Is it possible to set TokenEndpoint dynamically based on IncomingRequest?

[alefcarlos]

Hey, good ?

I'm trying to dynamically set the TokenEndpoint based on a downstream api, is that possible ? I was looking out ITokenRequestCustomizer and
AccessTokenRequestHandler.ITokenRetriever but I can only modify the TokenRequestParameters.

I was reading the internals to undarstand the flow

https://github.com/DuendeSoftware/foss/blob/3cebfeb062671db883fede60eca7a147ea3de648/access-token-management/src/AccessTokenManagement/Internal/ClientCredentialsTokenClient.cs#L182

Is there an existing recommended approach to override the TokenEndpoint dynamically per request, or is this not supported by the current design?

[wcabus]

At the moment, overriding the TokenEndpoint URL is not possible using either approach. We are however investigating adding this as a potential new feature in a next release (4.2.0 or later).

What you can try right now, depending on how much control you have over the token endpoint handler, is to include the tenant ID in the TokenRequestParameters.Parameters dictionary. These parameters will eventually be added to the form contents that are posted to the token endpoint.

Here's a sample implementation for a ITokenRequestCustomizer which adds a tenant_id to the form. If you need to inject services in your custom ITokenRequestCustomizer, you'll need to wait for the official 4.1.0 release of the Duende.AccessTokenManagement NuGet packages, as the current release candidate version does not yet support injecting this service type using a dependency injection resolver.

public class TenantTokenRequestCustomizer : ITokenRequestCustomizer
{
    public Task<TokenRequestParameters> Customize(
        HttpRequestMessage httpRequest,
        TokenRequestParameters baseParameters,
        CancellationToken cancellationToken = default)
    {
        if (httpRequest.Headers.TryGetValues("X-Tenant-Id", out var tenantIds))
        {
            var tenantId = tenantIds.FirstOrDefault();
            if (!string.IsNullOrEmpty(tenantId))
            {
                baseParameters.Parameters.Add("tenant_id", tenantId);
            }
        }
        else if (httpRequest.RequestUri?.Query.Contains("tenant_id") ?? false)
        {
            // Extract tenant_id from query parameters
            var queryParams = System.Web.HttpUtility.ParseQueryString(httpRequest.RequestUri.Query);
            var tenantId = queryParams["tenant_id"];
            if (!string.IsNullOrEmpty(tenantId))
            {
                baseParameters.Parameters.Add("tenant_id", tenantId);
            }
        }
        else
        {
            // Fallback tenant ID
            baseParameters.Parameters.Add("tenant_id", "default");
        }
        
        return Task.FromResult(baseParameters);
    }
}

[alefcarlos]

Thank so much you for the reply, i got it! For now I will create a proxy-service to handle that migration scenario.