diff --git a/package.json b/package.json
index b428bfc94..ebff92d13 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
 	"name": "syso",
 	"license": "MIT",
-	"version": "0.6.2",
+	"version": "0.0.7",
 	"description": "Library to compute the french social security contributions. Also a website that explains the calculations, and a generic engine to build similar simulators and computations.",
 	"main": "./dist/engine.js",
 	"files": ["dist/engine.js"],
@@ -69,7 +69,8 @@
 		"test-common": "mocha-webpack --webpack-config source/webpack.test.js --require source-map-support/register --include componentTestSetup.js --require mock-local-storage --require test/helpers/browser.js \"./{,!(node_modules)/**/}!(webpack).test.js\"",
 		"test": "yarn test-common",
 		"test-components": "mocha-webpack --webpack-config source/webpack.test.js --require source-map-support/register --include componentTestSetup.js --require mock-local-storage ---require test/helpers/browser.js \"source/components/**/*.test.js\" --watch",
-		"test-lib": "yarn test-common --grep 'library'"
+		"test-lib": "yarn test-common --grep 'library'",
+		"compile-lib": "yarn webpack --config source/webpack.lib.js"
 	},
 	"devDependencies": {
 		"@babel/core": "^7.1.0",
@@ -115,6 +116,7 @@
 		"http-server": "^0.11.1",
 		"intl": "^1.2.5",
 		"intl-locales-supported": "^1.0.0",
+		"isomorphic-style-loader": "^4.0.0",
 		"js-yaml": "^3.12.0",
 		"jsdom": "^12.0.0",
 		"json-loader": "^0.5.7",
@@ -132,7 +134,7 @@
 		"sinon": "^4.5.0",
 		"sinon-chai": "^3.0.0",
 		"source-map-support": "^0.5.4",
-		"style-loader": "^0.20.3",
+		"style-loader": "^0.23.1",
 		"url-loader": "^1.0.1",
 		"webpack": "^4.20.1",
 		"webpack-cli": "^3.1.1",
diff --git a/source/engine/index.js b/source/engine/index.js
index 9d4e61c76..c33933ed5 100644
--- a/source/engine/index.js
+++ b/source/engine/index.js
@@ -19,10 +19,10 @@ let enrichRules = input =>
 	(typeof input === 'string' ? yaml.safeLoad(input) : input).map(enrichRule)
 
 export default {
-	evaluate: (targetInput, nestedSituation, rulesConfig) => {
-		let rules = rulesConfig
+	evaluate: (targetInput, nestedSituation, config) => {
+		let rules = config
 			? do {
-					let { base, extra } = rulesConfig
+					let { base, extra } = config
 					;[
 						...(base ? enrichRules(base) : rulesFr),
 						...(extra ? enrichRules(extra) : [])
@@ -35,7 +35,10 @@ export default {
 			Array.isArray(targetInput) ? targetInput : [targetInput]
 		)(nestedSituationToStateSelector(rules)(nestedSituation))
 
+		if (config.debug) return evaluation
+
 		let values = evaluation.targets.map(t => t.nodeValue)
+
 		return Array.isArray(targetInput) ? values : values[0]
 	}
 }
diff --git a/source/webpack.common.js b/source/webpack.common.js
index 8f2a0cf41..8e672164e 100644
--- a/source/webpack.common.js
+++ b/source/webpack.common.js
@@ -2,6 +2,7 @@
 const HTMLPlugin = require('html-webpack-plugin')
 const CopyPlugin = require('copy-webpack-plugin')
 const path = require('path')
+const { universal, web } = require('./webpack.commonLoaders.js')
 
