cue-kind-definition

name	cue-kind-definition
license	Apache-2.0
description	Author CUE kind definitions for grafana-app-sdk apps - schemas, versioning, field constraints, named type definitions, custom routes, and codegen configuration. Scaffolds kinds via `grafana-app-sdk project kind add`, writes spec/status schemas with type constraints (regex, enum, range), defines `#`-prefixed named types for reusable structs, registers versions in the app manifest, and runs `grafana-app-sdk generate` with explicit error recovery. Use when working with CUE kinds, adding a new resource type, adding a version to an existing kind, writing schema field constraints, defining `#Definition` types, adding custom routes, editing files under `kinds/`, or when the user asks to "model a resource", "add a CUE schema", or "write a kind" — even without saying "CUE" explicitly.

CUE Kind Definition

Common Workflows

Adding a new kind

# 1. Scaffold the kind files
grafana-app-sdk project kind add MyKind --overwrite
# Produces kinds/mykind.cue + kinds/mykind_v1alpha1.cue + updates kinds/manifest.cue.

# 2. Edit the generated .cue files — fill in schema.spec / schema.status fields

# 3. Generate types and clients
grafana-app-sdk generate

# 4. Verify the generated artifacts exist
ls pkg/generated/    # should contain new types for MyKind

If generate fails with CUE errors:

• Read the error — CUE prints the offending file + line + which constraint failed
• Common causes: missing required field, type mismatch (e.g. string field assigned an int), unresolved reference between version files
• Fix the .cue source, re-run grafana-app-sdk generate. Never edit files under pkg/generated/ — they're overwritten on every run.

Adding a new version to an existing kind

# 1. Copy the existing version file
cp kinds/mykind_v1alpha1.cue kinds/mykind_v1.cue

# 2. Edit kinds/mykind_v1.cue — rename the top-level object (e.g. myKindv1) and adjust the schema

# 3. Register the new version in kinds/manifest.cue
#    Add a versions["v1"]: { schema: myKindv1 } entry

# 4. Re-generate
grafana-app-sdk generate

# 5. Verify both versions were generated — per-version Go types live under pkg/generated/<group>/<version>/
ls pkg/generated/             # should list both version directories (e.g. v1alpha1/ v1/)
# Optionally inspect the CRD spec under definitions/ to confirm both versions appear in `spec.versions[]`

Breaking changes (removing fields, changing types, adding required fields) must go into a new version — never modify a stable version (v1, v2) in place.

Kind file structure

The CLI produces a flat layout under kinds/:

kinds/
├── manifest.cue           # App manifest + version list declarations
├── mykind.cue             # Common (cross-version) kind metadata
└── mykind_v1alpha1.cue    # v1alpha1 schema + codegen config

For multi-version kinds, additional version files sit alongside (mykind_v1.cue, etc.). For very large kind sets (10+ kinds), consider the per-kind subdirectory layout — full kind anatomy reference in references/kind-layout.md.

CUE Kind Anatomy

Three layers per kind:

1. Common kind metadata

// kinds/mykind.cue
package kinds

myKind: {
    kind: "MyKind"               // Required: PascalCase kind name
    // other cross-version fields (scope, pluralName, validation, mutation, conversion, …)
    // Full field reference in references/kind-layout.md.
}

2. Per-version schema

// kinds/mykind_v1alpha1.cue
package kinds

myKindv1alpha1: myKind & {
    schema: {
        spec: {                       // desired state — user-set
            title:       string
            description: string | *""
            count:       int & >=0
            enabled:     bool | *true
        }
        status: {                     // observed state — operator-set
            lastObservedGeneration: int | *0
            state:                  string | *""
            message:                string | *""
        }
    }
    codegen: {
        ts: { enabled: true }
        go: { enabled: true }
    }
}

3. App manifest

// kinds/manifest.cue
package kinds

App: {
    appName: "my-app"
    versions: {
        "v1alpha1": { schema: myKindv1alpha1 }
    }
}

Codegen configuration

Control what gets generated per kind per version:

codegen: {
    ts: { enabled: true | false }   // TypeScript types
    go: { enabled: true | false }   // Go types + client
}

Disabling go for frontend-only apps avoids unused Go code. Disabling ts for backend-only resources reduces bundle size. Both default to true when omitted.

References

• references/kind-layout.md — full common-metadata field reference + app manifest fields + per-kind subdirectory layout
• references/schema-types.md — CUE schema field types (basic types, constraints, regex, enums, maps, lists) + #-prefixed named type definitions
• references/custom-routes.md — kind-level + version-level custom routes + handler registration in app.go

External resources

• grafana-app-sdk GitHub
• CUE Language Reference
• Example kinds layout