diff --git a/doc/hmdl.schema.json b/doc/hmdl.schema.json
new file mode 100644
index 0000000..9f0aa70
--- /dev/null
+++ b/doc/hmdl.schema.json
@@ -0,0 +1,665 @@
+{
+	"type": "object",
+	"additionalProperties": false,
+	"properties": {
+		"defaults": {
+			"description": "default values for checks",
+			"type": "object",
+			"additionalProperties": false,
+			"properties": {
+				"active": {
+					"type": "boolean",
+					"default": true
+				},
+				"threshold": {
+					"description": "how often a condition has to occur in order to be reported",
+					"type": "integer",
+					"minimum": 1,
+					"default": 3
+				},
+				"annoy": {
+					"description": "whether notifications shall be kept sending after the threshold has been surpassed",
+					"type": "boolean",
+					"default": false
+				},
+				"schedule": {
+					"type": "object",
+					"additionalProperties": false,
+					"properties": {
+						"regular_interval": {
+							"description": "in seconds or as text",
+							"anyOf": [
+								{
+									"type": "integer",
+									"exclusiveMinimum": 0
+								},
+								{
+									"type": "string",
+									"enum": [
+										"minute",
+										"hour",
+										"day",
+										"week"
+									]
+								}
+							],
+							"default": 3600
+						},
+						"attentive_interval": {
+							"description": "in seconds or as text",
+							"anyOf": [
+								{
+									"type": "integer",
+									"exclusiveMinimum": 0
+								},
+								{
+									"type": "string",
+									"enum": [
+										"minute",
+										"hour",
+										"day",
+										"week"
+									]
+								}
+							],
+							"default": 120
+						}
+					},
+					"required": []
+				},
+				"notifications": {
+					"type": "array",
+					"items": {
+						"anyOf": [
+							{
+								"title": "check kind 'console'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"console"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {},
+										"required": []
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							},
+							{
+								"title": "check kind 'file_touch'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"file_touch"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {
+											"path": {
+												"type": "string"
+											}
+										},
+										"required": [
+											"path"
+										]
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							},
+							{
+								"title": "check kind 'email'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"email"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {
+											"access": {
+												"type": "object",
+												"additionalProperties": false,
+												"properties": {
+													"host": {
+														"type": "string"
+													},
+													"port": {
+														"type": "integer"
+													},
+													"username": {
+														"type": "string"
+													},
+													"password": {
+														"type": "string"
+													}
+												},
+												"required": [
+													"host",
+													"port",
+													"username",
+													"password"
+												]
+											},
+											"sender": {
+												"type": "string"
+											},
+											"receivers": {
+												"type": "array",
+												"items": {
+													"type": "string"
+												}
+											},
+											"tags": {
+												"description": "list of strings, which will be placed in the e-mail subject",
+												"type": "array",
+												"items": {
+													"type": "string"
+												},
+												"default": []
+											}
+										},
+										"required": [
+											"access",
+											"sender",
+											"receivers"
+										]
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							},
+							{
+								"title": "check kind 'libnotify'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"libnotify"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {
+											"icon": {
+												"type": "string"
+											}
+										},
+										"required": []
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							}
+						]
+					},
+					"default": [
+						{
+							"kind": "console",
+							"parameters": {}
+						}
+					]
+				}
+			},
+			"required": []
+		},
+		"checks": {
+			"type": "array",
+			"items": {
+				"allOf": [
+					{
+						"description": "should represent a specific check",
+						"type": "object",
+						"unevaluatedProperties": false,
+						"properties": {
+							"name": {
+								"type": "string"
+							},
+							"title": {
+								"type": "string"
+							},
+							"active": {
+								"type": "boolean",
+								"default": true
+							},
+							"threshold": {
+								"description": "how often a condition has to occur in order to be reported",
+								"type": "integer",
+								"minimum": 1,
+								"default": 3
+							},
+							"annoy": {
+								"description": "whether notifications shall be kept sending after the threshold has been surpassed",
+								"type": "boolean",
+								"default": false
+							},
+							"schedule": {
+								"type": "object",
+								"additionalProperties": false,
+								"properties": {
+									"regular_interval": {
+										"description": "in seconds or as text",
+										"anyOf": [
+											{
+												"type": "integer",
+												"exclusiveMinimum": 0
+											},
+											{
+												"type": "string",
+												"enum": [
+													"minute",
+													"hour",
+													"day",
+													"week"
+												]
+											}
+										],
+										"default": 3600
+									},
+									"attentive_interval": {
+										"description": "in seconds or as text",
+										"anyOf": [
+											{
+												"type": "integer",
+												"exclusiveMinimum": 0
+											},
+											{
+												"type": "string",
+												"enum": [
+													"minute",
+													"hour",
+													"day",
+													"week"
+												]
+											}
+										],
+										"default": 120
+									}
+								},
+								"required": []
+							},
+							"notifications": {
+								"type": "array",
+								"items": {
+									"anyOf": [
+										{
+											"title": "check kind 'console'",
+											"type": "object",
+											"unevaluatedProperties": false,
+											"properties": {
+												"kind": {
+													"type": "string",
+													"enum": [
+														"console"
+													]
+												},
+												"parameters": {
+													"type": "object",
+													"additionalProperties": false,
+													"properties": {},
+													"required": []
+												}
+											},
+											"required": [
+												"kind",
+												"parameters"
+											]
+										},
+										{
+											"title": "check kind 'file_touch'",
+											"type": "object",
+											"unevaluatedProperties": false,
+											"properties": {
+												"kind": {
+													"type": "string",
+													"enum": [
+														"file_touch"
+													]
+												},
+												"parameters": {
+													"type": "object",
+													"additionalProperties": false,
+													"properties": {
+														"path": {
+															"type": "string"
+														}
+													},
+													"required": [
+														"path"
+													]
+												}
+											},
+											"required": [
+												"kind",
+												"parameters"
+											]
+										},
+										{
+											"title": "check kind 'email'",
+											"type": "object",
+											"unevaluatedProperties": false,
+											"properties": {
+												"kind": {
+													"type": "string",
+													"enum": [
+														"email"
+													]
+												},
+												"parameters": {
+													"type": "object",
+													"additionalProperties": false,
+													"properties": {
+														"access": {
+															"type": "object",
+															"additionalProperties": false,
