diff --git a/packages/twenty-sdk/src/cli/__tests__/apps/minimal-app/__integration__/app-dev-once/app-dev-once.integration.spec.ts b/packages/twenty-sdk/src/cli/__tests__/apps/minimal-app/__integration__/app-dev-once/app-dev-once.integration.spec.ts
index bd3b7450d7..86f04606be 100644
--- a/packages/twenty-sdk/src/cli/__tests__/apps/minimal-app/__integration__/app-dev-once/app-dev-once.integration.spec.ts
+++ b/packages/twenty-sdk/src/cli/__tests__/apps/minimal-app/__integration__/app-dev-once/app-dev-once.integration.spec.ts
@@ -94,7 +94,13 @@ describe('minimal-app dev-once', () => {
       );
 
       expect(
-        files.filter((file) => file.includes('.function.')).sort(),
+        files
+          .filter(
+            (file) =>
+              file.endsWith('.function.mjs') ||
+              file.endsWith('.function.mjs.map'),
+          )
+          .sort(),
       ).toEqual(['my.function.mjs', 'my.function.mjs.map']);
     });
 
@@ -104,8 +110,26 @@ describe('minimal-app dev-once', () => {
       );
 
       expect(
-        files.filter((file) => file.includes('.front-component.')).sort(),
+        files
+          .filter(
+            (file) =>
+              file.endsWith('.front-component.mjs') ||
+              file.endsWith('.front-component.mjs.map'),
+          )
+          .sort(),
       ).toEqual(['my.front-component.mjs', 'my.front-component.mjs.map']);
     });
   });
+
+  describe('source files', () => {
+    it('should include the logic function source', async () => {
+      expect(await pathExists(join(OUTPUT_PATH, 'my.function.ts'))).toBe(true);
+    });
+
+    it('should include the front component source', async () => {
+      expect(
+        await pathExists(join(OUTPUT_PATH, 'my.front-component.tsx')),
+      ).toBe(true);
+    });
+  });
 });
diff --git a/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts b/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts
index b24a05e84d..aed19bf457 100644
--- a/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts
+++ b/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts
@@ -130,6 +130,13 @@ export const buildApplication = async (
     onFileBuilt: collectFileBuilt,
   });
 
+  await copyStaticFiles({
+    appPath: options.appPath,
+    fileFolder: FileFolder.Source,
+    filePaths: [...new Set([...logicFunctions, ...frontComponents])],
+    collectFileBuilt,
+  });
+
   await copyStaticFiles({
     appPath: options.appPath,
     fileFolder: FileFolder.PublicAsset,
diff --git a/packages/twenty-server/src/engine/core-modules/application/application-install/application-install.service.ts b/packages/twenty-server/src/engine/core-modules/application/application-install/application-install.service.ts
index adac1a5d65..441dc797a7 100644
--- a/packages/twenty-server/src/engine/core-modules/application/application-install/application-install.service.ts
+++ b/packages/twenty-server/src/engine/core-modules/application/application-install/application-install.service.ts
@@ -27,6 +27,7 @@ import {
   VERSION_PROGRESSION_REASON_TO_INSTALL_EXCEPTION_CODE,
   VERSION_REASON_TO_APPLICATION_EXCEPTION_CODE,
 } from 'src/engine/core-modules/application/application-package/constants/version-reason-to-exception-code.constant';
+import { buildApplicationFileList } from 'src/engine/core-modules/application/application-install/utils/build-application-file-list.util';
 import { ApplicationManifestApplyService } from 'src/engine/core-modules/application/application-manifest/application-manifest-apply.service';
 import { ApplicationSyncService } from 'src/engine/core-modules/application/application-manifest/application-sync.service';
 import { CacheLockService } from 'src/engine/core-modules/cache-lock/cache-lock.service';
@@ -592,9 +593,9 @@ export class ApplicationInstallService {
     applicationUniversalIdentifier: string,
     workspaceId: string,
   ): Promise<void> {
-    const filesToWrite = this.buildFileList(manifest);
+    const filesToWrite = buildApplicationFileList(manifest);
 
-    for (const { relativePath, fileFolder } of filesToWrite) {
+    for (const { relativePath, fileFolder, isRequired } of filesToWrite) {
       const absolutePath = this.resolveWithinDirOrThrow(
         extractedDir,
         relativePath,
@@ -604,7 +605,20 @@ export class ApplicationInstallService {
 
       try {
         content = await fs.readFile(absolutePath);
-      } catch {
+      } catch (error) {
+        if (
+          !isRequired &&
+          error instanceof Error &&
+          'code' in error &&
+          error.code === 'ENOENT'
+        ) {
+          this.logger.warn(
+            `Source file not found in package: ${relativePath}; skipping for backward compatibility`,
+          );
+
+          continue;
+        }
+
         throw new ApplicationException(
           `File not found in package: ${relativePath}`,
           ApplicationExceptionCode.PACKAGE_RESOLUTION_FAILED,
@@ -677,40 +691,6 @@ export class ApplicationInstallService {
     return file.id;
   }
 
