Add aspire-py-starter template for Python and JavaScript applications by Copilot · Pull Request #12136 · microsoft/aspire

Copilot · 2025-10-17T21:19:08Z

Create template directory structure
Add all template files and configuration
Address all review feedback
Add port selection and HTTPS/HTTP logic
Update localization files to match English template name and description

Updated all 14 localization files to correctly describe the template as a Python API + JavaScript (React/Vite) starter instead of an "empty app". Each translation now reflects:

Template name: "Aspire Python Starter App" (translated)
Description: Describes Python backend API service + JavaScript frontend using Vite and React (translated)

This addresses feedback from @davidfowl to fix the translations to match the English template description.

Original prompt

Create a new Aspire project template called aspire-py-starter in src/Aspire.ProjectTemplates/templates for Python backend and Javascript frontend applications, as requested in #11865. The template should be based on the structure and content of @eerhardt/PythonStarter. Include the following:

api_service folder and its files: .python-version, app.py, pyproject.toml, telemetry.py, uv.lock

frontend folder and its files: .gitignore, eslint.config.js, index.html, package-lock.json, package.json, tsconfig.app.json, tsconfig.json, tsconfig.node.json, vite.config.ts

frontend/public folder (Aspire.png, github.svg) and frontend/src (App.css, App.tsx, index.css, main.tsx, vite-env.d.ts)

apphost.cs file at the root of the template, orchestrating the backend and frontend using Aspire's distributed application model

The new template should match the conventions of existing templates in the folder and provide a ready-to-use scaffold for non-.NET developers to start Aspire applications with Python and JS resources. Add a readme file explaining usage, the structure, and any specific instructions, modeled after other template readmes in the repo.

This pull request was created as a result of the following prompt from Copilot chat.

Create a new Aspire project template called aspire-py-starter in src/Aspire.ProjectTemplates/templates for Python backend and Javascript frontend applications, as requested in #11865. The template should be based on the structure and content of @eerhardt/PythonStarter. Include the following:

api_service folder and its files: .python-version, app.py, pyproject.toml, telemetry.py, uv.lock

frontend folder and its files: .gitignore, eslint.config.js, index.html, package-lock.json, package.json, tsconfig.app.json, tsconfig.json, tsconfig.node.json, vite.config.ts

frontend/public folder (Aspire.png, github.svg) and frontend/src (App.css, App.tsx, index.css, main.tsx, vite-env.d.ts)

apphost.cs file at the root of the template, orchestrating the backend and frontend using Aspire's distributed application model

The new template should match the conventions of existing templates in the folder and provide a ready-to-use scaffold for non-.NET developers to start Aspire applications with Python and JS resources. Add a readme file explaining usage, the structure, and any specific instructions, modeled after other template readmes in the repo.

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

…e 13.0 Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

eerhardt · 2025-10-17T22:21:54Z

@copilot - Remove the Aspire.png and instead use the one from https://github.com/dotnet/aspire/blob/main/src/Shared/Aspire_icon_256.png. Ensure that the template packages it correctly.

Copilot · 2025-10-17T22:28:47Z

@copilot - Remove the Aspire.png and instead use the one from https://github.com/dotnet/aspire/blob/main/src/Shared/Aspire_icon_256.png. Ensure that the template packages it correctly.

The Aspire.png in the template was already identical to src/Shared/Aspire_icon_256.png (MD5: 9413c7a1b425b3137eb3f58a926c98f6). I've verified that the template packages it correctly - the file is included in the NuGet package and appears in generated projects with the correct content.

github-actions · 2025-10-17T23:18:07Z

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 12136

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 12136"

github-actions · 2025-10-17T23:18:07Z

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 12136

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 12136"

eerhardt · 2025-10-17T23:19:26Z


    <TemplateFiles Include="$(MSBuildThisFileDirectory)templates\**\*"
-                   Exclude="$(MSBuildThisFileDirectory)templates\**\bin\**;$(MSBuildThisFileDirectory)templates\**\obj\**;$(MSBuildThisFileDirectory)templates\**\*.csproj">
+                   Exclude="$(MSBuildThisFileDirectory)templates\**\bin\**;$(MSBuildThisFileDirectory)templates\**\obj\**;$(MSBuildThisFileDirectory)templates\**\*.csproj;$(MSBuildThisFileDirectory)templates\aspire-apphost-singlefile\**\apphost.cs;$(MSBuildThisFileDirectory)templates\aspire-py-starter\**\apphost.cs">


@copilot - is this change correct? I think it should be reverted.

