Template Smart Defaults

SkillSecurity

Once added, your AI can create new .NET projects with the dotnet new command and fill in sensible default options for anything you leave out. It keeps related settings consistent, such as pairing the right target framework with native AOT or keeping HTTPS on when authentication is enabled, while never changing values you set yourself.

Available today. Use it from your connected AI after setup.

Add the skill, then ask your AI to create a new .NET project with dotnet new. It will apply the default rules to any options you leave out.

Then ask your AI: use the Template Smart Defaults skill

What your AI can do with it

  • Fill in missing options when creating .NET projects with dotnet new
  • Choose a target framework that pairs well with native AOT
  • Keep HTTPS enabled when authentication is turned on
  • Keep related project settings consistent with each other
  • Leave any options you set explicitly untouched

What this skill tells your AI

The instructions your AI receives, as published by dotnet/skills in plugins/dotnet-template-engine/skills/template-smart-defaults/SKILL.md and read by ahel’s review.

This skill helps an agent fill in cross-parameter defaults when creating a dotnet new project. The rules below are guidance heuristics that keep related parameters consistent — they only fill gaps and never override a value the user set explicitly.

When to Use

  • The user asks to create a project but leaves related parameters unspecified
  • A parameter the user chose implies a sensible value for another parameter
  • You need to explain why a particular default was selected

When Not to Use

  • User wants to actually create the project — route to template-instantiation
  • User wants to find or compare templates — route to template-discovery or template-comparison
  • User wants to author or validate a custom template — route to template-authoring or template-validation

Inputs

InputRequiredDescription
Template short nameYesThe template the project will be created from (e.g., webapi)
Parameters already chosenYesThe parameter values the user has explicitly set
Available choicesRecommendedParameter names/choices from dotnet new <template> --help

Workflow

  1. Gather the parameters the user has explicitly set.
  2. Apply each rule below only where the corresponding parameter is unset — never override a value the user set explicitly.
  3. 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.
  4. 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:

ParameterValueSourceWhy
--frameworknet10.0ruleNative AOT (from --aot) needs the latest AOT-capable TFM
--authIndividualuserExplicitly requested — left unchanged
--nameAotWorkerruleAdded 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

RuleDefault appliedRationale
--aot is set (on any template whose --help exposes it) and --framework is unsetSet --framework to the latest AOT-compatible framework the template offersNative 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 NoneDo NOT pass --no-httpsAuthentication flows (cookies, tokens, redirects) require HTTPS; disabling it breaks auth.
--use-controllers is setDo NOT also pass a minimal-API flagControllers and minimal APIs are mutually exclusive program models; passing both is contradictory.
User set a value explicitlyLeave it unchangedSmart defaults only fill gaps; explicit user intent always wins.
Advice-only command must not create filesAdd --dry-runThe 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.

Validation

  • A "Defaults applied" log was produced with a Source (user/rule) and rationale per row
  • The exact single dotnet new command line was emitted, listing only flags actually passed
  • No parameter the user set explicitly was overridden
  • Only unset parameters were filled
  • Exact parameter names/choices were confirmed against dotnet new <template> --help, including for advice-only exact commands
  • A no-file advice command includes --dry-run
  • Boolean switches are emitted without a trailing true

Common Pitfalls

PitfallSolution
Treating heuristics as enforcementThese are guidance rules, not validation. Always confirm against dotnet new <template> --help choices, since parameter names vary by template.
Overriding an explicit user valueApply a rule only when the target parameter is unset.
Assuming a flag nameThe exact flag differs per template — always verify with --help (e.g. --aot is present only where --help lists it; controllers use --use-controllers).
Picking a framework the template doesn't supportUse the latest framework that appears in the template's --framework choices, not an arbitrary newest version.
Showing a plain creation command after "don't create files"Append --dry-run so the displayed command is safe to execute.

More Info

Signals

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Last commit
Sep 2026
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Catalog kind
skill
Gateway key
template-smart-defaults
Source
github.com/dotnet/skills