diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 8ac9501..13660a1 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -52,3 +52,14 @@ The fourth character of the block is a `_` filler.
 `argv[i]` is the value of the rowid or id to match against for the point query.
 
 The remaining 3 characters of the block are `_` fillers.
+
+#### `VEC0_IDXSTR_KIND_METADATA_CONSTRAINT` (`'&'`)
+
+`argv[i]` is the value of the `WHERE` constraint for a metdata column in a KNN query.
+
+The second character of the block denotes which metadata column the constraint belongs to, using `A` to denote the first metadata column column, `B` for the second, etc. It is encoded with `'A' + metadata_idx` and can be decoded with `c - 'A'`.
+
+The third character of the block is the constraint operator. It will be one of `enum vec0_metadata_operator`, as only a subset of operators are supported on metadata column KNN filters.
+
+The foruth character of the block is a `_` filler.
+
diff --git a/TODO b/TODO
index 9351d32..a46b9bc 100644
--- a/TODO
+++ b/TODO
@@ -18,6 +18,7 @@
 - DELETE and UPDATE support
 - large strings
 - date/datetime
-- `v in (...)` handling
-- remaining TODO items
-- dictionary encoding?
+- later
+  - `v in (...)` handling
+  - remaining TODO items
+  - dictionary encoding?
diff --git a/sqlite-vec.c b/sqlite-vec.c
index 0a2f08d..f39bcc5 100644
--- a/sqlite-vec.c
+++ b/sqlite-vec.c
@@ -4074,7 +4074,12 @@ int vec0_result_metadata_value_for_rowid(vec0_vtab *p, i64 rowid, int metadata_i
       break;
     }
     case VEC0_METADATA_COLUMN_KIND_INT64: {
-      // TODO handle int64 values
+      i64 value;
+      rc = sqlite3_blob_read(blobValue, &value, sizeof(value), chunk_offset * sizeof(i64));
+      if(rc != SQLITE_OK) {
+        goto done;
+      }
+      sqlite3_result_int64(context, value);
       break;
     }
     case VEC0_METADATA_COLUMN_KIND_FLOAT: {
@@ -4087,7 +4092,13 @@ int vec0_result_metadata_value_for_rowid(vec0_vtab *p, i64 rowid, int metadata_i
       break;
     }
     case VEC0_METADATA_COLUMN_KIND_DOUBLE: {
-      // TODO handle double values
+      double value;
+      rc = sqlite3_blob_read(blobValue, &value, sizeof(value), chunk_offset * sizeof(double));
+      if(rc != SQLITE_OK) {
+        goto done;
+      }
+      sqlite3_result_double(context, value);
+      break;
       break;
     }
     case VEC0_METADATA_COLUMN_KIND_TEXT: {
@@ -5483,6 +5494,15 @@ static int vec0BestIndex(sqlite3_vtab *pVTab, sqlite3_index_info *pIdxInfo) {
           value = VEC0_METADATA_OPERATOR_NE;
           break;
         }
+        default: {
+          // IMP: V16511_00582
+          rc = SQLITE_ERROR;
+          vtab_set_error(pVTab,
+          "An illegal WHERE constraint was provided on a vec0 metadata column in a KNN query. "
+          "Only one of EQUALS, GREATER_THAN, LESS_THAN_OR_EQUAL, LESS_THAN, GREATER_THAN_OR_EQUAL, NOT_EQUALS is allowed."
