diff --git a/src/DataAccessGenerator.ts b/src/DataAccessGenerator.ts
new file mode 100644
index 0000000..43a7e29
--- /dev/null
+++ b/src/DataAccessGenerator.ts
@@ -0,0 +1,110 @@
+import { Collection, Entity, Property } from "./MySchema";
+import { FileWrite } from "./app";
+
+export function generateDataAccess(collections: Collection[]): FileWrite[] {
+    return collections.map(generateDataAccessFile);
+}
+
+function generateDataAccessFile(collection: Collection): FileWrite {
+    const definitions: string[] = [
+        defineImports(collection),
+        defineSave(collection),
+        defineParseEntity(collection.entities),
+        defineParseCollection(collection),
+        defineLoad(collection),
+        defineGeneral(),
+    ];
+
+    return {
+        location: collection.name + "DataAccess.ts",
+        content: definitions.join("\n\n") + "\n",
+    };
+}
+
+function defineImports(collection: Collection): string {
+    const entity = collection.entities;
+    return `import { ${collection.name}, ${entity.name} } from "./${collection.name}Model";
+import * as fs from "fs";`;
+}
+
+function defineSave(collection: Collection): string {
+    return `export function save(fileName: string, collection: ${collection.name}): void {
+    const content = JSON.stringify({ ...collection, $schema: "./${collection.name.toLowerCase()}.schema.json" });
+    fs.writeFileSync(fileName, content);
+}`;
+}
+
+function defineGeneral(): string {
+    return `function parseArrayProperty<O, T>(fieldName: keyof O, itemParser: (item: any) => T, data: any): T[]
+{
+    if(fieldName in data)
+    {
+        const valueList = data[fieldName];
+        if(Array.isArray(valueList))
+        {
+            return valueList.map(itemParser);
+        }
+    }
+    return [];
+}
+
+function parsePrimitiveProperty<O, T = string | number>(type: T extends string ? "string" : "int", fieldName: keyof O, defaultValue: T, obj: any): T
+{
+    if(fieldName in obj)
+    {
+        const fieldValue = obj[fieldName];
+        if(typeof fieldValue === type)
+        {
+            return fieldValue;
+        }
+    }
+    return defaultValue;
+}
+
+function canReadFile(path: string): boolean {
+    try {
+        fs.accessSync(path, fs.constants.R_OK);
+        return true;
+    } catch (error) {
+        return false;
+    }
+}`;
+}
+
+function defineParseEntity(entity: Entity): string {
+    const propParser = entity.properties.map(p => parseStringProperty(entity.name, p)).join("\n");
+    return `function parse${entity.name}(data: any): ${entity.name}
+{
+    return {
+        id: parsePrimitiveProperty<${entity.name}, number>("int", "id", 0, data),
+${propParser}
+    };
+}`;
+}
+
+function parseStringProperty(entityName: string, property: Property): string {
+    return `\t\t${property.key}: parsePrimitiveProperty<${entityName}, string>("string", "${property.key}", "", data),`;
+}
+
+function defineParseCollection(collection: Collection): string {
+    return `function parse${collection.name}(data: any): ${collection.name} {
+    return {
+        nextId: parsePrimitiveProperty<${collection.name}, number>("int", "nextId", 1, data),
+        items: parseArrayProperty<${collection.name}, ${collection.entities.name}>("items", parse${collection.entities.name}, data),
+    };
+}`;
+}
+
+function defineLoad(collection: Collection): string {
+    return `export function load(fileName: string): ${collection.name} {
+    if (!canReadFile(fileName)) {
+        return {
+            items: [],
+            nextId: 1,
+        };
+    }
+    const content = fs.readFileSync(fileName).toString();
+    const data = JSON.parse(content);
+    return parse${collection.name}(data);
+}`;
+}

