microsoft/aspire · error · DistributedApplicationException

Resource ' ' is a DotnetProjectResource. Automatic project…

Error message

Resource '{resourceNames[0]}' is a DotnetProjectResource. Automatic project publishing for this experimental resource type is not supported. For a C# AppHost project reference, use AddProject<TProject>(...). For a path-based project or file-based app, use AddCSharpApp(...) in C# or addCSharpApp(...) in TypeScript. To publish this resource using explicit container configuration, call PublishAsDockerFile(...) in C# or publishAsDockerFile(...) in TypeScript. If it is intentionally run-only, call ExcludeFromManifest() in C# or excludeFromManifest() in TypeScript.

What it means

Error "Resource '{resourceNames[0]}' is a DotnetProjectResource. Automatic project publishing for this experimental resource type is not supported. For a C# AppHost project reference, use AddProject<TProject>(...). For a path-based project or file-based app, use AddCSharpApp(...) in C# or addCSharpApp(...) in TypeScript. To publish this resource using explicit container configuration, call PublishAsDockerFile(...) in C# or publishAsDockerFile(...) in TypeScript. If it is intentionally run-only, call ExcludeFromManifest() in C# or excludeFromManifest() in TypeScript." thrown in microsoft/aspire.

Solutions

1. Use AddProject<TProject>(...) for C# AppHost project references
2. Use AddCSharpApp(...) (C#) or addCSharpApp(...) (TypeScript) for path-based projects and file-based apps
3. Call PublishAsDockerFile(...) / publishAsDockerFile(...) to publish with explicit container configuration
4. Call ExcludeFromManifest() / excludeFromManifest(...) if the resource is intentionally run-only

When it happens

Trigger: Thrown at src/Aspire.Hosting.Dotnet/DotnetProjectResource.cs:90 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/aspire@25830f84bd (2026-09-16). Data as JSON: /api/errors/eedf8cb43450fdf6. Report an issue: GitHub.

Appendix: source

Thrown at src/Aspire.Hosting.Dotnet/DotnetProjectResource.cs:90

        Annotations.Add(new PipelineStepAnnotation(context =>
        {
            var unsupportedResources = context.PipelineContext.Model.Resources
                .OfType<DotnetProjectResource>()
                .Where(static resource => resource.RequiresPublishValidation())
                .ToArray();

            if (unsupportedResources.Length == 0 || !ReferenceEquals(context.Resource, unsupportedResources[0]))
            {
                return [];
            }

            return
            [
                new PipelineStep
                {
                    Name = ValidateDotnetProjectPublishStepName,
                    Description = "Validates publish support for .NET project resources.",
                    Action = _ => throw new DistributedApplicationException(
                        GetUnsupportedPublishMessage(unsupportedResources.Select(resource => resource.Name).ToArray())),
                    Resource = unsupportedResources[0]
                }
            ];
        }));

        // Configuration callbacks run in model order, so later compute-environment callbacks may not have attached
        // build and push work to publish or deploy yet. Use those steps' stable aggregation roots to add the
        // validation dependency before any step action can be scheduled.
        Annotations.Add(new PipelineConfigurationAnnotation(context =>
        {
            var validationStep = context.Steps.SingleOrDefault(step =>
                step.Name == ValidateDotnetProjectPublishStepName &&
                step.Resource is DotnetProjectResource resource &&
                resource.RequiresPublishValidation());

            if (validationStep is null)
            {

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