diff --git a/tests/api/permissions.hurl b/tests/api/permissions.hurl
new file mode 100644
index 00000000..e30bb5b3
--- /dev/null
+++ b/tests/api/permissions.hurl
@@ -0,0 +1,344 @@
+# =============================================================
+# OxiCloud – Cross-user permission / IDOR scenarios
+# =============================================================
+# Verifies the ownership checks added to FolderService::create_folder
+# and FileManagementService move/copy/rename, plus the shared
+# FolderDbRepository::verify_owner helper.
+#
+# Plan reference: /Users/ed/.claude/plans/compiled-shimmying-bonbon.md
+#                 — "Verification → 2. Manual integration tests"
+#
+# Run via tests/api/run.sh; must be ordered LAST in the runner because
+# it creates a second user (bob) and writes into admin's home folder.
+# =============================================================
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 1 – Login as admin (the user created by setup.hurl)
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/auth/login
+Content-Type: application/json
+{
+  "username": "{{username}}",
+  "password": "{{password}}"
+}
+
+HTTP 200
+[Captures]
+admin_token: jsonpath "$.access_token"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 2 – Capture admin's home folder
+# ─────────────────────────────────────────────────────────────
+GET {{base_url}}/api/folders
+Authorization: Bearer {{admin_token}}
+
+HTTP 200
+[Captures]
+admin_home_id: jsonpath "$[0].id"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 3 – Admin creates a private folder inside their home
+#           This is the resource bob will attempt to attack.
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/folders
+Authorization: Bearer {{admin_token}}
+Content-Type: application/json
+{
+  "name": "admin-private-folder",
+  "parent_id": "{{admin_home_id}}"
+}
+
+HTTP 201
+[Captures]
+admin_private_id: jsonpath "$.id"
+[Asserts]
+jsonpath "$.name" == "admin-private-folder"
+jsonpath "$.parent_id" == {{admin_home_id}}
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 4 – Admin uploads a file into their home
+#           This is the file bob will attempt to access.
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/files/upload
+Authorization: Bearer {{admin_token}}
+[MultipartFormData]
+folder_id: {{admin_home_id}}
+file: file,fixtures/hello.txt; text/plain
+
+HTTP 201
+[Captures]
+admin_file_id: jsonpath "$.id"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 5 – Admin creates user bob (via /api/admin/users)
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/admin/users
+Authorization: Bearer {{admin_token}}
+Content-Type: application/json
+{
+  "username": "bob",
+  "password": "BobPassword1!",
+  "email": "bob@example.com",
+  "role": "user"
+}
+
+HTTP 201
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 6 – Login as bob, capture his token + home folder
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/auth/login
+Content-Type: application/json
+{
+  "username": "bob",
+  "password": "BobPassword1!"
+}
+
+HTTP 200
+[Captures]
+bob_token: jsonpath "$.access_token"
+
+GET {{base_url}}/api/folders
+Authorization: Bearer {{bob_token}}
+
+HTTP 200
+[Captures]
+bob_home_id: jsonpath "$[0].id"
+[Asserts]
+jsonpath "$" count == 1
+jsonpath "$[0].parent_id" == null
+
+
+# ═════════════════════════════════════════════════════════════
+# IDOR tests — every request below uses bob's token
+# ═════════════════════════════════════════════════════════════
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 7 – Bob attempts to create a folder inside admin's home
+#           Expected: 404 (NotFound, not 403, to avoid leaking
+#           the existence of admin's folder).
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/folders
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "name": "bob-attack-1",
+  "parent_id": "{{admin_home_id}}"
+}
+
+HTTP 404
+[Asserts]
+jsonpath "$.error_type" == "Not Found"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 8 – Bob attempts to create a folder inside admin's
+#           private folder. Same expectation as Step 7.
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/folders
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "name": "bob-attack-2",
+  "parent_id": "{{admin_private_id}}"
+}
+
+HTTP 404
+[Asserts]
+jsonpath "$.error_type" == "Not Found"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 9 – Bob omits parent_id (null). The REST handler
+#           auto-resolves null to the caller's home folder
+#           (folder_handler.rs:55-77), so the request succeeds
+#           and the folder lands in bob's home — NOT at the
+#           database root. The service-level validation_error
+#           ("Root folder creation is reserved for registration")
+#           is defense-in-depth for callers that bypass this
+#           handler convenience.
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/folders
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "name": "bob-auto-resolved",
+  "parent_id": null
+}
+
+HTTP 201
+[Asserts]
+jsonpath "$.name" == "bob-auto-resolved"
+jsonpath "$.parent_id" == {{bob_home_id}}
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 10 – Positive control: bob CAN create a folder inside
+#            his own home.
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/folders
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "name": "bob-own-folder",
+  "parent_id": "{{bob_home_id}}"
+}
+
+HTTP 201
+[Captures]
+bob_folder_id: jsonpath "$.id"
+[Asserts]
+jsonpath "$.name" == "bob-own-folder"
+jsonpath "$.parent_id" == {{bob_home_id}}
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 11 – Bob uploads a file into his own home (for the
+#            file-move tests below).
