diff --git a/sqlite-vec.c b/sqlite-vec.c
index d98a852..e8425be 100644
--- a/sqlite-vec.c
+++ b/sqlite-vec.c
@@ -3526,7 +3526,7 @@ void vec0_free(vec0_vtab *p) {
 }
 
 int vec0_num_defined_user_columns(vec0_vtab *p) {
-  return p->numVectorColumns + p->numPartitionColumns;
+  return p->numVectorColumns + p->numPartitionColumns + p->numAuxiliaryColumns;
 }
 
 /**
@@ -4501,7 +4501,7 @@ static int vec0_init(sqlite3 *db, void *pAux, int argc, const char *const *argv,
         *pzErr = sqlite3_mprintf(
             VEC_CONSTRUCTOR_ERROR
             "More than %d auxiliary columns were provided",
-            VEC0_MAX_PARTITION_COLUMNS);
+            VEC0_MAX_AUXILIARY_COLUMNS);
         goto error;
       }
       auxColumn.type = cType;
diff --git a/tests/__snapshots__/test-auxiliary.ambr b/tests/__snapshots__/test-auxiliary.ambr
new file mode 100644
index 0000000..30bb223
--- /dev/null
+++ b/tests/__snapshots__/test-auxiliary.ambr
@@ -0,0 +1,149 @@
+# serializer version: 1
+# name: test_constructor_limit[max 16 auxiliary columns]
+  dict({
+    'error': 'OperationalError',
+    'message': 'vec0 constructor error: More than 16 auxiliary columns were provided',
+  })
+# ---
+# name: test_normal.1
+  OrderedDict({
+    'sql': 'select * from v',
+    'rows': list([
+      OrderedDict({
+        'rowid': 1,
+        'a': b'\x11\x11\x11\x11',
+        'name': 'alex',
+      }),
+      OrderedDict({
+        'rowid': 2,
+        'a': b'""""',
+        'name': 'brian',
+      }),
+      OrderedDict({
+        'rowid': 3,
+        'a': b'3333',
+        'name': 'craig',
+      }),
+    ]),
+  })
+# ---
+# name: test_normal.2
+  dict({
+    'v_auxiliary': OrderedDict({
+      'sql': 'select * from v_auxiliary',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'value00': 'alex',
+        }),
+        OrderedDict({
+          'rowid': 2,
+          'value00': 'brian',
+        }),
+        OrderedDict({
+          'rowid': 3,
+          'value00': 'craig',
+        }),
+      ]),
+    }),
+    'v_chunks': OrderedDict({
+      'sql': 'select * from v_chunks',
+      'rows': list([
+        OrderedDict({
+          'chunk_id': 1,
+          'size': 8,
+          'validity': b'\x07',
+          'rowids': b'\x01\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
+        }),
+      ]),
+    }),
+    'v_rowids': OrderedDict({
+      'sql': 'select * from v_rowids',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'id': None,
+          'chunk_id': 1,
+          'chunk_offset': 0,
+        }),
+        OrderedDict({
+          'rowid': 2,
+          'id': None,
+          'chunk_id': 1,
+          'chunk_offset': 1,
+        }),
+        OrderedDict({
+          'rowid': 3,
+          'id': None,
+          'chunk_id': 1,
+          'chunk_offset': 2,
+        }),
+      ]),
+    }),
+    'v_vector_chunks00': OrderedDict({
+      'sql': 'select * from v_vector_chunks00',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'vectors': b'\x11\x11\x11\x11""""3333\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
+        }),
+      ]),
+    }),
+  })
+# ---
+# name: test_normal[sqlite_master]
+  OrderedDict({
+    'sql': 'select * from sqlite_master order by name',
+    'rows': list([
+      OrderedDict({
+        'type': 'index',
+        'name': 'sqlite_autoindex_v_vector_chunks00_1',
+        'tbl_name': 'v_vector_chunks00',
+        'rootpage': 6,
+        'sql': None,
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'sqlite_sequence',