+          );
+          goto done;
+        }
       }
 
       if(value) {
diff --git a/tests/__snapshots__/test-metadata.ambr b/tests/__snapshots__/test-metadata.ambr
new file mode 100644
index 0000000..428e40b
--- /dev/null
+++ b/tests/__snapshots__/test-metadata.ambr
@@ -0,0 +1,330 @@
+# serializer version: 1
+# name: test_constructor_limit[max 16 metadata columns]
+  dict({
+    'error': 'OperationalError',
+    'message': 'vec0 constructor error: More than 16 metadata columns were provided',
+  })
+# ---
+# name: test_knn.1
+  dict({
+    'error': 'OperationalError',
+    'message': 'An illegal WHERE constraint was provided on a vec0 metadata column in a KNN query. Only one of EQUALS, GREATER_THAN, LESS_THAN_OR_EQUAL, LESS_THAN, GREATER_THAN_OR_EQUAL, NOT_EQUALS is allowed.',
+  })
+# ---
+# name: test_knn[sqlite_master]
+  OrderedDict({
+    'sql': "select * from sqlite_master where type = 'table' order by name",
+    'rows': list([
+      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(vector float[1], name text, chunk_size=8)',
+      }),
+      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_metadata_chunks00',
+        'tbl_name': 'v_metadata_chunks00',
+        'rootpage': 7,
+        'sql': 'CREATE TABLE "v_metadata_chunks00"(rowid PRIMARY KEY, data 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)',
+      }),
+    ]),
+  })
+# ---
+# name: test_normal.1
+  dict({
+    'v_chunks': OrderedDict({
+      'sql': 'select * from v_chunks',
+      'rows': list([
+      ]),
+    }),
+    'v_metadata_chunks00': OrderedDict({
+      'sql': 'select * from v_metadata_chunks00',
+      'rows': list([
+      ]),
+    }),
+    'v_metadata_chunks01': OrderedDict({
+      'sql': 'select * from v_metadata_chunks01',
+      'rows': list([
+      ]),
+    }),
+    'v_metadata_chunks02': OrderedDict({
+      'sql': 'select * from v_metadata_chunks02',
+      'rows': list([
+      ]),
+    }),
+    'v_metadata_chunks03': OrderedDict({
+      'sql': 'select * from v_metadata_chunks03',
+      'rows': list([
+      ]),
+    }),
+    'v_metadata_chunks04': OrderedDict({
+      'sql': 'select * from v_metadata_chunks04',
+      'rows': list([
+      ]),
+    }),
+    'v_rowids': OrderedDict({
+      'sql': 'select * from v_rowids',
+      'rows': list([
+      ]),
+    }),
+    'v_vector_chunks00': OrderedDict({
+      'sql': 'select * from v_vector_chunks00',
+      'rows': list([
+      ]),
+    }),
+  })
+# ---
+# name: test_normal.2
+  OrderedDict({
+    'sql': 'insert into v(vector, n1, n2, f, d, t) values (?, ?, ?, ?, ?, ?)',
+    'rows': list([
+    ]),
+  })
+# ---
+# name: test_normal.3
+  OrderedDict({
+    'sql': 'insert into v(vector, n1, n2, f, d, t) values (?, ?, ?, ?, ?, ?)',
+    'rows': list([
+    ]),
+  })
+# ---
+# name: test_normal.4
+  OrderedDict({
+    'sql': 'insert into v(vector, n1, n2, f, d, t) values (?, ?, ?, ?, ?, ?)',
+    'rows': list([
+    ]),
+  })
+# ---
+# name: test_normal.5
+  OrderedDict({
+    'sql': 'select * from v',
+    'rows': list([
+      OrderedDict({
+        'rowid': 1,
+        'vector': b'\x11\x11\x11\x11',
+        'n1': 1,
+        'n2': 1,
+        'f': 1.100000023841858,
+        'd': 1.1,
+        't': 'one',
+      }),
+      OrderedDict({
+        'rowid': 2,
+        'vector': b'""""',
+        'n1': 2,
+        'n2': 2,
+        'f': 2.200000047683716,
+        'd': 2.2,
+        't': 'two',
+      }),
+      OrderedDict({
+        'rowid': 3,
+        'vector': b'3333',
+        'n1': 3,
+        'n2': 3,
+        'f': 3.299999952316284,
+        'd': 3.3,
+        't': 'three',
+      }),
+    ]),
+  })
+# ---
+# name: test_normal.6
+  dict({
+    '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_metadata_chunks00': OrderedDict({
+      'sql': 'select * from v_metadata_chunks00',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'data': b'\x01\x00\x00\x00\x02\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',
+        }),
+      ]),
+    }),
+    'v_metadata_chunks01': OrderedDict({
+      'sql': 'select * from v_metadata_chunks01',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'data': 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_metadata_chunks02': OrderedDict({
+      'sql': 'select * from v_metadata_chunks02',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'data': b'\xcd\xcc\x8c?\xcd\xcc\x0c@33S@\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
+        }),
+      ]),
+    }),
+    'v_metadata_chunks03': OrderedDict({
