diff --git a/schema/klighd/SKGraphSchema.json b/schema/klighd/SKGraphSchema.json
index 8e38b258..fb86effc 100644
--- a/schema/klighd/SKGraphSchema.json
+++ b/schema/klighd/SKGraphSchema.json
@@ -62,6 +62,18 @@
                         }
                     },
                     "default": { "width": 0.0, "height": 0.0 }
+                },
+                "position": {
+                    "type": "object",
+                    "properties": {
+                        "x": {
+                            "type": "number"
+                        },
+                        "y": {
+                            "type": "number"
+                        }
+                    },
+                    "default": { "x": 0.0, "y": 0.0 }
                 }
             }
             
@@ -76,6 +88,18 @@
                 },
                 "revision": {
                     "type": "number"
+                },
+                "children": {
+                    "type": "array",
+                    "required": ["items"],
+                    "items": [
+                        {
+                            "$ref": "#/definitions/SModelElement"
+                        }
+                    ],
+                    "default": [],
+                    "minItems": 1,
+                    "maxItems": 1
                 }
             }
         },
diff --git a/schema/klighd/ValuedSynthesisOption.json b/schema/klighd/ValuedSynthesisOption.json
new file mode 100644
index 00000000..b5705837
--- /dev/null
+++ b/schema/klighd/ValuedSynthesisOption.json
@@ -0,0 +1,141 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/ValuedSynthesisOption.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "ValuedSynthesisOption",
+    "type": "object",
+    "required": ["synthesisOption", "currentValue"],
+    "properties": {
+        "synthesisOption": {
+            "anyOf": [
+                {"$ref": "#/definitions/checkSynthesisOption"},
+                {"$ref": "#/definitions/choiceSynthesisOption"},
+                {"$ref": "#/definitions/rangeSynthesisOption"},
+                {"$ref": "#/definitions/textSynthesisOption"},
+                {"$ref": "#/definitions/separatorSynthesisOption"},
+                {"$ref": "#/definitions/categorySynthesisOption"}
+            ]
+        },
+        "currentValue": {
+            "type": ["string", "number", "boolean"]
+        }
+    },
+    "definitions": {
+        "SynthesisOption": {
+            "type": "object",
+            "required": ["id", "name", "type", "sourceHash", "initialValue"],
+            "properties": {
+                "id": {
+                    "type": "string"
+                },
+                "name": {
+                    "type": "string"
+                },
+                "type": {
+                    "type": "number",
+                    "enum": [0, 1, 2, 3, 4, 5]
+                },
+                "updateAction": {
+                    "type": "string"
+                },
+                "category": {
+                    "$ref": "#/definitions/categorySynthesisOption"
+                },
+                "sourceHash": {
+                    "type": "string"
+                },
+                "initialValue": {}
+            }
+        },
+        "checkSynthesisOption": {
+            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
+            "properties": {
+                "type": {
+                    "type": "number",
+                    "enum": [0]
+                },
+                "initialValue": {
+                    "type": "boolean"
+                }
+            }
+        },
+        "choiceSynthesisOption": {
+            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
+            "required": ["values"],
+            "properties": {
+                "type": {
+                    "type": "number",
+                    "enum": [1]
+                },
+                "initialValue": {
+                    "type": "string"
+                },
+                "values": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                }
+            }
+        },
+        "rangeSynthesisOption": {
+            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
+            "required": ["range", "stepSize"],
+            "properties": {
+                "type": {
+                    "type": "number",
+                    "enum": [2]
+                },
+                "initialValue": {
+                    "type": "number"
+                },
+                "range": {
+                    "type": "object",
+                    "properties": {
+                        "first": {
+                            "type": "number"
+                        },
+                        "second": {
+                            "type": "number"
+                        }
+                    }
+                },
+                "stepSize": {
+                    "type": "number"
+                }
+            }
+        },
+        "textSynthesisOption": {
+            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
+            "properties": {
+                "type": {
+                    "type": "number",
