diff --git a/lib/Controller/StoreController.php b/lib/Controller/StoreController.php
index 28c13599f..3bccd9aae 100644
--- a/lib/Controller/StoreController.php
+++ b/lib/Controller/StoreController.php
@@ -338,7 +338,10 @@ private function installComponents(array $components): array {
 			$configKey = SchemaSlugMap::SLUG_TO_CONFIG_KEY[$slug];
 
 			try {
-				$this->registry->save(schemaConfigKey: $configKey, data: $object);
+				$this->registry->save(
+					schemaConfigKey: $configKey,
+					data: $this->asNewObject(object: $object)
+				);
 				$report[] = ['schema' => $slug, 'status' => 'installed', 'message' => ''];
 			} catch (Throwable $e) {
 				$failed = true;
@@ -357,6 +360,39 @@ private function installComponents(array $components): array {
 		return ['success' => ($failed === false && $report !== []), 'components' => $report];
 	}//end installComponents()
 
+	/**
+	 * Strip every identity the remote payload carries, so an install CREATES.
+	 *
+	 * 🔴 WITHOUT THIS, "Install" IS AN OVERWRITE PRIMITIVE.
+	 *
+	 * OpenRegister's `saveObject()` resolves the object it is writing from the
+	 * payload itself: `extractUuidAndNormalizeObject()` reads
+	 * `$object['@self']['id'] ?? $object['id']` and treats a match as the uuid
+	 * to UPDATE. So a store item whose component carried the uuid of this
+	 * municipality's live case type would replace it rather than add one — and
+	 * the write is PUT-semantic, so keys the payload omits are nulled, not left
+	 * alone. The case type would not merely change, it would be gutted.
+	 *
+	 * The schema allowlist does not cover this. It governs WHICH schema a
+	 * component may write, never whether the write creates or replaces, so an
+	 * entirely legitimate `caseType` component is the attack.
+	 *
+	 * Identity is not the registry's to supply. An installed item is a NEW
+	 * local object, and if install ever needs to be idempotent it must key on
+	 * something dossiq controls rather than on a remote id.
+	 *
+	 * @param array<string, mixed> $object The component's object.
+	 *
+	 * @return array<string, mixed> The object with every identity key removed.
+	 *
+	 * @spec openspec/changes/dossiq-store-surface/specs/dossiq-store-surface/spec.md
+	 */
+	private function asNewObject(array $object): array {
+		unset($object['id'], $object['uuid'], $object['@self']);
+
+		return $object;
+	}//end asNewObject()
+
 	/**
 	 * Read the registry connection.
 	 *
diff --git a/openspec/changes/dossiq-store-surface/specs/dossiq-store-surface/spec.md b/openspec/changes/dossiq-store-surface/specs/dossiq-store-surface/spec.md
index 5bee62c35..351c3eb94 100644
--- a/openspec/changes/dossiq-store-surface/specs/dossiq-store-surface/spec.md
+++ b/openspec/changes/dossiq-store-surface/specs/dossiq-store-surface/spec.md
@@ -148,3 +148,31 @@ icon, in the footer section between Documentation and Reports.
 - **THEN** the entry labelled `Store` MUST declare `icon: "StoreOutline"`
 - **AND** it MUST sit in the `footer` section with an order between
   Documentation and Reports
+
+### Requirement: REQ-DSS-007 An install creates, and can never replace
+
+The install action SHALL strip every identity key the remote payload carries
+(`id`, `uuid`, `@self`) before writing, so an installed component is always a
+NEW local object.
+
+OpenRegister resolves the object it writes from the payload itself: `saveObject`
+reads `@self.id` first and `id` second, and treats a match as the uuid to
+UPDATE. The write is PUT-semantic, so keys the payload omits are nulled rather
+than left alone. A store item carrying the uuid of a live case type would
+therefore not merely change it, it would gut it.
+
+The schema allowlist does NOT cover this. It governs which schema a component
+may write, never whether the write creates or replaces, so a component naming a
+perfectly legitimate configuration schema is the attack.
+
+Identity is not a remote registry's to supply. If install ever needs to be
+idempotent it SHALL key on something dossiq controls.
+
+@e2e exclude Server-side, and the property is the ABSENCE of an addressed object. A browser sees an install succeed either way; only the payload handed to the write reveals which object it addressed. Proven by StoreControllerTest with a negative control: removing the strip makes the assertion fail.
+
+#### Scenario: A component carrying an id installs as a new object
+
+- **GIVEN** a store item whose component object carries `id`, `uuid` and `@self`
+- **WHEN** it is installed
+- **THEN** none of those keys MUST reach the write
+- **AND** the rest of the component MUST still install
diff --git a/tests/Unit/Controller/StoreControllerTest.php b/tests/Unit/Controller/StoreControllerTest.php
index 377423716..697b1f28c 100644
--- a/tests/Unit/Controller/StoreControllerTest.php
+++ b/tests/Unit/Controller/StoreControllerTest.php
@@ -412,6 +412,57 @@ public function testAFailedWriteIsReportedWithoutLeakingTheReason(): void {
 	}//end testAFailedWriteIsReportedWithoutLeakingTheReason()
 
 
+	/**
+	 * 🔴 A component carrying an id must NOT overwrite a local object.
+	 *
+	 * OpenRegister resolves the object it writes from the payload:
+	 * `saveObject()` reads `$object['@self']['id'] ?? $object['id']` and treats
+	 * a match as the uuid to UPDATE. So a registry that shipped the uuid of
+	 * this municipality's live case type would REPLACE it — and the write is
+	 * PUT-semantic, so omitted keys are nulled rather than left alone.
+	 *
+	 * The schema allowlist does not cover this: the component names an allowed
+	 * schema, which is exactly what makes it dangerous.
+	 *
+	 * @return void
+	 *
+	 * @spec openspec/changes/dossiq-store-surface/specs/dossiq-store-surface/spec.md#requirement-req-dss-003-install-accepts-configuration-and-refuses-records
+	 */
+	public function testAnInstalledComponentCannotOverwriteAnExistingObject(): void {
+		$this->storeService->method('resolve')->willReturn(
+			[
+				'slug' => 'hostile-item',
+				'components' => [
+					[
+						'schema' => 'caseType',
+						'object' => [
+							'id' => 'the-municipalitys-live-case-type',
+							'uuid' => 'the-municipalitys-live-case-type',
+							'@self' => ['id' => 'the-municipalitys-live-case-type'],
+							'title' => 'Replaced',
+						],
+					],
+				],
+			]
+		);
+
+		$written = null;
+		$this->registry->method('save')->willReturnCallback(
+			static function (string $key, array $data) use (&$written): array {
+				$written = $data;
+				return $data;
+			}
+		);
+
+		$this->controller->install(slug: 'hostile-item');
+
+		$this->assertIsArray($written);
+		$this->assertArrayNotHasKey('id', $written, 'a remote id must not address a local object');
+		$this->assertArrayNotHasKey('uuid', $written, 'nor a remote uuid');
+		$this->assertArrayNotHasKey('@self', $written, 'nor @self, which saveObject reads FIRST');
+		$this->assertSame('Replaced', $written['title'], 'the rest of the payload still installs');
+	}//end testAnInstalledComponentCannotOverwriteAnExistingObject()
+
 	/**
 	 * The token never comes back out.
 	 *