+															"properties": {
+																"host": {
+																	"type": "string"
+																},
+																"port": {
+																	"type": "integer"
+																},
+																"username": {
+																	"type": "string"
+																},
+																"password": {
+																	"type": "string"
+																}
+															},
+															"required": [
+																"host",
+																"port",
+																"username",
+																"password"
+															]
+														},
+														"sender": {
+															"type": "string"
+														},
+														"receivers": {
+															"type": "array",
+															"items": {
+																"type": "string"
+															}
+														},
+														"tags": {
+															"description": "list of strings, which will be placed in the e-mail subject",
+															"type": "array",
+															"items": {
+																"type": "string"
+															},
+															"default": []
+														}
+													},
+													"required": [
+														"access",
+														"sender",
+														"receivers"
+													]
+												}
+											},
+											"required": [
+												"kind",
+												"parameters"
+											]
+										},
+										{
+											"title": "check kind 'libnotify'",
+											"type": "object",
+											"unevaluatedProperties": false,
+											"properties": {
+												"kind": {
+													"type": "string",
+													"enum": [
+														"libnotify"
+													]
+												},
+												"parameters": {
+													"type": "object",
+													"additionalProperties": false,
+													"properties": {
+														"icon": {
+															"type": "string"
+														}
+													},
+													"required": []
+												}
+											},
+											"required": [
+												"kind",
+												"parameters"
+											]
+										}
+									]
+								},
+								"default": [
+									{
+										"kind": "console",
+										"parameters": {}
+									}
+								]
+							}
+						},
+						"required": [
+							"name"
+						]
+					},
+					{
+						"anyOf": [
+							{
+								"title": "notification channel 'script'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"script"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {
+											"path": {
+												"type": "string"
+											},
+											"arguments": {
+												"type": "array",
+												"item": {
+													"type": "string"
+												}
+											}
+										},
+										"required": [
+											"path"
+										]
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							},
+							{
+								"title": "notification channel 'file_timestamp'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"file_timestamp"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {
+											"path": {
+												"type": "string"
+											},
+											"warning_age": {
+												"type": "integer",
+												"exclusiveMinimum": 0,
+												"default": 3600
+											},
+											"critical_age": {
+												"type": "integer",
+												"exclusiveMinimum": 0,
+												"default": 86400
+											},
+											"condition_on_missing": {
+												"description": "which condition to report if file is missing",
+												"type": "string",
+												"enum": [
+													"unknown",
+													"ok",
+													"warning",
+													"critical"
+												],
+												"default": "warning"
+											},
+											"condition_on_implausible": {
+												"description": "which condition to report if the age is negative, i.e. the file is apparently from the future",
+												"type": "string",
+												"enum": [
+													"unknown",
+													"ok",
+													"warning",
+													"critical"
+												],
+												"default": "warning"
+											}
+										},
+										"required": [
+											"path"
+										]
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							},
+							{
+								"title": "notification channel 'http_request'",
+								"type": "object",
+								"unevaluatedProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"http_request"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": false,
+										"properties": {
+											"request": {
+												"type": "object",
+												"additionalProperties": false,
+												"properties": {
+													"target": {
+														"description": "URL",
+														"type": "string"
+													},
+													"method": {
+														"type": "string",
+														"enum": [
+															"GET",
+															"POST"
+														],
+														"default": "GET"
+													}
+												},
+												"required": [
+													"target"
+												]
+											},
+											"response": {
+												"type": "object",
+												"additionalProperties": false,
+												"properties": {
+													"status_code": {
+														"description": "checks whether the response status code is this",
+														"type": [
+															"null",
+															"integer"
+														],
+														"default": 200
+													},
+													"headers": {
+														"description": "conjunctively checks header key-value pairs",
+														"type": "object",
+														"additionalProperties": {
+															"description": "header value",
+															"type": "string"
+														},
+														"properties": {},
+														"required": [],
+														"default": {}
+													},
+													"body_part": {
+														"description": "checks whether the response body contains this string",
+														"type": "string"
+													}
+												},
+												"required": []
+											},
+											"as_warning": {
+												"description": "whether a violation of this check shall be exposed as warning instead of critical; default: false",
+												"type": "boolean",
+												"default": false
+											}
+										},
+										"required": [
+											"request"
+										]
+									}
+								},
+								"required": [
+									"kind",
+									"parameters"
+								]
+							}
+						]
+					}
+				]
+			}
+		}
+	},
+	"required": [
+		"defaults",
+		"checks"
+	]
+}
diff --git a/test.hmdl.json b/examples/test.hmdl.json
similarity index 78%
rename from test.hmdl.json
rename to examples/test.hmdl.json
index 6079d54..e7183eb 100644
--- a/test.hmdl.json
+++ b/examples/test.hmdl.json
@@ -1,12 +1,13 @@
 {
 	"defaults": {
 	},
-	"checks": {
-		"test": {
+	"checks": [
+		{
+			"name": "test",
 			"threshold": 1,
 			"annoy": true,
 			"schedule": {
-				"regular_interval": 60,
+				"regular_interval": 15,
 				"attentive_interval": 5
 			},
 			"notifications": [
@@ -18,7 +19,6 @@
 				{
 					"kind": "libnotify",
 					"parameters": {
-						"icon": "/home/fenris/bilder/zeug/heimdall.png"
 					}
 				}
 			],
@@ -29,5 +29,5 @@
 				"critical_age": 120
 			}
 		}
-	}
+	]
 }
diff --git a/hmdl.schema.json b/hmdl.schema.json
deleted file mode 100644
index 2a4ff15..0000000
--- a/hmdl.schema.json
+++ /dev/null
@@ -1,489 +0,0 @@
-{
-	"$defs": {
-		"active": {
-			"type": "boolean",
-			"default": true
-		},
-		"threshold": {
-			"description": "how often a condition has to occur in order to be reported",
-			"type": "integer",
-			"minimum": 1,
-			"default": 3
-		},
-		"annoy": {
-			"description": "whether notifications shall be kept sending after the threshold has been surpassed",
-			"type": "boolean",
-			"default": false
-		},
-		"schedule": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"regular_interval": {
-					"description": "in seconds or as text: minute, hour, day, week",
-					"type": ["integer", "string"]
-				},
-				"attentive_interval": {
-					"description": "in seconds or as text: minute, hour, day, week",
-					"type": ["integer", "string"]
-				}
-			},
-			"required": [