diff --git a/src/DataAccessGenerator.ts b/src/DataAccessGenerator.ts
new file mode 100644
index 0000000..43a7e29
--- /dev/null
+++ b/src/DataAccessGenerator.ts
@@ -0,0 +1,110 @@
+import { Collection, Entity, Property } from "./MySchema";
+import { FileWrite } from "./app";
+
+export function generateDataAccess(collections: Collection[]): FileWrite[] {
+    return collections.map(generateDataAccessFile);
+}
+
+function generateDataAccessFile(collection: Collection): FileWrite {
+    const definitions: string[] = [
+        defineImports(collection),
+        defineSave(collection),
+        defineParseEntity(collection.entities),
+        defineParseCollection(collection),
+        defineLoad(collection),
+        defineGeneral(),
+    ];
+
+    return {
+        location: collection.name + "DataAccess.ts",
+        content: definitions.join("\n\n") + "\n",
+    };
+}
+
+function defineImports(collection: Collection): string {
+    const entity = collection.entities;
+    return `import { ${collection.name}, ${entity.name} } from "./${collection.name}Model";
+import * as fs from "fs";`;
+}
+
+function defineSave(collection: Collection): string {
+    return `export function save(fileName: string, collection: ${collection.name}): void {
+    const content = JSON.stringify({ ...collection, $schema: "./${collection.name.toLowerCase()}.schema.json" });
+    fs.writeFileSync(fileName, content);
+}`;
+}
+
+function defineGeneral(): string {
+    return `function parseArrayProperty<O, T>(fieldName: keyof O, itemParser: (item: any) => T, data: any): T[]
+{
+    if(fieldName in data)
+    {
+        const valueList = data[fieldName];
+        if(Array.isArray(valueList))
+        {
+            return valueList.map(itemParser);
+        }
+    }
+    return [];
+}
+
+function parsePrimitiveProperty<O, T = string | number>(type: T extends string ? "string" : "int", fieldName: keyof O, defaultValue: T, obj: any): T
+{
+    if(fieldName in obj)
+    {
+        const fieldValue = obj[fieldName];
+        if(typeof fieldValue === type)
+        {
+            return fieldValue;
+        }
+    }
+    return defaultValue;
+}
+
+function canReadFile(path: string): boolean {
+    try {
+        fs.accessSync(path, fs.constants.R_OK);
+        return true;
+    } catch (error) {
+        return false;
+    }
+}`;
+}
+
+function defineParseEntity(entity: Entity): string {
+    const propParser = entity.properties.map(p => parseStringProperty(entity.name, p)).join("\n");
+    return `function parse${entity.name}(data: any): ${entity.name}
+{
+    return {
+        id: parsePrimitiveProperty<${entity.name}, number>("int", "id", 0, data),
+${propParser}
+    };
+}`;
+}
+
+function parseStringProperty(entityName: string, property: Property): string {
+    return `\t\t${property.key}: parsePrimitiveProperty<${entityName}, string>("string", "${property.key}", "", data),`;
+}
+
+function defineParseCollection(collection: Collection): string {
+    return `function parse${collection.name}(data: any): ${collection.name} {
+    return {
+        nextId: parsePrimitiveProperty<${collection.name}, number>("int", "nextId", 1, data),
+        items: parseArrayProperty<${collection.name}, ${collection.entities.name}>("items", parse${collection.entities.name}, data),
+    };
+}`;
+}
+
+function defineLoad(collection: Collection): string {
+    return `export function load(fileName: string): ${collection.name} {
+    if (!canReadFile(fileName)) {
+        return {
+            items: [],
+            nextId: 1,
+        };
+    }
+    const content = fs.readFileSync(fileName).toString();
+    const data = JSON.parse(content);
+    return parse${collection.name}(data);
+}`;
+}
diff --git a/src/ExampleOutput/DataAccess.ts b/src/ExampleOutput/DataAccess.ts
index 279da34..f98ce06 100644
--- a/src/ExampleOutput/DataAccess.ts
+++ b/src/ExampleOutput/DataAccess.ts
@@ -76,8 +76,7 @@
     if (!canReadFile(fileName)) {
         return emptyGraph();
     }
-    // TODO check if file exists
     const content = fs.readFileSync(fileName).toString();
     const data = JSON.parse(content);
     return parseGraph(data);
-}
\ No newline at end of file
+}

