diff --git a/crates/weaver-app/src/components/editor/actions.rs b/crates/weaver-app/src/components/editor/actions.rs
index a08165a..49c4d62 100644
--- a/crates/weaver-app/src/components/editor/actions.rs
+++ b/crates/weaver-app/src/components/editor/actions.rs
@@ -1,11 +1,11 @@
 //! Editor actions and keybinding system.
 //!
 //! This module re-exports core types and provides Dioxus-specific conversions
-//! and the concrete execute_action implementation for EditorDocument.
+//! and the concrete execute_action implementation for SignalEditorDocument.
 
 use dioxus::prelude::*;
 
-use super::document::EditorDocument;
+use super::document::SignalEditorDocument;
 use super::platform::Platform;
 
 // Re-export core types.
@@ -133,7 +133,7 @@ pub fn default_keybindings(platform: &Platform) -> KeybindingConfig {
 ///
 /// This is the central dispatch point for all editor operations.
 /// Returns true if the action was handled and the document was modified.
-pub fn execute_action(doc: &mut EditorDocument, action: &EditorAction) -> bool {
+pub fn execute_action(doc: &mut SignalEditorDocument, action: &EditorAction) -> bool {
     use super::formatting::{self, FormatAction};
     use super::input::{
         detect_list_context, find_line_end, find_line_start, get_char_at, is_list_item_empty,
@@ -573,7 +573,7 @@ pub fn execute_action(doc: &mut EditorDocument, action: &EditorAction) -> bool {
 }
 
 /// Find word boundary backward from cursor.
-fn find_word_boundary_backward(doc: &EditorDocument, cursor: usize) -> usize {
+fn find_word_boundary_backward(doc: &SignalEditorDocument, cursor: usize) -> usize {
     use super::input::get_char_at;
 
     if cursor == 0 {
@@ -603,7 +603,7 @@ fn find_word_boundary_backward(doc: &EditorDocument, cursor: usize) -> usize {
 }
 
 /// Find word boundary forward from cursor.
-fn find_word_boundary_forward(doc: &EditorDocument, cursor: usize) -> usize {
+fn find_word_boundary_forward(doc: &SignalEditorDocument, cursor: usize) -> usize {
     use super::input::get_char_at;
 
     let len = doc.len_chars();
@@ -639,7 +639,7 @@ fn find_word_boundary_forward(doc: &EditorDocument, cursor: usize) -> usize {
 /// are handled by beforeinput. Navigation (arrows, etc.) is passed
 /// through to the browser.
 pub fn handle_keydown_with_bindings(
-    doc: &mut EditorDocument,
+    doc: &mut SignalEditorDocument,
     config: &KeybindingConfig,
     combo: KeyCombo,
     range: Range,
diff --git a/crates/weaver-app/src/components/editor/beforeinput.rs b/crates/weaver-app/src/components/editor/beforeinput.rs
index 9967753..a2ad9b1 100644
--- a/crates/weaver-app/src/components/editor/beforeinput.rs
+++ b/crates/weaver-app/src/components/editor/beforeinput.rs
@@ -17,7 +17,7 @@
 use dioxus::prelude::*;
 
 use super::actions::{EditorAction, execute_action};
-use super::document::EditorDocument;
+use super::document::SignalEditorDocument;
 use super::platform::Platform;
 
 // Re-export types from extracted crates.
@@ -33,7 +33,7 @@ pub use weaver_editor_browser::StaticRange;
 /// Returns whether the event was handled and default should be prevented.
 #[allow(dead_code)]
 pub fn handle_beforeinput(
-    doc: &mut EditorDocument,
+    doc: &mut SignalEditorDocument,
     ctx: BeforeInputContext<'_>,
 ) -> BeforeInputResult {
     // During composition, let the browser handle most things.
@@ -316,7 +316,7 @@ pub fn handle_beforeinput(
 }
 
 /// Get the current range based on cursor and selection state.
-fn get_current_range(doc: &EditorDocument) -> Range {
+fn get_current_range(doc: &SignalEditorDocument) -> Range {
     if let Some(sel) = *doc.selection.read() {
         let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
         Range::new(start, end)
diff --git a/crates/weaver-app/src/components/editor/collab.rs b/crates/weaver-app/src/components/editor/collab.rs
index b9211b1..699310f 100644
--- a/crates/weaver-app/src/components/editor/collab.rs
+++ b/crates/weaver-app/src/components/editor/collab.rs
@@ -11,12 +11,12 @@
 
 // Only compile for WASM - no-op stub provided at end
 
-use super::document::EditorDocument;
+use super::document::SignalEditorDocument;
 
 use dioxus::prelude::*;
 
 #[cfg(target_arch = "wasm32")]
-use jacquard::smol_str::{format_smolstr, SmolStr};
+use jacquard::smol_str::{SmolStr, format_smolstr};
 #[cfg(target_arch = "wasm32")]
 use jacquard::types::string::AtUri;
 
@@ -38,7 +38,7 @@ const PEER_DISCOVERY_INTERVAL_MS: u32 = 30 * 1000; // 30 seconds
 #[derive(Props, Clone, PartialEq)]
 pub struct CollabCoordinatorProps {
     /// The editor document to sync
-    pub document: EditorDocument,
+    pub document: SignalEditorDocument,
     /// Resource URI for the document being edited
     pub resource_uri: String,
     /// Presence state signal (updated by coordinator)
@@ -239,7 +239,8 @@ pub fn CollabCoordinator(props: CollabCoordinatorProps) -> Element {
                                 let strong_ref = match fetcher.confirm_record_ref(&uri).await {
                                     Ok(r) => r,
                                     Err(e) => {
-                                        let err = format_smolstr!("Failed to get resource ref: {e}");
+                                        let err =
+                                            format_smolstr!("Failed to get resource ref: {e}");
                                         debug_state
                                             .with_mut(|ds| ds.last_error = Some(err.clone()));
                                         state.set(CoordinatorState::Error(err));
@@ -336,7 +337,9 @@ pub fn CollabCoordinator(props: CollabCoordinatorProps) -> Element {
                                                     })
                                                     .await
                                                 {
-                                                    tracing::error!("CollabCoordinator: AddPeers send failed: {e}");
+                                                    tracing::error!(
+                                                        "CollabCoordinator: AddPeers send failed: {e}"
+                                                    );
                                                 }
                                             } else {
                                                 tracing::error!("CollabCoordinator: sink is None!");
@@ -395,29 +398,37 @@ pub fn CollabCoordinator(props: CollabCoordinatorProps) -> Element {
                             let fetcher = fetcher.clone();
 
