diff --git a/.gitignore b/.gitignore
index 5549b63..64a185a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,14 +7,6 @@ __pycache__/
 # C extensions
 *.so
 
-# Project specify temporary / test files
-*.db
-.trove/
-ai
-tmp/
-ui/
-
-
 # Distribution / packaging
 .Python
 build/
diff --git a/trovedb/db.py b/trovedb/db.py
index 3156f15..762f4f2 100644
--- a/trovedb/db.py
+++ b/trovedb/db.py
@@ -213,7 +213,6 @@ class Sqlite3Trove:
         if object_id is None:
             object_id = uuid.uuid4()
         sid = _sql_id(object_id)
-        assert sid is not None
 
         # Preserve created timestamp on update
         row = self._con.execute(
diff --git a/trovedb/fs.py b/trovedb/fs.py
index 3b97e1b..97ba565 100644
--- a/trovedb/fs.py
+++ b/trovedb/fs.py
@@ -2,132 +2,99 @@ import os
 import sqlite3
 import tempfile
 import datetime as dt
-from pathlib import Path, PurePosixPath
-from typing import Optional, Dict, List, Self, Iterable, Iterator
+from pathlib import Path
+from typing import Optional, Dict, List, Self, Iterable
 
-from .trove import Note, Trove, TreeNote, BadNoteType, TreeEntry, NoteNotFound, ObjectId
+from .trove import Note, Trove, TreeNote, BadNoteType, TreeEntry, NoteNotFound
 from . import fs_util as fsu
-from . import trove as tr
+
 
 class FSNote(Note):
-    def __init__(self, trove: 'FSTrove', path: Path):
+    def __init__(self, trove: 'FSTrove', *, inode: int | None = None, path: Path | None = None):
         self._trove: FSTrove = trove
-        self._fs_path: Path = path.resolve()
-        if not self._fs_path.is_relative_to(trove.root):
-            raise ValueError("Path must be relative to the root directory")
-        self._object_id: str = path.relative_to(trove.root).as_posix()
+        self._fs_path: Path | None = path
+        self._inode: int | None = inode
+
+        if self._fs_path is not None:
+            inode = self._fs_path.stat().st_ino
+            if self._inode != inode and self._inode is not None:
+                raise ValueError(f"Inconsistent inode: {self._inode} vs {inode}")
+            self._inode = inode
 
     @property
-    def object_id(self) -> tr.ObjectId:
-        return self._object_id
-
-    @property
-    def fs_path(self) -> Path:
-        return self._fs_path
+    def object_id(self) -> int:
+        if self._inode is None:
+            raise ValueError("Note not yet saved to disk")
+        return self._inode
 
     @property
     def mtime(self):
         """Return modification time as datetime."""
-        stat = self._fs_path.stat()
+        stat = self._path.stat()
         return dt.datetime.fromtimestamp(stat.st_mtime, tz=dt.timezone.utc)
 
     @property
     def readonly(self) -> bool:
         """Check if the note is readonly based on file permissions."""
-        return not os.access(self._fs_path, os.W_OK)
+        if self._inode is None:
+            return False
+        return not os.access(self._path, os.W_OK)
 
     @property
     def mime(self) -> str:
         """Return MIME type, defaulting to generic binary stream."""
-        if self._fs_path.is_dir():
-            return "inode/directory"
         return "application/octet-stream"
 
+    @property
+    def _path(self) -> Path:
+        if self._fs_path is not None:
+            if self._fs_path.exists():
+                return self._fs_path
+            self._fs_path = None
+        if self._inode is None:
+            raise ValueError("Note not yet saved to disk")
+        self._fs_path = self._trove.get_path_by_inode(self._inode)
+        assert self._fs_path is not None
+        return self._fs_path
+
     def get_raw_metadata(self, key: str) -> Optional[bytes]:
-        # TODO: FIXME
-        return None
+        return self._trove._get_metadata(self._inode, key)
 
     def set_raw_metadata(self, key: str, value: bytes) -> None:
-        # TODO: FIXME
-        pass
+        self._trove._set_metadata(self._inode, key, value)
 
     def read_content(self) -> bytes:
         """Read the raw content of the note."""
-        if self._fs_path.is_file():
-            return self._fs_path.read_bytes()
+        content_file = fsu.get_content_path(self._path)
+        if content_file.exists():
+            return content_file.read_bytes()
         return b""
 