diff --git a/src/DataAccessGenerator.ts b/src/DataAccessGenerator.ts
new file mode 100644
index 0000000..43a7e29
--- /dev/null
+++ b/src/DataAccessGenerator.ts
@@ -0,0 +1,110 @@
+import { Collection, Entity, Property } from "./MySchema";
+import { FileWrite } from "./app";
+
+export function generateDataAccess(collections: Collection[]): FileWrite[] {
+    return collections.map(generateDataAccessFile);
+}
+
+function generateDataAccessFile(collection: Collection): FileWrite {
+    const definitions: string[] = [
+        defineImports(collection),
+        defineSave(collection),
+        defineParseEntity(collection.entities),
+        defineParseCollection(collection),
+        defineLoad(collection),
+        defineGeneral(),
+    ];
+
+    return {
+        location: collection.name + "DataAccess.ts",
+        content: definitions.join("\n\n") + "\n",
+    };
+}
+
+function defineImports(collection: Collection): string {
+    const entity = collection.entities;
+    return `import { ${collection.name}, ${entity.name} } from "./${collection.name}Model";
+import * as fs from "fs";`;
+}
+
+function defineSave(collection: Collection): string {
+    return `export function save(fileName: string, collection: ${collection.name}): void {
+    const content = JSON.stringify({ ...collection, $schema: "./${collection.name.toLowerCase()}.schema.json" });
+    fs.writeFileSync(fileName, content);
+}`;
+}
+
+function defineGeneral(): string {
+    return `function parseArrayProperty<O, T>(fieldName: keyof O, itemParser: (item: any) => T, data: any): T[]
+{
+    if(fieldName in data)
+    {
+        const valueList = data[fieldName];
+        if(Array.isArray(valueList))
+        {
+            return valueList.map(itemParser);
+        }
+    }
+    return [];
+}
+
+function parsePrimitiveProperty<O, T = string | number>(type: T extends string ? "string" : "int", fieldName: keyof O, defaultValue: T, obj: any): T
+{
+    if(fieldName in obj)
+    {
+        const fieldValue = obj[fieldName];
+        if(typeof fieldValue === type)
+        {
+            return fieldValue;
+        }
+    }
+    return defaultValue;
+}
+
+function canReadFile(path: string): boolean {
+    try {
+        fs.accessSync(path, fs.constants.R_OK);
+        return true;
+    } catch (error) {
+        return false;
+    }
+}`;
+}
+
+function defineParseEntity(entity: Entity): string {
+    const propParser = entity.properties.map(p => parseStringProperty(entity.name, p)).join("\n");
+    return `function parse${entity.name}(data: any): ${entity.name}
+{
+    return {
+        id: parsePrimitiveProperty<${entity.name}, number>("int", "id", 0, data),
+${propParser}
+    };
+}`;
+}
+
+function parseStringProperty(entityName: string, property: Property): string {
+    return `\t\t${property.key}: parsePrimitiveProperty<${entityName}, string>("string", "${property.key}", "", data),`;
+}
+
+function defineParseCollection(collection: Collection): string {
+    return `function parse${collection.name}(data: any): ${collection.name} {
+    return {
+        nextId: parsePrimitiveProperty<${collection.name}, number>("int", "nextId", 1, data),
+        items: parseArrayProperty<${collection.name}, ${collection.entities.name}>("items", parse${collection.entities.name}, data),
+    };
+}`;
+}
+
+function defineLoad(collection: Collection): string {
+    return `export function load(fileName: string): ${collection.name} {
+    if (!canReadFile(fileName)) {
+        return {
+            items: [],
+            nextId: 1,
+        };
+    }
+    const content = fs.readFileSync(fileName).toString();
+    const data = JSON.parse(content);
+    return parse${collection.name}(data);
+}`;
+}
diff --git a/src/ExampleOutput/DataAccess.ts b/src/ExampleOutput/DataAccess.ts
index 279da34..f98ce06 100644
--- a/src/ExampleOutput/DataAccess.ts
+++ b/src/ExampleOutput/DataAccess.ts
@@ -76,8 +76,7 @@
     if (!canReadFile(fileName)) {
         return emptyGraph();
     }
-    // TODO check if file exists
     const content = fs.readFileSync(fileName).toString();
     const data = JSON.parse(content);
     return parseGraph(data);
-}
\ No newline at end of file
+}
diff --git a/src/ModelGenerator.ts b/src/ModelGenerator.ts
index 29550ef..d471407 100644
--- a/src/ModelGenerator.ts
+++ b/src/ModelGenerator.ts
@@ -23,7 +23,7 @@
 