                             // Get our profile info and send BroadcastJoin
-                            let (our_did, our_display_name): (SmolStr, SmolStr) = match fetcher.current_did().await {
+                            let (our_did, our_display_name): (SmolStr, SmolStr) = match fetcher
+                                .current_did()
+                                .await
+                            {
                                 Some(did) => {
-                                    let display_name: SmolStr = match fetcher.fetch_profile(&did.clone().into()).await {
-                                        Ok(profile) => {
-                                            match &profile.inner {
-                                                ProfileDataViewInner::ProfileView(p) => {
-                                                    p.display_name.as_ref().map(|s| s.as_ref().into()).unwrap_or_else(|| did.as_ref().into())
-                                                }
-                                                ProfileDataViewInner::ProfileViewDetailed(p) => {
-                                                    p.display_name.as_ref().map(|s| s.as_ref().into()).unwrap_or_else(|| did.as_ref().into())
-                                                }
+                                    let display_name: SmolStr =
+                                        match fetcher.fetch_profile(&did.clone().into()).await {
+                                            Ok(profile) => match &profile.inner {
+                                                ProfileDataViewInner::ProfileView(p) => p
+                                                    .display_name
+                                                    .as_ref()
+                                                    .map(|s| s.as_ref().into())
+                                                    .unwrap_or_else(|| did.as_ref().into()),
+                                                ProfileDataViewInner::ProfileViewDetailed(p) => p
+                                                    .display_name
+                                                    .as_ref()
+                                                    .map(|s| s.as_ref().into())
+                                                    .unwrap_or_else(|| did.as_ref().into()),
                                                 ProfileDataViewInner::TangledProfileView(p) => {
                                                     p.handle.as_ref().into()
                                                 }
                                                 _ => did.as_ref().into(),
-                                            }
-                                        }
-                                        Err(_) => did.as_ref().into(),
-                                    };
+                                            },
+                                            Err(_) => did.as_ref().into(),
+                                        };
                                     (did.as_ref().into(), display_name)
                                 }
                                 None => {
-                                    tracing::warn!("CollabCoordinator: no current DID for Join message");
+                                    tracing::warn!(
+                                        "CollabCoordinator: no current DID for Join message"
+                                    );
                                     ("unknown".into(), "Anonymous".into())
                                 }
                             };
@@ -430,7 +441,9 @@ pub fn CollabCoordinator(props: CollabCoordinatorProps) -> Element {
                                     })
                                     .await
                                 {
-                                    tracing::error!("CollabCoordinator: BroadcastJoin send failed: {e}");
+                                    tracing::error!(
+                                        "CollabCoordinator: BroadcastJoin send failed: {e}"
+                                    );
                                 }
                             }
                         }
@@ -460,11 +473,18 @@ pub fn CollabCoordinator(props: CollabCoordinatorProps) -> Element {
             let position = cursor.offset;
             let sel = selection.map(|s| (s.anchor, s.head));
 
-            tracing::debug!(position, ?sel, "CollabCoordinator: cursor changed, broadcasting");
+            tracing::debug!(
+                position,
+                ?sel,
+                "CollabCoordinator: cursor changed, broadcasting"
+            );
 
             spawn(async move {
                 if let Some(ref mut s) = *worker_sink.write() {
-                    tracing::debug!(position, "CollabCoordinator: sending BroadcastCursor to worker");
+                    tracing::debug!(
+                        position,
+                        "CollabCoordinator: sending BroadcastCursor to worker"
+                    );
                     if let Err(e) = s
                         .send(WorkerInput::BroadcastCursor {
                             position,
@@ -475,7 +495,10 @@ pub fn CollabCoordinator(props: CollabCoordinatorProps) -> Element {
                         tracing::warn!("Failed to send BroadcastCursor to worker: {e}");
                     }
                 } else {
-                    tracing::debug!(position, "CollabCoordinator: worker sink not ready, skipping cursor broadcast");
+                    tracing::debug!(
+                        position,
+                        "CollabCoordinator: worker sink not ready, skipping cursor broadcast"
+                    );
                 }
             });
         });
diff --git a/crates/weaver-app/src/components/editor/component.rs b/crates/weaver-app/src/components/editor/component.rs
index fef4a57..e22c7c4 100644
--- a/crates/weaver-app/src/components/editor/component.rs
+++ b/crates/weaver-app/src/components/editor/component.rs
@@ -9,7 +9,7 @@ use super::actions::{
 use super::beforeinput::{BeforeInputContext, BeforeInputResult, InputType, handle_beforeinput};
 #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
 use super::beforeinput::{get_data_from_event, get_target_range_from_event};
-use super::document::{CompositionState, EditorDocument, LoadedDocState};
+use super::document::{CompositionState, LoadedDocState, SignalEditorDocument};
 #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
 use super::dom_sync::update_paragraph_dom;
 use super::dom_sync::{sync_cursor_from_dom, sync_cursor_from_dom_with_direction};
@@ -421,7 +421,7 @@ fn MarkdownEditorInner(
 
     #[allow(unused_mut)]
     let mut document = use_hook(|| {
-        let mut doc = EditorDocument::from_loaded_state(loaded_state.clone());
+        let mut doc = SignalEditorDocument::from_loaded_state(loaded_state.clone());
 
         // Seed collected_refs with existing record embeds so they get fetched/rendered
         let record_embeds = doc.record_embeds();
@@ -469,6 +469,8 @@ fn MarkdownEditorInner(
     let entry_index_for_memo = entry_index.clone();
     #[allow(unused_mut)]
     let mut paragraphs = use_memo(move || {
+        // Read content_changed to establish reactive dependency
+        let _ = doc_for_memo.content_changed.read();
         let edit = doc_for_memo.last_edit();
         let cache = render_cache.peek();
         let resolver = image_resolver();
@@ -481,7 +483,7 @@ fn MarkdownEditorInner(
 
         let cursor_offset = doc_for_memo.cursor.read().offset;
         let (paras, new_cache, refs) = render::render_paragraphs_incremental(
-            doc_for_memo.loro_text(),
+            doc_for_memo.buffer(),
             Some(&cache),
             cursor_offset,
             edit.as_ref(),
@@ -501,9 +503,9 @@ fn MarkdownEditorInner(
     // Background fetch for AT embeds via worker
     #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
     {
-        use weaver_embed_worker::{EmbedWorker, EmbedWorkerInput, EmbedWorkerOutput};
         use dioxus::prelude::Writable;
         use gloo_worker::Spawnable;
+        use weaver_embed_worker::{EmbedWorker, EmbedWorkerInput, EmbedWorkerOutput};
 