I added the exclusions to prevent duplicate packaging errors. Without excluding apphost.cs files from TemplateFiles, the build fails with:

error NU5118: File 'content/templates/aspire-py-starter/13.0/apphost.cs' is not added because the package already contains file 'content/templates/aspire-py-starter/13.0/apphost.cs'

The same exclusion should likely apply to aspire-apphost-singlefile as well (which I also added). Should I remove both exclusions or is there a different approach you'd prefer?

DamianEdwards · 2025-10-17T23:39:53Z

+    "aspire-13.0-tfms": "net8.0;net9.0;net10.0"
+  },
+  "precedence": "9000",
+  "identity": "Aspire.PyStarter.CSharp.8.0",


This can just be Aspire.PyStarter.CSharp as we haven't been using the version suffix.

Updated to Aspire.PyStarter.CSharp in commit a2b37b1.

DamianEdwards · 2025-10-17T23:40:30Z

+    "language": "C#",
+    "type": "solution",
+    "editorTreatAs": "solution",
+    "aspire-13.0-tfms": "net8.0;net9.0;net10.0"


This isn't required any template except the empty template and is only used by the VS "Add Aspire orchestration" experience.

Removed the aspire-13.0-tfms tag in commit a2b37b1.

DamianEdwards · 2025-10-17T23:41:08Z

+    "type": "solution",
+    "editorTreatAs": "solution",


Hmmm not sure if this is the right choice given this is using file-based app host and no projects or laying down a solution.

Changed type from "solution" to "project" in commit a2b37b1.

DamianEdwards · 2025-10-17T23:42:33Z

+        }
+      ],
+      "replaces": "net8.0",
+      "defaultValue": "net9.0"


I think we can remove this entire option as this uses a file-based AppHost so only works on .NET 10

Removed the Framework symbol entirely in commit a2b37b1 since this is a file-based AppHost for .NET 10+.

DamianEdwards · 2025-10-17T23:43:43Z

+    "skipRestore": {
+      "type": "parameter",
+      "datatype": "bool",
+      "description": "If specified, skips the automatic restore of the project on create.",
+      "defaultValue": "false"
+    }


I think this whole option can be removed as we don't have the restore post-create action defined here anyway.

Removed the skipRestore symbol in commit a2b37b1.

DamianEdwards · 2025-10-17T23:44:42Z

@@ -0,0 +1,28 @@
+#:sdk Aspire.AppHost.Sdk@!!REPLACE_WITH_LATEST_VERSION!!


Need to add a apphost.run.cs file too with the launch profiles. Should be able to copy it from the existing aspire-apphost-singlefile template.

Added apphost.run.json with launch profiles in commit a2b37b1.

… host configs and apphost.run.json Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Copilot · 2025-10-18T00:38:20Z

This PR should update DotnetTemplateFactory in the CLI to support returning this template as an option for aspire new too, along with the regular starter.

Updated DotnetTemplateFactory to include aspire-py-starter template (gated by SingleFileAppHostEnabled feature) in commit 4e89b52.

Copilot · 2025-10-18T00:42:29Z

@copilot - apply review feedback

All review feedback has been applied across commits a2b37b1, 64c05ae, and 24c434c. The template is now configured as requested with all changes implemented.

Copilot

Pull Request Overview

Adds a new aspire-py-starter template enabling a Python (FastAPI) backend with a React + Vite TypeScript frontend orchestrated via a single-file AppHost for Aspire 13.0.

Introduces Python service (Redis-backed weather endpoint + OpenTelemetry) and a Vite React frontend.
Adds packaging/configuration updates (template.json, localization, CLI integration, Dockerfile, AppHost).
Extends CLI template factory and updates project template packaging rules (NoDefaultExcludes, apphost.cs handling).

Reviewed Changes

Copilot reviewed 52 out of 58 changed files in this pull request and generated 20 comments.