+                    "enum": [3]
+                },
+                "initialValue": {
+                    "type": "string"
+                }
+            }
+        },
+        "separatorSynthesisOption": {
+            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
+            "properties": {
+                "type": {
+                    "type": "number",
+                    "enum": [4]
+                }
+            }
+        },
+        "categorySynthesisOption": {
+            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
+            "properties": {
+                "type": {
+                    "type": "number",
+                    "enum": [5]
+                },
+                "initialValue": {
+                    "type": "boolean"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/checkImages.json b/schema/klighd/actions/checkImages.json
new file mode 100644
index 00000000..c5c7006a
--- /dev/null
+++ b/schema/klighd/actions/checkImages.json
@@ -0,0 +1,34 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/checkImages.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "checkImages",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind", "images"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["checkImages"]
+        },
+        "images": {
+            "type": "array",
+            "items": {
+                "$ref": "#/definitions/image"
+            }
+        }
+    },
+    "definitions": {
+        "image": {
+            "type": "object",
+            "required": ["bundleName", "imagePath"],
+            "properties": {
+                "bundleName": {
+                    "type": "string"
+                },
+                "imagePath": {
+                    "type": "string"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/checkedImages.json b/schema/klighd/actions/checkedImages.json
new file mode 100644
index 00000000..6e5445cc
--- /dev/null
+++ b/schema/klighd/actions/checkedImages.json
@@ -0,0 +1,37 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/checkedImages.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "checkedImages",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind", "notCached", "responseId"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["checkedImages"]
+        },
+        "notCached": {
+            "type": "array",
+            "items": {
+                "$ref": "#/definitions/notCachedImage"
+            }
+        },
+        "responseId": {
+            "type": "string"
+        }
+    },
+    "definitions": {
+        "notCachedImage": {
+            "type": "object",
+            "required": ["k", "v"],
+            "properties": {
+                "k": {
+                    "type": "string"
+                },
+                "v": {
+                    "type": "string"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/performAction.json b/schema/klighd/actions/performAction.json
new file mode 100644
index 00000000..0dfe923d
--- /dev/null
+++ b/schema/klighd/actions/performAction.json
@@ -0,0 +1,26 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/performAction.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "performAction",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/actions/action.json"}],
+    "required": ["kind", "actionId", "kGraphElementId", "kRenderingId", "revision"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["performAction"]
+        },
+        "actionId": {
+            "type": "string"
+        },
+        "kGraphElementId": {
+            "type": "string"
+        },
+        "kRenderingId": {
+            "type": "string"
+        },
+        "revision": {
+            "type": "number"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/refreshDiagram.json b/schema/klighd/actions/refreshDiagram.json
new file mode 100644
index 00000000..56fc6379
--- /dev/null
+++ b/schema/klighd/actions/refreshDiagram.json
@@ -0,0 +1,14 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/refreshDiagram.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "refreshDiagram",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["refreshDiagram"]
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/refreshLayout.json b/schema/klighd/actions/refreshLayout.json
new file mode 100644
index 00000000..0f322b89
--- /dev/null
+++ b/schema/klighd/actions/refreshLayout.json
@@ -0,0 +1,14 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/refreshLayout.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "refreshLayout",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["refreshLayout"]
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/requestDiagramPiece.json b/schema/klighd/actions/requestDiagramPiece.json
new file mode 100644
index 00000000..9d92c8eb
--- /dev/null
+++ b/schema/klighd/actions/requestDiagramPiece.json
@@ -0,0 +1,17 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/requestDiagramPiece.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "requestDiagramPiece",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind", "modelElementId"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["requestDiagramPiece"]
+        },
+        "modelElementId": {
