diff --git a/packages/@n8n/utils/src/types.ts b/packages/@n8n/utils/src/types.ts
index ba811ed07fa..1a160903795 100644
--- a/packages/@n8n/utils/src/types.ts
+++ b/packages/@n8n/utils/src/types.ts
@@ -12,3 +12,47 @@
  * type WithoutKind = DistributiveOmit<Event, never>;
  */
 export type DistributiveOmit<T, K extends PropertyKey> = T extends unknown ? Omit<T, K> : never;
+
+/**
+ * Converts a union into an intersection of its members.
+ *
+ * @example
+ * type Merged = UnionToIntersection<{ a: string } | { b: number }>;
+ * // => { a: string } & { b: number }
+ */
+export type UnionToIntersection<U> = (U extends unknown ? (x: U) => void : never) extends (
+	x: infer I,
+) => void
+	? I
+	: never;
+
+/**
+ * Picks one member of a union (the last one in the compiler's internal order).
+ * Mainly a building block for iterating over union members.
+ *
+ * @example
+ * type Last = LastOf<'a' | 'b'>;
+ * // => 'b'
+ */
+export type LastOf<U> = UnionToIntersection<
+	U extends unknown ? () => U : never
+> extends () => infer R
+	? R
+	: never;
+
+/**
+ * Joins a union of string literals into a single quoted, comma-separated string literal.
+ * Useful for building readable custom compile-error messages. Uses single quotes so the
+ * result renders without escapes when the compiler prints it inside a double-quoted string.
+ *
+ * @example
+ * type Keys = JoinKeys<'a' | 'b'>;
+ * // => "'a', 'b'"
+ */
+export type JoinKeys<U extends string> = [U] extends [never]
+	? ''
+	: JoinKeys<Exclude<U, LastOf<U>>> extends infer TRest extends string
+		? TRest extends ''
+			? `'${LastOf<U> & string}'`
+			: `${TRest}, '${LastOf<U> & string}'`
+		: never;
diff --git a/packages/cli/src/modules/n8n-packages/entities/credential/credential.serializer.ts b/packages/cli/src/modules/n8n-packages/entities/credential/credential.serializer.ts
index af5c1bfeb6e..fc4262ce753 100644
--- a/packages/cli/src/modules/n8n-packages/entities/credential/credential.serializer.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/credential/credential.serializer.ts
@@ -5,14 +5,39 @@ import {
 	serializedCredentialSchema,
 	type SerializedCredential,
 } from '../../spec/serialized/credential.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
+
+type CredentialPackageKeyHandling = {
+	id: 'copy';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	name: 'copy';
+	data: 'exclude';
+	type: 'copy';
+	shared: 'exclude';
+	isManaged: 'exclude';
+	isGlobal: 'exclude';
+	isResolvable: 'exclude';
+	resolvableAllowFallback: 'exclude';
+	resolverId: 'exclude';
+	usageScope: 'exclude';
+};
+
+const serializePayload = definePackageSerializationPayload<
+	CredentialsEntity,
+	SerializedCredential,
+	CredentialPackageKeyHandling
+>();
 
 @Service()
 export class CredentialSerializer {
 	serialize(credential: CredentialsEntity): SerializedCredential {
-		return serializedCredentialSchema.parse({
-			id: credential.id,
-			name: credential.name,
-			type: credential.type,
-		});
+		return serializedCredentialSchema.parse(
+			serializePayload({
+				id: credential.id,
+				name: credential.name,
+				type: credential.type,
+			}),
+		);
 	}
 }
diff --git a/packages/cli/src/modules/n8n-packages/entities/data-table/data-table.serializer.ts b/packages/cli/src/modules/n8n-packages/entities/data-table/data-table.serializer.ts
index 2db9529446b..e569e0b22d1 100644
--- a/packages/cli/src/modules/n8n-packages/entities/data-table/data-table.serializer.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/data-table/data-table.serializer.ts
@@ -1,25 +1,67 @@
 import { Service } from '@n8n/di';
 