-				"regular_interval"
-			]
-		},
-		"check_kind_test": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "test"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"condition": {
-							"type": "string",
-							"enum": [
-								"unknown",
-								"ok",
-								"warning",
-								"critical"
-							],
-							"default": "warning"
-						},
-						"output": {
-							"type": "string",
-							"default": ""
-						}
-					},
-					"required": [
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"check_kind_script": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "script"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"path": {
-							"type": "string"
-						},
-						"arguments": {
-							"type": "array",
-							"item": {
-								"type": "string"
-							}
-						}
-					},
-					"required": [
-						"path"
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"check_kind_file_timestamp": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "file_timestamp"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"path": {
-							"type": "string"
-						},
-						"warning_age": {
-							"type": "integer",
-							"exclusiveMinimum": 0,
-							"default": 3600
-						},
-						"critical_age": {
-							"type": "integer",
-							"exclusiveMinimum": 0,
-							"default": 86400
-						},
-						"condition_on_missing": {
-							"description": "which condition to report if file is missing",
-							"type": "string",
-							"enum": [
-								"unknown",
-								"ok",
-								"warning",
-								"critical"
-							],
-							"default": "warning"
-						},
-						"condition_on_implausible": {
-							"description": "which condition to report if the age is negative, i.e. the file is apparently from the future",
-							"type": "string",
-							"enum": [
-								"unknown",
-								"ok",
-								"warning",
-								"critical"
-							],
-							"default": "warning"
-						}
-					},
-					"required": [
-						"path"
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"check_kind_http_request": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "http_request"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"request": {
-							"type": "object",
-							"additionalProperties": false,
-							"properties": {
-								"target": {
-									"description": "URL",
-									"type": "string"
-								},
-								"method": {
-									"type": "string",
-									"enum": [
-										"GET",
-										"POST"
-									],
-									"default": "GET"
-								}
-							},
-							"required": [
-								"target"
-							]
-						},
-						"response": {
-							"type": "object",
-							"additionalProperties": false,
-							"properties": {
-								"status_code": {
-									"description": "checks whether the response status code is this",
-									"type": ["null", "integer"],
-									"default": 200
-								},
-								"headers": {
-									"description": "conjunctively checks header key-value pairs",
-									"type": "object",
-									"additionalProperties": {
-										"description": "header value",
-										"type": "string"
-									},
-									"properties": {
-									},
-									"required": [
-									],
-									"default": {}
-								},
-								"body_part": {
-									"description": "checks whether the response body contains this string",
-									"type": "string"
-								}
-							},
-							"required": [
-							]
-						},
-						"as_warning": {
-							"description": "whether a violation of this check shall be exposed as warning instead of critical; default: false",
-							"type": "boolean",
-							"default": false
-						}
-					},
-					"required": [
-						"request"
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"notification_channel_console": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "console"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-					},
-					"required": [
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"notification_channel_file_touch": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "file_touch"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"path": {
-							"type": "string"
-						}
-					},
-					"required": [
-						"path"
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"notification_channel_libnotify": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "libnotify"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"icon": {
-							"type": "string"
-						}
-					},
-					"required": [
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"notification_channel_email": {
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"kind": {
-					"type": "string",
-					"const": "email"
-				},
-				"parameters": {
-					"type": "object",
-					"additionalProperties": false,
-					"properties": {
-						"access": {
-							"type": "object",
-							"additionalProperties": false,
-							"properties": {
-								"host": {
-									"type": "string"
-								},
-								"port": {
-									"type": "integer"
-								},
-								"username": {
-									"type": "string"
-								},
-								"password": {
-									"type": "string"
-								}
-							},
-							"required": [
-								"host",
-								"port",
-								"username",
-								"password"
-							]
-						},
-						"sender": {
-							"type": "string"
-						},
-						"receivers": {
-							"type": "array",
-							"item": {
-								"type": "string"
-							}
-						},
-						"tags": {
-							"description": "list of strings, which will be placed in the e-mail subject",
-							"type": "array",
-							"item": {
-								"type": "string"
-							},
-							"default": []
-						}
-					},
-					"required": [
-						"access",
-						"sender",
-						"receivers"
-					]
-				}
-			},
-			"required": [
-				"kind",
-				"parameters"
-			]
-		},
-		"notifications": {
-			"type": "array",
-			"item": {
-				"anyOf": [
-					{
-						"$ref": "#/$defs/notification_channel_console"
-					},
-					{
-						"$ref": "#/$defs/notification_channel_file_touch"
-					},
-					{
-						"$ref": "#/$defs/notification_channel_email"
-					}
-				]
-			},
-			"default": [
-				{
-					"kind": "console",
-					"parameters": {
-					}
-				}
-			]
-		}
-	},
-	"type": "object",
-	"additionalProperties": false,
-	"properties": {
-		"defaults": {
-			"description": "default values for checks",
-			"type": "object",
-			"additionalProperties": false,
-			"properties": {
-				"active": {
-					"$ref": "#/$defs/active"
-				},
-				"threshold": {
-					"$ref": "#/$defs/threshold"
-				},
-				"annoy": {
-					"$ref": "#/$defs/annoy"
-				},
-				"schedule": {
-					"$ref": "#/$defs/schedule"
-				},
-				"notifications": {
-					"$ref": "#/$defs/notifications"
-				}
-			},
-			"required": [
-			]
-		},
-		"checks": {
-			"type": "object",
-			"additionalProperties": {
-				"allOf": [
-					{
-						"description": "should represent a specific check",
-						"type": "object",
-						"additionalProperties": false,
-						"properties": {
-							"title": {
-								"type": "string"
-							},
-							"active": {
-								"$ref": "#/$defs/active"
-							},
-							"threshold": {
-								"$ref": "#/$defs/threshold"
-							},
-							"annoy": {
-								"$ref": "#/$defs/annoy"
-							},
-							"schedule": {
-								"$ref": "#/$defs/schedule"
-							},
-							"notifications": {
-								"$ref": "#/$defs/notifications"
-							}
-						},
-						"required": [
-						]
-					},
-					{
-						"anyOf": [
-							{
-								"$ref": "#/$defs/check_kind_test"
-							},
-							{
-								"$ref": "#/$defs/check_kind_script"
-							},
-							{
-								"$ref": "#/$defs/check_kind_file_timestamp"
-							},
-							{
-								"$ref": "#/$defs/check_kind_http_request"
-							}
-						]
-					}
-				]
-			},
-			"properties": {
-			},
-			"required": [
-			]
-		}
-	},
-	"required": [
-		"defaults",
-		"groups"
-	]
-}
diff --git a/source/check_kinds/_interface.py b/source/check_kinds/_interface.py
index 00943d0..fedecfd 100644
--- a/source/check_kinds/_interface.py
+++ b/source/check_kinds/_interface.py
@@ -1,5 +1,9 @@
 class interface_check_kind(object):
 	