         let resolved_content_for_fetch = resolved_content;
         let mut embed_worker_bridge: Signal<Option<gloo_worker::WorkerBridge<EmbedWorker>>> =
@@ -559,7 +561,7 @@ fn MarkdownEditorInner(
                 .filter_map(|r| match r {
                     weaver_common::ExtractedRef::AtEmbed { uri, .. } => {
                         // Skip if already resolved
-                        if let Ok(at_uri) = jacquard::types::string::AtUri::new(uri) {
+                        if let Ok(at_uri) = jacquard::types::string::AtUri::new_owned(uri) {
                             if current_resolved.get_embed_content(&at_uri).is_none() {
                                 return Some(uri.clone());
                             }
@@ -598,7 +600,7 @@ fn MarkdownEditorInner(
                 .filter_map(|r| match r {
                     weaver_common::ExtractedRef::AtEmbed { uri, .. } => {
                         // Skip if already resolved
-                        if let Ok(at_uri) = jacquard::types::string::AtUri::new(uri) {
+                        if let Ok(at_uri) = jacquard::types::string::AtUri::new_owned(uri) {
                             if current_resolved.get_embed_content(&at_uri).is_none() {
                                 return Some(uri.clone());
                             }
@@ -731,10 +733,10 @@ fn MarkdownEditorInner(
     // Worker-based autosave (offloads export + encode to worker thread)
     #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
     {
-        use weaver_editor_crdt::{EditorReactor, WorkerInput, WorkerOutput};
         use gloo_storage::Storage;
         use gloo_worker::Spawnable;
         use gloo_worker::reactor::ReactorBridge;
+        use weaver_editor_crdt::{EditorReactor, WorkerInput, WorkerOutput};
 
         use futures_util::stream::{SplitSink, SplitStream};
 
@@ -1810,7 +1812,7 @@ fn MarkdownEditorInner(
 #[component]
 fn RemoteCursors(
     presence: Signal<weaver_common::transport::PresenceSnapshot>,
-    document: EditorDocument,
+    document: SignalEditorDocument,
     render_cache: Signal<render::RenderCache>,
 ) -> Element {
     let presence_read = presence.read();
diff --git a/crates/weaver-app/src/components/editor/document.rs b/crates/weaver-app/src/components/editor/document.rs
index 65b95e2..5eb60af 100644
--- a/crates/weaver-app/src/components/editor/document.rs
+++ b/crates/weaver-app/src/components/editor/document.rs
@@ -7,18 +7,13 @@
 //!
 //! Individual fields are wrapped in Dioxus Signals for fine-grained reactivity:
 //! - Cursor/selection changes don't trigger content re-renders
-//! - Content changes (via `last_edit`) trigger paragraph memo re-evaluation
+//! - Content changes bump `content_changed` Signal to trigger paragraph re-renders
 //! - The document struct itself is NOT wrapped in a Signal - use `use_hook`
 
-use std::borrow::Cow;
-use std::cell::RefCell;
-use std::rc::Rc;
-
 use dioxus::prelude::*;
 use loro::{
-    ExportMode, Frontiers, LoroDoc, LoroList, LoroMap, LoroResult, LoroText, LoroValue, ToJson,
-    UndoManager, VersionVector,
-    cursor::{Cursor, Side},
+    Frontiers, LoroDoc, LoroList, LoroMap, LoroResult, LoroText, LoroValue, ToJson, VersionVector,
+    cursor::Cursor,
 };
 
 use jacquard::IntoStatic;
@@ -28,10 +23,12 @@ use jacquard::types::string::AtUri;
 use weaver_api::com_atproto::repo::strong_ref::StrongRef;
 use weaver_api::sh_weaver::embed::images::Image;
 use weaver_api::sh_weaver::embed::records::RecordEmbed;
-pub use weaver_editor_core::{
-    Affinity, CompositionState, CursorState, EditInfo, Selection, BLOCK_SYNTAX_ZONE,
-};
 use weaver_api::sh_weaver::notebook::entry::Entry;
+use weaver_editor_core::EditorDocument;
+use weaver_editor_core::TextBuffer;
+use weaver_editor_core::UndoManager;
+pub use weaver_editor_core::{Affinity, CompositionState, CursorState, EditInfo, Selection};
+use weaver_editor_crdt::LoroTextBuffer;
 
 /// Helper for working with editor images.
 /// Constructed from LoroMap data, NOT serialized directly.
@@ -47,7 +44,7 @@ pub struct EditorImage {
 
 /// Single source of truth for editor state.
 ///
-/// Contains the document text (backed by Loro CRDT), cursor position,
+/// Contains the document text (backed by Loro CRDT via LoroTextBuffer), cursor position,
 /// selection, and IME composition state. Mirrors the `sh.weaver.notebook.entry`
 /// schema with CRDT containers for each field.
 ///
@@ -56,23 +53,22 @@ pub struct EditorImage {
 /// The document itself is NOT wrapped in a Signal. Instead, individual fields
 /// that need reactivity are wrapped in Signals:
 /// - `cursor`, `selection`, `composition` - high-frequency, cursor-only updates
-/// - `last_edit` - triggers paragraph re-renders when content changes
+/// - `content_changed` - bumped to trigger paragraph re-renders when content changes
 ///
-/// Use `use_hook(|| EditorDocument::new(...))` in components, not `use_signal`.
+/// Use `use_hook(|| SignalEditorDocument::new(...))` in components, not `use_signal`.
 ///
 /// # Cloning
 ///
-/// EditorDocument is cheap to clone - Loro types are Arc-backed handles,
+/// SignalEditorDocument is cheap to clone - LoroTextBuffer and Loro types are Arc-backed,
 /// and Signals are Copy. Closures can capture clones without overhead.
 #[derive(Clone)]
-pub struct EditorDocument {
-    /// The Loro document containing all editor state.
-    doc: LoroDoc,
+pub struct SignalEditorDocument {
+    /// The text buffer wrapping LoroDoc with undo/redo and cursor tracking.
+    /// Access the underlying LoroDoc via `buffer.doc()`.
+    buffer: LoroTextBuffer,
 
     // --- Entry schema containers (Loro handles interior mutability) ---
-    /// Markdown content (maps to entry.content)
-    content: LoroText,
-
+    // These are obtained from buffer.doc() but cached for convenience.
     /// Entry title (maps to entry.title)
     title: LoroText,
 