     def write_content(self, data:bytes) -> None:
         """Write the raw content of the note."""
-        self._fs_path.write_bytes(data)
-
-    def _new_child_subdir(self, name: str, exist_ok: bool = True) -> Path:
-        ex_path = self._fs_path / name
-        try:
-            ex_path.mkdir(exist_ok=exist_ok)
-            return ex_path
-        except FileExistsError:
-            raise tr.ErrorExists(str(ex_path)) from None
-        except OSError as e:
-            raise tr.ErrorWithErrno(e.errno, str(e)) from None
-
-    def new_child(self, name: str, mime: str, content: bytes | None, executable: bool, hidden: bool) -> Note:
-        """Create a new child note."""
-
-        if content is None:
-            content = b""
-
-        if mime == 'inode/directory':
-            if content is not None:
-                raise NotImplementedError("FSNote does not support children")
-            return FSTreeNote(self._trove, self._new_child_subdir(name, False))
-
-        ex_path = self._fs_path / name
-        ex_path.write_bytes(content)
-        return FSNote(self._trove, ex_path)
-
-    def child(self, name: str) -> Note:
-        """Retrieve a child not by name."""
-        target_path = self._fs_path / name
-        return self._trove.get_raw_note_by_path(target_path)
-
-    def rm_child(self, name: str, recurse: bool):
-        target_path = self._fs_path / name
-        if not target_path.exists():
-            raise tr.ErrorNotFound(name)
-        if target_path.is_dir():
-            if recurse:
-                raise NotImplementedError("Recursive deletion not supported")
-            else:
-                target_path.rmdir()
-        else:
-            target_path.unlink()
-            # TODO: remove meta directory!
-
-
-    def children(self) -> Iterator[TreeEntry]:
-        """Get all children of this note."""
-        if not self._fs_path.is_dir():
-            return
-        for item in self._fs_path.iterdir():
-            if item.name == ".trove":
-                continue
-            yield TreeEntry(name=item.name, object_id=item.stat().st_ino)
+        content_file = fsu.get_content_path(self._path)
+        content_file.write_bytes(data)
 
 class FSTreeNote(FSNote, TreeNote):
+    @property
+    def mime(self) -> str:
+        """Return MIME type for directory/tree nodes."""
+        return "inode/directory"
+
     def link(self, name: str, note: Note):
         if not isinstance(note, FSNote):
             raise BadNoteType("Only blob notes can be linked")
 
-        target_path = self._fs_path / name
+        target_path = self._path / name
         if target_path.exists():
             self.unlink(name)
         
-        note_path = note._fs_path
+        note_path = note._path
         
         # If the note is in .working, move it to the new location.
         if self._trove.working in note_path.parents:
             os.rename(note_path, target_path)
+            self._trove._update_cache(note.object_id, target_path)
         else:
             # If it's already linked somewhere, create a hard link if it's a file.
             if note_path.is_file():
@@ -140,9 +107,11 @@ class FSTreeNote(FSNote, TreeNote):
                 # Directories cannot be hardlinked. 
                 # We move it to the new location.
                 os.rename(note_path, target_path)
+            
+            self._trove._update_cache(note.object_id, target_path)
 
     def unlink(self, name: str):
-        target_path = self._fs_path / name
+        target_path = self._path / name
         if not target_path.exists():
             return
         if target_path.is_dir():
@@ -151,20 +120,39 @@ class FSTreeNote(FSNote, TreeNote):
             target_path.unlink()
 
     def mkdir(self, name: str) -> 'FSTreeNote':
-        target_path = self._fs_path / name
+        target_path = self._path / name
         target_path.mkdir(exist_ok=True)
-        return FSTreeNote(self._trove, path=target_path)
+        inode = target_path.stat().st_ino
+        self._trove._update_cache(inode, target_path)
+        return FSTreeNote(self._trove, inode=inode, path=target_path)
 
     def entries(self) -> Iterable[TreeEntry]:
         try:
-            for item in self._fs_path.iterdir():
+            for item in self._path.iterdir():
                 if item.name == ".trove":
                     continue
-                yield TreeEntry(name=item.name, object_id=str(item))
+                inode = item.stat().st_ino
+                self._trove._update_cache(inode, item)
+                yield TreeEntry(name=item.name, object_id=inode)
         except OSError:
             pass
 