+	def parameters_schema(self):
+		raise NotImplementedError
+		
+	
 	def normalize_conf_node(self, node):
 		raise NotImplementedError
 	
diff --git a/source/check_kinds/file_timestamp.py b/source/check_kinds/file_timestamp.py
index 1748acc..f40f2ac 100644
--- a/source/check_kinds/file_timestamp.py
+++ b/source/check_kinds/file_timestamp.py
@@ -1,5 +1,55 @@
 class implementation_check_kind_file_timestamp(interface_check_kind):
 
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+				"path": {
+					"type": "string"
+				},
+				"warning_age": {
+					"type": "integer",
+					"exclusiveMinimum": 0,
+					"default": (60 * 60)
+				},
+				"critical_age": {
+					"type": "integer",
+					"exclusiveMinimum": 0,
+					"default": (60 * 60 * 24)
+				},
+				"condition_on_missing": {
+					"description": "which condition to report if file is missing",
+					"type": "string",
+					"enum": [
+						"unknown",
+						"ok",
+						"warning",
+						"critical"
+					],
+					"default": "warning"
+				},
+				"condition_on_implausible": {
+					"description": "which condition to report if the age is negative, i.e. the file is apparently from the future",
+					"type": "string",
+					"enum": [
+						"unknown",
+						"ok",
+						"warning",
+						"critical"
+					],
+					"default": "warning"
+				}
+			},
+			"required": [
+				"path"
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
@@ -62,4 +112,3 @@ class implementation_check_kind_file_timestamp(interface_check_kind):
 					),
 				}
 		
-	
diff --git a/source/check_kinds/http_request.py b/source/check_kinds/http_request.py
index e78f734..02ccdcf 100644
--- a/source/check_kinds/http_request.py
+++ b/source/check_kinds/http_request.py
@@ -1,5 +1,76 @@
 class implementation_check_kind_http_request(interface_check_kind):
 