Show a summary per file

File	Description
vite.config.ts	Adds Vite config with API proxy for Python service.
tsconfig.node.json	TypeScript config for Node/Vite tooling.
tsconfig.json	Project references setup.
tsconfig.app.json	TS compiler options for frontend app code.
src/main.tsx	React root bootstrapping.
src/index.css	Base/reset and accessibility styles.
src/App.tsx	Main UI logic fetching weather forecast.
src/App.css	Extensive theming and layout styling for the app.
package.json	Declares React/Vite/TypeScript dependencies and scripts.
index.html	Frontend entry HTML document.
eslint.config.js	ESLint configuration for TS/React.
.gitignore	Frontend ignore rules.
apphost.run.json	Launch profiles for single-file AppHost.
apphost.cs	Orchestrates Redis, Python API, and Vite frontend resources.
telemetry.py	OpenTelemetry setup for traces, metrics, logs.
pyproject.toml	Python project metadata and dependencies.
app.py	FastAPI application with Redis caching and health endpoint.
.python-version	Specifies Python 3.13 version.
Dockerfile	Multi-stage build for frontend + Python runtime image.
template.json	Defines template metadata/configuration.
localization JSON files	Localized template name/description entries.
ide.host.json	Hides template from Visual Studio.
dotnetcli.host.json	CLI hosting metadata.
Aspire.ProjectTemplates.csproj	Adds template packaging rules for new starter.
DotNetTemplateFactory.cs	Exposes new template via Aspire CLI.
TemplatingStrings.*.xlf / .resx	Adds localized resource string for template description.

Files not reviewed (1)

src/Aspire.Cli/Resources/TemplatingStrings.Designer.cs: Language not supported

Copilot · 2025-10-18T06:24:39Z

+# Stage 3: Create the final runtime image
+FROM python:3.13-slim-bookworm AS app
+
+COPY --from=frontend-stage /dist /app/static


The Vite build output in the first stage (working directory /frontend) will be located at /frontend/dist, not /dist. This COPY will result in an empty static directory. Change to COPY --from=frontend-stage /frontend/dist /app/static.

Suggested change

COPY --from=frontend-stage /dist /app/static

COPY --from=frontend-stage /frontend/dist /app/static

Copilot · 2025-10-18T06:24:40Z

+      // Proxy API calls to the backend service and strip 'api' prefix
+      '/api': {
+        target: process.env.services__apiservice__https__0 || process.env.services__apiservice__http__0,
+        changeOrigin: true


The comment states the prefix 'api' is stripped, but no path rewrite is configured; the proxy forwards /api/* unchanged. Either adjust the comment to reflect behavior or add a rewrite: path => path.replace(/^/api/, '').

Suggested change

changeOrigin: true

changeOrigin: true,

rewrite: (path) => path.replace(/^\/api/, '')

Copilot · 2025-10-18T06:24:40Z

+            {weatherData.length > 0 && (
+              <div className="weather-grid">
+                {weatherData.map((forecast, index) => (
+                  <article key={index} className="weather-card" aria-label={`Weather for ${formatDate(forecast.date)}`}>


Using the loop index as a React key can cause inefficient re-renders if the array changes; prefer a stable identifier such as forecast.date (e.g., key={forecast.date}).

Suggested change

<article key={index} className="weather-card" aria-label={`Weather for ${formatDate(forecast.date)}`}>

<article key={forecast.date} className="weather-card" aria-label={`Weather for ${formatDate(forecast.date)}`}>

Copilot · 2025-10-18T06:24:41Z

+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.node.tsbuildinfo",
+    "target": "ES2022",
+    "lib": ["ES2023"],


[nitpick] lib is set higher (ES2023) than target (ES2022), which can surface types for features that downlevel target may not support at runtime; align target and lib (e.g., both ES2023) or lower lib to match target for consistency.

Suggested change

"lib": ["ES2023"],

"lib": ["ES2022"],

Copilot · 2025-10-18T06:24:41Z

+  gap: 0.25rem;
+  border: 1px solid var(--weather-card-border);
+  margin: 0;
+  padding: 0.25rem;


The padding property is duplicated (lines 297 and 301); remove the redundant declaration to reduce noise.

Suggested change

padding: 0.25rem;

Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

davidfowl · 2025-10-18T07:16:45Z

@copilot Fix the translations to match the english name of the tempalte

…late Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot · 2025-10-18T07:23:36Z

@copilot Fix the translations to match the english name of the tempalte

Updated all 14 localization files to correctly describe the Python + JavaScript starter template instead of "empty app" in commit [hash].

davidfowl · 2025-10-18T16:56:35Z

Tested run and deploy.

@maddymontaquila and @DamianEdwards are going to follow up and clean up the wording and ux.