 function defineCollection(collection: Collection): string {
     return `export interface ${collection.name} {
-    nodes: ${collection.entities.name}[];
+    items: ${collection.entities.name}[];
     nextId: number;
 }`;
 }
@@ -43,16 +43,16 @@
     ref: string;
 }
 
-export function toPayload(node: ${entity.name}): ${entity.name}Payload {
+export function toPayload(item: ${entity.name}): ${entity.name}Payload {
     return {
-        ...node,
-        ref: \`/${collection.name.toLowerCase()}/\${node.id}\`,
+        ...item,
+        ref: \`/${collection.name.toLowerCase()}/\${item.id}\`,
     }
 }`;
 }
 
 function defineFindFunction(collection: Collection): string {
-    return `export function findSingle(graph: ${collection.name}, id: number) {
-    return graph.nodes.find(n => n.id === id);
+    return `export function findSingle(collection: ${collection.name}, id: number) {
+    return collection.items.find(n => n.id === id);
 }`;
 }

diff --git a/src/DataAccessGenerator.ts b/src/DataAccessGenerator.ts
new file mode 100644
index 0000000..43a7e29
--- /dev/null
+++ b/src/DataAccessGenerator.ts
@@ -0,0 +1,110 @@
+import { Collection, Entity, Property } from "./MySchema";
+import { FileWrite } from "./app";
+
+export function generateDataAccess(collections: Collection[]): FileWrite[] {
+    return collections.map(generateDataAccessFile);
+}
+
+function generateDataAccessFile(collection: Collection): FileWrite {
+    const definitions: string[] = [
+        defineImports(collection),
+        defineSave(collection),
+        defineParseEntity(collection.entities),
+        defineParseCollection(collection),
+        defineLoad(collection),
+        defineGeneral(),
+    ];
+
+    return {
+        location: collection.name + "DataAccess.ts",
+        content: definitions.join("\n\n") + "\n",
+    };
+}
+
+function defineImports(collection: Collection): string {
+    const entity = collection.entities;
+    return `import { ${collection.name}, ${entity.name} } from "./${collection.name}Model";
+import * as fs from "fs";`;
+}
+
+function defineSave(collection: Collection): string {
+    return `export function save(fileName: string, collection: ${collection.name}): void {
+    const content = JSON.stringify({ ...collection, $schema: "./${collection.name.toLowerCase()}.schema.json" });
+    fs.writeFileSync(fileName, content);
+}`;
+}
+
+function defineGeneral(): string {
+    return `function parseArrayProperty<O, T>(fieldName: keyof O, itemParser: (item: any) => T, data: any): T[]
+{
+    if(fieldName in data)
+    {
+        const valueList = data[fieldName];
+        if(Array.isArray(valueList))
+        {
+            return valueList.map(itemParser);
+        }
+    }
+    return [];
+}
+
+function parsePrimitiveProperty<O, T = string | number>(type: T extends string ? "string" : "int", fieldName: keyof O, defaultValue: T, obj: any): T
+{
+    if(fieldName in obj)
+    {
+        const fieldValue = obj[fieldName];
+        if(typeof fieldValue === type)
+        {
+            return fieldValue;
+        }
+    }
+    return defaultValue;
+}
+
+function canReadFile(path: string): boolean {
+    try {
+        fs.accessSync(path, fs.constants.R_OK);
+        return true;
+    } catch (error) {
+        return false;
+    }
+}`;
+}
+
+function defineParseEntity(entity: Entity): string {
+    const propParser = entity.properties.map(p => parseStringProperty(entity.name, p)).join("\n");
+    return `function parse${entity.name}(data: any): ${entity.name}
+{
+    return {
+        id: parsePrimitiveProperty<${entity.name}, number>("int", "id", 0, data),
+${propParser}
+    };
+}`;
+}
+
+function parseStringProperty(entityName: string, property: Property): string {
+    return `\t\t${property.key}: parsePrimitiveProperty<${entityName}, string>("string", "${property.key}", "", data),`;
+}
+
+function defineParseCollection(collection: Collection): string {
+    return `function parse${collection.name}(data: any): ${collection.name} {
+    return {
+        nextId: parsePrimitiveProperty<${collection.name}, number>("int", "nextId", 1, data),
+        items: parseArrayProperty<${collection.name}, ${collection.entities.name}>("items", parse${collection.entities.name}, data),
+    };
+}`;
+}
+
+function defineLoad(collection: Collection): string {
+    return `export function load(fileName: string): ${collection.name} {
+    if (!canReadFile(fileName)) {
+        return {
+            items: [],
+            nextId: 1,
+        };
+    }
+    const content = fs.readFileSync(fileName).toString();
+    const data = JSON.parse(content);
+    return parse${collection.name}(data);
+}`;
+}
diff --git a/src/ExampleOutput/DataAccess.ts b/src/ExampleOutput/DataAccess.ts
index 279da34..f98ce06 100644
--- a/src/ExampleOutput/DataAccess.ts
+++ b/src/ExampleOutput/DataAccess.ts
@@ -76,8 +76,7 @@
     if (!canReadFile(fileName)) {
         return emptyGraph();
     }
-    // TODO check if file exists
     const content = fs.readFileSync(fileName).toString();
     const data = JSON.parse(content);
     return parseGraph(data);
-}
\ No newline at end of file
+}
diff --git a/src/ModelGenerator.ts b/src/ModelGenerator.ts
index 29550ef..d471407 100644
--- a/src/ModelGenerator.ts
+++ b/src/ModelGenerator.ts
@@ -23,7 +23,7 @@
 
