diff --git a/apps/backend/src/app/files/files.service.ts b/apps/backend/src/app/files/files.service.ts
index 929c93f..c2c648d 100644
--- a/apps/backend/src/app/files/files.service.ts
+++ b/apps/backend/src/app/files/files.service.ts
@@ -1,9 +1,20 @@
-import { Injectable, NotFoundException, StreamableFile } from '@nestjs/common';
-import { DbService } from 'apps/backend/src/app/db/db.service';
-import { FilesTable } from 'apps/backend/src/app/db/schema';
-import { StorageService } from 'apps/backend/src/app/storage/storage.service';
-import { eq, ilike } from 'drizzle-orm';
-
+import {
+	Injectable,
+	InternalServerErrorException,
+	NotFoundException,
+	StreamableFile,
+} from "@nestjs/common";
+import { DbService } from "apps/backend/src/app/db/db.service";
+import {
+	FilesForMachinesTable,
+	FilesGroupTable,
+	FilesTable,
+	FilesTypeForMachine,
+	MachinesTable,
+} from "apps/backend/src/app/db/schema";
+import { StorageService } from "apps/backend/src/app/storage/storage.service";
+import { data } from "autoprefixer";
+import { eq, ilike } from "drizzle-orm";
 
 @Injectable()
 export class FilesService {
@@ -12,7 +23,7 @@ export class FilesService {
 		private readonly database: DbService,
 	) {}
 
-  /**
+	/**
 	 * Retrieves a file and its related information from the database and associated storage.
 	 *
 	 * @param fileId The unique identifier for the file to be retrieved.
@@ -30,8 +41,8 @@ export class FilesService {
 
 		if (foundFiles.length === 0)
 			throw new NotFoundException("File not found", {
-        description: `Identifier : ${fileId}`
-      });
+				description: `Identifier : ${fileId}`,
+			});
 
 		if (foundFiles.length > 1)
 			console.log(
@@ -51,7 +62,7 @@ export class FilesService {
 		);
 		const fileNameWithoutSpaces = file.fileName.replace(/\s/g, "_");
 		return new StreamableFile(fileBuffer, {
-			disposition: `attachment; filename="${fileNameWithoutSpaces}.${fileInformation.fileType.ext.toLowerCase()}"`
+			disposition: `attachment; filename="${fileNameWithoutSpaces}.${fileInformation.fileType.ext.toLowerCase()}"`,
 		});
 	}
 
@@ -68,7 +79,90 @@ export class FilesService {
 	}
 
 	//TODO save a file
-	public async save() {
+	public async save(file: Buffer, data: Map<string, unknown>) {
+		const _machineIds = Array.from(data.get("machineId") as string[]);
+		const machinesIds = new Set<string>();
+		console.log(
+			`Checking if machine with ID ${_machineIds} exist in the database...`,
+		);
+		for (const machineId of _machineIds) {
+			const machineExists = await this.database
+				.use()
+				.select({
+					uuid: MachinesTable.id,
+				})
+				.from(MachinesTable)
+				.where(eq(MachinesTable.id, machineId))
+				.prepare("checkMachineExists")
+				.execute();
 
+			if (machineExists.length === 0) {
+				throw new NotFoundException(`Machine with ID "${machineId}" not found`);
+			}
+
+			machinesIds.add(machineExists[0].uuid);
+		}
+
+		const _group = data.get("groupId") as string;
+		// verify that the group exist in the database
+		const groupExists = await this.database
+			.use()
+			.select()
+			.from(FilesGroupTable)
+			.where(eq(FilesGroupTable.uuid, _group))
+			.prepare("checkGroupExists")
+			.execute();
+
+		if (groupExists.length === 0) {
+			throw new NotFoundException(`Group with ID "${_group}" not found`);
+		}
+
+		try {
+			const saveResult = await this.storage.new(
+				data.get("fileName") as string,
+				file,
+				_machineIds,
+				Boolean(data.get("isDocumentation")),
+			);
+			const inserted = await this.database
+				.use()
+				.insert(FilesTable)
+				.values({
+					fileName: data.get("fileName") as string,
+					checksum: saveResult.fileChecksum,
+					extension: saveResult.fileType.ext,
+					fileSize: saveResult.fileSize,
+					fileType: saveResult.fileType.mime,
+					isRestricted: Boolean(data.get("isRestricted")),
+					isDocumentation: Boolean(data.get("isDocumentation")),
+					uploadedBy: data.get("uploadedBy") as string,
+				})
+				.returning();
+
+			for (const machineId of machinesIds) {
+				//TODO insert a link betwen fileId and MachineIds[]
+				const linkRow = await this.database
+					.use()
+					.insert(FilesForMachinesTable)
+					.values({
+						fileId: inserted[0].uuid,
+						machineId: machineId,
+					});
+			}
+		} catch (e) {
+			throw new InternalServerErrorException(
+				"It seems that the insertion in the database failed.",
+				{
+					cause:
+						process.env.NODE_ENV === "production"
+							? "Internal server error"
+							: {
+									message: e.message,
+									stack: e.stack,
+								},
+					description: `Nom de fichier : "${data.get("fileName")}" `,
+				},
+			);
+		}
 	}
 }