+            "type": "string"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/setDiagramPiece.json b/schema/klighd/actions/setDiagramPiece.json
new file mode 100644
index 00000000..b538bb30
--- /dev/null
+++ b/schema/klighd/actions/setDiagramPiece.json
@@ -0,0 +1,17 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/setDiagramPiece.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "setDiagramPiece",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind", "diagramPiece"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["setDiagramPiece"]
+        },
+        "diagramPiece": {
+            "$ref": "/kieler/klighd-vscode/tree/main/schema/klighd/SKGraphSchema.json#/definitions/SKNode"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/setSynthesis.json b/schema/klighd/actions/setSynthesis.json
new file mode 100644
index 00000000..1cdc4d50
--- /dev/null
+++ b/schema/klighd/actions/setSynthesis.json
@@ -0,0 +1,17 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/setSynthesis.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "setSynthesis",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind", "id"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["setSynthesis"]
+        },
+        "id": {
+            "type": "string"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/storeImages.json b/schema/klighd/actions/storeImages.json
new file mode 100644
index 00000000..c58f4c66
--- /dev/null
+++ b/schema/klighd/actions/storeImages.json
@@ -0,0 +1,27 @@
+
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/actions/storeImages.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "storeImages",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/action.json"}],
+    "required": ["kind", "images"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["storeImages"]
+        },
+        "images": {
+            "type": "object",
+            "required": ["k", "v"],
+            "properties": {
+                "k": {
+                    "$ref": "/kieler/klighd-vscode/tree/main/schema/klighd/actions/checkedImages.json#/definitions/notCachedImage"
+                },
+                "v": {
+                    "type": "string"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/actions/updateOptions.json b/schema/klighd/actions/updateOptions.json
index b570d319..8084bf9a 100644
--- a/schema/klighd/actions/updateOptions.json
+++ b/schema/klighd/actions/updateOptions.json
@@ -13,7 +13,7 @@
         "valuedSynthesisOptions": {
             "type": "array",
             "items": {
-                "$ref": "#/definitions/ValuedSynthesisOption"
+                "$ref": "/kieler/klighd-vscode/tree/main/schema/klighd/valuedSynthesisOption.json"
             }
         },
         "layoutOptions": {
@@ -25,143 +25,5 @@
         "modelUri": {
             "type": "string"
         }
-    },
-    "definitions": {
-        "ValuedSynthesisOption": {
-            "type": "object",
-            "required": ["synthesisOption", "currentValue"],
-            "properties": {
-                "synthesisOption": {
-                    "anyOf": [
-                        {"$ref": "#/definitions/checkSynthesisOption"},
-                        {"$ref": "#/definitions/choiceSynthesisOption"},
-                        {"$ref": "#/definitions/rangeSynthesisOption"},
-                        {"$ref": "#/definitions/textSynthesisOption"},
-                        {"$ref": "#/definitions/separatorSynthesisOption"},
-                        {"$ref": "#/definitions/categorySynthesisOption"}
-                    ]
-                },
-                "currentValue": {
-                    "type": ["string", "number", "boolean"]
-                }
-            }
-        },
-        "SynthesisOption": {
-            "type": "object",
-            "required": ["id", "name", "type", "sourceHash", "initialValue"],
-            "properties": {
-                "id": {
-                    "type": "string"
-                },
-                "name": {
-                    "type": "string"
-                },
-                "type": {
-                    "type": "number",
-                    "enum": [0, 1, 2, 3, 4, 5]
-                },
-                "updateAction": {
-                    "type": "string"
-                },
-                "category": {
-                    "$ref": "#/definitions/categorySynthesisOption"
-                },
-                "sourceHash": {
-                    "type": "string"
-                },
-                "initialValue": {}
-            }
-        },
-        "checkSynthesisOption": {
-            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
-            "properties": {
-                "type": {
-                    "type": "number",
-                    "enum": [0]
-                },
-                "initialValue": {
-                    "type": "boolean"
-                }
-            }
-        },
-        "choiceSynthesisOption": {
-            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
-            "required": ["values"],
-            "properties": {
-                "type": {
-                    "type": "number",
-                    "enum": [1]