@@ -119,14 +115,6 @@ pub struct EditorDocument {
     /// The diff rkey (TID) is time-sortable, so we skip diffs with rkey <= this.
     pub last_seen_diffs: Signal<std::collections::HashMap<AtUri<'static>, AtUri<'static>>>,
 
-    // --- Editor state (non-reactive) ---
-    /// Undo manager for the document.
-    undo_mgr: Rc<RefCell<UndoManager>>,
-
-    /// CRDT-aware cursor that tracks position through remote edits and undo/redo.
-    /// Recreated after our own edits, queried after undo/redo/remote edits.
-    loro_cursor: Option<Cursor>,
-
     // --- Reactive editor state (Signal-wrapped for fine-grained updates) ---
     /// Current cursor position. Signal so cursor changes don't dirty content memos.
     pub cursor: Signal<CursorState>,
@@ -141,9 +129,9 @@ pub struct EditorDocument {
     /// Used for Safari workaround: ignore Enter keydown within 500ms of compositionend.
     pub composition_ended_at: Signal<Option<web_time::Instant>>,
 
-    /// Most recent edit info for incremental rendering optimization.
-    /// Signal so paragraphs memo can subscribe to content changes only.
-    pub last_edit: Signal<Option<EditInfo>>,
+    /// Bumped when content changes to trigger paragraph re-renders.
+    /// Actual EditInfo is obtained from `buffer.last_edit()`.
+    pub content_changed: Signal<()>,
 
     /// Pending snap direction for cursor restoration after edits.
     /// Set by input handlers, consumed by cursor restoration.
@@ -154,14 +142,11 @@ pub struct EditorDocument {
     pub collected_refs: Signal<Vec<weaver_common::ExtractedRef>>,
 }
 
-// CursorState, Affinity, Selection, CompositionState, EditInfo, and BLOCK_SYNTAX_ZONE
-// are imported from weaver_editor_core.
-
 /// Pre-loaded document state that can be created outside of reactive context.
 ///
 /// This struct holds the raw LoroDoc (which is safe outside reactive context)
-/// along with sync state metadata. Use `EditorDocument::from_loaded_state()`
-/// inside a `use_hook` to convert this into a reactive EditorDocument.
+/// along with sync state metadata. Use `SignalEditorDocument::from_loaded_state()`
+/// inside a `use_hook` to convert this into a reactive SignalEditorDocument.
 ///
 /// Note: Clone is a shallow/reference clone for LoroDoc (Arc-backed).
 /// PartialEq always returns false since we can't meaningfully compare docs.
@@ -197,36 +182,19 @@ impl PartialEq for LoadedDocState {
     }
 }
 
-impl EditorDocument {
-    /// Check if a character position is within the block-syntax zone of its line.
-    fn is_in_block_syntax_zone(&self, pos: usize) -> bool {
-        if pos <= BLOCK_SYNTAX_ZONE {
-            return true;
-        }
-
-        // Search backwards from pos-1, only need to check BLOCK_SYNTAX_ZONE + 1 chars.
-        let search_start = pos.saturating_sub(BLOCK_SYNTAX_ZONE + 1);
-        for i in (search_start..pos).rev() {
-            if self.content.char_at(i).ok() == Some('\n') {
-                // Found newline at i, distance from line start is pos - i - 1.
-                return (pos - i - 1) <= BLOCK_SYNTAX_ZONE;
-            }
-        }
-        // No newline found in search range, and pos > BLOCK_SYNTAX_ZONE, so not in zone.
-        false
-    }
-
+impl SignalEditorDocument {
     /// Create a new editor document with the given content.
     /// Sets `created_at` to current time.
     ///
     /// # Note
     /// This creates Dioxus Signals for reactive fields. Call from within
-    /// a component using `use_hook(|| EditorDocument::new(...))`.
+    /// a component using `use_hook(|| SignalEditorDocument::new(...))`.
     pub fn new(initial_content: String) -> Self {
-        let doc = LoroDoc::new();
+        // Create the LoroTextBuffer which owns the LoroDoc
+        let mut buffer = LoroTextBuffer::new();
+        let doc = buffer.doc().clone();
 
-        // Get all containers
-        let content = doc.get_text("content");
+        // Get other containers from the doc
         let title = doc.get_text("title");
         let path = doc.get_text("path");
         let created_at = doc.get_text("created_at");
@@ -235,9 +203,7 @@ impl EditorDocument {
 
         // Insert initial content if any
         if !initial_content.is_empty() {
-            content
-                .insert(0, &initial_content)
-                .expect("failed to insert initial content");
+            buffer.insert(0, &initial_content);
         }
 
         // Set created_at to current time (ISO 8601)
@@ -246,17 +212,8 @@ impl EditorDocument {
             .insert(0, &now)
             .expect("failed to set created_at");
 
-        // Set up undo manager with merge interval for batching keystrokes
-        let mut undo_mgr = UndoManager::new(&doc);
-        undo_mgr.set_merge_interval(300); // 300ms merge window
-        undo_mgr.set_max_undo_steps(100);
-
-        // Create initial Loro cursor at position 0
-        let loro_cursor = content.get_cursor(0, Side::default());
-
         Self {
-            doc,
-            content,
+            buffer,
             title,
             path,
             created_at,
@@ -268,9 +225,6 @@ impl EditorDocument {
             last_diff: Signal::new(None),
             last_synced_version: Signal::new(None),
             last_seen_diffs: Signal::new(std::collections::HashMap::new()),
-            undo_mgr: Rc::new(RefCell::new(undo_mgr)),
-            loro_cursor,
-            // Reactive editor state - wrapped in Signals
             cursor: Signal::new(CursorState {
                 offset: 0,
                 affinity: Affinity::Before,
@@ -278,13 +232,13 @@ impl EditorDocument {
             selection: Signal::new(None),
             composition: Signal::new(None),
             composition_ended_at: Signal::new(None),
-            last_edit: Signal::new(None),
+            content_changed: Signal::new(()),
             pending_snap: Signal::new(None),
             collected_refs: Signal::new(Vec::new()),
         }
     }
 
-    /// Create an EditorDocument from a fetched Entry.
+    /// Create a SignalEditorDocument from a fetched Entry.
     ///
     /// MUST be called from within a reactive context (e.g., `use_hook`) to
     /// properly initialize Dioxus Signals.
@@ -341,44 +295,54 @@ impl EditorDocument {
 
     /// Get the underlying LoroText for read operations on content.
     pub fn loro_text(&self) -> &LoroText {
-        &self.content
+        self.buffer.content()
     }
 