+    def list(self) -> dict[str, int]:
+        res = {}
+        try:
+            for item in self._path.iterdir():
+                if item.name == ".trove":
+                    continue
+                res[item.name] = item.stat().st_ino
+                self._trove._update_cache(res[item.name], item)
+        except OSError:
+            pass
+        return res
 
+    def child(self, name: str) -> Note:
+        """Retrieve a child not by name."""
+        target_path = self._path / name
+        return self._trove.get_raw_note_by_path(target_path)
 
 
 class FSTrove(Trove):
@@ -173,9 +161,14 @@ class FSTrove(Trove):
         self._root_inode = self.root.stat().st_ino
         self.dot_trove = self.root / ".trove"
         self.working = self.dot_trove / ".working"
+        
         self.dot_trove.mkdir(exist_ok=True)
         self.working.mkdir(exist_ok=True)
         
+        db_path = self.dot_trove / "trovecache.db"
+        self.con = sqlite3.connect(str(db_path))
+        self._init_db()
+        
     @classmethod
     def open(cls, path: str | Path, create: bool = False) -> 'FSTrove':
         p = Path(path)
@@ -185,30 +178,101 @@ class FSTrove(Trove):
             p.mkdir(parents=True)
         return cls(p)
 
-    def get_raw_note_by_path(self, path: Path) -> Note:
-        if not path.exists():
-            raise tr.ErrorNotFound(str(path))
-        if path.is_dir():
-            return FSTreeNote(self, path=path)
-        return FSNote(self, path=path)
+    def _init_db(self):
+        self.con.execute("CREATE TABLE IF NOT EXISTS cache (inode INTEGER PRIMARY KEY, path TEXT)")
+        self.con.execute("CREATE TABLE IF NOT EXISTS metadata (inode INTEGER, key TEXT, value BLOB, PRIMARY KEY(inode, key))")
+        self.con.commit()
 
-    def get_raw_note(self, note_id: ObjectId) -> Note:
-        p = self.root / str(note_id)
-        if not p.exists():
+    def _update_cache(self, inode: int, path: Path):
+        try:
+            rel_path = path.relative_to(self.root)
+            path_str = str(rel_path)
+            if path_str == ".":
+                path_str = ""
+        except ValueError:
+            # Path not under root, maybe it's the root itself?
+            if path == self.root:
+                path_str = ""
+            else:
+                return # Not under root, don't cache
+
+        self.con.execute("INSERT OR REPLACE INTO cache (inode, path) VALUES (?, ?)", (inode, path_str))
+        self.con.commit()
+
+    def get_path_by_inode(self, inode: int) -> Optional[Path]:
+        if inode == self._root_inode:
+            return self.root
+        
+        row = self.con.execute("SELECT path FROM cache WHERE inode = ?", (inode,)).fetchone()
+        if row:
+            p = self.root / row[0]
+            try:
+                if p.exists() and p.stat().st_ino == inode:
+                    return p
+            except OSError:
+                pass
+        
+        # search
+        for root_dir, dirs, files in os.walk(self.root):
+            # Skip .trove
+            if ".trove" in dirs:
+                dirs.remove(".trove")
+            
+            for name in dirs + files:
+                p = Path(root_dir) / name
+                try:
+                    st = p.stat()
+                    if st.st_ino == inode:
+                        self._update_cache(inode, p)
+                        return p
+                except OSError:
+                    continue
+        return None
+
+    def get_raw_note_by_path(self, target_path: Path) -> Note:
+        if not target_path.exists():
+            raise NoteNotFound(target_path.relative_to(self.root))
+        note_id = target_path.stat().st_ino
+        if target_path.is_dir():
+            return FSTreeNote(self, inode=note_id, path=target_path)
+        else:
+            return FSNote(self, inode=note_id, path=target_path)
+
+    def get_raw_note(self, note_id: int) -> Note:
+        p = self.get_path_by_inode(note_id)
+        if not p:
             raise NoteNotFound(note_id)
         return self.get_raw_note_by_path(p)
 