-                },
-                "initialValue": {
-                    "type": "string"
-                },
-                "values": {
-                    "type": "array",
-                    "items": {
-                        "type": "string"
-                    }
-                }
-            }
-        },
-        "rangeSynthesisOption": {
-            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
-            "required": ["range", "stepSize"],
-            "properties": {
-                "type": {
-                    "type": "number",
-                    "enum": [2]
-                },
-                "initialValue": {
-                    "type": "number"
-                },
-                "range": {
-                    "type": "object",
-                    "properties": {
-                        "first": {
-                            "type": "number"
-                        },
-                        "second": {
-                            "type": "number"
-                        }
-                    }
-                },
-                "stepSize": {
-                    "type": "number"
-                }
-            }
-        },
-        "textSynthesisOption": {
-            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
-            "properties": {
-                "type": {
-                    "type": "number",
-                    "enum": [3]
-                },
-                "initialValue": {
-                    "type": "string"
-                }
-            }
-        },
-        "separatorSynthesisOption": {
-            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
-            "properties": {
-                "type": {
-                    "type": "number",
-                    "enum": [4]
-                }
-            }
-        },
-        "categorySynthesisOption": {
-            "allOf": [{"$ref": "#/definitions/SynthesisOption"}],
-            "properties": {
-                "type": {
-                    "type": "number",
-                    "enum": [5]
-                },
-                "initialValue": {
-                    "type": "boolean"
-                }
-            }
-        }
-    }   
+    }
 }
\ No newline at end of file
diff --git a/schema/klighd/messages/diagramOptionsPerformAction.json b/schema/klighd/messages/diagramOptionsPerformAction.json
new file mode 100644
index 00000000..48628e22
--- /dev/null
+++ b/schema/klighd/messages/diagramOptionsPerformAction.json
@@ -0,0 +1,25 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/messages/diagramOptionsPerformAction.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "keith/diagramOptions/performAction",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/requestMessage.json"}],
+    "required": ["method", "params"],
+    "properties": {
+        "method": {
+            "type": "string",
+            "enum": ["keith/diagramOptions/performAction"]
+        },
+        "params": {
+            "type": "object",
+            "required": ["actionId", "uri"],
+            "properties": {
+                "actionId": {
+                    "type": "string"
+                },
+                "uri": {
+                    "type": "string"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/messages/diagramOptionsSetLayoutOptions.json b/schema/klighd/messages/diagramOptionsSetLayoutOptions.json
new file mode 100644
index 00000000..cacc7e8e
--- /dev/null
+++ b/schema/klighd/messages/diagramOptionsSetLayoutOptions.json
@@ -0,0 +1,35 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/messages/diagramOptionsSetLayoutOptions.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "keith/diagramOptions/setLayoutOptions",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/requestMessage.json"}],
+    "required": ["method", "params"],
+    "properties": {
+        "method": {
+            "type": "string",
+            "enum": ["keith/diagramOptions/setLayoutOptions"]
+        },
+        "params": {
+            "type": "object",
+            "required": ["layoutOptions", "uri"],
+            "properties": {
+                "layoutOptions": {
+                    "type": "array",
+                    "items": {
+                        "type": "object",
+                        "required": ["optionId", "value"],
+                        "properties": {
+                            "optionId": {
+                                "type": "string"
+                            },
+                            "value": {}
+                        }
+                    }
+                },
+                "uri": {
+                    "type": "string"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/messages/diagramOptionsSetSynthesisOptions.json b/schema/klighd/messages/diagramOptionsSetSynthesisOptions.json
new file mode 100644
index 00000000..6d60dae1
--- /dev/null
+++ b/schema/klighd/messages/diagramOptionsSetSynthesisOptions.json
@@ -0,0 +1,28 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/messages/diagramOptionsSetSynthesisOptions.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "keith/diagramOptions/setSynthesisOptions",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/requestMessage.json"}],