+import type { DataTableColumn } from '@/modules/data-table/data-table-column.entity';
 import type { DataTable } from '@/modules/data-table/data-table.entity';
 
 import {
 	serializedDataTableSchema,
+	type SerializedDataTableColumn,
 	type SerializedDataTable,
 } from '../../spec/serialized/data-table.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
+
+type DataTablePackageKeyHandling = {
+	id: 'copy';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	name: 'copy';
+	columns: 'transform';
+	project: 'transform';
+	projectId: 'transform';
+};
+
+type DataTableColumnPackageKeyHandling = {
+	id: 'exclude';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	dataTableId: 'exclude';
+	name: 'copy';
+	type: 'copy';
+	index: 'copy';
+	dataTable: 'exclude';
+};
+
+const serializeDataTablePayload = definePackageSerializationPayload<
+	DataTable,
+	SerializedDataTable,
+	DataTablePackageKeyHandling
+>();
+
+const serializeColumnPayload = definePackageSerializationPayload<
+	DataTableColumn,
+	SerializedDataTableColumn,
+	DataTableColumnPackageKeyHandling
+>();
 
 @Service()
 export class DataTableSerializer {
 	serialize(dataTable: DataTable): SerializedDataTable {
-		return serializedDataTableSchema.parse({
-			id: dataTable.id,
-			name: dataTable.name,
-			columns: [...dataTable.columns]
-				.sort((a, b) => a.index - b.index)
-				.map((column) => ({
+		const columns = [...dataTable.columns]
+			.sort((a, b) => a.index - b.index)
+			.map((column) =>
+				serializeColumnPayload({
 					name: column.name,
 					type: column.type,
 					index: column.index,
-				})),
-		});
+				}),
+			);
+
+		return serializedDataTableSchema.parse(
+			serializeDataTablePayload({
+				id: dataTable.id,
+				name: dataTable.name,
+				columns,
+			}),
+		);
 	}
 }
diff --git a/packages/cli/src/modules/n8n-packages/entities/folder/folder.serializer.ts b/packages/cli/src/modules/n8n-packages/entities/folder/folder.serializer.ts
index f8d7ce23e9c..ccd945afee3 100644
--- a/packages/cli/src/modules/n8n-packages/entities/folder/folder.serializer.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/folder/folder.serializer.ts
@@ -2,14 +2,36 @@ import type { Folder } from '@n8n/db';
 import { Service } from '@n8n/di';
 
 import { serializedFolderSchema, type SerializedFolder } from '../../spec/serialized/folder.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
+
+type FolderPackageKeyHandling = {
+	id: 'copy';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	name: 'copy';
+	parentFolderId: 'transform';
+	parentFolder: 'exclude';
+	subFolders: 'exclude';
+	homeProject: 'transform';
+	workflows: 'exclude';
+	tags: 'exclude';
+};
+
+const serializePayload = definePackageSerializationPayload<
+	Folder,
+	SerializedFolder,
+	FolderPackageKeyHandling
+>();
 