+
     def create_blob(self, data: bytes | None = None) -> Note:
-        raise NotImplementedError("FSTrove does not support blobs")
+        fd, temp_path = tempfile.mkstemp(dir=self.working)
+        try:
+            if data:
+                os.write(fd, data)
+        finally:
+            os.close(fd)
+        p = Path(temp_path)
+        inode = p.stat().st_ino
+        self._update_cache(inode, p)
+        return FSNote(self, inode=inode, path=p)
 
     def get_root(self) -> TreeNote:
-        return FSTreeNote(self, path=self.root)
+        return FSTreeNote(self, inode=self._root_inode, path=self.root)
 
     def _get_metadata(self, inode: int, key: str) -> Optional[bytes]:
-        raise NotImplementedError("FSTrove does not support metadata")
+        row = self.con.execute("SELECT value FROM metadata WHERE inode = ? AND key = ?", (inode, key)).fetchone()
+        return row[0] if row else None
 
     def _set_metadata(self, inode: int, key: str, value: bytes):
-        raise NotImplementedError("FSTrove does not support metadata")
+        self.con.execute("INSERT OR REPLACE INTO metadata (inode, key, value) VALUES (?, ?, ?)", (inode, key, value))
+        self.con.commit()
 
     def close(self):
-        pass
+        self.con.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
diff --git a/trovedb/fs_util.py b/trovedb/fs_util.py
index 83dd673..2654be7 100644
--- a/trovedb/fs_util.py
+++ b/trovedb/fs_util.py
@@ -90,8 +90,8 @@ def get_content_index_name_from_path(path: Path) -> str:
     """Return the name of the index file for a directory."""
     # TODO: improve handling and mimetype logic
     if not path.suffix:
-        return 'index.dat'
-    return f'index{path.suffix}'
+        return '_index.dat'
+    return f'_index{path.suffix}'
 
 def get_content_path(path: str | Path) -> Path:
     """Return the path to the content file for a directory or file"""
diff --git a/trovedb/fuse/server.py b/trovedb/fuse/server.py
index fea7c92..f933972 100644
--- a/trovedb/fuse/server.py
+++ b/trovedb/fuse/server.py
@@ -20,9 +20,7 @@ import pyfuse3
 import trio
 from pyfuse3 import InodeT, FileHandleT
 
-from trovedb.trove import Trove, Note, Tree as TroveTree, TreeNote, ObjectId, TreeExists
-
-import trovedb.trove as tr
+from trovedb.trove import Trove, Note, Tree as TroveTree, TreeNote, Blob as TroveBlob, ObjectId, TreeExists
 
 logger = logging.getLogger(__name__)
 
@@ -142,7 +140,7 @@ class TroveFuseOps(pyfuse3.Operations):
             raise pyfuse3.FUSEError(errno.ENOTDIR)
         try:
             note = parent.child(name.decode())
-        except (KeyError, tr.ErrorNotFound):
+        except KeyError:
             logger.debug("lookup failed: %d -> %s", parent_inode, name.decode())
             raise pyfuse3.FUSEError(errno.ENOENT) from None
         ent = self._create_get_ent_from_note(note)
@@ -186,8 +184,8 @@ class TroveFuseOps(pyfuse3.Operations):
         # Determine basic information
         is_tree = True
         size = 0
-        if not hasattr(note, 'mkdir'):
-            size = len(note.read_content())
+        if isinstance(note, TroveBlob):
+            size = len(note.read())
             is_tree = False
 
         # Create and fill attr structure
@@ -241,13 +239,13 @@ class TroveFuseOps(pyfuse3.Operations):
         ent = self._get_ent_from_inode(inode)
         note = self._get_ent_note(ent)
         if fields.update_size:
-            if not hasattr(note, 'mkdir'):
-                current = note.read_content()
+            if isinstance(note, TroveBlob):
+                current = note.read()
                 new_size = attr.st_size
                 if new_size < len(current):
-                    note.write_content(current[:new_size])
+                    note.write(current[:new_size])
                 elif new_size > len(current):
-                    note.write_content(current + b"\x00" * (new_size - len(current)))
+                    note.write(current + b"\x00" * (new_size - len(current)))
             else:
                 raise pyfuse3.FUSEError(errno.EINVAL)
         return self._get_attr(ent, note)
@@ -280,13 +278,13 @@ class TroveFuseOps(pyfuse3.Operations):
         if not isinstance(note, TroveTree):
             logger.debug("attempted readdir on %d not a tree", fh)
             raise pyfuse3.FUSEError(errno.ENOTDIR)
-        entries = list(note.entries())  # [(name, object_id), ...]
+        entries = list(note.list().items())  # [(name, object_id), ...]
 
