diff --git a/packages/api/src/__tests__/assistant-tools-master-data-mutation-test-helpers.ts b/packages/api/src/__tests__/assistant-tools-master-data-mutation-test-helpers.ts
new file mode 100644
index 0000000..dceafe0
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-master-data-mutation-test-helpers.ts
@@ -0,0 +1,29 @@
+import { PermissionKey, SystemRole } from "@capakraken/shared";
+
+import type { ToolContext } from "../router/assistant-tools.js";
+
+export function createToolContext(
+  db: Record<string, unknown>,
+  options?: {
+    permissions?: PermissionKey[];
+    userRole?: SystemRole;
+  },
+): ToolContext {
+  const userRole = options?.userRole ?? SystemRole.ADMIN;
+  return {
+    db: db as ToolContext["db"],
+    userId: "user_1",
+    userRole,
+    permissions: new Set(options?.permissions ?? []),
+    session: {
+      user: { email: "assistant@example.com", name: "Assistant User", image: null },
+      expires: "2026-03-29T00:00:00.000Z",
+    },
+    dbUser: {
+      id: "user_1",
+      systemRole: userRole,
+      permissionOverrides: null,
+    },
+    roleDefaults: null,
+  };
+}