diff --git a/python/numbersprotocol_capture/verify.py b/python/numbersprotocol_capture/verify.py
index 2f93993..d8704d1 100644
--- a/python/numbersprotocol_capture/verify.py
+++ b/python/numbersprotocol_capture/verify.py
@@ -5,7 +5,7 @@
 digital asset provenance.
 """
 
-from urllib.parse import urlencode
+from urllib.parse import quote, urlencode
 
 VERIFY_BASE_URL = "https://verify.numbersprotocol.io"
 
@@ -24,7 +24,7 @@ def search_by_nid(nid: str) -> str:
         >>> url = search_by_nid("bafybei...")
         >>> # => "https://verify.numbersprotocol.io/search?nid=bafybei..."
     """
-    return f"{VERIFY_BASE_URL}/search?nid={nid}"
+    return f"{VERIFY_BASE_URL}/search?nid={quote(nid, safe='')}"
 
 
 def search_by_nft(token_id: str, contract: str) -> str:
@@ -60,7 +60,7 @@ def asset_profile(nid: str) -> str:
         >>> url = asset_profile("bafybei...")
         >>> # => "https://verify.numbersprotocol.io/asset-profile?nid=bafybei..."
     """
-    return f"{VERIFY_BASE_URL}/asset-profile?nid={nid}"
+    return f"{VERIFY_BASE_URL}/asset-profile?nid={quote(nid, safe='')}"
 
 
 def asset_profile_by_nft(token_id: str, contract: str) -> str:
diff --git a/python/tests/test_verify.py b/python/tests/test_verify.py
new file mode 100644
index 0000000..0919efc
--- /dev/null
+++ b/python/tests/test_verify.py
@@ -0,0 +1,69 @@
+"""
+Unit tests for Verify Engine URL helpers.
+"""
+
+import pytest
+
+from numbersprotocol_capture.verify import (
+    VERIFY_BASE_URL,
+    asset_profile,
+    asset_profile_by_nft,
+    search_by_nft,
+    search_by_nid,
+)
+
+NORMAL_NID = "bafybeif3mhxhkhfwuszl2lybtai3hz3q6naqpfisd4q55mcc7opkmiv5ei"
+
+
+class TestSearchByNid:
+    def test_normal_nid(self):
+        url = search_by_nid(NORMAL_NID)
+        assert url == f"{VERIFY_BASE_URL}/search?nid={NORMAL_NID}"
+
+    def test_special_characters_are_encoded(self):
+        url = search_by_nid("nid with spaces&param=injected")
+        assert " " not in url
+        assert "&param=injected" not in url
+        assert url == f"{VERIFY_BASE_URL}/search?nid=nid%20with%20spaces%26param%3Dinjected"
+
+    def test_hash_character_is_encoded(self):
+        url = search_by_nid("nid#fragment")
+        assert "#" not in url
+        assert url == f"{VERIFY_BASE_URL}/search?nid=nid%23fragment"
+
+
+class TestAssetProfile:
+    def test_normal_nid(self):
+        url = asset_profile(NORMAL_NID)
+        assert url == f"{VERIFY_BASE_URL}/asset-profile?nid={NORMAL_NID}"
+
+    def test_special_characters_are_encoded(self):
+        url = asset_profile("nid with spaces&param=injected")
+        assert " " not in url
+        assert "&param=injected" not in url
+        assert url == f"{VERIFY_BASE_URL}/asset-profile?nid=nid%20with%20spaces%26param%3Dinjected"
+
+    def test_hash_character_is_encoded(self):
+        url = asset_profile("nid#fragment")
+        assert "#" not in url
+        assert url == f"{VERIFY_BASE_URL}/asset-profile?nid=nid%23fragment"
+
+
+class TestSearchByNft:
+    def test_normal_nft(self):
+        url = search_by_nft("123", "0x1234abcd")
+        assert url == f"{VERIFY_BASE_URL}/search?nft=123&contract=0x1234abcd"
+
+    def test_special_characters_are_encoded(self):
+        url = search_by_nft("token id with space", "0x1234")
+        assert "token+id+with+space" in url or "token%20id%20with%20space" in url
+
+
+class TestAssetProfileByNft:
+    def test_normal_nft(self):
+        url = asset_profile_by_nft("123", "0x1234abcd")
+        assert url == f"{VERIFY_BASE_URL}/asset-profile?nft=123&contract=0x1234abcd"
+
+    def test_special_characters_are_encoded(self):
+        url = asset_profile_by_nft("token id with space", "0x1234")
+        assert "token+id+with+space" in url or "token%20id%20with%20space" in url