diff --git a/src/aipass/commons/apps/handlers/artifacts/artifact_ops.py b/src/aipass/commons/apps/handlers/artifacts/artifact_ops.py
index f68d9607..595db77d 100644
--- a/src/aipass/commons/apps/handlers/artifacts/artifact_ops.py
+++ b/src/aipass/commons/apps/handlers/artifacts/artifact_ops.py
@@ -75,8 +75,8 @@ def _validate_metadata(metadata_str: str) -> Optional[dict]:
 
 
 def _resolve_branch_name(mention: str) -> Optional[str]:
-    """Resolve a @mention to a branch name."""
-    name = mention.lstrip("@").upper()
+    """Resolve a @mention to a branch name (lowercase-normalized)."""
+    name = mention.lstrip("@").lower()
 
     if not os.path.exists(BRANCH_REGISTRY_PATH):
         return None
@@ -85,7 +85,7 @@ def _resolve_branch_name(mention: str) -> Optional[str]:
         with open(BRANCH_REGISTRY_PATH, encoding="utf-8") as f:
             registry = json.load(f)
         for branch in registry.get("branches", []):
-            if branch.get("name") == name:
+            if branch.get("name", "").lower() == name:
                 return name
         return None
     except Exception:
diff --git a/src/aipass/commons/apps/handlers/artifacts/trade_ops.py b/src/aipass/commons/apps/handlers/artifacts/trade_ops.py
index e90f06df..5128cf73 100644
--- a/src/aipass/commons/apps/handlers/artifacts/trade_ops.py
+++ b/src/aipass/commons/apps/handlers/artifacts/trade_ops.py
@@ -54,8 +54,8 @@ RARITY_COLORS = {
 
 
 def _resolve_branch_name(mention: str) -> Optional[str]:
-    """Resolve a @mention to a branch name."""
-    name = mention.lstrip("@").upper()
+    """Resolve a @mention to a branch name (lowercase-normalized)."""
+    name = mention.lstrip("@").lower()
 
     if not os.path.exists(BRANCH_REGISTRY_PATH):
         return None
@@ -64,7 +64,7 @@ def _resolve_branch_name(mention: str) -> Optional[str]:
         with open(BRANCH_REGISTRY_PATH, encoding="utf-8") as f:
             registry = json.load(f)
         for branch in registry.get("branches", []):
-            if branch.get("name") == name:
+            if branch.get("name", "").lower() == name:
                 return name
         return None
     except Exception:
diff --git a/src/aipass/commons/apps/handlers/profiles/profile_ops.py b/src/aipass/commons/apps/handlers/profiles/profile_ops.py
index b0b75958..f7bddbb5 100644
--- a/src/aipass/commons/apps/handlers/profiles/profile_ops.py
+++ b/src/aipass/commons/apps/handlers/profiles/profile_ops.py
@@ -58,7 +58,7 @@ def show_profile(args: List[str]) -> dict:
 
     # Determine which branch to show
     if args:
-        target_branch = args[0].upper()
+        target_branch = args[0].lower()
     else:
         caller = get_caller_branch()
         if not caller:
diff --git a/src/aipass/commons/apps/handlers/search/search_ops.py b/src/aipass/commons/apps/handlers/search/search_ops.py
index 581a7a6a..9401db72 100644
--- a/src/aipass/commons/apps/handlers/search/search_ops.py
+++ b/src/aipass/commons/apps/handlers/search/search_ops.py
@@ -62,7 +62,7 @@ def _parse_search_args(args: List[str]) -> dict:
             result["room"] = remaining[i + 1].lower()
             i += 2
         elif flag == "--author" and i + 1 < len(remaining):
-            result["author"] = remaining[i + 1].upper()
+            result["author"] = remaining[i + 1].lower()
             i += 2
         elif flag == "--type" and i + 1 < len(remaining):
             search_type = remaining[i + 1].lower()
diff --git a/src/aipass/commons/apps/handlers/welcome/welcome_ops.py b/src/aipass/commons/apps/handlers/welcome/welcome_ops.py
index 5573a523..4b972f38 100644
--- a/src/aipass/commons/apps/handlers/welcome/welcome_ops.py
+++ b/src/aipass/commons/apps/handlers/welcome/welcome_ops.py
@@ -55,7 +55,7 @@ def run_welcome(args: List[str]) -> dict:
         conn = get_db()
 
