diff --git a/.github/workflows/yamllint.yaml b/.github/workflows/yamllint.yaml
new file mode 100644
index 0000000..16a78d3
--- /dev/null
+++ b/.github/workflows/yamllint.yaml
@@ -0,0 +1,15 @@
+name: yamllint
+on: [pull_request]
+jobs:
+  yamllint:
+    name: runner / yamllint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: yamllint
+        uses: reviewdog/action-yamllint@v1.9.0
+        with:
+          reporter: github-pr-review
+          filter_mode: nofilter
+          yamllint_flags: 'apis/'
+          fail_on_error: true
diff --git a/.yamllint b/.yamllint
new file mode 100644
index 0000000..669c864
--- /dev/null
+++ b/.yamllint
@@ -0,0 +1,5 @@
+extends: default
+
+rules:
+  line-length: disable
+  document-start: disable
diff --git a/Makefile b/Makefile
index 7822e77..e3698de 100644
--- a/Makefile
+++ b/Makefile
@@ -67,4 +67,12 @@ uptest: $(UPTEST) $(KUBECTL) $(KUTTL)
 # - UPTEST_CLOUD_CREDENTIALS, cloud credentials for the provider being tested, e.g. export UPTEST_CLOUD_CREDENTIALS=$(cat ~/.aws/credentials)
 e2e: build controlplane.up local.xpkg.deploy.configuration.$(PROJECT_NAME) uptest
 
-.PHONY: uptest e2e
+render:
+	crossplane beta render examples/app-claim.yaml apis/composition.yaml examples/functions.yaml -r
+
+yamllint:
+	@$(INFO) running yamllint
+	@yamllint ./apis || $(FAIL)
+	@$(OK) running yamllint
+
+.PHONY: uptest e2e render yamllint
diff --git a/apis/definition.yaml b/apis/definition.yaml
index 16f1e29..6d1276e 100644
--- a/apis/definition.yaml
+++ b/apis/definition.yaml
@@ -12,57 +12,57 @@ spec:
     kind: App
     plural: apps
   versions:
-  - name: v1alpha1
-    served: true
-    referenceable: true
-    schema:
-      openAPIV3Schema:
-        type: object
-        properties:
-          spec:
-            type: object
-            properties:
-              parameters:
-                type: object
-                description: App configuration parameters.
-                properties:
-                  deletionPolicy:
-                    description: Delete the external resources when the Claim/XR is deleted. Defaults to Delete
-                    enum:
-                      - Delete
-                      - Orphan
-                    type: string
-                    default: Delete
-                  providerConfigName:
-                    description: Crossplane ProviderConfig to use for provisioning this resources
-                    type: string
-                  helm:
-                    type: object
-                    description: Configuration for operators.
-                    properties:
-                      chart:
-                        type: object
-                        description: Configuration for the Helm Chart
-                        properties:
-                          name:
-                            type: string
-                            description: chart name
-                          repo:
-                            type: string
-                            description: chart repo
-                          version:
-                            type: string
-                            description: chart version
-                  passwordSecretRef:
-                    type: object
-                    description: "A reference to the Secret object containing database credentials"
-                    properties:
-                      namespace:
-                        type: string
-                      name:
-                        type: string
-                    required:
-                      - namespace
-                      - name
-                required:
-                - providerConfigName
+    - name: v1alpha1
+      served: true
+      referenceable: true
+      schema:
+        openAPIV3Schema:
+          type: object
+          properties:
+            spec:
+              type: object
+              properties:
+                parameters:
+                  type: object
+                  description: App configuration parameters.
+                  properties:
+                    deletionPolicy:
+                      description: Delete the external resources when the Claim/XR is deleted. Defaults to Delete
+                      enum:
+                        - Delete
+                        - Orphan
+                      type: string
+                      default: Delete
+                    providerConfigName:
+                      description: Crossplane ProviderConfig to use for provisioning this resources
+                      type: string
+                    helm:
+                      type: object
+                      description: Configuration for operators.
+                      properties:
+                        chart:
+                          type: object
+                          description: Configuration for the Helm Chart
+                          properties:
+                            name:
+                              type: string
+                              description: chart name
+                            repo:
+                              type: string
+                              description: chart repo
+                            version:
+                              type: string
+                              description: chart version
+                    passwordSecretRef:
+                      type: object
+                      description: "A reference to the Secret object containing database credentials"
+                      properties:
+                        namespace:
+                          type: string
+                        name:
+                          type: string
+                      required:
+                        - namespace
+                        - name
+                  required:
+                    - providerConfigName
diff --git a/examples/functions.yaml b/examples/functions.yaml
new file mode 100644
index 0000000..98c28bd
--- /dev/null
+++ b/examples/functions.yaml
@@ -0,0 +1,6 @@
+apiVersion: pkg.crossplane.io/v1beta1
+kind: Function
+metadata:
+  name: upbound-function-patch-and-transform
+spec:
+  package: xpkg.upbound.io/upbound/function-patch-and-transform:v0.2.1