 module.exports = {
 	resolve: {
@@ -21,70 +22,17 @@ module.exports = {
 		infrance: ['./source/sites/mycompanyinfrance.fr/entry.js'],
 		embauche: ['./source/sites/embauche.gouv.fr/entry.js'],
 		// To not introduce breaking into the iframe integration, we serve simulateur.js from a 'dist' subdirectory
-		'dist/simulateur': ['./source/sites/embauche.gouv.fr/iframe-script.js'],
-		engine: ['./source/engine/index.js']
+		'dist/simulateur': ['./source/sites/embauche.gouv.fr/iframe-script.js']
 	},
 	output: {
 		path: path.resolve('./dist/'),
 		filename: ({ chunk }) =>
-			['dist/simulateur', 'engine'].includes(chunk.name)
+			['dist/simulateur'].includes(chunk.name)
 				? '[name].js'
-				: '[name].[hash].js',
-		libraryTarget: 'umd',
-		library: 'Syso'
+				: '[name].[hash].js'
 	},
 	module: {
-		rules: [
-			{
-				test: /\.css$/,
-				use: [
-					{
-						loader: 'style-loader'
-					},
-					{
-						loader: 'css-loader',
-						options: {
-							sourceMap: true,
-							importLoaders: 1
-						}
-					},
-					{
-						loader: 'postcss-loader'
-					}
-				]
-			},
-			{
-				test: /\.(jpe?g|png|svg)$/,
-				use: {
-					loader: 'file-loader',
-					options: {
-						name: 'images/[name].[ext]'
-					}
-				}
-			},
-			{
-				test: /\.yaml$/,
-				loader: 'json-loader!yaml-loader'
-			},
-			{
-				test: /\.js$/,
-				exclude: /node_modules|dist/,
-				loader: 'babel-loader'
-			},
-			{
-				test: /\.csv$/,
-				loader: 'csv-loader',
-				options: {
-					dynamicTyping: true,
-					header: true,
-					skipEmptyLines: true
-				}
-			},
-			{
-				test: /\.ne$/,
-				loader: 'babel-loader!nearley-loader'
-			}
-		]
+		rules: [...web, ...universal]
 	},
 	plugins: [
 		new HTMLPlugin({
diff --git a/source/webpack.commonLoaders.js b/source/webpack.commonLoaders.js
new file mode 100644
index 000000000..7ac82e428
--- /dev/null
+++ b/source/webpack.commonLoaders.js
@@ -0,0 +1,44 @@
+module.exports = {
+	web: [
+		{
+			test: /\.css$/,
+			use: [
+				'style-loader',
+				{
+					loader: 'css-loader',
+					options: {
+						sourceMap: true,
+						importLoaders: 1
+					}
+				},
+				{
+					loader: 'postcss-loader'
+				}
+			]
+		}
+	],
+	universal: [
+		{
+			test: /\.(jpe?g|png|svg)$/,
+			use: {
+				loader: 'file-loader',
+				options: {
+					name: 'images/[name].[ext]'
+				}
+			}
+		},
+		{
+			test: /\.yaml$/,
+			loader: 'json-loader!yaml-loader'
+		},
+		{
+			test: /\.js$/,
+			exclude: /node_modules|dist/,
+			loader: 'babel-loader'
+		},
+		{
+			test: /\.ne$/,
+			loader: 'babel-loader!nearley-loader'
+		}
+	]
+}
diff --git a/source/webpack.lib.js b/source/webpack.lib.js
new file mode 100644
index 000000000..432e62128
--- /dev/null
+++ b/source/webpack.lib.js
@@ -0,0 +1,38 @@
+const common = require('./webpack.common.js')
+const { universal } = require('./webpack.commonLoaders.js')
+const path = require('path')
+
+module.exports = {
+	resolve: common.resolve,
+	entry: './source/engine/index.js',
+	mode: 'development',
+	devtool: 'source-map',
+	output: {
+		path: path.resolve('./dist/'),
+		filename: 'engine.js',
+		library: 'Syso',
+		libraryTarget: 'umd',
+		globalObject: "(typeof window !== 'undefined' ? window : this)"
+	},
+	module: {
+		rules: [
+			...universal,
+			{
+				test: /\.css$/,
+				use: [
+					'isomorphic-style-loader',
+					{
+						loader: 'css-loader',
+						options: {
+							sourceMap: true,
+							importLoaders: 1
+						}
+					},
+					{
+						loader: 'postcss-loader'
+					}
+				]
+			}
+		]
+	}
+}
diff --git a/test/library.test.js b/test/library.test.js
index 36f106432..b3fcf7b3b 100644
--- a/test/library.test.js
+++ b/test/library.test.js
@@ -75,4 +75,58 @@ describe('library', function() {
 		)
 		console.log({ revenuDisponible, dividendes })
 	})
+
+	it('temp', function() {
+		let règles = `
+- nom:  revenu imposable
+  question: Quel est votre revenu imposable ?
+  format: euros
+
+- nom: revenu abattu
+  formule:
+    allègement:
+      assiette: revenu imposable
+      abattement: 10%
+
+
+- nom: impôt sur le revenu
+  formule:
+    barème:
+      assiette: revenu abattu
+      tranches:
+        - en-dessous de: 9807
+          taux: 0%
+        - de: 9807
+          à: 27086
+          taux: 14%
+        - de: 27086
+          à: 72617
+          taux: 30%
+        - de: 72617
+          à: 153783
+          taux: 41%
+        - au-dessus de: 153783
+          taux: 45%
+
+
+- nom: impôt sur le revenu à payer
+  formule:
+    allègement:
+      assiette: impôt sur le revenu
+      décote:
+        plafond: 1177
+        taux: 75%
+`
+
+		let target = 'impôt sur le revenu à payer'
+
+		let value = Syso.evaluate(
+			target,
+			{ 'revenu imposable': '48000' },
+			{ extra: règles }
+		)
+		console.log(value)
+
+		expect(value).to.equal(7000)
+	})
 })
diff --git a/yarn.lock b/yarn.lock
index 154291f25..4e0ed177e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1512,7 +1512,7 @@ babel-polyfill@^6.26.0:
     core-js "^2.5.0"
     regenerator-runtime "^0.10.5"
 
