diff --git a/schemas/schema-ap.json b/schemas/schema-ap.json
new file mode 100644
index 0000000..506682e
--- /dev/null
+++ b/schemas/schema-ap.json
@@ -0,0 +1,217 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "https://smorrone.github.io/test.schema/schemas/ap-model.json#",
+
+  "title": "ap Model Extension",
+  "description": "STAC Analysis and processing resources (ap) Model Extension for STAC Items.",
+  "oneOf": [
+    {
+      "$comment": "This is the schema for STAC Items. Remove this object if this extension only applies to Collections.",
+      "allOf": [
+        {
+          "$ref": "#/definitions/stac_extensions"
+        },
+        {
+          "type": "object",
+          "required": [
+            "type",
+            "properties",
+            "assets"
+          ],
+          "properties": {
+            "type": {
+              "const": "Feature"
+            },
+            "properties": {
+              "allOf": [
+                {
+                  "$comment": "Require fields here for Item Properties.",
+                  "required": [
+                    "ml-model:type",
+                    "ml-model:learning_approach",
+                    "ml-model:prediction_type",
+                    "ml-model:architecture"
+                  ]
+                },
+                {
+                  "$ref": "#/definitions/common_fields"
+                }
+              ]
+            },
+            "assets": {
+              "$comment": "This validates the fields in Item Assets, but does not require them.",
+              "type": "object",
+              "additionalProperties": {
+                "$ref": "#/definitions/common_fields"
+              }
+            }
+          }
+        }
+      ]
+    },
+    {
+      "$comment": "This is the schema for STAC Collections.",
+      "type": "object",
+      "allOf": [
+        {
+          "required": [
+            "type"
+          ],
+          "properties": {
+            "type": {
+              "const": "Collection"
+            }
+          }
+        },
+        {
+          "$ref": "#/definitions/stac_extensions"
+        }
+      ],
+      "anyOf": [
+        {
+          "$comment": "This validates the fields in Collection Assets, but does not require them.",
+          "required": [
+            "assets"
+          ],
+          "properties": {
+            "assets": {
+              "type": "object",
+              "not": {
+                "additionalProperties": {
+                  "not": {
+                    "allOf": [
+                      {
+                        "$ref": "#/definitions/require_any_field"
+                      },
+                      {
+                        "$ref": "#/definitions/common_fields"
+                      }
+                    ]
+                  }
+                }
+              }
+            }
+          }
+        },
+        {
+          "$comment": "This is the schema for the fields in Item Asset Definitions. It doesn't require any fields.",
+          "required": [
+            "item_assets"
+          ],
+          "properties": {
+            "item_assets": {
+              "type": "object",
+              "not": {
+                "additionalProperties": {
+                  "not": {
+                    "allOf": [
+                      {
+                        "$ref": "#/definitions/require_any_field"
+                      },
+                      {
+                        "$ref": "#/definitions/common_fields"
+                      }
+                    ]
+                  }
+                }
+              }
+            }
+          }
+        },
+        {
+          "$comment": "This is the schema for the fields in Summaries. By default, only checks the existance of the properties, but not the schema of the summaries.",
+          "required": [
+            "summaries"
+          ],
+          "properties": {
+            "summaries": {
+              "$ref": "#/definitions/require_any_field"
+            }
+          }
+        }
+      ]
+    }
+  ],
+  "definitions": {
+    "stac_extensions": {
+      "type": "object",
+      "required": [
+        "stac_extensions"
+      ],
+      "properties": {
+        "stac_extensions": {
+          "type": "array",
+          "contains": {
+            "const": "https://stac-extensions.github.io/ml-model/v1.0.0/schema.json"
+          }
+        }
+      }
+    },
+    "require_any_field": {
+      "$comment": "Please list all fields here so that we can force the existance of one of them in other parts of the schemas.",
+      "anyOf": [
+        {
+          "required": [
+            "ml-model:learning_approach"
+          ]
+        },
+        {
+          "required": [
+            "ml-model:prediction_type"
+          ]
+        },
+        {
+          "required": [
+            "ml-model:architecture"
+          ]
+        },
+        {
+          "required": [
+            "ml-model:input_data_used"
+          ]
+        },
+        {
+          "required": [
+            "ml-model:output_data_obtained"
+          ]
+        }
+      ]
+    },
+    "common_fields": {
+      "$comment": "Add your new Item fields here. Don't require them here, do that above in the corresponding schema.",
+      "type": "object",
+      "properties": {
+        "ml-model:type": {
+          "const": "ml-model"
+        },
+        "ml-model:learning_approach": {
+          "type": "string"
+        },
+        "ml-model:prediction_type": {
+          "type": "string"
+        },
+        "ml-model:architecture": {
+          "type": "string"
+        },
+        "ml-model:training-os": {
+          "type": "string"
+        },
+         "ap-model:input_data_used": {
+          "type": "string"
+        },
+         "ap-model:output_data_obtained": {
+          "type": "string"
+        },
+        "ml-model:training-processor-type": {
+          "type": "string",
+          "enum": ["cpu", "gpu"]
+        }
+      },
+      "patternProperties": {
+        "^(?!ml-model:)": {},
+        "^(?!ap-model:)": {} 
+      },
+      "additionalProperties": false
+    }
+  }
+}
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