+    "required": ["method", "params"],
+    "properties": {
+        "method": {
+            "type": "string",
+            "enum": ["keith/diagramOptions/setSynthesisOptions"]
+        },
+        "params": {
+            "type": "object",
+            "required": ["synthesisOptions"],
+            "properties": {
+                "synthesisOptions": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "/kieler/klighd-vscode/tree/main/schema/klighd/valuedSynthesisOption.json"
+                    }
+                },
+                "uri": {
+                    "type": "string"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/klighd/messages/setPreferences.json b/schema/klighd/messages/preferencesSetPreferences.json
similarity index 94%
rename from schema/klighd/messages/setPreferences.json
rename to schema/klighd/messages/preferencesSetPreferences.json
index 75c6b943..227f8265 100644
--- a/schema/klighd/messages/setPreferences.json
+++ b/schema/klighd/messages/preferencesSetPreferences.json
@@ -1,5 +1,5 @@
 {
-    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/messages/setPreferences.json",
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/klighd/messages/preferencesSetPreferences.json",
     "$schema": "http://json-schema.org/draft-07/schema#",
     "title": "keith/preferences/setPreferences",
     "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/requestMessage.json"}],
diff --git a/schema/lsp/generalSendMessage.json b/schema/lsp/generalSendMessage.json
new file mode 100644
index 00000000..6da08838
--- /dev/null
+++ b/schema/lsp/generalSendMessage.json
@@ -0,0 +1,19 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/lsp/generalSendMessage.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "general/sendMessage",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/lsp/requestMessage.json"}],
+    "required": ["method", "params"],
+    "properties": {
+        "method": {
+            "type": "string",
+            "enum": ["general/sendMessage"]
+        },
+        "params": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/lsp/range.json b/schema/lsp/range.json
new file mode 100644
index 00000000..47f7a90a
--- /dev/null
+++ b/schema/lsp/range.json
@@ -0,0 +1,29 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/lsp/range.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "range",
+    "type": "object",
+    "required": ["start", "end"],
+    "properties": {
+        "start": {
+            "$ref": "#/definitions/editorPosition.json"
+        },
+        "end": {
+            "$ref": "#/definitions/editorPosition.json"
+        }
+    },
+    "definitions": {
+        "editorPosition.json": {
+            "type": "object",
+            "required": ["line", "character"],
+            "properties": {
+                "line": {
+                    "type": "integer"
+                },
+                "character": {
+                    "type": "integer"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/lsp/requestMessage.json b/schema/lsp/requestMessage.json
index 1fa41a01..03924db3 100644
--- a/schema/lsp/requestMessage.json
+++ b/schema/lsp/requestMessage.json
@@ -3,7 +3,7 @@
     "$schema": "http://json-schema.org/draft-07/schema#",
     "title": "message",
     "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/lsp/message.json"}],
-    "required": ["id", "method"],
+    "required": ["method"],
     "properties": {
         "id": {
             "type": ["number", "string"]
diff --git a/schema/lsp/textDocumentDocumentHighlight.json b/schema/lsp/textDocumentDocumentHighlight.json
new file mode 100644
index 00000000..998e3fbe
--- /dev/null
+++ b/schema/lsp/textDocumentDocumentHighlight.json
@@ -0,0 +1,29 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/lsp/textDocumentDocumentHighlight.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "textDocument/documentHighlight",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/lsp/requestMessage.json"}],
+    "required": ["method", "params"],
+    "properties": {
+        "method": {
+            "type": "string",
+            "enum": ["textDocument/documentHighlight"]
+        },
+        "params": {
+            "type": "object",
+            "properties": {
+                "textDocument": {
+                    "type":"object",
+                    "properties": {
+                        "uri": {
+                            "type": "string"
+                        }
+                    }
+                },
+                "position": {
+                    "$ref": "/kieler/klighd-vscode/tree/main/schema/lsp/position.json"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/sprotty/actions/action.json b/schema/sprotty/actions/action.json
index 067295b0..2cb2fa92 100644
--- a/schema/sprotty/actions/action.json
+++ b/schema/sprotty/actions/action.json
@@ -7,6 +7,9 @@
     "properties": {
         "kind": {
             "type": "string"
+        },
+        "requestId": {
+            "type": "string"
         }
     }
 }
\ No newline at end of file
diff --git a/schema/sprotty/actions/allSelected.json b/schema/sprotty/actions/allSelected.json
