Guides creation and validation of custom dotnet new templates from existing projects.
Template Smart Defaults
Applies cross-parameter default rules when creating .NET projects with dotnet new, filling gaps consistently without overriding values the user set explicitly. USE FOR: choosing which target framework to pair with native AOT, deciding whether to keep HTTPS when authentication is enabled, recognizing that controllers and minimal-API flags are mutually exclusive, filling unset related parameters during project creation, explaining why a default was applied and ensuring an explicit user value is never overridden. DO NOT USE FOR: creating the project itself (use template-instantiation), finding or comparing templates (use template-discovery and template-comparison), authoring or validating custom templates (use template-authoring and template-validation).
Workflow
- Gather the parameters the user has explicitly set.
- Apply each rule below only where the corresponding parameter is unset — never override a value the user set explicitly.
- Confirm the chosen parameter names and choices against
dotnet new <template> --help
whenever the user asks for an exact command. This inspection does not create files and is worthwhile even for advice-only requests. Skip it only for a conceptual explanation that does not claim exact option names.
- Emit the two required outputs (see below) — this is what makes the skill decisive rather than inert.
For advice-only prompts that say "don't create files", make the displayed command safe to run by appending --dry-run. If a scenario needs a named example and the user omitted the name, choose a short descriptive sample name and mark it Source = rule. Do not add a name when the user asked for a command containing only explicitly requested choices or when the template can demonstrate those choices safely without one.
Required output
Always produce both, in this order:
A. A "Defaults applied" log — one row per parameter, covering both the explicit values you preserved (Source = user) and the gaps you filled by rule (Source = rule), so the user can see and override every choice:
| Parameter | Value | Source | Why | |-----------|-------|--------|-----| | --framework | net10.0 | rule | Native AOT (from --aot) needs the latest AOT-capable TFM | | --auth | Individual | user | Explicitly requested — left unchanged | | --name | AotWorker | rule | Added a descriptive sample name for this named example |
Use Source = user for explicit values (never overridden) and Source = rule for gap-fills.
B. The exact single `dotnet new` command line you would run — include only the flags you are actually passing. Do not list flags you decided *not* to pass (e.g. don't mention --no-https when you are keeping HTTPS; don't mention a minimal-API flag when using controllers). Silence on an omitted flag is the correct, decisive signal.
Always emit a flag the user explicitly requested when the observed template help exposes it, even when its value matches the template default; this keeps intent visible and reproducible (for example, --auth None). Omit only inferred defaults that you are not actually passing. Boolean switches such as --no-https are passed without true.
> AOT at create time vs publish time. --aot is a dotnet new flag only on the templates that expose it — always confirm with dotnet new <template> --help rather than assuming a given template does or doesn't offer it. There is no --publish-aot template flag — publish-time native AOT is enabled with the MSBuild property PublishAot=true (via dotnet publish or in the .csproj), not through dotnet new. Apply the framework rule only when the template actually offers --aot.
Rules
| Rule | Default applied | Rationale | |------|-----------------|-----------| | --aot is set (on any template whose --help exposes it) and --framework is unset | Set --framework to the latest AOT-compatible framework the template offers | Native AOT requires a recent, AOT-capable target framework; using the latest avoids build failures. (A framework already pinned by the workspace or global.json counts as set — keep it unless it's incompatible with AOT.) | | --auth is anything other than None | Do NOT pass --no-https | Authentication flows (cookies, tokens, redirects) require HTTPS; disabling it breaks auth. | | --use-controllers is set | Do NOT also pass a minimal-API flag | Controllers and minimal APIs are mutually exclusive program models; passing both is contradictory. | | User set a value explicitly | Leave it unchanged | Smart defaults only fill gaps; explicit user intent always wins. | | Advice-only command must not create files | Add --dry-run | The command itself must honor the no-write constraint, not only the agent's behavior. |
When controllers are explicitly requested, the command must contain the controller option shown by --help; explaining controllers without passing the option is incomplete.
Related skills
Compares two or more dotnet new templates side by side to help users choose between them based on parameters, feature support, frameworks, and classifications.
Helps find, inspect, and compare (at a high level) .NET project templates.
Building AI agents on .NET?
Managed Code builds production AI agents in C# and .NET.