+      'sql': 'select * from v_metadata_chunks03',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'data': b'\x9a\x99\x99\x99\x99\x99\xf1?\x9a\x99\x99\x99\x99\x99\x01@ffffff\n@\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_metadata_chunks04': OrderedDict({
+      'sql': 'select * from v_metadata_chunks04',
+      'rows': list([
+        OrderedDict({
+          'rowid': 1,
+          'data': b'\x03\x00\x00\x00one?\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00two@\x01\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00three\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\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 where type = 'table' order by name",
+    'rows': list([
+      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(vector float[1], n1 int, n2 int64, f float, d double, t text, chunk_size=8)',
+      }),
+      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_metadata_chunks00',
+        'tbl_name': 'v_metadata_chunks00',
+        'rootpage': 7,
+        'sql': 'CREATE TABLE "v_metadata_chunks00"(rowid PRIMARY KEY, data BLOB NOT NULL)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_metadata_chunks01',
+        'tbl_name': 'v_metadata_chunks01',
+        'rootpage': 9,
+        'sql': 'CREATE TABLE "v_metadata_chunks01"(rowid PRIMARY KEY, data BLOB NOT NULL)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_metadata_chunks02',
+        'tbl_name': 'v_metadata_chunks02',
+        'rootpage': 11,
+        'sql': 'CREATE TABLE "v_metadata_chunks02"(rowid PRIMARY KEY, data BLOB NOT NULL)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_metadata_chunks03',
+        'tbl_name': 'v_metadata_chunks03',
+        'rootpage': 13,
+        'sql': 'CREATE TABLE "v_metadata_chunks03"(rowid PRIMARY KEY, data BLOB NOT NULL)',
+      }),
+      OrderedDict({
+        'type': 'table',
+        'name': 'v_metadata_chunks04',
+        'tbl_name': 'v_metadata_chunks04',
+        'rootpage': 15,
+        'sql': 'CREATE TABLE "v_metadata_chunks04"(rowid PRIMARY KEY, data 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-metadata.py b/tests/test-metadata.py
new file mode 100644
index 0000000..a967473
--- /dev/null
+++ b/tests/test-metadata.py
@@ -0,0 +1,113 @@
+import sqlite3
+from collections import OrderedDict
+
+
+def test_constructor_limit(db, snapshot):
+    pass
+    assert exec(
+        db,
+        f"""
+        create virtual table v using vec0(
+          {",".join([f"metadata{x} integer" for x in range(17)])}
+          v float[1]
+        )
+      """,
+    ) == snapshot(name="max 16 metadata columns")
+
+
+def test_normal(db, snapshot):
+    db.execute(
+        "create virtual table v using vec0(vector float[1], n1 int, n2 int64, f float, d double, t text, chunk_size=8)"
+    )
+    assert exec(
+        db, "select * from sqlite_master where type = 'table' order by name"
+    ) == snapshot(name="sqlite_master")
+
+    assert vec0_shadow_table_contents(db, "v") == snapshot()
+
+    INSERT = "insert into v(vector, n1, n2, f, d, t) values (?, ?, ?, ?, ?, ?)"
+    assert exec(db, INSERT, [b"\x11\x11\x11\x11", 1, 1, 1.1, 1.1, "one"]) == snapshot()
+    assert exec(db, INSERT, [b"\x22\x22\x22\x22", 2, 2, 2.2, 2.2, "two"]) == snapshot()
+    assert (
+        exec(db, INSERT, [b"\x33\x33\x33\x33", 3, 3, 3.3, 3.3, "three"]) == snapshot()
+    )
+
+    assert exec(db, "select * from v") == snapshot()
+    assert vec0_shadow_table_contents(db, "v") == snapshot()
+
+
+#
+# assert exec(db, "select * from v") == snapshot()
+# assert vec0_shadow_table_contents(db, "v") == snapshot()
+#
+# db.execute("drop table v;")
+# assert exec(db, "select * from sqlite_master order by name") == snapshot(
+#    name="sqlite_master post drop"
+# )
+
+
+def test_types(db, snapshot):
+    pass
+
+
+def test_updates(db, snapshot):
+    pass
+
+
+def test_deletes(db, snapshot):
+    pass
+
+
+def test_knn(db, snapshot):
+    db.execute(
+        "create virtual table v using vec0(vector float[1], name text, chunk_size=8)"
+    )
+    assert exec(
+        db, "select * from sqlite_master where type = 'table' order by name"
+    ) == snapshot(name="sqlite_master")
+    db.executemany(
+        "insert into v(vector, name) values (?, ?)",
+        [("[1]", "alex"), ("[2]", "brian"), ("[3]", "craig")],
+    )
+
+    # EVIDENCE-OF: V16511_00582 catches "illegal" constraints on metadata columns
+    assert (
+        exec(
+            db,
+            "select *, distance from v where vector match '[5]' and k = 3 and name like 'illegal'",
+        )
+        == snapshot()
+    )
+
+
+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