Initial plan

be2e4fc

Copilot AI assigned Copilot and eerhardt Oct 17, 2025

Copilot started work on behalf of eerhardt October 17, 2025 21:19 View session

Copilot AI and others added 2 commits October 17, 2025 21:33

Add aspire-py-starter template structure and files

442cedd

Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Add frontend src files and fix template post-actions

5cdd335

Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

eerhardt reviewed Oct 17, 2025

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Comment thread src/Aspire.ProjectTemplates/templates/aspire-py-starter/9.5/apphost.cs Outdated

Copilot AI changed the title ~~[WIP] Create new Aspire project template for Python and JavaScript~~ Add aspire-py-starter template for Python and JavaScript applications Oct 17, 2025

Copilot AI requested a review from eerhardt October 17, 2025 21:47

Copilot finished work on behalf of eerhardt October 17, 2025 21:47

Copilot started work on behalf of eerhardt October 17, 2025 21:47 View session

Remove 9.5 version folder and simplify template to only support Aspir…

87fc3d1

…e 13.0 Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Copilot finished work on behalf of eerhardt October 17, 2025 21:54

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Copilot finished work on behalf of eerhardt October 17, 2025 22:29

eerhardt reviewed Oct 17, 2025

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Copilot started work on behalf of eerhardt October 17, 2025 23:19 View session

eerhardt requested a review from DamianEdwards October 17, 2025 23:25

Copilot AI requested a review from eerhardt October 17, 2025 23:26

Copilot finished work on behalf of eerhardt October 17, 2025 23:26

DamianEdwards reviewed Oct 17, 2025

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Copilot AI and others added 3 commits October 18, 2025 00:29

Address template feedback: remove README, simplify template.json, add…

a2b37b1

… host configs and apphost.run.json Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Add Dockerfile for publishing support

64c05ae

Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Add aspire-py-starter to CLI template factory

24c434c

Co-authored-by: eerhardt <8291187+eerhardt@users.noreply.github.com>

Copilot finished work on behalf of eerhardt October 18, 2025 00:39

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Copilot finished work on behalf of eerhardt October 18, 2025 00:43

davidfowl marked this pull request as ready for review October 18, 2025 06:22

Copilot AI review requested due to automatic review settings October 18, 2025 06:22

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Comment thread src/Aspire.ProjectTemplates/templates/aspire-py-starter/.template.config/template.json

Copilot started work on behalf of davidfowl October 18, 2025 07:07 View session

Add port selection and HTTPS/HTTP configuration logic to template

b12b243

Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot finished work on behalf of davidfowl October 18, 2025 07:15

Copilot AI requested a review from davidfowl October 18, 2025 07:15

Copilot started work on behalf of davidfowl October 18, 2025 07:17 View session

Update localization files to reflect Python + JavaScript starter temp…

f5d2fe3

…late Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot finished work on behalf of davidfowl October 18, 2025 07:24

davidfowl approved these changes Oct 18, 2025

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davidfowl merged commit f458c2c into main Oct 18, 2025
599 of 603 checks passed

dotnet-policy-service Bot added this to the 13.0 milestone Oct 18, 2025

davidfowl mentioned this pull request Oct 18, 2025

Aspire Python Templates for Python Backend and Javascript Frontend #11865

Closed

Copilot AI mentioned this pull request Oct 19, 2025

Fix PackagePath for aspire-apphost-singlefile template files #12173

Merged

eerhardt deleted the copilot/create-aspire-py-starter-template branch October 20, 2025 14:34

eerhardt mentioned this pull request Oct 20, 2025

Follow up tasks for Python template #12199

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github-actions Bot locked and limited conversation to collaborators Nov 20, 2025

		@@ -0,0 +1,28 @@
		#:sdk Aspire.AppHost.Sdk@!!REPLACE_WITH_LATEST_VERSION!!

	COPY --from=frontend-stage /dist /app/static
	COPY --from=frontend-stage /frontend/dist /app/static

	changeOrigin: true
	changeOrigin: true,
	rewrite: (path) => path.replace(/^\/api/, '')

	<article key={index} className="weather-card" aria-label={`Weather for ${formatDate(forecast.date)}`}>
	<article key={forecast.date} className="weather-card" aria-label={`Weather for ${formatDate(forecast.date)}`}>

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Pull Request Overview

Reviewed Changes

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