         if filtered_args:
-            branch_name = filtered_args[0].upper()
+            branch_name = filtered_args[0].lower()
             if dry_run:
                 already = has_been_welcomed(conn, branch_name)
                 close_db(conn)
@@ -114,7 +114,7 @@ def _welcome_specific(conn, branch_name: str) -> dict:
     Returns:
         Dict with success and welcome result
     """
-    agent = conn.execute("SELECT branch_name FROM agents WHERE branch_name = ?", (branch_name,)).fetchone()
+    agent = conn.execute("SELECT branch_name FROM agents WHERE LOWER(branch_name) = ?", (branch_name,)).fetchone()
 
     if not agent:
         return {"success": False, "error": f"Branch '{branch_name}' not found in The Commons."}
diff --git a/src/aipass/commons/tests/test_curation_explore_welcome_ops.py b/src/aipass/commons/tests/test_curation_explore_welcome_ops.py
index 81ecb46b..5a90e252 100644
--- a/src/aipass/commons/tests/test_curation_explore_welcome_ops.py
+++ b/src/aipass/commons/tests/test_curation_explore_welcome_ops.py
@@ -993,7 +993,7 @@ def test_run_welcome_dry_run_specific_branch(
     """run_welcome <branch> --dry-run reports whether the branch would be welcomed."""
     from aipass.commons.apps.handlers.welcome.welcome_ops import run_welcome
 
-    _seed_agent(initialized_db, "GAMMA")
+    _seed_agent(initialized_db, "gamma")
 
     mock_get_db.return_value = initialized_db
     mock_close.side_effect = lambda c: None
@@ -1001,7 +1001,7 @@ def test_run_welcome_dry_run_specific_branch(
     result = run_welcome(["gamma", "--dry-run"])
     assert result["success"] is True
     assert result["dry_run"] is True
-    assert result["branch"] == "GAMMA"
+    assert result["branch"] == "gamma"
     assert result["would_welcome"] is True
 
 
@@ -1076,7 +1076,7 @@ def test_run_welcome_specific_branch_success(
     """run_welcome <branch> creates a welcome post for that branch."""
     from aipass.commons.apps.handlers.welcome.welcome_ops import run_welcome
 
-    _seed_agent(initialized_db, "EPSILON")
+    _seed_agent(initialized_db, "epsilon")
 
     mock_get_db.return_value = initialized_db
     mock_close.side_effect = lambda c: None
@@ -1085,7 +1085,7 @@ def test_run_welcome_specific_branch_success(
     assert result["success"] is True
     assert result["action"] == "specific"
     assert result["already_welcomed"] is False
-    assert result["branch"] == "EPSILON"
+    assert result["branch"] == "epsilon"
     assert result["post_id"] is not None
 
 
diff --git a/src/aipass/commons/tests/test_search.py b/src/aipass/commons/tests/test_search.py
index 4ff57dc8..9c400656 100644
--- a/src/aipass/commons/tests/test_search.py
+++ b/src/aipass/commons/tests/test_search.py
@@ -58,10 +58,10 @@ def test_parse_search_args_room_flag():
 
 
 def test_parse_search_args_author_flag():
-    """The --author flag should set the author filter and uppercase it."""
+    """The --author flag should set the author filter and lowercase it."""
     result = _parse_search_args(["test", "--author", "drone"])
     assert result["query"] == "test"
-    assert result["author"] == "DRONE"
+    assert result["author"] == "drone"
 
 
 def test_parse_search_args_type_flag_valid():
@@ -94,7 +94,7 @@ def test_parse_search_args_all_flags():
     )
     assert result["query"] == "registry"
     assert result["room"] == "dev"
-    assert result["author"] == "FLOW"
+    assert result["author"] == "flow"
     assert result["search_type"] == "posts"