-        for idx, entry in enumerate(entries):
+        for idx, (name, child_id) in enumerate(entries):
             if idx < start_id:
                 continue
 
-            child = self._trove.get_raw_note(entry.object_id)
+            child = self._trove.get_raw_note(child_id)
             if child is None:
                 continue
 
@@ -294,7 +292,7 @@ class TroveFuseOps(pyfuse3.Operations):
             attr = self._get_attr(child_ent, child)
             self._ref_entry(child_ent)
 
-            if not pyfuse3.readdir_reply(token, entry.name.encode(), attr, idx + 1):
+            if not pyfuse3.readdir_reply(token, name.encode(), attr, idx + 1):
                 break
 
     async def releasedir(self, fh: FileHandleT) -> None:
@@ -304,18 +302,19 @@ class TroveFuseOps(pyfuse3.Operations):
 
     async def mkdir(self, parent_inode: InodeT, name: bytes, mode: int, ctx) -> pyfuse3.EntryAttributes:
         logger.debug("mkdir inode:%d name:%s", parent_inode, name)
-
+        # Grab parent note, verify is tree
         parent = self._get_inode_note(parent_inode)
-        # TODO: consider implications here, maybe look at ext on dir for mime?
+        if not isinstance(parent, TreeNote):
+            raise pyfuse3.FUSEError(errno.ENOTDIR)
+        # Create new directory in note
         try:
-            note = tr.new_child(parent, name.decode(), mime='inode/directory')
-        except tr.ErrorWithErrno as e:
-            raise pyfuse3.FUSEError(e.errno) from None
-
+            new_tree: TreeNote = parent.mkdir(name.decode())
+        except TreeExists:
+            raise pyfuse3.FUSEError(errno.EEXIST) from None
         # Grab entity for kernel
-        ent = self._create_get_ent_from_note(note)
+        ent = self._create_get_ent_from_note(new_tree)
         self._ref_entry(ent)
-        return self._get_attr(ent, note)
+        return self._get_attr(ent, new_tree)
 
     async def rmdir(self, parent_inode: InodeT, name: bytes, ctx) -> None:
         logger.debug("rmdir inode:%d name:%s", parent_inode, name)
@@ -342,35 +341,37 @@ class TroveFuseOps(pyfuse3.Operations):
     async def create(self, parent_inode: InodeT, name: bytes, mode: int, flags, ctx) -> tuple:
         logger.debug("create inode:%d name:%s", parent_inode, name)
         parent = self._get_inode_note(parent_inode)
-
-        # TODO: handle mode
-        # TODO: handle flags
-
+        if not isinstance(parent, TroveTree):
+            raise pyfuse3.FUSEError(errno.ENOTDIR)
         name_str = name.decode()
-        note = tr.new_child(parent, name_str)
-        ent = self._create_get_ent_from_note(note)
+        if name_str in parent.list():
+            raise pyfuse3.FUSEError(errno.EEXIST)
+        blob = self._trove.create_blob(b"")
+        parent.link(name_str, blob)
+
+        ent = self._create_get_ent_from_note(blob)
         self._ref_entry(ent)
 
         handle = self._open_handle(ent.sys_inode)
-        attr = self._get_attr(ent, note)
+        attr = self._get_attr(ent, blob)
         return pyfuse3.FileInfo(fh=handle.handle_id), attr
 
     async def read(self, fh: FileHandleT, offset: int, length: int) -> bytes:
         logger.debug("read fh:%d offset:%d length:%d", fh, offset, length)
         handle = self._get_handle(fh)
         note = handle.note
-        if not hasattr(note, 'mkdir'):
-            return note.read_content()[offset:offset + length]
+        if isinstance(note, TroveBlob):
+            return note.read()[offset:offset + length]
         raise pyfuse3.FUSEError(errno.EBADF)
 
     async def write(self, fh: FileHandleT, offset: int, data: bytes) -> int:
         handle = self._get_handle(fh)
         note = handle.note
-        if not hasattr(note, 'mkdir'):
-            existing = note.read_content()
+        if isinstance(note, TroveBlob):
+            existing = note.read()
             if offset > len(existing):
                 existing = existing + b"\x00" * (offset - len(existing))
-            note.write_content(existing[:offset] + data + existing[offset + len(data):])
+            note.write(existing[:offset] + data + existing[offset + len(data):])
         return len(data)
 