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/files/upload
+Authorization: Bearer {{bob_token}}
+[MultipartFormData]
+folder_id: {{bob_home_id}}
+file: file,fixtures/hello.txt; text/plain
+
+HTTP 201
+[Captures]
+bob_file_id: jsonpath "$.id"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 12 – Bob attempts to move his own file into admin's
+#            private folder. He owns the file but not the target
+#            → verify_target_folder_owner rejects with 404.
+# ─────────────────────────────────────────────────────────────
+PUT {{base_url}}/api/files/{{bob_file_id}}/move
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "folder_id": "{{admin_private_id}}"
+}
+
+HTTP 404
+[Asserts]
+jsonpath "$.error_type" == "Not Found"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 13 – Bob moves his file to folder_id: null (his root
+#            namespace). storage.files.folder_id IS NULL is a
+#            legitimate state — verify_target_folder_owner
+#            short-circuits to Ok(()) when target is None.
+# ─────────────────────────────────────────────────────────────
+PUT {{base_url}}/api/files/{{bob_file_id}}/move
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "folder_id": null
+}
+
+HTTP 200
+[Asserts]
+jsonpath "$.id" == {{bob_file_id}}
+jsonpath "$.folder_id" == null
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 14 – Bob attempts to access admin's file directly.
+#            verify_owner on the file (not the folder) catches
+#            this — IDOR on file reads, also 404.
+# ─────────────────────────────────────────────────────────────
+GET {{base_url}}/api/files/{{admin_file_id}}
+Authorization: Bearer {{bob_token}}
+
+HTTP 404
+[Asserts]
+jsonpath "$.error_type" == "Not Found"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 15 – Admin's private folder still exists & is untouched.
+#            Bob's attacks must not have polluted admin's tree.
+# ─────────────────────────────────────────────────────────────
+GET {{base_url}}/api/folders/{{admin_home_id}}/contents
+Authorization: Bearer {{admin_token}}
+
+HTTP 200
+[Asserts]
+jsonpath "$[*].id" contains {{admin_private_id}}
+jsonpath "$[*].name" not contains "bob-attack-1"
+jsonpath "$[*].name" not contains "bob-attack-2"
+
+
+# ═════════════════════════════════════════════════════════════
+# WebDAV MKCOL — namespace isolation
+# ═════════════════════════════════════════════════════════════
+# WebDAV requests are isolated per-user by `resolve_webdav_path`
+# (webdav_handler.rs:189). If the requested path doesn't begin
+# with the caller's home folder name ("My Folder - <username>"),
+# the handler silently prefixes the caller's home folder path
+# onto the front. Effect: any WebDAV path a client sends is
+# always resolved INSIDE the caller's own tree, regardless of
+# what they wrote.
+#
+# These tests assert the isolation works (regression guard) and
+# that the service-level verify_owner still acts as
+# defense-in-depth for the legitimate path.
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 16 – Bob crafts a path that looks like it targets admin's
+#            home. The WebDAV handler rewrites the path to live
+#            under bob's home, so the request succeeds (201) but
+#            the new folders land in BOB's tree — never admin's.
+# ─────────────────────────────────────────────────────────────
+MKCOL {{base_url}}/webdav/My%20Folder%20-%20admin/bob-webdav-attack
+Authorization: Bearer {{bob_token}}
+
+HTTP 201
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 17 – Positive control: bob MKCOL inside his own home.
+# ─────────────────────────────────────────────────────────────
+MKCOL {{base_url}}/webdav/My%20Folder%20-%20bob/bob-webdav-own
+Authorization: Bearer {{bob_token}}
+
+HTTP 201
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 18 – Bob's home now contains:
+#            - "bob-webdav-own"    (from Step 17, normal MKCOL)
+#            - "My Folder - admin" (from Step 16 — the prefix
+#              rewrite turned admin's home name into a literal
+#              sub-folder name inside bob's tree).
+#            This proves the path prefix re-rooted the attack
+#            into bob's own namespace.
+# ─────────────────────────────────────────────────────────────
+GET {{base_url}}/api/folders/{{bob_home_id}}/contents
+Authorization: Bearer {{bob_token}}
+
+HTTP 200
+[Asserts]
+jsonpath "$[*].name" contains "bob-webdav-own"
+jsonpath "$[*].name" contains "My Folder - admin"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 19 – Admin's tree is unchanged by bob's WebDAV traffic.
+# ─────────────────────────────────────────────────────────────
+GET {{base_url}}/api/folders/{{admin_home_id}}/contents
+Authorization: Bearer {{admin_token}}
+
+HTTP 200
+[Asserts]
+jsonpath "$[*].name" not contains "bob-webdav-attack"
+jsonpath "$[*].name" not contains "bob-webdav-own"
diff --git a/tests/api/run.sh b/tests/api/run.sh
index 5f660b71..48e9f438 100755
--- a/tests/api/run.sh
+++ b/tests/api/run.sh
@@ -96,7 +96,8 @@ hurl --variables-file "$API_DIR/test.env" --file-root "$REPO_ROOT/tests" --test
   "$API_DIR/recent.hurl" \
   "$API_DIR/batch_folder_copy.hurl" \
   "$API_DIR/dedup_blob_cleanup.hurl" \
-  "$API_DIR/contacts.hurl"
+  "$API_DIR/contacts.hurl" \
+  "$API_DIR/permissions.hurl"
 
 #bash "$API_DIR/dedup_bulk_upload.sh"