Authored by David Fowler, this article explores Aspire’s role as a modern DevOps toolchain, detailing its design philosophy, core features, and broad support for polyglot distributed app development.

Aspire: A Modern DevOps Toolchain

By David Fowler

Aspire was initially launched to transform how developers build distributed applications. Over time, however, its uses expanded far beyond its original scope. Developers began applying Aspire to greenfield deployments, developer onboarding, test scaffolding, service bootstrapping, infrastructure automation, and even as a flexible glue layer for local DevOps tasks. This diversity in use cases raised new and important questions about Aspire’s place in modern software development:

  • Is Aspire just for local development?
  • Does it handle deployment as well?
  • What about CI/CD pipelines?
  • Can it be used outside Azure?
  • How does it fit into a multi-repo setup?
  • Can it bridge a JavaScript frontend with a .NET backend, or integrate with Python AI modules?

These were not fringe concerns but challenges faced by real teams solving real problems. Aspire was already addressing these issues, albeit quietly. This led the Aspire team to clarify their message and refocus on what truly sets Aspire apart.

Why Aspire Exists

Aspire represents a modern vision for a DevOps toolchain tailored to application developers. The core belief is straightforward: applications are more than just code—they are networks of resources (APIs, databases, queues, frontends, secrets, containers) and the relationships between them.

In today’s landscape, connecting these resources is laborious, often involving numerous fragile scripts and configurations. Developers can lose days battling environment inconsistencies, reworking infrastructure scripts, or debugging “works on my machine” problems. Aspire addresses these periods of lost productivity by formalizing these tasks within a programmable application model—a single source of truth for running, testing, and deploying distributed systems.

From Local Dev to Deployment: One Unified Model

Aspire’s process eliminates the need to juggle multiple tools and scripts (such as Docker Compose files, cloud templates, test harnesses, and onboarding scripts). Instead, Aspire introduces a phased workflow built on a shared model:

model → run → test → publish → deploy

Each phase uses the same model as its foundation:

  • Run: Launches the full system locally with orchestration—services, sample data, and HTTPS are available out of the box.
  • Test: Allows end-to-end testing with the actual system model, away from mocks or duplicated logic.
  • Publish: Generates images, configurations, and infrastructure definitions from the model, enabling integration with existing toolchains.
  • Deploy: Uses plugins or custom code (with the model as input) to automate rollout to Docker, Kubernetes, or cloud providers.

Phases are optional, and each is extensible. Developers can customize or integrate Aspire as much or as little as needed, always treating the application model as the single source of truth.

The Application Model: Code as Infrastructure, Documentation, and Workflow

The application model at the heart of Aspire is a directed acyclic graph (DAG), describing the full system—containers, APIs, databases, secrets, queues, and how they connect.

This model isn’t static. It is a live representation that powers:

  • aspire run: Launches all system components for development.
  • Testing: The model serves as the test fixture.
  • Deployment: Orchestration and rollout is driven from the same model.
  • Onboarding: Helps new developers get started without digging through scripts or outdated documentation.

Developers are freed from piecing together infrastructure knowledge across disparate wikis and scripts. They simply execute the application model.

Designed for Real-World Use Cases

Aspire was shaped by extensive feedback from developers encountering these problems firsthand. The team’s philosophy is to provide robust building blocks and paved paths, not to force full adoption from the start. Common entrypoints include:

  • Adding resources to test environments
  • Seeding local databases
  • Automating secrets injection during development
  • Gradually expanding to publishing and deployment with custom environment extensions

Developers decide what Aspire manages and how it integrates with existing systems, keeping control and flexibility.

Aspire at Microsoft

Within Microsoft, Aspire isn’t just a tool for external developers—internal teams are adopting and expanding Aspire as well. The team is developing extensions that support onboarding, deployment, and automation for Microsoft’s own services. This drives first-class support and broader adoption across Microsoft’s engineering ecosystem.

Aspire Beyond .NET: Embracing Polyglot Development

Aspire was often mistaken for a .NET-only framework, but that’s no longer the case. The roadmap includes:

  • Official support for Python and JavaScript (including opinionated pip and npm packages for telemetry, service discovery, and configuration)
  • Improved integration parity for Python and JavaScript with .NET projects
  • A cross-runtime host prototype leveraging WebAssembly (WASM) and WebAssembly Interface Types (WIT)

Today’s distributed applications are inherently polyglot, and Aspire’s aim is to match that reality.

What’s Next: Aspire as a DevOps IDE

While jokingly referred to as a “DevOps IDE,” Aspire’s vision is to provide developers with the tooling required to reason about, operate, and ship entire systems—not just code. Aspire targets teams that:

  • Lose time managing infrastructure wiring
  • Struggle with test harnesses
  • Face slow or confusing onboarding
  • Need to coordinate multi-environment rollouts
  • Experience inconsistent builds or unreliable setups

Aspire offers a focused solution for these scenarios.

Get Involved

Aspire is developed openly, with the team welcoming community feedback, questions, and contributions.

Aspire is evolving as a flexible and powerful toolchain aimed squarely at the challenges of modern, distributed, and polyglot app development.

David Fowler – Distinguished Engineer at Microsoft

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