     async def release(self, fh: FileHandleT) -> None:
@@ -379,8 +380,12 @@ class TroveFuseOps(pyfuse3.Operations):
 
     async def unlink(self, parent_inode: InodeT, name: bytes, ctx) -> None:
         parent_note = self._get_inode_note(parent_inode)
+        if not isinstance(parent_note, TroveTree):
+            raise pyfuse3.FUSEError(errno.ENOTDIR)
         name_str = name.decode()
-        parent_note.rm_child(name_str, False)
+        if name_str not in parent_note.list():
+            raise pyfuse3.FUSEError(errno.ENOENT)
+        parent_note.unlink(name.decode())
 
     async def rename(self, parent_inode_old: InodeT, name_old: bytes, parent_inode_new: InodeT, name_new: bytes, flags, ctx):
         # Decode / validate names
diff --git a/trovedb/qgui/main_window.py b/trovedb/qgui/main_window.py
index 11e1ac4..d4cdde4 100644
--- a/trovedb/qgui/main_window.py
+++ b/trovedb/qgui/main_window.py
@@ -22,20 +22,20 @@ class TroveMainWindow(QMainWindow):
         self.setWindowTitle("Trove")
 
         # ── Toolbar ──
-        # toolbar = QToolBar("Main")
-        # toolbar.setObjectName("maintoolbar")
-        # toolbar.setMovable(False)
-        # self.addToolBar(toolbar)
-        #
-        # new_action = QAction("New", self)
-        # new_action.setShortcut(QKeySequence.StandardKey.New)
-        # toolbar.addAction(new_action)
-        #
-        # save_action = QAction("Save", self)
-        # save_action.setShortcut(QKeySequence.StandardKey.Save)
-        # toolbar.addAction(save_action)
-        #
-        # toolbar.addSeparator()
+        toolbar = QToolBar("Main")
+        toolbar.setObjectName("maintoolbar")
+        toolbar.setMovable(False)
+        self.addToolBar(toolbar)
+
+        new_action = QAction("New", self)
+        new_action.setShortcut(QKeySequence.StandardKey.New)
+        toolbar.addAction(new_action)
+
+        save_action = QAction("Save", self)
+        save_action.setShortcut(QKeySequence.StandardKey.Save)
+        toolbar.addAction(save_action)
+
+        toolbar.addSeparator()
 
         # ── Central layout ──
         central = QWidget()
diff --git a/trovedb/qgui/tool_basic_editor.py b/trovedb/qgui/tool_basic_editor.py
index 1f667e5..8c0f408 100644
--- a/trovedb/qgui/tool_basic_editor.py
+++ b/trovedb/qgui/tool_basic_editor.py
@@ -1,6 +1,5 @@
 """Tool Supporting Basic Editor Functions"""
 from typing import cast, Protocol
-from PySide6.QtCore import QTimer
 from PySide6.QtWidgets import QTextEdit, QVBoxLayout
 
 import trovedb.trove as tr
@@ -17,33 +16,7 @@ class ToolBasicEditor(Tool):
 
         self._text_edit = QTextEdit()
         layout.addWidget(self._text_edit)
-
-        self._content_dirty = False
-        self._auto_save_timer = QTimer(self)
-        self._auto_save_timer.setSingleShot(True)
-        self._auto_save_timer.setInterval(2000)  # 2 seconds after typing stops
-        self._auto_save_timer.timeout.connect(self._perform_auto_save)
-
-        self._text_edit.textChanged.connect(self._schedule_auto_save)
-
         self.refresh()
 
     def refresh(self):
         self._text_edit.setPlainText(self.note.read_content().decode("utf-8"))
-        self._content_dirty = False
-
-    def _schedule_auto_save(self):
-        self._content_dirty = True
-        self._auto_save_timer.stop()
-        self._auto_save_timer.start()
-
-    def _perform_auto_save(self):
-        if self._content_dirty:
-            content = self._text_edit.toPlainText().encode("utf-8")
-            self.note.write_content(content)
-            self._content_dirty = False
-
-    def closeEvent(self, event):
-        if self._content_dirty:
-            self._perform_auto_save()
-        super().closeEvent(event)
diff --git a/trovedb/trove.py b/trovedb/trove.py
index 06ee331..a3a47f8 100644
--- a/trovedb/trove.py
+++ b/trovedb/trove.py
@@ -1,39 +1,14 @@
-from typing import Protocol, runtime_checkable, Optional, Dict, List, Self, NamedTuple, Iterable, TypedDict, Iterator
+from typing import Protocol, runtime_checkable, Optional, Dict, List, Self, NamedTuple, Iterable, TypedDict
 from uuid import UUID
+from pathlib import PurePosixPath
 import datetime as dt
-import errno
+
 
 type ObjectId = int | str | UUID
 
 class TroveError(Exception):
     """Base class for all Trove errors."""
 