new file mode 100644
index 00000000..1214c45a
--- /dev/null
+++ b/schema/sprotty/actions/allSelected.json
@@ -0,0 +1,17 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/sprotty/actions/allSelected.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "allSelected",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/actions/action.json"}],
+    "required": ["kind", "select"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["allSelected"]
+        },
+        "select": {
+            "type": "boolean"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/sprotty/actions/elementSelected.json b/schema/sprotty/actions/elementSelected.json
new file mode 100644
index 00000000..f19c3619
--- /dev/null
+++ b/schema/sprotty/actions/elementSelected.json
@@ -0,0 +1,29 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/sprotty/actions/elementSelected.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "elementSelected",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/actions/action.json"}],
+    "required": ["kind", "selectedElementsIDs", "deselectedElementsIDs", "preventOpenSelection"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["elementSelected"]
+        },
+        "selectedElementsIDs": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        },
+        "deselectedElementsIDs": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        },
+        "preventOpenSelection": {
+            "type": "boolean"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/sprotty/actions/fit.json b/schema/sprotty/actions/fit.json
new file mode 100644
index 00000000..9a82a5cf
--- /dev/null
+++ b/schema/sprotty/actions/fit.json
@@ -0,0 +1,26 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/sprotty/actions/fit.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "fit",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/actions/action.json"}],
+    "required": ["kind", "elementIds", "maxZoom", "animate"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["fit"]
+        },
+        "elementIds": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        },
+        "maxZoom": {
+            "type": "number"
+        },
+        "animate": {
+            "type": "boolean"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/sprotty/actions/setModel.json b/schema/sprotty/actions/setModel.json
new file mode 100644
index 00000000..ff8d309d
--- /dev/null
+++ b/schema/sprotty/actions/setModel.json
@@ -0,0 +1,17 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/sprotty/actions/setModel.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "setModel",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/actions/action.json"}],
+    "required": ["kind", "newRoot"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["setModel"]
+        },
+        "newRoot": {
+            "$ref": "/kieler/klighd-vscode/tree/main/schema/klighd/SKGraphSchema#/definitions/SKGraph"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/sprotty/actions/updateModel.json b/schema/sprotty/actions/updateModel.json
new file mode 100644
index 00000000..a6c1a1b8
--- /dev/null
+++ b/schema/sprotty/actions/updateModel.json
@@ -0,0 +1,17 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/sprotty/actions/updateModel.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "updateModel",
+    "type": "object",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/actions/action.json"}],
+    "required": ["kind", "newRoot"],
+    "properties": {
+        "kind": {
+            "type": "string",
+            "enum": ["updateModel"]
+        },
+        "newRoot": {
+            "$ref": "/kieler/klighd-vscode/tree/main/schema/klighd/SKGraphSchema#/definitions/SKGraph"
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/sprotty/diagramOpenInTextEditor.json b/schema/sprotty/diagramOpenInTextEditor.json
new file mode 100644
index 00000000..0be1cbd9
--- /dev/null
+++ b/schema/sprotty/diagramOpenInTextEditor.json
@@ -0,0 +1,39 @@
+{
+    "$id": "https://github.com/kieler/klighd-vscode/tree/main/schema/sprotty/messages/diagramOpenInTextEditor.json",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "diagram/openInTextEditor",
+    "allOf": [{"$ref": "/kieler/klighd-vscode/tree/main/schema/sprotty/requestMessage.json"}],
+    "required": ["method", "params"],
+    "properties": {
+        "method": {
+            "type": "string",
+            "enum": ["diagram/openInTextEditor"]
+        },
+        "params": {
+            "type": "object",
+            "required": ["location", "forceOpen"],
+            "properties": {
+                "location": {
+                    "$ref": "#/definitions/location"
+                },
+                "forceOpen": {
+                    "type": "boolean"
+                }
+            }
+        }
+    },
+    "definitions": {
+        "location": {
+            "type": "object",
+            "required": ["uri", "range"],
+            "properties": {
+                "uri": {
+                    "type": "string"
+                },
+                "range": {
+                    "$ref": "/kieler/klighd-vscode/tree/main/schema/lsp/range.json"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file