minutes)
var serviceCollection = resourceGroup.Value.GetApiManagementServices();
var operation = await serviceCollection.CreateOrUpdateAsync(
    WaitUntil.Completed,
    "my-apim-service",
    serviceData);

ApiManagementServiceResource service = operation.Value;

var apiData = new ApiCreateOrUpdateContent
{
    DisplayName = "My API",
    Path = "myapi",
    Protocols = { ApiOperationInvokableProtocol.Https },
    ServiceUri = new Uri("https://backend.contoso.com/api")
};

var apiCollection = service.GetApis();
var apiOperation = await apiCollection.CreateOrUpdateAsync(
    WaitUntil.Completed,
    "my-api",
    apiData);

ApiResource api = apiOperation.Value;

var productData = new ApiManagementProductData
{
    DisplayName = "Starter",
    Description = "Starter tier with limited access",
    IsSubscriptionRequired = true,
    IsApprovalRequired = false,
    SubscriptionsLimit = 1,
    State = ApiManagementProductState.Published
};

var productCollection = service.GetApiManagementProducts();
var productOperation = await productCollection.CreateOrUpdateAsync(
    WaitUntil.Completed,
    "starter",
    productData);

ApiManagementProductResource product = productOperation.Value;

// Add API to product
await product.GetProductApis().CreateOrUpdateAsync(
    WaitUntil.Completed,
    "my-api");

var subscriptionData = new ApiManagementSubscriptionCreateOrUpdateContent
{
    DisplayName = "My Subscription",
    Scope = $"/products/{product.Data.Name}",
    State = ApiManagementSubscriptionState.Active
};

var subscriptionCollection = service.GetApiManagementSubscriptions();
var subOperation = await subscriptionCollection.CreateOrUpdateAsync(
    WaitUntil.Completed,
    "my-subscription",
    subscriptionData);

ApiManagementSubscriptionResource subscription = subOperation.Value;

// Get subscription keys
var keys = await subscription.GetSecretsAsync();
Console.WriteLine($"Primary Key: {keys.Value.PrimaryKey}");

var policyXml = @"
<policies>
    <inbound>
        <rate-limit calls=""100"" renewal-period=""60"" />
        <set-header name=""X-Custom-Header"" exists-action=""override"">
            <value>CustomValue</value>
        </set-header>
        <base />
    </inbound>
    <backend>
        <base />
    </backend>
    <outbound>
        <base />
    </outbound>
    <on-error>
        <base />
    </on-error>
</policies>";

var policyData = new PolicyContractData
{
    Value = policyXml,
    Format = PolicyContentFormat.Xml
};

await api.GetApiPolicy().CreateOrUpdateAsync(
    WaitUntil.Completed,
    policyData);

// Backup
var backupParams = new ApiManagementServiceBackupRestoreContent(
    storageAccount: "mystorageaccount",
    containerName: "apim-backups",
    backupName: "backup-2024-01-15")
{
    AccessType = StorageAccountAccessType.SystemAssignedManagedIdentity
};

await service.BackupAsync(WaitUntil.Completed, backupParams);

// Restore
await service.RestoreAsync(WaitUntil.Completed, backupParams);

using Azure;

try
{
    var operation = await serviceCollection.CreateOrUpdateAsync(
        WaitUntil.Completed, serviceName, serviceData);
}
catch (RequestFailedException ex) when (ex.Status == 409)
{
    Console.WriteLine("Service already exists");
}
catch (RequestFailedException ex) when (ex.Status == 400)
{
    Console.WriteLine($"Bad request: {ex.Message}");
}
catch (RequestFailedException ex)
{
    Console.WriteLine($"ARM Error: {ex.Status} - {ex.ErrorCode}: {ex.Message}");
}