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+				"request": {
+					"type": "object",
+					"additionalProperties": False,
+					"properties": {
+						"target": {
+							"description": "URL",
+							"type": "string"
+						},
+						"method": {
+							"type": "string",
+							"enum": [
+								"GET",
+								"POST"
+							],
+							"default": "GET"
+						}
+					},
+					"required": [
+						"target"
+					]
+				},
+				"response": {
+					"type": "object",
+					"additionalProperties": False,
+					"properties": {
+						"status_code": {
+							"description": "checks whether the response status code is this",
+							"type": ["null", "integer"],
+							"default": 200
+						},
+						"headers": {
+							"description": "conjunctively checks header key-value pairs",
+							"type": "object",
+							"additionalProperties": {
+								"description": "header value",
+								"type": "string"
+							},
+							"properties": {
+							},
+							"required": [
+							],
+							"default": {}
+						},
+						"body_part": {
+							"description": "checks whether the response body contains this string",
+							"type": "string"
+						}
+					},
+					"required": [
+					]
+				},
+				"as_warning": {
+					"description": "whether a violation of this check shall be exposed as warning instead of critical; default: false",
+					"type": "boolean",
+					"default": False
+				}
+			},
+			"required": [
+				"request"
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
@@ -118,3 +189,4 @@ class implementation_check_kind_http_request(interface_check_kind):
 					),
 					"output": "\n".join(lines),
 				}
+
diff --git a/source/check_kinds/script.py b/source/check_kinds/script.py
index 7085048..562d4ad 100644
--- a/source/check_kinds/script.py
+++ b/source/check_kinds/script.py
@@ -1,5 +1,29 @@
 class implementation_check_kind_script(interface_check_kind):
 
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+				"path": {
+					"type": "string"
+				},
+				"arguments": {
+					"type": "array",
+					"item": {
+						"type": "string"
+					}
+				}
+			},
+			"required": [
+				"path"
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
diff --git a/source/main.py b/source/main.py
index 87414cb..66c7d91 100644
--- a/source/main.py
+++ b/source/main.py
@@ -5,7 +5,7 @@ def state_encode(state):
 		"count": state["count"],
 	}
 	
-	
+
 def state_decode(state_encoded):
 	return {
 		"timestamp": state_encoded["timestamp"],
@@ -14,6 +14,179 @@ def state_decode(state_encoded):
 	}
 	
 
+def schema_active():
+	return {
+		"type": "boolean",
+		"default": True
+	}
+	
+
+def schema_threshold():
+	return {
+		"description": "how often a condition has to occur in order to be reported",
+		"type": "integer",
+		"minimum": 1,
+		"default": 3
+	}
+	
+
+def schema_annoy():
+	return {
+		"description": "whether notifications shall be kept sending after the threshold has been surpassed",
+		"type": "boolean",
+		"default": False
+	}
+	
+
+def schema_interval(default):
+	return {
+		"description": "in seconds or as text",
+		"anyOf": [
+			{
+				"type": "integer",
+				"exclusiveMinimum": 0
+			},
+			{
+				"type": "string",
+				"enum": [
+					"minute",
+					"hour",
+					"day",
+					"week",
+				]
+			},
+		],
+		"default": default,
+	}
+	
+
+def schema_schedule():
+	return {
+		"type": "object",
+		"additionalProperties": False,
+		"properties": {
+			"regular_interval": schema_interval(60 * 60),
+			"attentive_interval": schema_interval(60 * 2),
+		},
+		"required": [
+		]
+	}
+	
+
+def schema_notifications(notification_channel_implementations):
+	return {
+		"type": "array",
+		"items": {
+			"anyOf": list(
+				map(
+					lambda pair: {
+						"title": ("check kind '%s'" % pair[0]),
+						"type": "object",
+						"unevaluatedProperties": False,
+						"properties": {
+							"kind": {
+								"type": "string",
+								"enum": [pair[0]]
+							},
+							"parameters": pair[1].parameters_schema(),
+						},
+						"required": [
+							"kind",
+							"parameters"
+						]
+					},
+					notification_channel_implementations.items()
+				)
+			)
+		},
+		"default": [
+			{
+				"kind": "console",
+				"parameters": {
+				}
+			}
+		]
+	}
+	
+
+def schema_root(check_kind_implementations, notification_channel_implementations):
+	return {
+		"type": "object",
+		"additionalProperties": False,
+		"properties": {
+			"defaults": {
+				"description": "default values for checks",
+				"type": "object",
+				"additionalProperties": False,
+				"properties": {
+					"active": schema_active(),
+					"threshold": schema_threshold(),
+					"annoy": schema_annoy(),
+					"schedule": schema_schedule(),
+					"notifications": schema_notifications(notification_channel_implementations),
+				},
+				"required": [
+				]
+			},
+			"checks": {
+				"type": "array",
+				"items": {
+					"allOf": [
+						{
+							"description": "should represent a specific check",
+							"type": "object",
+							"unevaluatedProperties": False,
+							"properties": {
+								"name": {
+									"type": "string"
+								},
+								"title": {
+									"type": "string"
+								},
+								"active": schema_active(),
+								"threshold": schema_threshold(),
+								"annoy": schema_annoy(),
+								"schedule": schema_schedule(),
+								"notifications": schema_notifications(notification_channel_implementations),
+							},
+							"required": [
+								"name",
+							]
+						},
+						{
+							"anyOf": list(
+								map(
+									lambda pair: {
+										"title": ("notification channel '%s'" % pair[0]),
+										"type": "object",
+										"unevaluatedProperties": False,
+										"properties": {
+											"kind": {
+												"type": "string",
+												"enum": [pair[0]]
+											},
+											"parameters": pair[1].parameters_schema(),
+										},
+										"required": [
+											"kind",
+											"parameters"
+										]
+									},
+									check_kind_implementations.items()
+								)
+							),
+						},
+					]
+				}
+			}
+		},
+		"required": [
+			"defaults",
+			"checks",
+		]
+	}
+	
+
 def conf_normalize_interval(interval_raw):
 	if (type(interval_raw) == int):
 		return interval_raw
@@ -46,8 +219,15 @@ def conf_normalize_schedule(node):
 	}
 	
