aspire-configuration

1# Aspire Configuration
2 
3## When to Use This Skill
4 
5Use this skill when:
6- Wiring AppHost resources to application configuration in Aspire-based repos
7- Ensuring production configuration is transparent and portable outside of Aspire
8- Avoiding Aspire client/service-discovery packages inside application code
9- Designing feature toggles for dev/test without changing app code paths
10 
11---
12 
13## Core Principles
14 
151. **AppHost owns Aspire infrastructure packages**
16   - Aspire Hosting packages belong in AppHost only.
17   - App projects should not reference Aspire client/service-discovery packages.
18 
192. **Explicit configuration only**
20   - AppHost must translate resource outputs into explicit config keys (env vars).
21   - App code binds to `IOptions<T>` or `Configuration` only.
22 
233. **Production parity and transparency**
24   - Every value injected by AppHost must be representable in production as env vars
25     or config files without Aspire.
26   - Avoid opaque service discovery and implicit configuration.
27 
28---
29 
30## Configuration Flow
31 
32```
33AppHost resource -> WithEnvironment(...) -> app config keys -> IOptions<T> in app
34```
35 
36The AppHost is responsible for turning Aspire resources into explicit app settings.
37The application never consumes Aspire clients or service discovery directly.
38 
39---
40 
41## AppHost Patterns (Explicit Mapping)
42 
43### Example: Database + Blob Storage
44 
45```csharp
46// AppHost/Program.cs
47var builder = DistributedApplication.CreateBuilder(args);
48…