Creating applications

An Application is the deployable unit in SpinUP. Every function lives inside one.

From the UI

1. Open the UI (default http://localhost:5173).
2. Click New application.
3. Fill in:
   • Name: DNS-1123 compliant (lowercase alphanumerics + hyphens, starts + ends with a letter or digit). This becomes the SpinApp name, the OCI image name, and the K8s Service name.
   • Language: Go, JavaScript, TypeScript, or Rust. Determines which builder image runs.
   • Description (optional): shows in the applications list.
4. Click Create.

SpinUP auto-creates a first Function with the same name as the Application, and pre-populates its main.go / index.js / index.ts / lib.rs with the language template. You land on the function detail page ready to edit.

From the API

curl -X POST http://localhost:8080/api/v1/applications \
  -H 'content-type: application/json' \
  -d '{
    "name": "greeter",
    "language": "go",
    "description": "Says hi in five ways"
  }'

Response includes the new Application ID and its auto-created first Function:

{
  "id": "…",
  "name": "greeter",
  "language": "go",
  "functions": [
    { "id": "…", "name": "greeter", "route": "/..." }
  ]
}

Adding more functions

An Application can host multiple functions, each with its own HTTP route. All functions in an Application share:

• One Spin runtime process (one pod)
• One OCI image per build
• One spin.toml (with N [[trigger.http]] blocks and N [component.X] blocks)

Add a function via the + Add function button on the application page, or:

curl -X POST "http://localhost:8080/api/v1/applications/$APP_ID/functions" \
  -H 'content-type: application/json' \
  -d '{"name": "farewell", "route": "/bye/..."}'

The route defaults to /{function-name}/... if you omit it.

Deleting

Deleting an Application removes:

• The applications row (cascades to functions, sources, builds)
• The SpinApp CR
• Function pods, Services, and any Ingress/Gateway resources tied to the SpinApp

It doesn't delete:

• The pushed OCI images in the registry — garbage-collect those separately
• Historical metric time series in your TSDB — they age out via retention policy

curl -X DELETE http://localhost:8080/api/v1/applications/$APP_ID

What you can change vs what you can't

Property	Editable after create?
name	No — used as the SpinApp CR name
language	No — locks the builder
description	Yes
Function route	Yes — takes effect on next build
Function source	Yes — takes effect on next build
Function count	Yes — add or remove functions

Everything on the right is metadata; the left column would require recreating the Application.