 
-def conf_normalize_defaults(node):
-	return dict_merge(
+def conf_normalize_notification(notification_channel_implementations, node):
+	return {
+		"kind": node["kind"],
+		"parameters": notification_channel_implementations[node["kind"]].normalize_conf_node(node["parameters"]),
+	}
+	
+
+def conf_normalize_defaults(notification_channel_implementations, node):
+	node_ = dict_merge(
 		{
 			"active": True,
 			"threshold": 3,
@@ -61,54 +241,88 @@ def conf_normalize_defaults(node):
 		},
 		node
 	)
-	
-
-def conf_normalize_check(check_kind_implementations, defaults, name, node):
-	if ("kind" not in node):
-		raise ValueError("missing mandatory 'check' field 'kind'")
-	else:
-		if (node["kind"] not in check_kind_implementations):
-			raise ValueError("unhandled kind: %s" % node["kind"])
-		else:
-			node_ = dict_merge(
-				{
-					"title": name,
-					"active": defaults["active"],
-					"threshold": defaults["threshold"],
-					"annoy": defaults["annoy"],
-					"schedule": defaults["schedule"],
-					"notifications": defaults["notifications"],
-					"parameters": {},
-				},
-				node
+	return {
+		"active": node_["active"],
+		"threshold": node_["threshold"],
+		"annoy": node_["annoy"],
+		"schedule": node_["schedule"],
+		"notifications": list(
+			map(
+				lambda x: conf_normalize_notification(notification_channel_implementations, x),
+				node_["notifications"]
 			)
-			return {
-				"title": node_["title"],
-				"active": node_["active"],
-				"threshold": node_["threshold"],
-				"annoy": node_["annoy"],
-				"schedule": conf_normalize_schedule(node_["schedule"]),
-				"notifications": node_["notifications"],
-				"kind": node_["kind"],
-				"parameters": check_kind_implementations[node_["kind"]].normalize_conf_node(node_["parameters"]),
-			}
+		),
+	}
 	
 
-def conf_normalize_root(check_kind_implementations, node):
-	return dict(
-		map(
-			lambda check_pair: (
-				check_pair[0],
-				conf_normalize_check(
-					check_kind_implementations,
-					conf_normalize_defaults(node["defaults"]),
-					check_pair[0],
-					check_pair[1]
-				),
-			),
-			node["checks"].items()
+def conf_normalize_check(check_kind_implementations, notification_channel_implementations, defaults, node):
+	if ("name" not in node):
+		raise ValueError("missing mandatory 'check' field 'name'")
+	else:
+		if ("kind" not in node):
+			raise ValueError("missing mandatory 'check' field 'kind'")
+		else:
+			if (node["kind"] not in check_kind_implementations):
+				raise ValueError("unhandled kind: %s" % node["kind"])
+			else:
+				node_ = dict_merge(
+					{
+						"title": node["name"],
+						"active": defaults["active"],
+						"threshold": defaults["threshold"],
+						"annoy": defaults["annoy"],
+						"schedule": defaults["schedule"],
+						"notifications": defaults["notifications"],
+						"parameters": {},
+					},
+					node
+				)
+				return {
+					"name": node_["name"],
+					"title": node_["title"],
+					"active": node_["active"],
+					"threshold": node_["threshold"],
+					"annoy": node_["annoy"],
+					"schedule": conf_normalize_schedule(node_["schedule"]),
+					"notifications": list(
+						map(
+							lambda x: conf_normalize_notification(notification_channel_implementations, x),
+							node_["notifications"]
+						)
+					),
+					"kind": node_["kind"],
+					"parameters": check_kind_implementations[node_["kind"]].normalize_conf_node(node_["parameters"]),
+				}
+	
+
+def conf_normalize_root(check_kind_implementations, notification_channel_implementations, node):
+	counts = {}
+	for node_ in node["checks"]:
+		if (node_["name"] not in counts):
+			counts[node_["name"]] = 0
+		counts[node_["name"]] += 1
+	fails = list(filter(lambda pair: (pair[1] > 1), counts.items()))
+	if (len(fails) > 0):
+		raise ValueError(
+			string_coin(
+				"ambiguous check names: {{names}}",
+				{
+					"names": ",".join(counts.keys()),
+				}
+			)
+		)
+	else:
+		return list(
+			map(
+				lambda node_: conf_normalize_check(
+					check_kind_implementations,
+					notification_channel_implementations,
+					conf_normalize_defaults(notification_channel_implementations, node["defaults"]),
+					node_
+				),
+				node["checks"]
+			)
 		)
-	)
 	
 
 def main():
@@ -127,7 +341,7 @@ def main():
 		help = "path to the configuration file"
 	)
 	argumentparser.add_argument(
-		"-s",
+		"-f",
 		"--state-path",
 		type = str,
 		default = None,
@@ -143,6 +357,14 @@ def main():
 		dest = "erase_state",
 		help = "whether the state shall be deleted on start; this will cause that all checks are executed"
 	)
+	argumentparser.add_argument(
+		"-s",
+		"--show-schema",
+		action = "store_true",
+		default = False,
+		dest = "show_schema",
+		help = "print the hmdl JSON schema to stdout and exit"
+	)
 	argumentparser.add_argument(
 		"-e",
 		"--expose-full-conf",
@@ -166,8 +388,6 @@ def main():
 	
