AppHost

Aspire resources/Glossary/AppHost

AppHost

Aspire resources Glossary AppHost

Definition

Term type

Concept

The executable application model that declares your services, resources, connections, and local orchestration.

Also known as

orchestration project

You can write an AppHost in C# or any guest language supported through the Aspire Type System (ATS). It declares your resources and how they connect, orchestrates local development, and supplies an application model to deployment integrations.

Guest languages use generated SDKs to access exported hosting APIs. The available AppHost languages and APIs depend on your Aspire version and integrations.

The AppHost runs alongside your services; it is not the server that handles users’ requests. Configure an explicit readiness dependency when one resource must wait for another to become healthy.

Practical example

Model a frontend, an API, and a PostgreSQL database together, then give the API a database reference and an explicit readiness dependency.

Define your application with an AppHost

Related terms

• Aspire Type SystemA portable contract that exposes Aspire's .NET hosting APIs to supported guest languages through generated SDKs.
• Distributed applicationAn application whose parts communicate across process or network boundaries, rather than running as a single unit.
• ResourceA building block in the Aspire application model, such as a service, container, executable, cloud resource, or parameter.
• WaitForDelays a resource's startup until a dependency is running and its configured health checks pass.
• WithReferenceSupplies a consuming resource with connection strings or service endpoint configuration from another resource.