     /// Get the underlying LoroDoc for subscriptions and advanced operations.
     pub fn loro_doc(&self) -> &LoroDoc {
-        &self.doc
+        self.buffer.doc()
+    }
+
+    /// Get direct access to the LoroTextBuffer.
+    pub fn buffer(&self) -> &LoroTextBuffer {
+        &self.buffer
+    }
+
+    /// Get mutable access to the LoroTextBuffer.
+    pub fn buffer_mut(&mut self) -> &mut LoroTextBuffer {
+        &mut self.buffer
     }
 
     // --- Content accessors ---
 
     /// Get the markdown content as a string.
     pub fn content(&self) -> String {
-        self.content.to_string()
+        weaver_editor_core::TextBuffer::to_string(&self.buffer)
     }
 
     /// Convert the document content to a string (alias for content()).
     pub fn to_string(&self) -> String {
-        self.content.to_string()
+        weaver_editor_core::TextBuffer::to_string(&self.buffer)
     }
 
     /// Get the length of the content in characters.
     pub fn len_chars(&self) -> usize {
-        self.content.len_unicode()
+        weaver_editor_core::TextBuffer::len_chars(&self.buffer)
     }
 
     /// Get the length of the content in UTF-8 bytes.
     pub fn len_bytes(&self) -> usize {
-        self.content.len_utf8()
+        weaver_editor_core::TextBuffer::len_bytes(&self.buffer)
     }
 
     /// Get the length of the content in UTF-16 code units.
     pub fn len_utf16(&self) -> usize {
-        self.content.len_utf16()
+        self.buffer.content().len_utf16()
     }
 
     /// Check if the content is empty.
     pub fn is_empty(&self) -> bool {
-        self.content.len_unicode() == 0
+        weaver_editor_core::TextBuffer::len_chars(&self.buffer) == 0
     }
 
     // --- Entry metadata accessors ---
@@ -652,91 +616,35 @@ impl EditorDocument {
             .map(|r| r.into_static())
     }
 
-    /// Insert text into content and record edit info for incremental rendering.
+    /// Insert text into content and bump content_changed for re-rendering.
+    /// Edit info is tracked automatically by the buffer.
     pub fn insert_tracked(&mut self, pos: usize, text: &str) -> LoroResult<()> {
-        let in_block_syntax_zone = self.is_in_block_syntax_zone(pos);
-        let len_before = self.content.len_unicode();
-        let result = self.content.insert(pos, text);
-        let len_after = self.content.len_unicode();
-        self.last_edit.set(Some(EditInfo {
-            edit_char_pos: pos,
-            inserted_len: len_after.saturating_sub(len_before),
-            deleted_len: 0,
-            contains_newline: text.contains('\n'),
-            in_block_syntax_zone,
-            doc_len_after: len_after,
-            timestamp: web_time::Instant::now(),
-        }));
-        result
+        self.buffer.insert(pos, text);
+        self.content_changed.set(());
+        Ok(())
     }
 
     /// Push text to end of content. Faster than insert for appending.
     pub fn push_tracked(&mut self, text: &str) -> LoroResult<()> {
-        let pos = self.content.len_unicode();
-        let in_block_syntax_zone = self.is_in_block_syntax_zone(pos);
-        let result = self.content.push_str(text);
-        let len_after = self.content.len_unicode();
-        self.last_edit.set(Some(EditInfo {
-            edit_char_pos: pos,
-            inserted_len: text.chars().count(),
-            deleted_len: 0,
-            contains_newline: text.contains('\n'),
-            in_block_syntax_zone,
-            doc_len_after: len_after,
-            timestamp: web_time::Instant::now(),
-        }));
-        result
+        let pos = weaver_editor_core::TextBuffer::len_chars(&self.buffer);
+        self.buffer.insert(pos, text);
+        self.content_changed.set(());
+        Ok(())
     }
 
-    /// Remove text range from content and record edit info for incremental rendering.
+    /// Remove text range from content and bump content_changed for re-rendering.
+    /// Edit info is tracked automatically by the buffer.
     pub fn remove_tracked(&mut self, start: usize, len: usize) -> LoroResult<()> {
-        let contains_newline = self
-            .content
-            .slice(start, start + len)
-            .map(|s| s.contains('\n'))
-            .unwrap_or(false);
-        let in_block_syntax_zone = self.is_in_block_syntax_zone(start);
-
-        let result = self.content.delete(start, len);
-        self.last_edit.set(Some(EditInfo {
-            edit_char_pos: start,
-            inserted_len: 0,
-            deleted_len: len,
-            contains_newline,
-            in_block_syntax_zone,
-            doc_len_after: self.content.len_unicode(),
-            timestamp: web_time::Instant::now(),
-        }));
-        result
+        self.buffer.delete(start..start + len);
+        self.content_changed.set(());
+        Ok(())
     }
 
-    /// Replace text in content (delete then insert) and record combined edit info.
+    /// Replace text in content (atomic splice) and bump content_changed.
+    /// Edit info is tracked automatically by the buffer.
     pub fn replace_tracked(&mut self, start: usize, len: usize, text: &str) -> LoroResult<()> {
-        let delete_has_newline = self
-            .content
-            .slice(start, start + len)
-            .map(|s| s.contains('\n'))
-            .unwrap_or(false);
-        let in_block_syntax_zone = self.is_in_block_syntax_zone(start);
-
-        let len_before = self.content.len_unicode();
-        // Use splice for atomic replace
-        self.content.splice(start, len, text)?;
-        let len_after = self.content.len_unicode();
-
-        // inserted_len = (len_after - len_before) + deleted_len
-        // because: len_after = len_before - deleted + inserted
-        let inserted_len = (len_after + len).saturating_sub(len_before);
-
-        self.last_edit.set(Some(EditInfo {
-            edit_char_pos: start,
-            inserted_len,
-            deleted_len: len,
-            contains_newline: delete_has_newline || text.contains('\n'),
-            in_block_syntax_zone,
-            doc_len_after: len_after,
-            timestamp: web_time::Instant::now(),
-        }));
+        self.buffer.replace(start..start + len, text);
+        self.content_changed.set(());
         Ok(())
     }
 
@@ -746,12 +654,12 @@ impl EditorDocument {
         // so it tracks through the undo operation
         self.sync_loro_cursor();
 
-        let result = self.undo_mgr.borrow_mut().undo()?;
+        let result = self.buffer.undo();
         if result {
             // After undo, query Loro cursor for new position
             self.sync_cursor_from_loro();
             // Signal content change for re-render
-            self.last_edit.set(None);
+            self.content_changed.set(());
         }
         Ok(result)
     }
@@ -761,30 +669,30 @@ impl EditorDocument {
         // Sync Loro cursor to current position BEFORE redo
         self.sync_loro_cursor();
 