 	## exec
 	
-	_sys.stderr.write(">> state file path: %s\n" % state_path)
-	
 	### load check kind implementations
 	check_kind_implementations = {
 		"script": implementation_check_kind_script(),
@@ -183,111 +403,131 @@ def main():
 		"libnotify": implementation_notification_channel_libnotify(),
 	}
 	
-	### get configuration data
-	checks = conf_normalize_root(check_kind_implementations, _json.loads(file_read(args.conf_path)))
-	if (args.expose_full_conf):
-		_sys.stdout.write(_json.dumps(checks, indent = "\t") + "\n")
-		_sys.exit(1)
+	if (args.show_schema):
+		_sys.stdout.write(
+			_json.dumps(
+				schema_root(
+					check_kind_implementations,
+					notification_channel_implementations
+				),
+				indent = "\t"
+			)
+			+
+			"\n"
+		)
 	else:
-		### get state data
-		if (
-			(not _os.path.exists(state_path))
-			or
-			args.erase_state
-		):
-			state_data = {}
-			file_write(state_path, _json.dumps(state_data, indent = "\t"))
-		else:
-			state_data = _json.loads(file_read(state_path))
+		_sys.stderr.write(">> state file path: %s\n" % state_path)
 		
-		### iterate through checks
-		for (check_name, check_data, ) in checks.items():
-			if (not check_data["active"]):
-				pass
+		### get configuration data
+		checks = conf_normalize_root(
+			check_kind_implementations,
+			notification_channel_implementations,
+			_json.loads(file_read(args.conf_path))
+		)
+		if (args.expose_full_conf):
+			_sys.stdout.write(_json.dumps(checks, indent = "\t") + "\n")
+			_sys.exit(1)
+		else:
+			### get state data
+			if (
+				(not _os.path.exists(state_path))
+				or
+				args.erase_state
+			):
+				state_data = {}
+				file_write(state_path, _json.dumps(state_data, indent = "\t"))
 			else:
-				### get old state and examine whether the check shall be executed
-				old_item_state = (
-					None
-					if (check_name not in state_data) else
-					state_decode(state_data[check_name])
-				)
-				timestamp = get_current_timestamp()
-				due = (
-					(old_item_state is None)
-					or
-					(old_item_state["condition"] != enum_condition.ok)
-					or
-					((timestamp - old_item_state["timestamp"]) >= check_data["schedule"]["regular_interval"])
-					or
-					(
-						(old_item_state["count"] is not None)
-						and
-						((timestamp - old_item_state["timestamp"]) >= check_data["schedule"]["attentive_interval"])
-					)
-				)
-				if (not due):
+				state_data = _json.loads(file_read(state_path))
+			
+			### iterate through checks
+			for check_data in checks:
+				if (not check_data["active"]):
 					pass
 				else:
-					_sys.stderr.write(
-						string_coin(
-							"-- {{check_name}}\n",
-							{
-								"check_name": check_name,
-							}
-						)
+					### get old state and examine whether the check shall be executed
+					old_item_state = (
+						None
+						if (check_data["name"] not in state_data) else
+						state_decode(state_data[check_data["name"]])
 					)
-					
-					### execute check and set new state
-					result = check_kind_implementations[check_data["kind"]].run(check_data["parameters"])
-					new_item_state = {
-						"timestamp": timestamp,
-						"condition": result["condition"],
-						"count": (
-							1
-							if (
-								(old_item_state is None)
-								or
-								(old_item_state["condition"] != result["condition"])
-							) else
-							(
-								(old_item_state["count"] + 1)
-								if (
-									(old_item_state["count"] is not None)
-									and
-									((old_item_state["count"] + 1) <= check_data["threshold"])
-								) else
-								None
-							)
-						),
-					}
-					state_data[check_name] = state_encode(new_item_state)
-					file_write(state_path, _json.dumps(state_data, indent = "\t"))
-					
-					### send notifications
-					if (
-						(
-							(new_item_state["count"] is not None)
-							and
-							(new_item_state["count"] == check_data["threshold"])
-						)
+					timestamp = get_current_timestamp()
+					due = (
+						(old_item_state is None)
+						or
+						(old_item_state["condition"] != enum_condition.ok)
+						or
+						((timestamp - old_item_state["timestamp"]) >= check_data["schedule"]["regular_interval"])
 						or
 						(
-							(new_item_state["count"] is None)
+							(old_item_state["count"] is not None)
 							and
-							check_data["annoy"]
+							((timestamp - old_item_state["timestamp"]) >= check_data["schedule"]["attentive_interval"])
 						)
-					):
-						for notification in check_data["notifications"]:
-							if (notification["kind"] in notification_channel_implementations):
-								notification_channel_implementations[notification["kind"]].notify(
-									notification["parameters"],
-									check_name,
-									check_data,
-									new_item_state,
-									result["output"]
+					)
+					if (not due):
+						pass
+					else:
+						_sys.stderr.write(
+							string_coin(
+								"-- {{check_name}}\n",
+								{
+									"check_name": check_data["name"],
+								}
+							)
+						)
+						
+						### execute check and set new state
+						result = check_kind_implementations[check_data["kind"]].run(check_data["parameters"])
+						new_item_state = {
+							"timestamp": timestamp,
+							"condition": result["condition"],
+							"count": (
+								1
+								if (
+									(old_item_state is None)
+									or
+									(old_item_state["condition"] != result["condition"])
+								) else
+								(
+									(old_item_state["count"] + 1)
+									if (
+										(old_item_state["count"] is not None)
+										and
+										((old_item_state["count"] + 1) <= check_data["threshold"])
+									) else
+									None
 								)
-							else:
-								raise ValueError("invalid notification kind: %s" % notification["kind"])
-	
+							),
+						}
+						state_data[check_data["name"]] = state_encode(new_item_state)
+						file_write(state_path, _json.dumps(state_data, indent = "\t"))
+						
+						### send notifications
+						if (
+							(
+								(new_item_state["count"] is not None)
+								and
+								(new_item_state["count"] == check_data["threshold"])
+							)
+							or
+							(
+								(new_item_state["count"] is None)
+								and
+								check_data["annoy"]
+							)
+						):
+							for notification in check_data["notifications"]:
+								if (notification["kind"] in notification_channel_implementations):
+									notification_channel_implementations[notification["kind"]].notify(
+										notification["parameters"],
+										check_data["name"],
+										check_data,
+										new_item_state,
+										result["output"]
+									)
+								else:
+									raise ValueError("invalid notification kind: %s" % notification["kind"])
+		
 