-  private buildFileList(
-    manifest: Manifest,
-  ): Array<{ relativePath: string; fileFolder: FileFolder }> {
-    const files: Array<{ relativePath: string; fileFolder: FileFolder }> = [];
-
-    files.push(
-      { relativePath: 'package.json', fileFolder: FileFolder.Dependencies },
-      { relativePath: 'manifest.json', fileFolder: FileFolder.Source },
-    );
-
-    for (const logicFunction of manifest.logicFunctions ?? []) {
-      files.push({
-        relativePath: logicFunction.builtHandlerPath,
-        fileFolder: FileFolder.BuiltLogicFunction,
-      });
-    }
-
-    for (const frontComponent of manifest.frontComponents ?? []) {
-      files.push({
-        relativePath: frontComponent.builtComponentPath,
-        fileFolder: FileFolder.BuiltFrontComponent,
-      });
-    }
-
-    for (const publicAsset of manifest.publicAssets ?? []) {
-      files.push({
-        relativePath: publicAsset.filePath,
-        fileFolder: FileFolder.PublicAsset,
-      });
-    }
-
-    return files;
-  }
-
   private async ensureApplicationExists(params: {
     existingApplication: ApplicationEntity | null;
     universalIdentifier: string;
diff --git a/packages/twenty-server/src/engine/core-modules/application/application-install/utils/__tests__/build-application-file-list.util.spec.ts b/packages/twenty-server/src/engine/core-modules/application/application-install/utils/__tests__/build-application-file-list.util.spec.ts
new file mode 100644
index 0000000000..bbf819883b
--- /dev/null
+++ b/packages/twenty-server/src/engine/core-modules/application/application-install/utils/__tests__/build-application-file-list.util.spec.ts
@@ -0,0 +1,62 @@
+import { type Manifest } from 'twenty-shared/application';
+import { FileFolder } from 'twenty-shared/types';
+
+import { buildApplicationFileList } from 'src/engine/core-modules/application/application-install/utils/build-application-file-list.util';
+
+describe('buildApplicationFileList', () => {
+  it('includes source and built files for logic functions and front components', () => {
+    const manifest = {
+      logicFunctions: [
+        {
+          sourceHandlerPath: 'src/send-email.function.ts',
+          builtHandlerPath: 'src/send-email.function.mjs',
+        },
+      ],
+      frontComponents: [
+        {
+          sourceComponentPath: 'src/inbox.front-component.tsx',
+          builtComponentPath: 'src/inbox.front-component.mjs',
+        },
+      ],
+      publicAssets: [{ filePath: 'assets/logo.svg' }],
+    } as Manifest;
+
+    expect(buildApplicationFileList(manifest)).toEqual([
+      {
+        relativePath: 'package.json',
+        fileFolder: FileFolder.Dependencies,
+        isRequired: true,
+      },
+      {
+        relativePath: 'manifest.json',
+        fileFolder: FileFolder.Source,
+        isRequired: true,
+      },
+      {
+        relativePath: 'src/send-email.function.ts',
+        fileFolder: FileFolder.Source,
+        isRequired: false,
+      },
+      {
+        relativePath: 'src/send-email.function.mjs',
+        fileFolder: FileFolder.BuiltLogicFunction,
+        isRequired: true,
+      },
+      {
+        relativePath: 'src/inbox.front-component.tsx',
+        fileFolder: FileFolder.Source,
+        isRequired: false,
+      },
+      {
+        relativePath: 'src/inbox.front-component.mjs',
+        fileFolder: FileFolder.BuiltFrontComponent,
+        isRequired: true,
+      },
+      {
+        relativePath: 'assets/logo.svg',
+        fileFolder: FileFolder.PublicAsset,
+        isRequired: true,
+      },
+    ]);
+  });
+});
diff --git a/packages/twenty-server/src/engine/core-modules/application/application-install/utils/build-application-file-list.util.ts b/packages/twenty-server/src/engine/core-modules/application/application-install/utils/build-application-file-list.util.ts
new file mode 100644
index 0000000000..158924c99d
--- /dev/null
+++ b/packages/twenty-server/src/engine/core-modules/application/application-install/utils/build-application-file-list.util.ts
@@ -0,0 +1,65 @@
+import { type Manifest } from 'twenty-shared/application';
+import { FileFolder } from 'twenty-shared/types';
+
+export type ApplicationFileToStore = {
+  relativePath: string;
+  fileFolder: FileFolder;
+  isRequired: boolean;
+};
+
+export const buildApplicationFileList = (
+  manifest: Manifest,
+): ApplicationFileToStore[] => {
+  const files: ApplicationFileToStore[] = [
+    {
+      relativePath: 'package.json',
+      fileFolder: FileFolder.Dependencies,
+      isRequired: true,
+    },
+    {
+      relativePath: 'manifest.json',
+      fileFolder: FileFolder.Source,
+      isRequired: true,
+    },
+  ];
+
+  for (const logicFunction of manifest.logicFunctions ?? []) {
+    files.push(
+      {
+        relativePath: logicFunction.sourceHandlerPath,
+        fileFolder: FileFolder.Source,
+        isRequired: false,
+      },
+      {
+        relativePath: logicFunction.builtHandlerPath,
+        fileFolder: FileFolder.BuiltLogicFunction,
+        isRequired: true,
+      },
+    );
+  }
+
+  for (const frontComponent of manifest.frontComponents ?? []) {
+    files.push(
+      {
+        relativePath: frontComponent.sourceComponentPath,
+        fileFolder: FileFolder.Source,
+        isRequired: false,
+      },
+      {
+        relativePath: frontComponent.builtComponentPath,
+        fileFolder: FileFolder.BuiltFrontComponent,
+        isRequired: true,
+      },
+    );
+  }
+
+  for (const publicAsset of manifest.publicAssets ?? []) {
+    files.push({
+      relativePath: publicAsset.filePath,
+      fileFolder: FileFolder.PublicAsset,
+      isRequired: true,
+    });
+  }
+
+  return files;
+};