 @Service()
 export class FolderSerializer {
 	serialize(folder: Folder, parentFolderId: string | null): SerializedFolder {
-		return serializedFolderSchema.parse({
-			id: folder.id,
-			name: folder.name,
-			parentFolderId,
-		});
+		return serializedFolderSchema.parse(
+			serializePayload({
+				id: folder.id,
+				name: folder.name,
+				parentFolderId,
+			}),
+		);
 	}
 }
diff --git a/packages/cli/src/modules/n8n-packages/entities/package-serialization.types.ts b/packages/cli/src/modules/n8n-packages/entities/package-serialization.types.ts
new file mode 100644
index 00000000000..c49c1663976
--- /dev/null
+++ b/packages/cli/src/modules/n8n-packages/entities/package-serialization.types.ts
@@ -0,0 +1,77 @@
+/**
+ * The types below are hairy, but they exist for one reason: whenever a field is added to,
+ * renamed on, or removed from a core entity (workflow, credential, ...), package import/export
+ * must be updated too. Each serializer declares an export decision (`copy`, `transform`,
+ * `exclude`) for every entity key, and these types turn any drift between the entity and its
+ * decisions into a compile error — instead of silently dropping data from packages.
+ */
+import type { JoinKeys } from '@n8n/utils/types';
+
+// Entity properties only; methods are ignored.
+type EntityDataKeys<TEntity> = {
+	[K in keyof TEntity]-?: TEntity[K] extends (...args: never[]) => unknown ? never : K;
+}[keyof TEntity];
+
+// Forces every entity property to be classified for export.
+type PackageEntityKeyHandling<TEntity> = Record<
+	EntityDataKeys<TEntity>,
+	'copy' | 'transform' | 'exclude'
+>;
+
+// Turns into a readable constraint error in two cases:
+// - entity keys without a decision (e.g. `nodeGroups` added to the entity but not here)
+// - decisions for keys not on the entity (e.g. `nodeGroups` renamed but still listed here)
+type ExportDecisionConstraint<TEntity, TKeyHandling> = [
+	Exclude<EntityDataKeys<TEntity>, keyof TKeyHandling>,
+] extends [never]
+	? [Exclude<keyof TKeyHandling, EntityDataKeys<TEntity>>] extends [never]
+		? PackageEntityKeyHandling<TEntity>
+		: `Export decisions include key(s) that do not exist on the entity: ${JoinKeys<
+				Extract<Exclude<keyof TKeyHandling, EntityDataKeys<TEntity>>, string>
+			>}`
+	: `Every entity key has a package export decision, missing export decision for key(s): ${JoinKeys<
+			Extract<Exclude<EntityDataKeys<TEntity>, keyof TKeyHandling>, string>
+		>}`;
+
+// Entity keys exported unchanged (copy key handling).
+type PackageCopiedEntityKeys<TEntity, TKeyHandling> = {
+	[K in EntityDataKeys<TEntity>]-?: K extends keyof TKeyHandling
+		? TKeyHandling[K] extends 'copy'
+			? K
+			: never
+		: never;
+}[EntityDataKeys<TEntity>];
+
+// Entity keys intentionally omitted from export (exclude key handling).
+type PackageExcludedEntityKeys<TEntity, TKeyHandling> = {
+	[K in EntityDataKeys<TEntity>]-?: K extends keyof TKeyHandling
+		? TKeyHandling[K] extends 'exclude'
+			? K
+			: never
+		: never;
+}[EntityDataKeys<TEntity>];
+
+// Copied entity keys absent from the inferred payload.
+type CopiedEntityKeysMissingFromPayload<TEntity, TKeyHandling, TPayload> = Exclude<
+	PackageCopiedEntityKeys<TEntity, TKeyHandling>,
+	keyof TPayload
+>;
+
+// Preserves exact payload keys while enforcing the export decisions and serialized schema.
+// The handling map must give every entity key a decision, or this fails to compile with a
+// message listing the undecided keys.
+export function definePackageSerializationPayload<
+	TEntity,
+	TSerialized extends object,
+	TKeyHandling extends ExportDecisionConstraint<TEntity, TKeyHandling>,
+>() {
+	return <const TPayload extends TSerialized>(
+		payload: TPayload &
+			// Every copied key must be present, including optional keys.
+			Record<CopiedEntityKeysMissingFromPayload<TEntity, TKeyHandling, TPayload>, never> &
+			// Excluded entity keys cannot be emitted.
+			Partial<Record<PackageExcludedEntityKeys<TEntity, TKeyHandling>, never>> &
+			// Payload keys must exist in the serialized schema.
+			Record<Exclude<keyof TPayload, keyof TSerialized>, never>,
+	): TPayload => payload;
+}
diff --git a/packages/cli/src/modules/n8n-packages/entities/project/project.serializer.ts b/packages/cli/src/modules/n8n-packages/entities/project/project.serializer.ts
index 083945b479e..49ebde82121 100644
--- a/packages/cli/src/modules/n8n-packages/entities/project/project.serializer.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/project/project.serializer.ts
@@ -5,18 +5,46 @@ import {
 	serializedProjectSchema,
 	type SerializedProject,
 } from '../../spec/serialized/project.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
+
+type ProjectPackageKeyHandling = {
+	id: 'copy';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	name: 'copy';
+	type: 'exclude';
+	icon: 'copy';
+	description: 'copy';
+	customTelemetryTags: 'copy';
+	projectRelations: 'exclude';
+	sharedCredentials: 'exclude';
+	sharedWorkflows: 'exclude';
+	secretsProviderAccess: 'exclude';
+	variables: 'exclude';
+	roleMappingRules: 'exclude';
+	creatorId: 'exclude';
+	creator: 'exclude';
+};
+
+const serializePayload = definePackageSerializationPayload<
+	Project,
+	SerializedProject,
+	ProjectPackageKeyHandling
+>();
 
