C# - Amazon Selling Partner API Usage Samples

This repository contains examples of how to use the new Amazon Selling Partner API using NSwag generated clients.

I have refactored the existing example from Amazon to use HttpClient vs RestSharp with improved DI support and optional token caching.

Follow the Selling Partner API Guide in order to obtain your credentials.

Then use the examples below to get started.

Useful overview video on the sp api workflow can be found on Amazon Seller University

Example usage using microsoft dependency injection

// get credentials
var awsKey = "AWS_KEY";
var awsSecret = "AWS_SECRET";
var roleArn = "arn:aws:iam::1234:role/ROLE_NAME";
var clientId = "amzn1.application-oa2-client.xyz";
var clientSecret = "CLIENT_SECRET";
var refreshToken = "REFRESH_TOKEN";

var spEndpoint = AmazonSpApiEndpoint.Europe.Endpoint.EnsureTrailingSlash();
var lwaEndpoint = EndpointConstants.LwaToken;
var region = RegionEndpoint.EUWest1;

// add services
var services = new ServiceCollection();

// add memory cache for token (if required)
services.AddMemoryCache();

// add message handlers to sign requests
services.AddTransient<AmazonSpAccessTokenHandler>();
services.AddTransient<AmazonSpSecurityTokenHandler>();

// add security token resolver (used by message handlers)
services.AddScoped<IAmazonSecurityTokenCredentialResolver>(sp => new MemoryCacheAmazonSecurityTokenCredentialResolver(sp.GetRequiredService<IMemoryCache>(), spEndpoint, roleArn, awsKey, awsSecret, region));

// add lwa client to obtain access token (used by message handlers)
services.AddHttpClient("amzn-lwa", httpClient => { httpClient.BaseAddress = new Uri(lwaEndpoint); });
services.AddScoped<ILwaClient>(sp =>
{
    var clientFactory = sp.GetRequiredService<IHttpClientFactory>();
    var lwaCredentials = new LwaAuthorizationCredentials
    {
        ClientId = clientId,
        ClientSecret = clientSecret,
        RefreshToken = refreshToken,
        Endpoint = new Uri(lwaEndpoint),
        Scopes = null
    };
    return new MemoryCacheHttpLwaClient(clientFactory.CreateClient("amzn-lwa"), lwaCredentials, sp.GetRequiredService<IMemoryCache>());
});

// add amazon sp api clients
// order 
services.AddHttpClient<IAmazonSellingPartnerOrdersClient, AmazonSellingPartnerOrdersClient>(client =>
    {
        client.BaseAddress = new Uri(spEndpoint);
        return new AmazonSellingPartnerOrdersClient(client)
        {
            JsonSerializerSettings =
            {
                // needed if some required fields are not going to be returned due to PII restrictions
                ContractResolver = new AmazonSellingPartnerSafeContractResolver()
            }
        };
    }).AddHttpMessageHandler<AmazonSpAccessTokenHandler>()
    .AddHttpMessageHandler<AmazonSpSecurityTokenHandler>();

// sales
services.AddHttpClient<IAmazonSellingPartnerSalesClient, AmazonSellingPartnerSalesClient>(client =>
    {
        client.BaseAddress = new Uri(spEndpoint);
        return new AmazonSellingPartnerSalesClient(client);
    }).AddHttpMessageHandler<AmazonSpAccessTokenHandler>()
    .AddHttpMessageHandler<AmazonSpSecurityTokenHandler>();

// build service provider
var serviceProvider = services.BuildServiceProvider();

// resolve services and call api
var salesClient = serviceProvider.GetRequiredService<IAmazonSellingPartnerSalesClient>();
var ordersClient = serviceProvider.GetRequiredService<IAmazonSellingPartnerOrdersClient>();

var startDate = new DateTime(2022, 03, 01, 00, 00, 00, DateTimeKind.Utc);
var endDate = new DateTime(2022, 03, 07, 00, 00, 00, DateTimeKind.Utc);

var salesResponse = await salesClient.GetOrderMetricsAsync(new[] { AmazonMarketplace.UK.MarketplaceId }, AmazonDateUtil.ConvertToString(startDate, endDate), Granularity.Total);

// access token and security from 1st call will be cached and used again for the 2nd request
var ordersResponse = await ordersClient.GetOrdersAsync(new[] { AmazonMarketplace.UK.MarketplaceId }, createdAfter: startDate.ToAmazonDateTimeString(),
    createdBefore: endDate.ToAmazonDateTimeString());

Example usage without dependency injection

// get credentials
var awsKey = "AWS_KEY";
var awsSecret = "AWS_SECRET";
var roleArn = "arn:aws:iam::1234:role/ROLE_NAME";
var clientId = "amzn1.application-oa2-client.xyz";
var clientSecret = "CLIENT_SECRET";
var refreshToken = "REFRESH_TOKEN";

var spEndpoint = AmazonSpApiEndpoint.Europe.Endpoint.EnsureTrailingSlash();
var lwaEndpoint = EndpointConstants.LwaToken;
var region = RegionEndpoint.EUWest1;

IAmazonSecurityTokenCredentialResolver securityTokenResolver = new AmazonSecurityTokenCredentialResolver(spEndpoint, roleArn, awsKey, awsSecret, region);

var lwaAuthorizationCredentials = new LwaAuthorizationCredentials
{
    ClientId = clientId,
    ClientSecret = clientSecret,
    RefreshToken = refreshToken,
    Endpoint = new Uri(lwaEndpoint),
    Scopes = null
};

ILwaClient lwaClient = new HttpLwaClient(lwaAuthorizationCredentials);

AmazonSpAccessTokenHandler pipeline = new AmazonSpAccessTokenHandler(lwaClient)
{
    InnerHandler = new AmazonSpSecurityTokenHandler(securityTokenResolver)
    {
        InnerHandler = new HttpClientHandler()
    }
};

var httpClient = new HttpClient(pipeline)
{
    BaseAddress = new Uri(spEndpoint)
};
IAmazonSellingPartnerOrdersClient ordersClient = new AmazonSellingPartnerOrdersClient(httpClient)
{
    JsonSerializerSettings =
    {
        // needed if some required fields are not going to be returned due to PII restrictions
        ContractResolver = new AmazonSellingPartnerSafeContractResolver()
    }
};

var startDate = new DateTime(2022, 03, 01, 00, 00, 00, DateTimeKind.Utc);
var endDate = new DateTime(2022, 03, 07, 00, 00, 00, DateTimeKind.Utc);

var ordersResponse = await ordersClient.GetOrdersAsync(new[] { AmazonMarketplace.UK.MarketplaceId }, createdAfter: startDate.ToAmazonDateTimeString(),
    createdBefore: endDate.ToAmazonDateTimeString());

Tests

Navigate to the Amazon.SellingPartner.IntegrationTests directory and initialize the user-secret store.

dotnet user-secrets init

Now you can add your credentials which will be used by the integration tests.

dotnet user-secrets set "Amzn:AWSKey" "AWS_KEY"
dotnet user-secrets set "Amzn:AWSSecret" "AWS_SECRET"
dotnet user-secrets set "Amzn:ClientId" "amzn1.application-oa2-client.xyz"
dotnet user-secrets set "Amzn:ClientSecret" "CLIENT_SECRET"
dotnet user-secrets set "Amzn:RefreshToken" "REFRESH_TOKEN"
dotnet user-secrets set "Amzn:RoleARN" "arn:aws:iam::1234:role/ROLE_NAME"