Polyglot samples for Aspire — demonstrating service orchestration across Python, JavaScript/Vite, Go, Java, C#, and mixed-language applications.
The hosted slides for the related talk can be found at:
https://chris-ayers.com/aspire-polyglot/
The source deck for this presentation lives in slides/ and is built with Marp.
Quick Start: cd samples/<sample> && aspire run
Prerequisites: Aspire CLI, Docker
The Aspire dashboard is a standalone container — point any OpenTelemetry app at it for logs, traces, and metrics, with no AppHost and no .NET.
| Sample | Entry point | Description |
|---|---|---|
| standalone-dashboard | docker-compose.yml |
Standalone dashboard + polyglot OTEL emitters (Node.js + Python + Go) — traces, metrics, and logs from three languages in one dashboard |
The whole dev-time orchestrator is a single file — no AppHost project, no Program.cs.
| Sample | AppHost | Description |
|---|---|---|
| dotnet-react-postgres | apphost.cs |
C# single-file AppHost — ASP.NET Core Minimal API + PostgreSQL + Vite React quotes board |
| hono-redis-urls | apphost.ts |
TypeScript single-file AppHost — Hono API + Redis + Vite URL shortener |
Single-file AppHosts focused on Docker images, aspire publish, and polyglot services.
| Sample | AppHost | Description |
|---|---|---|
| postgres-adminer | apphost.cs |
C# — adds two public Docker images directly (PostgreSQL + Adminer) with AddContainer; no Dockerfiles |
| go-redis-compose | apphost.cs |
C# + Go — aspire publish generates a runnable docker-compose.yaml (Go hit-counter API + Redis) |
| python-fastapi-docker | apphost.cs |
C# + Python — FastAPI runs natively (uvicorn) in dev; aspire publish auto-generates its Dockerfile |
| java-javalin-redis | apphost.cs |
C# + Java — Javalin leaderboard API (multi-stage Maven build) + Redis via AddDockerfile |
| Sample | AppHost | Description |
|---|---|---|
| vite-react-api | apphost.ts |
Vite + React + FastAPI + Redis — TODO app with caching |
| Sample | AppHost | Description |
|---|---|---|
| dotnet-angular-cosmos | AppHost/ |
ASP.NET Core + Angular 19 + CosmosDB emulator — recipe manager |
| Sample | AppHost | Description |
|---|---|---|
| polyglot-event-stream | AppHost/ |
C# producer + Python consumer + Node.js dashboard + Kafka — IoT sensor streaming |
Experimental polyglot AppHosts (Python, Go, Java) live under
samples/preview/. They rely on Aspire's preview polyglot AppHost support and may change as those languages stabilize.
| Sample | AppHost | Description |
|---|---|---|
| flask-markdown-wiki | apphost.py |
Flask + SQLite — Markdown wiki with create/edit/render pages |
| django-htmx-polls | apphost.py |
Django + HTMX — interactive voting polls with real-time bar charts |
| svelte-go-bookmarks | apphost.go |
Svelte SPA + Go API via AddDockerfile — bookmark manager with tagging |
| spring-boot-postgres | AppHost.java |
Spring Boot + PostgreSQL + pgAdmin — notes REST API via AddDockerfile |
Aspire is polyglot on two independent axes: the language you author the AppHost in, and the languages your workloads are written in. You mix and match freely — a C# AppHost can orchestrate Python and Go, a TypeScript AppHost can orchestrate .NET, and so on.
The orchestrator itself can be written in several languages. C# and TypeScript are generally available; Python, Go, and Java are experimental preview (enabled via the polyglotSupportEnabled feature — see aspire.config.json).
| AppHost language | File | Status | Sample(s) |
|---|---|---|---|
| C# | apphost.cs (single-file) or AppHost.csproj |
GA | dotnet-react-postgres, postgres-adminer, go-redis-compose, python-fastapi-docker, java-javalin-redis, dotnet-angular-cosmos, polyglot-event-stream |
| TypeScript | apphost.ts (legacy) / apphost.mts |
GA (13.4) | hono-redis-urls, vite-react-api, ts-starter |
| Python | apphost.py |
Preview | flask-markdown-wiki, django-htmx-polls |
| Go | apphost.go |
Preview | svelte-go-bookmarks |
| Java | AppHost.java |
Preview | spring-boot-postgres |
| Rust | apphost.rs |
Planned (SDK codegen groundwork exists) | — |
The same
.NEThosting integrations are surfaced to every AppHost language through the Aspire Type System (ATS): the CLI auto-generates a typed SDK (into.aspire/modules/, or.modules/for legacyapphost.ts) so guest-language AppHosts call the same integrations without hand-written bindings.
Inside the AppHost, each service is added with an Add* method. Some are language/runtime-specific; three are language-agnostic escape hatches that cover anything else.
| Mechanism | Adds | Demonstrated in |
|---|---|---|
AddProject<T>() |
A .NET project | dotnet-react-postgres, dotnet-angular-cosmos, polyglot-event-stream |
AddViteApp() |
Vite frontends (React, Vue, Svelte, Angular 17+, Astro) | dotnet-react-postgres, ts-starter |
AddNodeApp() |
A Node.js entry file | ts-starter |
AddJavaScriptApp() + .WithYarn() / .WithPnpm() / .WithBun() |
Any JS/TS app, auto-detecting the package manager | discussed — see JavaScript apps in the AppHost |
AddUvicornApp() (+ .WithUv()) / AddPythonApp() |
Python ASGI / script apps | python-fastapi-docker (AddUvicornApp), polyglot-event-stream (AddPythonApp) |
AddGoApp() — first-class Aspire.Hosting.Go (new in 13.4; Community Toolkit Golang deprecated) |
A Go module (go run, auto-Dockerfile on publish) |
discussed — repo currently orchestrates Go via AddDockerfile/AddExecutable; see Go apps in the AppHost |
AddBunApp() — Aspire.Hosting.JavaScript (now core in 13.4) |
A Bun app/script | discussed — see Bun integration |
AddDenoApp() / AddDenoTask() — Community Toolkit |
A Deno run script or deno task |
discussed — see Deno apps in the AppHost |
AddBlazorWasmProject() + AddBlazorGateway() (13.4 preview) |
Blazor WebAssembly + browser-facing gateway | discussed — see Blazor hosting |
AddSpringApp() — Community Toolkit |
A Java Spring Boot app | discussed — spring-boot-postgres orchestrates Spring via AddDockerfile |
AddDockerfile() |
Any language built from a Dockerfile | go-redis-compose (Go), java-javalin-redis (Java), hono-redis-urls & vite-react-api (Node/Python) |
AddContainer() |
Any prebuilt public image | postgres-adminer, and Redis in java-javalin-redis / hono-redis-urls |
AddExecutable() |
Any process/CLI | svelte-go-bookmarks (runs npm for the Svelte dev server) |
These wire the services together regardless of language — every runtime reads plain environment variables:
- Service discovery — Aspire injects
services__<name>__<protocol>__<index>into each service. - Connection strings — resources publish
ConnectionStrings__<resource>to their consumers (WithReference). - OpenTelemetry — any app that speaks OTLP shows up in the dashboard; the standalone dashboard needs no AppHost at all.
- Publishing —
aspire publishtargets Docker Compose (AddDockerComposeEnvironment), Kubernetes, or bakes SPAs into a container (PublishWithContainerFiles), independent of workload language.