+        'tbl_name': 'sqlite_sequence',
+        'rootpage': 3,
+        'sql': 'CREATE TABLE sqlite_sequence(name,seq)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v',
+        'tbl_name': 'v',
+        'rootpage': 0,
+        'sql': 'CREATE VIRTUAL TABLE v using vec0(a float[1], +name text, chunk_size=8)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_auxiliary',
+        'tbl_name': 'v_auxiliary',
+        'rootpage': 7,
+        'sql': 'CREATE TABLE "v_auxiliary"( rowid integer PRIMARY KEY , value00)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_chunks',
+        'tbl_name': 'v_chunks',
+        'rootpage': 2,
+        'sql': 'CREATE TABLE "v_chunks"(chunk_id INTEGER PRIMARY KEY AUTOINCREMENT,size INTEGER NOT NULL,validity BLOB NOT NULL,rowids BLOB NOT NULL)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_rowids',
+        'tbl_name': 'v_rowids',
+        'rootpage': 4,
+        'sql': 'CREATE TABLE "v_rowids"(rowid INTEGER PRIMARY KEY AUTOINCREMENT,id,chunk_id INTEGER,chunk_offset INTEGER)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_vector_chunks00',
+        'tbl_name': 'v_vector_chunks00',
+        'rootpage': 5,
+        'sql': 'CREATE TABLE "v_vector_chunks00"(rowid PRIMARY KEY,vectors BLOB NOT NULL)',
+      }),
+    ]),
+  })
+# ---
diff --git a/tests/test-auxiliary.py b/tests/test-auxiliary.py
new file mode 100644
index 0000000..edb52aa
--- /dev/null
+++ b/tests/test-auxiliary.py
@@ -0,0 +1,79 @@
+import sqlite3
+from collections import OrderedDict
+
+
+def test_constructor_limit(db, snapshot):
+    assert exec(
+        db,
+        f"""
+        create virtual table v using vec0(
+          {",".join([f"+aux{x} integer" for x in range(17)])}
+          v float[1]
+        )
+      """,
+    ) == snapshot(name="max 16 auxiliary columns")
+
+
+def test_normal(db, snapshot):
+    db.execute(
+        "create virtual table v using vec0(a float[1], +name text, chunk_size=8)"
+    )
+    assert exec(db, "select * from sqlite_master order by name") == snapshot(
+        name="sqlite_master"
+    )
+
+    db.execute("insert into v(a, name) values (?, ?)", [b"\x11\x11\x11\x11", "alex"])
+    db.execute("insert into v(a, name) values (?, ?)", [b"\x22\x22\x22\x22", "brian"])
+    db.execute("insert into v(a, name) values (?, ?)", [b"\x33\x33\x33\x33", "craig"])
+
+    assert exec(db, "select * from v") == snapshot()
+    assert vec0_shadow_table_contents(db, "v") == snapshot()
+
+
+def test_types(db, snapshot):
+    pass
+
+
+def test_updates(db, snapshot):
+    pass
+
+
+def test_deletes(db, snapshot):
+    pass
+
+
+def test_knn(db, snapshot):
+    pass
+
+
+def exec(db, sql, parameters=[]):
+    try:
+        rows = db.execute(sql, parameters).fetchall()
+    except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
+        return {
+            "error": e.__class__.__name__,
+            "message": str(e),
+        }
+    a = []
+    for row in rows:
+        o = OrderedDict()
+        for k in row.keys():
+            o[k] = row[k]
+        a.append(o)
+    result = OrderedDict()
+    result["sql"] = sql
+    result["rows"] = a
+    return result
+
+
+def vec0_shadow_table_contents(db, v):
+    shadow_tables = [
+        row[0]
+        for row in db.execute(
+            "select name from sqlite_master where name like ? order by 1", [f"{v}_%"]
+        ).fetchall()
+    ]
+    o = {}
+    for shadow_table in shadow_tables:
+        o[shadow_table] = exec(db, f"select * from {shadow_table}")
+    return o