diff --git a/source/conf.ts b/source/conf.ts
new file mode 100644
index 0000000..ace3388
--- /dev/null
+++ b/source/conf.ts
@@ -0,0 +1,120 @@
+/**
+ * @todo generate generic
+ */
+function schema(
+) : any
+{
+	return {
+		"type": "object",
+		"additionalProperties": false,
+		"properties": {
+			"domains": {
+				"type": "array",
+				"items": {
+					"type": "object",
+					"additionalProperties": false,
+					"properties": {
+						"name": {
+							"type": "string"
+						},
+						"description": {
+							"type": ["null", "string"],
+							"default": null
+						},
+						"key_field": {
+							"type": ["null","object"],
+							"additionalProperties": false,
+							"properties": {
+								"name": {
+									"type": "string"
+								},
+								"description": {
+									"type": ["null", "string"],
+									"default": null
+								}
+							},
+							"required": [
+								"name"
+							],
+							"default": null
+						},
+						"data_fields": {
+							"type": "array",
+							"items": {
+								"type": "object",
+								"additionalProperties": false,
+								"properties": {
+									"name": {
+										"type": "string"
+									},
+									"description": {
+										"type": ["null", "string"],
+										"default": null
+									},
+									"type": {
+										"type": "string",
+										"enum": [
+											"boolean",
+											"integer",
+											"float",
+											"string_short",
+											"string_medium",
+											"string_long"
+										]
+									},
+									"nullable": {
+										"type": "boolean",
+										"default": true
+									},
+									"default": {
+										"type": ["null", "boolean", "integer", "float", "string"],
+										"default": null
+									}
+								},
+								"required": [
+									"name",
+									"type"
+								]
+							},
+							"default": []
+						},
+						"constraints": {
+							"type": "array",
+							"items": {
+								"type": "object",
+								"additionalProperties": false,
+								"properties": {
+									"kind": {
+										"type": "string",
+										"enum": [
+											"unique",
+											"foreign_key"
+										]
+									},
+									"parameters": {
+										"type": "object",
+										"additionalProperties": "string",
+										"properties": {
+										},
+										"required": [
+										]
+									}
+								},
+								"required": [
+									"kind"
+								]
+							},
+							"default": []
+						}
+					},
+					"required": [
+						"name"
+					]
+				}
+			}
+		},
+		"required": [
+			"domains"
+		]
+	}
+}
diff --git a/source/main.ts b/source/main.ts
index 2d16f30..15e7841 100644
--- a/source/main.ts
+++ b/source/main.ts
@@ -1,3 +1,5 @@
+/**
+ */
 async function main(
 	args_raw : Array<string>
 ) : Promise<void>
@@ -21,22 +23,66 @@ async function main(
 				},
 				"info": "output format",
 			}),
+			"schema": new lib_args.class_argument({
+				"name": "schema",
+				"type": lib_args.enum_type.boolean,
+				"kind": lib_args.enum_kind.volatile,
+				"mode": lib_args.enum_mode.replace,
+				"default": false,
+				"parameters": {
+					"indicators_long": ["schema"],
+					"indicators_short": ["s"],
+				},
+				"info": "print sindri JSON schema to stdout and exit",
+			}),
+			"help": new lib_args.class_argument({
+				"name": "help",
+				"type": lib_args.enum_type.boolean,
+				"kind": lib_args.enum_kind.volatile,
+				"mode": lib_args.enum_mode.replace,
+				"default": false,
+				"parameters": {
+					"indicators_long": ["help"],
+					"indicators_short": ["h"],
+				},
+				"info": "print help to stdout and exit",
+			}),
 		}
 	);
 	const args : Record<string, any> = arg_handler.read(lib_args.enum_environment.cli, args_raw.join(" "));
 	
-	const input_content : string = await lib_plankton.file.read_stdin();
-	const input_data : type_input_data = lib_json.decode(input_content);
-	
-	// TODO: sanitize & normalize input_data
-	
-	if (! outputs.hasOwnProperty(args["format"])) {
-		throw (new Error("unhandled output format: " + args["format"]));
+	if (args["help"]) {
+		process.stdout.write(
+			arg_handler.generate_help(
+				{
+					"programname": "sindri",
+					"author": "Christian Fraß <frass@greenscale.de>",
+					"description": "create data model scripts in different output formats (MySQL, SQLite, …) on basis of an abstract description; feed with .sindri.json file via stdin!",
+					"executable": "sindri",
+				}
+			)
+		);
 	}
 	else {
-		const output_content : string = outputs[args["format"]].render(input_data);
-		process.stdout.write(output_content);
-		// return Promise.resolve<void>(undefined);
+		if (args["schema"]) {
+			process.stdout.write(
+				JSON.stringify(schema(), undefined, "\t")
+			);
+		}
+		else {
+			const input_content : string = await lib_plankton.file.read_stdin();
+			const input_data : type_input_data = lib_json.decode(input_content);
+			
+			// TODO: sanitize & normalize input_data
+			
+			if (! outputs.hasOwnProperty(args["format"])) {
+				throw (new Error("unhandled output format: " + args["format"]));
+			}
+			else {
+				const output_content : string = outputs[args["format"]].render(input_data);
+				process.stdout.write(output_content);
+			}
+		}
 	}
 }
 
diff --git a/tools/makefile b/tools/makefile
index c0611a4..7be20ac 100644
--- a/tools/makefile
+++ b/tools/makefile
@@ -3,6 +3,7 @@
 cmd_create_directory := mkdir --parents
 cmd_typescript_compile := tsc
 cmd_concatenate := cat
+cmd_chmod := chmod
 cmd_echo := echo -e
 cmd_log := echo -e "--"
 
@@ -10,21 +11,23 @@ cmd_log := echo -e "--"
 ## rules
 
 .PHONY: all
-all: build/datamodel.js
+all: build/sindri
 
-temp/datamodel-unlinked.js: \
+temp/sindri-unlinked.js: \
 lib/plankton/plankton.d.ts \
 source/types.ts \
 source/outputs/sqlite.ts \
 source/outputs/mysql.ts \
+source/conf.ts \
 source/main.ts
 	@ ${cmd_log} "compiling …"
 	@ ${cmd_create_directory} temp
 	@ ${cmd_typescript_compile} $^ --lib es2020 --target es6 --outFile $@
 
-build/datamodel.js: lib/plankton/plankton.js temp/datamodel-unlinked.js
+build/sindri: lib/plankton/plankton.js temp/sindri-unlinked.js
 	@ ${cmd_log} "linking …"
 	@ ${cmd_create_directory} build
 	@ ${cmd_echo} "#!/usr/bin/env node\n" > temp/head.js
 	@ ${cmd_concatenate} temp/head.js $^ > $@
+	@ ${cmd_chmod} +x $@