-class ErrorWithErrno(TroveError):
-    """Raised when an error occurs with an errno."""
-
-    def __init__(self, error: int, *args):
-        super().__init__(*args)
-        self.errno = error
-
-class ErrorExists(ErrorWithErrno):
-    """Raised when a note already exists."""
-
-    def __init__(self, *args):
-        super().__init__(errno.EEXIST, *args)
-
-class ErrorNotFound(ErrorWithErrno):
-    """Raised when a note is not found."""
-
-    def __init__(self, *args):
-        super().__init__(errno.ENOENT, *args)
-
-class ErrorNotEmpty(ErrorWithErrno):
-    """Raised when a directory is not empty."""
-
-    def __init__(self, *args):
-        super().__init__(errno.ENOTEMPTY, *args)
-
-
 class BadNoteType(TypeError):
     """Raised when an invalid note type is encountered."""
 
@@ -46,12 +21,6 @@ class NoteNotFound(KeyError):
 class OpenArguments(TypedDict):
     create: bool
 
-class TreeEntry(NamedTuple):
-    name: str
-    object_id: ObjectId
-
-DEFAULT_MIME = "application/octet-stream"
-
 @runtime_checkable
 class Note(Protocol):
     """
@@ -95,30 +64,10 @@ class Note(Protocol):
         """Write the raw content of the note."""
         ...
 
-    def children(self) -> Iterator[TreeEntry]:
-        """Get all children of this note."""
-        ...
-
-    def child(self, name: str) -> 'Note':
-        """Retrieve a child note by name."""
-        ...
-
-    def new_child(self, name: str, mime: str, content: bytes | None, executable: bool, hidden: bool) -> 'Note':
-        """Create a new child note."""
-        ...
-
-    def rm_child(self, name: str, recurse: bool):
-        """Remove a child note."""
-        ...
-
-    def has_children(self) -> bool:
-        """Check if note has children."""
-        return next(self.children(), None) is not None
-
-
-def new_child(note: Note, name: str, mime: str = DEFAULT_MIME, content: bytes | None = None, executable: bool = False, hidden: bool = False) -> Note:
-    return note.new_child(name=name, mime=mime, content=content, executable=executable, hidden=hidden)
 
+class TreeEntry(NamedTuple):
+    name: str
+    object_id: ObjectId
 
 @runtime_checkable
 class Tree(Protocol):
@@ -138,10 +87,17 @@ class Tree(Protocol):
         """Remove a directory from the tree."""
         ...
 
+    def child(self, name: str) -> Note:
+        """Retrieve a child note by name."""
+        ...
+
     def entries(self) -> Iterable[TreeEntry]:
         """Return all entries in the directory"""
         ...
 
+    def list(self) -> dict[str, int]:
+        """Return all entries as {name: object_id}."""
+        ...
 
 @runtime_checkable
 class TreeNote(Note, Tree, Protocol):
diff --git a/trovedb/trovedb.py b/trovedb/trovedb.py
index 30dfa6d..77aaa23 100644
--- a/trovedb/trovedb.py
+++ b/trovedb/trovedb.py
@@ -5,10 +5,9 @@ Implements BlobNote, TreeNote, and Trove protocols defined in trove.py.
 Depends on db.py (Sqlite3Trove) for storage.
 """
 
-from typing import Optional, Iterator
+from typing import Optional
 from pathlib import Path
 import datetime as dt
-import uuid
 
 from .db import Sqlite3Trove, NOTE_ROOT_ID
 
@@ -21,19 +20,9 @@ class NoteImpl(Note):
     """Concrete note implementation."""
 
