What causes "template" in microsoft/aspire?

Pass --template explicitly, e.g. 'aspire new --template aspire-starter'

microsoft/aspire · error · NonInteractiveException

template

Error message

template

What it means

In non-interactive environments, NewCommand cannot prompt for a template. Instead of prompting, it displays the error and available template names and throws NonInteractiveException with the missing argument name 'template'.

Solutions

Pass --template explicitly, e.g. 'aspire new --template aspire-starter'
Run the command in an interactive terminal so the prompt can appear
Pre-provision the project with a script that always supplies --template

Example fix

// before
aspire new
// after
aspire new --template aspire-starter -n MyApp

Defensive patterns

Strategy: validation

Validate before calling

if (string.IsNullOrWhiteSpace(template) && !console.IsInputRedirected)
{
    template = await PromptForTemplateAsync(); // or fail fast with a clear message
}

Try / catch

try
{
    exitCode = await aspireNew.RunAsync(...);
}
catch (NonInteractiveException ex) when (ex.Message == "template")
{
    Console.Error.WriteLine("Pass --template <name> when running non-interactively.");
    exitCode = 1;
}

Prevention

Always pass --template in CI/non-TTY environments
Detect non-interactive stdin before invoking aspire new
Enumerate available templates once and pin the name in scripts

When it happens

Trigger: Running 'aspire new' (or a template-dependent new command) without --template in an environment where SupportsInteractiveInput is false (CI, non-TTY, piped stdin).

Common situations: CI pipelines or scripts running 'aspire new' without the --template flag; running inside a non-interactive shell where prompting is disabled.

Understand the failure class

Background: "no subcommand specified" and "... is required": CLI errors when a required argument is missing — this error's family across 13 libraries.

Related errors

AI-assisted analysis of microsoft/aspire@25830f84bd (2026-09-16). Data as JSON: /api/errors/55a53b48b79bf46e. Report an issue: GitHub.

Appendix: source

Thrown at src/Aspire.Cli/Commands/NewCommand.cs:325

            // The template subcommand was parsed successfully but the template is
            // not available at runtime (e.g. .NET SDK is not installed).
            InteractionService.DisplayError($"Template '{parseResult.CommandResult.Command.Name}' is not available. Ensure the required runtime is installed.");
            return null;
        }

        var templatesForTemplateArgument = GetTemplatesForTemplateArgument(availableTemplates, parseResult);
        if (templatesForTemplateArgument.Length == 0)
        {
            InteractionService.DisplayError("No templates are available for the current environment.");
            return null;
        }

        if (!_hostEnvironment.SupportsInteractiveInput)
        {
            InteractionService.DisplayError(NewCommandStrings.NonInteractiveTemplateRequired);
            var templateNames = string.Join(", ", templatesForTemplateArgument.Select(t => t.Name));
            InteractionService.DisplaySubtleMessage(string.Format(CultureInfo.CurrentCulture, InteractionServiceStrings.NonInteractiveAvailableValues, templateNames));
            throw new NonInteractiveException("template");
        }

        var templatesForPrompt = GetTemplatesForPrompt(availableTemplates, parseResult);
        if (templatesForPrompt.Length == 0)
        {
            InteractionService.DisplayError("No templates are available for the current environment.");
            return null;
        }

        var result = await _prompter.PromptForTemplateAsync(templatesForPrompt, cancellationToken);

        return result;
    }

    private sealed class ResolveTemplateVersionResult
    {
        public string? Version { get; init; }

View on GitHub (pinned to 25830f84bd)