-        let result = self.undo_mgr.borrow_mut().redo()?;
+        let result = self.buffer.redo();
         if result {
             // After redo, query Loro cursor for new position
             self.sync_cursor_from_loro();
             // Signal content change for re-render
-            self.last_edit.set(None);
+            self.content_changed.set(());
         }
         Ok(result)
     }
 
     /// Check if undo is available.
     pub fn can_undo(&self) -> bool {
-        self.undo_mgr.borrow().can_undo()
+        UndoManager::can_undo(&self.buffer)
     }
 
     /// Check if redo is available.
     pub fn can_redo(&self) -> bool {
-        self.undo_mgr.borrow().can_redo()
+        UndoManager::can_redo(&self.buffer)
     }
 
     /// Get a slice of the content text.
     /// Returns None if the range is invalid.
-    pub fn slice(&self, start: usize, end: usize) -> Option<String> {
-        self.content.slice(start, end).ok()
+    pub fn slice(&self, start: usize, end: usize) -> Option<SmolStr> {
+        self.buffer.slice(start..end)
     }
 
     /// Sync the Loro cursor to the current cursor.offset position.
@@ -792,18 +700,20 @@ impl EditorDocument {
     pub fn sync_loro_cursor(&mut self) {
         let offset = self.cursor.read().offset;
         tracing::debug!(offset, "sync_loro_cursor: saving cursor position to Loro");
-        self.loro_cursor = self.content.get_cursor(offset, Side::default());
+        self.buffer.sync_cursor(offset);
     }
 
     /// Update cursor.offset from the Loro cursor's tracked position.
     /// Call this after undo/redo or remote edits where the position may have shifted.
     /// Returns the new offset, or None if the cursor couldn't be resolved.
     pub fn sync_cursor_from_loro(&mut self) -> Option<usize> {
-        let loro_cursor = self.loro_cursor.as_ref()?;
-        let result = self.doc.get_cursor_pos(loro_cursor).ok()?;
         let old_offset = self.cursor.read().offset;
-        let new_offset = result.current.pos.min(self.len_chars());
-        let jump = if new_offset > old_offset { new_offset - old_offset } else { old_offset - new_offset };
+        let new_offset = self.buffer.resolve_cursor()?;
+        let jump = if new_offset > old_offset {
+            new_offset - old_offset
+        } else {
+            old_offset - new_offset
+        };
         if jump > 100 {
             tracing::warn!(
                 old_offset,
@@ -812,22 +722,26 @@ impl EditorDocument {
                 "sync_cursor_from_loro: LARGE CURSOR JUMP detected"
             );
         }
-        tracing::debug!(old_offset, new_offset, "sync_cursor_from_loro: updating cursor from Loro");
+        tracing::debug!(
+            old_offset,
+            new_offset,
+            "sync_cursor_from_loro: updating cursor from Loro"
+        );
         self.cursor.with_mut(|c| c.offset = new_offset);
         Some(new_offset)
     }
 
     /// Get the Loro cursor for serialization.
-    pub fn loro_cursor(&self) -> Option<&Cursor> {
-        self.loro_cursor.as_ref()
+    pub fn loro_cursor(&self) -> Option<Cursor> {
+        self.buffer.loro_cursor()
     }
 
     /// Set the Loro cursor (used when restoring from storage).
     pub fn set_loro_cursor(&mut self, cursor: Option<Cursor>) {
         tracing::debug!(has_cursor = cursor.is_some(), "set_loro_cursor called");
-        self.loro_cursor = cursor;
+        self.buffer.set_loro_cursor(cursor);
         // Sync cursor.offset from the restored Loro cursor
-        if self.loro_cursor.is_some() {
+        if self.buffer.loro_cursor().is_some() {
             self.sync_cursor_from_loro();
         }
     }
@@ -835,24 +749,30 @@ impl EditorDocument {
     /// Export the document as a binary snapshot.
     /// This captures all CRDT state including undo history.
     pub fn export_snapshot(&self) -> Vec<u8> {
-        self.doc.export(ExportMode::Snapshot).unwrap_or_default()
+        self.buffer.export_snapshot()
     }
 
     /// Get the current state frontiers for change detection.
     /// Frontiers represent the "version" of the document state.
     pub fn state_frontiers(&self) -> Frontiers {
-        self.doc.state_frontiers()
+        self.buffer.doc().state_frontiers()
     }
 
     /// Get the current version vector.
     pub fn version_vector(&self) -> VersionVector {
-        self.doc.oplog_vv()
+        self.buffer.version()
     }
 
     /// Get the last edit info for incremental rendering.
-    /// Reading this creates a reactive dependency on content changes.
+    /// This comes from the buffer's internal tracking.
     pub fn last_edit(&self) -> Option<EditInfo> {
-        self.last_edit.read().clone()
+        self.buffer.last_edit()
+    }
+
+    /// Bump the content_changed signal to trigger re-renders.
+    /// Call this after remote imports or other external content changes.
+    pub fn notify_content_changed(&mut self) {
+        self.content_changed.set(());
     }
 
     // --- Collected refs accessors ---
@@ -916,7 +836,7 @@ impl EditorDocument {
     /// Check if there are unsynced changes since the last PDS sync.
     pub fn has_unsynced_changes(&self) -> bool {
         match &*self.last_synced_version.read() {
-            Some(synced_vv) => self.doc.oplog_vv() != *synced_vv,
+            Some(synced_vv) => self.buffer.version() != *synced_vv,
             None => true, // Never synced, so there are changes
         }
     }
@@ -926,44 +846,27 @@ impl EditorDocument {
     /// After successful upload, call `mark_synced()` to update the sync marker.
     pub fn export_updates_since_sync(&self) -> Option<Vec<u8>> {
         let from_vv = self.last_synced_version.read().clone().unwrap_or_default();
-        let current_vv = self.doc.oplog_vv();
-
-        // No changes since last sync
-        if from_vv == current_vv {
-            return None;
-        }
-
-        let updates = self
-            .doc
-            .export(ExportMode::Updates {
-                from: Cow::Owned(from_vv),
-            })
-            .ok()?;
-
-        // Don't return empty updates
-        if updates.is_empty() {
-            return None;
-        }
-
-        Some(updates)
+        self.buffer.export_updates_since(&from_vv)
     }
 