     def __init__(self, parent: 'TroveImpl', object_id: ObjectId):
-        if not isinstance(object_id, uuid.UUID):
-            object_id = uuid.UUID(str(object_id))
-        assert isinstance(object_id, uuid.UUID)
-
         self._parent = parent
         self._db = parent.db
-        self._object_id: uuid.UUID = object_id
-
-    @staticmethod
-    def get_impl_id(note: Note) -> uuid.UUID:
-        if not isinstance(note.object_id, uuid.UUID):
-            raise TypeError("Note not compatible with NoteImpl")
-        return note.object_id
+        self._object_id = object_id
 
     # Note protocol
     @property
@@ -47,8 +36,7 @@ class NoteImpl(Note):
     @property
     def mtime(self) -> dt.datetime:
         """Return modification time as UTC datetime."""
-        mtime = self._db.get_mtime(self._object_id)
-        return mtime if mtime is not None else dt.datetime.now(tz=dt.timezone.utc)
+        return self._db.get_mtime(self._object_id)
 
     @property
     def mime(self) -> str:
@@ -69,39 +57,6 @@ class NoteImpl(Note):
     def write_content(self, data: bytes) -> None:
         self._db.write_content(self._object_id, data)
 
-    def children(self) -> Iterator[TreeEntry]:
-        """Get all children of this note."""
-        for name, object_id in self._db.list_tree(self._object_id).items():
-            yield TreeEntry(name, object_id)
-
-    def new_child(self, name: str, mime: str, content: bytes | None, executable: bool, hidden: bool) -> Note:
-        """Create a new child note."""
-        content = content if content is not None else b""
-        object_id = self._db.write_blob(data=content, object_id=None, dtype=mime, executable=executable, hidden=hidden)
-        # TODO fix this
-        if mime == 'inode/directory':
-            return TreeNoteImpl(self._parent, object_id)
-        return NoteImpl(self._parent, object_id)
-
-    def child(self, name: str) -> Note:
-        """Retrieve a child note by name."""
-        entries = self._db.list_tree(self._object_id)
-        if name not in entries:
-            raise tr.ErrorNotFound(name)
-        child_id = entries[name]
-        value = self._parent.get_raw_note(child_id)
-        if value is None:
-            raise tr.ErrorNotFound("dangling child link") # FIXME: better errors
-        return value
-
-    def rm_child(self, name: str, recurse: bool) -> None:
-        """Remove a child note."""
-        note = self.child(name)
-        if note.has_children() and not recurse:
-            raise tr.ErrorNotEmpty(name)
-        self._db.unlink(self._object_id, name)
-
-
 
 class TreeNoteImpl(NoteImpl, TreeNote):
     """Concrete TreeNote: a tree object backed by the tree_entries table."""
@@ -109,7 +64,7 @@ class TreeNoteImpl(NoteImpl, TreeNote):
     # Tree protocol
     def link(self, name: str, note: Note) -> None:
         """Link name to an existing note."""
-        self._db.link(self._object_id, name, NoteImpl.get_impl_id(note))
+        self._db.link(self._object_id, name, note.object_id)
 
     def unlink(self, name: str) -> None:
         """Remove an entry by name."""
@@ -126,13 +81,25 @@ class TreeNoteImpl(NoteImpl, TreeNote):
         """Remove a directory from the tree."""
         self.unlink(name)
 
-
+    def child(self, name: str) -> Note:
+        """Retrieve a child note by name."""
+        entries = self._db.list_tree(self._object_id)
+        if name not in entries:
+            raise KeyError(f"Entry '{name}' not found")
+        child_id = entries[name]
+        value = self._parent.get_raw_note(child_id)
+        if value is None:
+            raise KeyError(f"Entry '{name}' has no value")
+        return value
 
     def entries(self):
         """Return all entries as an iterable of TreeEntry."""
         for name, object_id in self._db.list_tree(self._object_id).items():
             yield TreeEntry(name, object_id)
 
+    def list(self) -> dict[str, ObjectId]:
+        """Return all entries as {name: object_id}."""
+        return self._db.list_tree(self._object_id)
 
 
 # ---------------------------------------------------------------------------
@@ -170,8 +137,6 @@ class TroveImpl:
     # Trove protocol
     def get_raw_note(self, note_id: ObjectId) -> Note:
         """Return a BlobNote or TreeNote for the given id, or None if not found."""
-        if not isinstance(note_id, uuid.UUID):
-            note_id = uuid.UUID(str(note_id))
         info = self._db.get_info(note_id)
         if info is None:
             raise NoteNotFound(note_id)