 @Service()
 export class ProjectSerializer {
 	serialize(project: Project): SerializedProject {
-		return serializedProjectSchema.parse({
-			id: project.id,
-			name: project.name,
-			...(project.description !== null ? { description: project.description } : {}),
-			...(project.icon !== null ? { icon: project.icon } : {}),
-			...(project.customTelemetryTags?.length
-				? { customTelemetryTags: project.customTelemetryTags }
-				: {}),
-		});
+		return serializedProjectSchema.parse(
+			serializePayload({
+				id: project.id,
+				name: project.name,
+				...(project.description !== null ? { description: project.description } : {}),
+				...(project.icon !== null ? { icon: project.icon } : {}),
+				...(project.customTelemetryTags?.length
+					? { customTelemetryTags: project.customTelemetryTags }
+					: {}),
+			}),
+		);
 	}
 }
diff --git a/packages/cli/src/modules/n8n-packages/entities/tag/tag.exporter.ts b/packages/cli/src/modules/n8n-packages/entities/tag/tag.exporter.ts
index f564c545471..00ec5f5d9fd 100644
--- a/packages/cli/src/modules/n8n-packages/entities/tag/tag.exporter.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/tag/tag.exporter.ts
@@ -1,12 +1,30 @@
+import type { TagEntity } from '@n8n/db';
 import { Service } from '@n8n/di';
 
 import type { PackageWriter } from '../../io/package-writer';
 import { UniqueFilenameAllocator } from '../../io/unique-filename-allocator';
 import type { ManifestEntry } from '../../spec/manifest.schema';
 import type { PackageTagRequirement } from '../../spec/requirements.schema';
-import { serializedTagSchema } from '../../spec/serialized/tag.schema';
+import { serializedTagSchema, type SerializedTag } from '../../spec/serialized/tag.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
 import { compareTagsByName, type WorkflowTagUsage } from './tag.types';
 
+type TagPackageKeyHandling = {
+	id: 'copy';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	name: 'copy';
+	workflows: 'exclude';
+	workflowMappings: 'exclude';
+	folderMappings: 'exclude';
+};
+
+const serializePayload = definePackageSerializationPayload<
+	TagEntity,
+	SerializedTag,
+	TagPackageKeyHandling
+>();
+
 export interface TagExportRequest {
 	usages: WorkflowTagUsage[];
 	writer: PackageWriter;
@@ -41,7 +59,7 @@ export class TagExporter {
 
 		for (const { id, name } of requirements) {
 			const tagDirectory = allocator.allocate(name);
-			const serializedTag = serializedTagSchema.parse({ id, name });
+			const serializedTag = serializedTagSchema.parse(serializePayload({ id, name }));
 			request.writer.writeDirectory(tagDirectory);
 			request.writer.writeFile(
 				`${tagDirectory}/tag.json`,
diff --git a/packages/cli/src/modules/n8n-packages/entities/variable/variable.serializer.ts b/packages/cli/src/modules/n8n-packages/entities/variable/variable.serializer.ts
index e245ef90a35..be37b86e110 100644
--- a/packages/cli/src/modules/n8n-packages/entities/variable/variable.serializer.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/variable/variable.serializer.ts
@@ -5,6 +5,21 @@ import {
 	serializedVariableSchema,
 	type SerializedVariable,
 } from '../../spec/serialized/variable.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
+
+type VariablePackageKeyHandling = {
+	id: 'exclude';
+	key: 'transform';
+	type: 'copy';
+	value: 'copy';
+	project: 'transform';
+};
+
+const serializePayload = definePackageSerializationPayload<
+	Variables,
+	SerializedVariable,
+	VariablePackageKeyHandling
+>();
 