 main()
+
diff --git a/source/notification_channels/_interface.py b/source/notification_channels/_interface.py
index 1df1fb9..7a5ca1f 100644
--- a/source/notification_channels/_interface.py
+++ b/source/notification_channels/_interface.py
@@ -1,5 +1,9 @@
 class interface_notification_channel(object):
 	
+	def parameters_schema(self):
+		raise NotImplementedError
+		
+	
 	def normalize_conf_node(self, node):
 		raise NotImplementedError
 		
diff --git a/source/notification_channels/console.py b/source/notification_channels/console.py
index a8c2599..df75065 100644
--- a/source/notification_channels/console.py
+++ b/source/notification_channels/console.py
@@ -1,5 +1,19 @@
 class implementation_notification_channel_console(interface_notification_channel):
 	
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+			},
+			"required": [
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
diff --git a/source/notification_channels/email.py b/source/notification_channels/email.py
index 2113a71..3631cd6 100644
--- a/source/notification_channels/email.py
+++ b/source/notification_channels/email.py
@@ -1,5 +1,63 @@
 class implementation_notification_channel_email(interface_notification_channel):
 	
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+				"access": {
+					"type": "object",
+					"additionalProperties": False,
+					"properties": {
+						"host": {
+							"type": "string"
+						},
+						"port": {
+							"type": "integer"
+						},
+						"username": {
+							"type": "string"
+						},
+						"password": {
+							"type": "string"
+						}
+					},
+					"required": [
+						"host",
+						"port",
+						"username",
+						"password"
+					]
+				},
+				"sender": {
+					"type": "string"
+				},
+				"receivers": {
+					"type": "array",
+					"items": {
+						"type": "string"
+					}
+				},
+				"tags": {
+					"description": "list of strings, which will be placed in the e-mail subject",
+					"type": "array",
+					"items": {
+						"type": "string"
+					},
+					"default": []
+				}
+			},
+			"required": [
+				"access",
+				"sender",
+				"receivers"
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
diff --git a/source/notification_channels/file_touch.py b/source/notification_channels/file_touch.py
index f97151f..dc8106b 100644
--- a/source/notification_channels/file_touch.py
+++ b/source/notification_channels/file_touch.py
@@ -1,5 +1,23 @@
 class implementation_notification_channel_file_touch(interface_notification_channel):
 	
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+				"path": {
+					"type": "string"
+				}
+			},
+			"required": [
+				"path"
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
diff --git a/source/notification_channels/libnotify.py b/source/notification_channels/libnotify.py
index 78ca83c..f751cd1 100644
--- a/source/notification_channels/libnotify.py
+++ b/source/notification_channels/libnotify.py
@@ -1,12 +1,29 @@
 class implementation_notification_channel_libnotify(interface_notification_channel):
 	
+	'''
+	[implementation]
+	'''
+	def parameters_schema(self):
+		return {
+			"type": "object",
+			"additionalProperties": False,
+			"properties": {
+				"icon": {
+					"type": "string"
+				}
+			},
+			"required": [
+			]
+		}
+		
+	
 	'''
 	[implementation]
 	'''
 	def normalize_conf_node(self, node):
 		return dict_merge(
 			{
-				"icon": None,
+				"icon": "/usr/local/share/icons/heimdall.png",
 			},
 			node
 		)
diff --git a/todo.md b/todo.md
index 30a5f7c..ceec363 100644
--- a/todo.md
+++ b/todo.md
@@ -3,8 +3,8 @@
 - Selbst-Test
 - Benachrichtigungs-Kanäle:
 	- Matrix
-- JSON-Schema für Konfiguration von Programm erzeugen lassen
 - Möglichkeit dauerhaft laufen zulassen (evtl. als systemd-Dienst)
 - Versionierung
 - Umbenennung: `output` zu `info`
 - Test-Routinen
+