-babel-runtime@6.x, babel-runtime@^6.11.6, babel-runtime@^6.18.0, babel-runtime@^6.22.0, babel-runtime@^6.26.0:
+babel-runtime@6.x, babel-runtime@^6.11.6, babel-runtime@^6.18.0, babel-runtime@^6.22.0, babel-runtime@^6.25.0, babel-runtime@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.26.0.tgz#965c7058668e82b55d7bfe04ff2337bc8b5647fe"
   dependencies:
@@ -4003,7 +4003,7 @@ hoek@4.x.x:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/hoek/-/hoek-4.2.1.tgz#9634502aa12c445dd5a7c5734b572bb8738aacbb"
 
-hoist-non-react-statics@^2.3.1, hoist-non-react-statics@^2.5.0, hoist-non-react-statics@^2.5.4:
+hoist-non-react-statics@^2.2.2, hoist-non-react-statics@^2.3.1, hoist-non-react-statics@^2.5.0, hoist-non-react-statics@^2.5.4:
   version "2.5.5"
   resolved "https://registry.yarnpkg.com/hoist-non-react-statics/-/hoist-non-react-statics-2.5.5.tgz#c5903cf409c0dfd908f388e619d86b9c1174cb47"
 
@@ -4593,6 +4593,15 @@ isobject@^3.0.0, isobject@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/isobject/-/isobject-3.0.1.tgz#4e431e92b11a9731636aa1f9c8d1ccbcfdab78df"
 
+isomorphic-style-loader@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/isomorphic-style-loader/-/isomorphic-style-loader-4.0.0.tgz#0d8faa12885e2830918c54815042c0e3b55dc38d"
+  dependencies:
+    babel-runtime "^6.25.0"
+    hoist-non-react-statics "^2.2.2"
+    loader-utils "^1.1.0"
+    prop-types "^15.5.10"
+
 isstream@~0.1.2:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/isstream/-/isstream-0.1.2.tgz#47e63f7af55afa6f92e1500e690eb8b8529c099a"
@@ -7753,12 +7762,12 @@ strip-json-comments@^2.0.1, strip-json-comments@~2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/strip-json-comments/-/strip-json-comments-2.0.1.tgz#3c531942e908c2697c0ec344858c286c7ca0a60a"
 
-style-loader@^0.20.3:
-  version "0.20.3"
-  resolved "https://registry.yarnpkg.com/style-loader/-/style-loader-0.20.3.tgz#ebef06b89dec491bcb1fdb3452e913a6fd1c10c4"
+style-loader@^0.23.1:
+  version "0.23.1"
+  resolved "https://registry.yarnpkg.com/style-loader/-/style-loader-0.23.1.tgz#cb9154606f3e771ab6c4ab637026a1049174d925"
   dependencies:
     loader-utils "^1.1.0"
-    schema-utils "^0.4.5"
+    schema-utils "^1.0.0"
 
 supports-color@5.1.0:
   version "5.1.0"