 function defineCollection(collection: Collection): string {
     return `export interface ${collection.name} {
-    nodes: ${collection.entities.name}[];
+    items: ${collection.entities.name}[];
     nextId: number;
 }`;
 }
@@ -43,16 +43,16 @@
     ref: string;
 }
 
-export function toPayload(node: ${entity.name}): ${entity.name}Payload {
+export function toPayload(item: ${entity.name}): ${entity.name}Payload {
     return {
-        ...node,
-        ref: \`/${collection.name.toLowerCase()}/\${node.id}\`,
+        ...item,
+        ref: \`/${collection.name.toLowerCase()}/\${item.id}\`,
     }
 }`;
 }
 
 function defineFindFunction(collection: Collection): string {
-    return `export function findSingle(graph: ${collection.name}, id: number) {
-    return graph.nodes.find(n => n.id === id);
+    return `export function findSingle(collection: ${collection.name}, id: number) {
+    return collection.items.find(n => n.id === id);
 }`;
 }
diff --git a/src/app.ts b/src/app.ts
index 46ec548..dcdb3b4 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -2,6 +2,7 @@
 import { join } from "path";
 import * as fs from "fs";
 import { generateModel } from "./ModelGenerator";
+import { generateDataAccess } from "./DataAccessGenerator";
 
 interface Options {
     typeScriptOutputFolder: string;
@@ -34,13 +35,18 @@
 
 function generate(options: Options, description: Description): FileWrite[] {
     // generate model files
+    const modelWrites = generateModel(description.collections);
+    modelWrites.forEach(w => {w.location = join(options.typeScriptOutputFolder, w.location)})
+
     // generate data access files
+    const dataAccessWrites = generateDataAccess(description.collections);
+    dataAccessWrites.forEach(w => {w.location = join(options.typeScriptOutputFolder, w.location)})
+
     // generate middleware file
     // generate openapi file
     //  -> see https://swagger.io/docs/specification/describing-responses/
-    const writes = generateModel(description.collections);
-    writes.forEach(w => {w.location = join(options.typeScriptOutputFolder, w.location)})
-    return writes;
+
+    return [...modelWrites, ...dataAccessWrites];
 }
 
 function execute() {