aspire

Aspire — Polyglot Distributed-App Orchestration

Aspire is a code-first, polyglot toolchain for building observable, production-ready distributed applications. It orchestrates containers, executables, and cloud resources from a single AppHost project — regardless of whether the workloads are C#, Python, JavaScript/TypeScript, Go, Java, Rust, Bun, Deno, or PowerShell.

Mental model: The AppHost is a conductor — it doesn't play the instruments, it tells every service when to start, how to find each other, and watches for problems.

Detailed reference material lives in the references/ folder — load on demand.

References

1. Researching Aspire Documentation

The Aspire team ships an MCP server that provides documentation tools directly inside your AI assistant. See MCP Server for setup details.

Aspire CLI 13.2+ (recommended — has built-in docs search)

If running Aspire CLI 13.2 or later (aspire --version), the MCP server includes docs search tools:

These tools were added in PR #14028.

Aspire CLI 13.1 (integration tools only)

On 13.1, the MCP server provides integration lookup but not docs search:

For general docs queries on 13.1, use Context7 as your primary source (see below).

Fallback: Context7

Use Context7 (mcp_context7) when the Aspire MCP docs tools are unavailable (13.1) or the MCP server isn't running:

Step 1 — Resolve the library ID (one-time per session):

Call mcp_context7_resolve-library-id with libraryName: ".NET Aspire".

Step 2 — Query docs:

libraryId: "/microsoft/aspire.dev", query: "Python integration AddPythonApp service discovery"
libraryId: "/communitytoolkit/aspire", query: "Golang Java Node.js community integrations"

Fallback: GitHub search (when Context7 is also unavailable)

Search the official docs repo on GitHub:

• Docs repo: microsoft/aspire.dev — path: src/frontend/src/content/docs/
• Source repo: dotnet/aspire
• Samples repo: dotnet/aspire-samples
• Community integrations: CommunityToolkit/Aspire

2. Prerequisites & Install

# Verify
aspire --version

# Install templates
dotnet new install Aspire.ProjectTemplates

3. Project Templates

4. AppHost Quick Start (Polyglot)

The AppHost orchestrates all services. Non-.NET workloads run as containers or executables.

var builder = DistributedApplication.CreateBuilder(args);

// Infrastructure
var redis = builder.AddRedis("cache");
var postgres = builder.AddPostgres("pg").AddDatabase("catalog");

// .NET API
var api = builder.AddProject<Projects.CatalogApi>("api")
    .WithReference(postgres).WithReference(redis);

// Python ML service
var ml = builder.AddPythonApp("ml-service", "../ml-service", "main.py")
    .WithHttpEndpoint(targetPort: 8000).WithReference(redis);

// React frontend (Vite)
var web = builder.AddViteApp("web", "../frontend")
    .WithHttpEndpoint(targetPort: 5173).WithReference(api);

// Go worker
var worker = builder.AddGolangApp("worker", "../go-worker")
    .WithReference(redis);

builder.Build().Run();

For complete API signatures, see Polyglot APIs.

5. Core Concepts (Summary)

6. CLI Quick Reference

Valid commands in Aspire CLI 13.1:

Full command reference with flags: CLI Reference.

7. Common Patterns

Adding a new service

1. Create your service directory (any language)
2. Add to AppHost: Add*App() or AddProject<T>()
3. Wire dependencies: .WithReference()
4. Gate on health: .WaitFor() if needed
5. Run: aspire run

Migrating from Docker Compose

1. aspire new aspire-apphost-singlefile (empty AppHost)
2. Replace each docker-compose service with an Aspire resource
3. depends_on → .WithReference() + .WaitFor()
4. ports → .WithHttpEndpoint()
5. environment → .WithEnvironment() or .WithReference()

8. Key URLs