     /// Mark the current state as synced.
     /// Call this after successfully uploading a diff to the PDS.
     pub fn mark_synced(&mut self) {
-        self.last_synced_version.set(Some(self.doc.oplog_vv()));
+        self.last_synced_version.set(Some(self.buffer.version()));
     }
 
     /// Import updates from a PDS diff blob.
     /// Used when loading edit history from the PDS.
     pub fn import_updates(&mut self, updates: &[u8]) -> LoroResult<()> {
-        let len_before = self.content.len_unicode();
-        let vv_before = self.doc.oplog_vv();
+        let len_before = weaver_editor_core::TextBuffer::len_chars(&self.buffer);
+        let vv_before = self.buffer.version();
 
-        self.doc.import(updates)?;
+        self.buffer
+            .import(updates)
+            .map_err(|e| loro::LoroError::DecodeError(e.to_string().into()))?;
 
-        let len_after = self.content.len_unicode();
-        let vv_after = self.doc.oplog_vv();
+        let len_after = weaver_editor_core::TextBuffer::len_chars(&self.buffer);
+        let vv_after = self.buffer.version();
         let vv_changed = vv_before != vv_after;
         let len_changed = len_before != len_after;
 
@@ -977,7 +880,7 @@ impl EditorDocument {
 
         // Only trigger re-render if something actually changed
         if vv_changed {
-            self.last_edit.set(None);
+            self.content_changed.set(());
         }
         Ok(())
     }
@@ -985,25 +888,7 @@ impl EditorDocument {
     /// Export updates since the given version vector.
     /// Used for real-time P2P sync where we track broadcast version separately from PDS sync.
     pub fn export_updates_from(&self, from_vv: &VersionVector) -> Option<Vec<u8>> {
-        let current_vv = self.doc.oplog_vv();
-
-        // No changes since the given version
-        if *from_vv == current_vv {
-            return None;
-        }
-
-        let updates = self
-            .doc
-            .export(ExportMode::Updates {
-                from: Cow::Borrowed(from_vv),
-            })
-            .ok()?;
-
-        if updates.is_empty() {
-            return None;
-        }
-
-        Some(updates)
+        self.buffer.export_updates_since(from_vv)
     }
 
     /// Set the sync state when loading from PDS.
@@ -1016,10 +901,10 @@ impl EditorDocument {
     ) {
         self.edit_root.set(Some(edit_root));
         self.last_diff.set(last_diff);
-        self.last_synced_version.set(Some(self.doc.oplog_vv()));
+        self.last_synced_version.set(Some(self.buffer.version()));
     }
 
-    /// Create a new EditorDocument from a binary snapshot.
+    /// Create a new SignalEditorDocument from a binary snapshot.
     /// Falls back to empty document if import fails.
     ///
     /// If `loro_cursor` is provided, it will be used to restore the cursor position.
@@ -1037,29 +922,30 @@ impl EditorDocument {
         loro_cursor: Option<Cursor>,
         fallback_offset: usize,
     ) -> Self {
-        let doc = LoroDoc::new();
-
-        if !snapshot.is_empty() {
-            if let Err(e) = doc.import(snapshot) {
-                tracing::warn!("Failed to import snapshot: {:?}, creating empty doc", e);
+        // Create buffer from snapshot
+        let buffer = if snapshot.is_empty() {
+            LoroTextBuffer::new()
+        } else {
+            match LoroTextBuffer::from_snapshot(snapshot) {
+                Ok(buf) => buf,
+                Err(e) => {
+                    tracing::warn!("Failed to import snapshot: {:?}, creating empty doc", e);
+                    LoroTextBuffer::new()
+                }
             }
-        }
+        };
+
+        let doc = buffer.doc().clone();
 
-        // Get all containers (they will contain data from the snapshot if import succeeded)
-        let content = doc.get_text("content");
+        // Get other containers from the doc
         let title = doc.get_text("title");
         let path = doc.get_text("path");
         let created_at = doc.get_text("created_at");
         let tags = doc.get_list("tags");
         let embeds = doc.get_map("embeds");
 
-        // Set up undo manager - tracks operations from this point forward only
-        let mut undo_mgr = UndoManager::new(&doc);
-        undo_mgr.set_merge_interval(300);
-        undo_mgr.set_max_undo_steps(100);
-
         // Try to restore cursor from Loro cursor, fall back to offset
-        let max_offset = content.len_unicode();
+        let max_offset = weaver_editor_core::TextBuffer::len_chars(&buffer);
         let cursor_offset = if let Some(ref lc) = loro_cursor {
             doc.get_cursor_pos(lc)
                 .map(|r| r.current.pos)
@@ -1073,13 +959,16 @@ impl EditorDocument {
             affinity: Affinity::Before,
         };
 
-        // If no Loro cursor provided, create one at the restored position
-        let loro_cursor =
-            loro_cursor.or_else(|| content.get_cursor(cursor_state.offset, Side::default()));
+        // Set up the Loro cursor
+        let buffer = buffer;
+        if let Some(lc) = loro_cursor {
+            buffer.set_loro_cursor(Some(lc));
+        } else {
+            buffer.sync_cursor(cursor_state.offset);
+        }
 
         Self {
-            doc,
-            content,
+            buffer,
             title,
             path,
             created_at,
@@ -1091,20 +980,17 @@ impl EditorDocument {
             last_diff: Signal::new(None),
             last_synced_version: Signal::new(None),
             last_seen_diffs: Signal::new(std::collections::HashMap::new()),
-            undo_mgr: Rc::new(RefCell::new(undo_mgr)),
-            loro_cursor,
-            // Reactive editor state - wrapped in Signals
             cursor: Signal::new(cursor_state),
             selection: Signal::new(None),
             composition: Signal::new(None),
             composition_ended_at: Signal::new(None),
-            last_edit: Signal::new(None),
+            content_changed: Signal::new(()),
             pending_snap: Signal::new(None),
             collected_refs: Signal::new(Vec::new()),
         }
     }
 
-    /// Create an EditorDocument from pre-loaded state.
+    /// Create a SignalEditorDocument from pre-loaded state.
     ///
     /// Use this when loading from PDS/localStorage merge outside reactive context.
     /// The `LoadedDocState` contains a pre-merged LoroDoc; this method wraps it
@@ -1113,32 +999,30 @@ impl EditorDocument {
     /// # Note
     /// This creates Dioxus Signals. Call from within a component using `use_hook`.
     pub fn from_loaded_state(state: LoadedDocState) -> Self {
-        let doc = state.doc;
+        // Create buffer from the loaded doc
+        let buffer = LoroTextBuffer::from_doc(state.doc.clone(), "content");
+        let doc = buffer.doc().clone();
 