 @Service()
 export class VariableSerializer {
@@ -12,10 +27,14 @@ export class VariableSerializer {
 		variable: Variables,
 		{ includeValue = true }: { includeValue?: boolean } = {},
 	): SerializedVariable {
-		return serializedVariableSchema.parse({
-			name: variable.key,
-			type: variable.type,
-			...(includeValue ? { value: variable.value } : {}),
-		});
+		const type = serializedVariableSchema.shape.type.parse(variable.type);
+
+		return serializedVariableSchema.parse(
+			serializePayload({
+				name: variable.key,
+				type,
+				...(includeValue ? { value: variable.value } : {}),
+			}),
+		);
 	}
 }
diff --git a/packages/cli/src/modules/n8n-packages/entities/workflow/workflow.serializer.ts b/packages/cli/src/modules/n8n-packages/entities/workflow/workflow.serializer.ts
index 668f3982f62..e7651db2943 100644
--- a/packages/cli/src/modules/n8n-packages/entities/workflow/workflow.serializer.ts
+++ b/packages/cli/src/modules/n8n-packages/entities/workflow/workflow.serializer.ts
@@ -6,14 +6,48 @@ import {
 	serializedWorkflowSchema,
 	type SerializedWorkflow,
 } from '../../spec/serialized/workflow.schema';
+import { definePackageSerializationPayload } from '../package-serialization.types';
 import { compareTagsByName } from '../tag/tag.types';
 
-/** Fields restored from package workflow.json; the target instance assigns the rest. */
+type WorkflowPackageKeyHandling = {
+	id: 'copy';
+	createdAt: 'exclude';
+	updatedAt: 'exclude';
+	name: 'copy';
+	description: 'exclude';
+	active: 'exclude';
+	isArchived: 'copy';
+	nodes: 'copy';
+	connections: 'copy';
+	settings: 'copy';
+	staticData: 'exclude';
+	meta: 'exclude';
+	nodeGroups: 'exclude';
+	tags: 'transform';
+	tagMappings: 'exclude';
+	shared: 'exclude';
+	pinData: 'exclude';
+	versionId: 'copy';
+	activeVersionId: 'transform';
+	activeVersion: 'exclude';
+	versionCounter: 'exclude';
+	triggerCount: 'exclude';
+	parentFolder: 'transform';
+	testRuns: 'exclude';
+	sourceWorkflowId: 'exclude';
+};
+
 type WorkflowPackageContent = Pick<
 	WorkflowEntity,
 	'name' | 'nodes' | 'connections' | 'isArchived' | 'settings'
 >;
 
+const serializePayload = definePackageSerializationPayload<
+	WorkflowEntity,
+	SerializedWorkflow,
+	WorkflowPackageKeyHandling
+>();
+
 @Service()
 export class WorkflowSerializer {
 	serialize(workflow: WorkflowEntity, options: { includeTags: boolean }): SerializedWorkflow {
@@ -23,18 +57,20 @@ export class WorkflowSerializer {
 			? [...(workflow.tags ?? [])].sort(compareTagsByName)
 			: undefined;
 
-		return serializedWorkflowSchema.parse({
-			id: workflow.id,
-			name: workflow.name,
-			nodes: workflow.nodes,
-			connections: workflow.connections,
-			settings: workflow.settings,
-			versionId: workflow.versionId,
-			parentFolderId: workflow.parentFolder?.id ?? null,
-			isPublished: workflow.activeVersionId === workflow.versionId,
-			isArchived: workflow.isArchived,
-			...(tags ? { tagIds: tags.map((tag) => tag.id) } : {}),
-		});
+		return serializedWorkflowSchema.parse(
+			serializePayload({
+				id: workflow.id,
+				name: workflow.name,
+				nodes: workflow.nodes,
+				connections: workflow.connections,
+				settings: workflow.settings ? { ...workflow.settings } : undefined,
+				versionId: workflow.versionId,
+				parentFolderId: workflow.parentFolder?.id ?? null,
+				isPublished: workflow.activeVersionId === workflow.versionId,
+				isArchived: workflow.isArchived,
+				...(tags ? { tagIds: tags.map((tag) => tag.id) } : {}),
+			}),
+		);
 	}
 
 	/**