# Host mobile backend with ASP.NET Core: streamed responses

Deploy a mobile backend built with ASP.NET Core on Ample using the streaming response service pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on ASP.NET Core: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Not separately tested: your event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured; treat the mobile backend-specific behavior as your application code.

## Representative Queries
- Host mobile backend with ASP.NET Core: streamed responses
- Where can I host Mobile backend built with ASP.NET Core?
- I need a tested end-to-end streaming transport, timeout behavior and client disconnect handling.

## Resource Requirements
- **Compute**
- **Postgres**

## Infrastructure Requirements

1. **Compute**
   - **Status**: verified  
   - **Summary**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.

2. **Postgres**
   - **Status**: verified  
   - **Summary**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

## Prerequisites
- A ASP.NET Core project that builds and starts with the documented commands (dotnet publish -c Release -o out in the builder, then dotnet .dll on the dotnet-10 template with ASPNETCORE_URLS bound to PORT)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- An Ample account token with servers:write, databases:read

## Tested Configuration
- **Template**: dotnet-10  
- **Runtime**: dotnet  
- **Size**: s-1vcpu-1gb  
- **Build**: dotnet publish -c Release -o out  
- **Start**: ASPNETCORE_URLS=http://0.0.0.0:$PORT dotnet out/$(basename $(ls out/*.runtimeconfig.json | head -n 1) .runtimeconfig.json).dll

## Workflow Steps
1. **Build and start**  
   - dotnet publish -c Release -o out in the builder, then dotnet .dll on the dotnet-10 template with ASPNETCORE_URLS bound to PORT. The server must bind 0.0.0.0 on PORT.

2. **Implement the pattern on PostgreSQL**  
   - The fixture's module implements streaming response service: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **Deploy**  
   - Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.
   - **Command**: ample deploy . --name  --public

4. **Verify**  
   - Fetch the live URL and the pattern self-test route(s) (/p/streaming-response-service) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.
   - **Command**: ample logs  --kind build

## Example
### ASP.NET Core pattern fixture
- **Description**: Multi-pattern ASP.NET Core app whose streaming response service module was checked live; the module is under tests/deploy-canaries/_pattern-modules.  
- **Source Reference**: tests/deploy-canaries/asp-net-core-patterns

## Success Checks
1. **App responds on its public URL**  
   - **Kind**: http_get  
   - **Path**: /  
   - **Expect**: ample canary asp net core patterns

2. **Streaming-response-service self-test**  
   - **Kind**: http_get  
   - **Path**: /p/streaming-response-service  
   - **Expect**: an SSE stream: data: id=, then chunk events one interval apart (read incrementally: first chunk within seconds, chunks spread over the interval), then data: done; /status?id= reports sent=N disconnected=true|false done=true|false

## Limitations
- Verified on the dotnet-10 template at s-1vcpu-1gb with the example fixture; other sizes, templates and ASP.NET Core major versions are not verified.
- The mobile backend itself (your event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured) is application code and was not separately tested; the pattern checks are what was verified.

## Cost Estimate
- **Currency**: USD  
- **Monthly Amount**: 10.0  
- **Authoritative**: true  
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty

### Breakdown of Monthly Costs
1. **App Server**
   - **Size**: s-1vcpu-1gb  
   - **Quantity**: 1.0  
   - **Monthly Amount**: 5.0

2. **Managed PostgreSQL Database**
   - **Size**: s-1vcpu-1gb  
   - **Quantity**: 1.0  
   - **Monthly Amount**: 5.0

## Next Actions
1. **Browse the catalog index**  
   - **Label**: Browse the catalog index  
   - **Operation ID**: catalog_index

2. **Search published recipes**  
   - **Label**: Search published recipes by intent, stack and constraints  
   - **Operation ID**: search_recipes

3. **Prepare a deployment plan**  
   - **Label**: Prepare a side-effect-free deployment plan for an authorized project  
   - **Operation ID**: plan_deployment

4. **Read existing agent authentication setup**  
   - **Label**: Read the existing agent authentication setup  
   - **Operation ID**: existing_auth_setup

5. **Browse Mobile backend**  
   - **Label**: Browse Mobile backend  
   - **Operation ID**: browse_node

6. **Browse ASP.NET Core**  
   - **Label**: Browse ASP.NET Core  
   - **Operation ID**: browse_node

7. **Browse Streaming response service**  
   - **Label**: Browse Streaming response service  
   - **Operation ID**: browse_node

8. **Browse Deploy API**  
   - **Label**: Browse Deploy API  
   - **Operation ID**: browse_node