-        // Get all containers from the loaded doc
-        let content = doc.get_text("content");
+        // Get other containers from the doc
         let title = doc.get_text("title");
         let path = doc.get_text("path");
         let created_at = doc.get_text("created_at");
         let tags = doc.get_list("tags");
         let embeds = doc.get_map("embeds");
 
-        // Set up undo manager
-        let mut undo_mgr = UndoManager::new(&doc);
-        undo_mgr.set_merge_interval(300);
-        undo_mgr.set_max_undo_steps(100);
-
         // Position cursor at end of content
-        let cursor_offset = content.len_unicode();
+        let cursor_offset = weaver_editor_core::TextBuffer::len_chars(&buffer);
         let cursor_state = CursorState {
             offset: cursor_offset,
             affinity: Affinity::Before,
         };
-        let loro_cursor = content.get_cursor(cursor_offset, Side::default());
+
+        // Set up the Loro cursor
+        let buffer = buffer;
+        buffer.sync_cursor(cursor_offset);
 
         Self {
-            doc,
-            content,
+            buffer,
             title,
             path,
             created_at,
@@ -1151,28 +1035,26 @@ impl EditorDocument {
             // Use the synced version from state (tracks the PDS version vector)
             last_synced_version: Signal::new(state.synced_version),
             last_seen_diffs: Signal::new(state.last_seen_diffs),
-            undo_mgr: Rc::new(RefCell::new(undo_mgr)),
-            loro_cursor,
             cursor: Signal::new(cursor_state),
             selection: Signal::new(None),
             composition: Signal::new(None),
             composition_ended_at: Signal::new(None),
-            last_edit: Signal::new(None),
+            content_changed: Signal::new(()),
             pending_snap: Signal::new(None),
             collected_refs: Signal::new(Vec::new()),
         }
     }
 }
 
-impl PartialEq for EditorDocument {
+impl PartialEq for SignalEditorDocument {
     fn eq(&self, _other: &Self) -> bool {
-        // EditorDocument uses interior mutability, so we can't meaningfully compare.
+        // SignalEditorDocument uses interior mutability, so we can't meaningfully compare.
         // Return false to ensure components re-render when passed as props.
         false
     }
 }
 
-impl weaver_editor_crdt::CrdtDocument for EditorDocument {
+impl weaver_editor_crdt::CrdtDocument for SignalEditorDocument {
     fn export_snapshot(&self) -> Vec<u8> {
         self.export_snapshot()
     }
@@ -1191,26 +1073,72 @@ impl weaver_editor_crdt::CrdtDocument for EditorDocument {
     }
 
     fn edit_root(&self) -> Option<StrongRef<'static>> {
-        self.edit_root()
+        SignalEditorDocument::edit_root(self)
     }
 
     fn set_edit_root(&mut self, root: Option<StrongRef<'static>>) {
-        self.set_edit_root(root);
+        SignalEditorDocument::set_edit_root(self, root);
     }
 
     fn last_diff(&self) -> Option<StrongRef<'static>> {
-        self.last_diff()
+        SignalEditorDocument::last_diff(self)
     }
 
     fn set_last_diff(&mut self, diff: Option<StrongRef<'static>>) {
-        self.set_last_diff(diff);
+        SignalEditorDocument::set_last_diff(self, diff);
     }
 
     fn mark_synced(&mut self) {
-        self.mark_synced();
+        SignalEditorDocument::mark_synced(self);
     }
 
     fn has_unsynced_changes(&self) -> bool {
-        self.has_unsynced_changes()
+        SignalEditorDocument::has_unsynced_changes(self)
+    }
+}
+
+impl EditorDocument for SignalEditorDocument {
+    type Buffer = LoroTextBuffer;
+
+    fn buffer(&self) -> &Self::Buffer {
+        &self.buffer
+    }
+
+    fn buffer_mut(&mut self) -> &mut Self::Buffer {
+        &mut self.buffer
+    }
+
+    fn cursor(&self) -> CursorState {
+        *self.cursor.read()
+    }
+
+    fn set_cursor(&mut self, cursor: CursorState) {
+        self.cursor.set(cursor);
+    }
+
+    fn selection(&self) -> Option<Selection> {
+        self.selection.read().clone()
+    }
+
+    fn set_selection(&mut self, selection: Option<Selection>) {
+        self.selection.set(selection);
+    }
+
+    fn last_edit(&self) -> Option<EditInfo> {
+        self.buffer.last_edit()
+    }
+
+    fn set_last_edit(&mut self, _edit: Option<EditInfo>) {
+        // Buffer tracks edit info internally. We use this hook to
+        // bump content_changed for reactive re-rendering.
+        self.content_changed.set(());
+    }
+
+    fn composition(&self) -> Option<CompositionState> {
+        self.composition.read().clone()
+    }
+
+    fn set_composition(&mut self, composition: Option<CompositionState>) {
+        self.composition.set(composition);
     }
 }
diff --git a/crates/weaver-app/src/components/editor/dom_sync.rs b/crates/weaver-app/src/components/editor/dom_sync.rs
index 5ec1794..8f3dc1d 100644
--- a/crates/weaver-app/src/components/editor/dom_sync.rs
+++ b/crates/weaver-app/src/components/editor/dom_sync.rs
@@ -8,7 +8,9 @@
 #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
 use super::cursor::restore_cursor_position;
 #[allow(unused_imports)]
-use super::document::{EditorDocument, Selection};
+use super::document::Selection;
+#[allow(unused_imports)]
+use super::document::SignalEditorDocument;
 use super::paragraph::ParagraphRender;
 #[allow(unused_imports)]
 use dioxus::prelude::*;
@@ -25,7 +27,7 @@ pub use weaver_editor_browser::dom_position_to_text_offset;
 /// Pass `SnapDirection::Backward` for left/up arrow keys, `SnapDirection::Forward` for right/down.
 #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
 pub fn sync_cursor_from_dom(
-    doc: &mut EditorDocument,
+    doc: &mut SignalEditorDocument,
     editor_id: &str,
     paragraphs: &[ParagraphRender],
 ) {
@@ -37,7 +39,7 @@ pub fn sync_cursor_from_dom(
 /// Use this when handling arrow keys to ensure cursor snaps in the expected direction.
 #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
 pub fn sync_cursor_from_dom_with_direction(
-    doc: &mut EditorDocument,
+    doc: &mut SignalEditorDocument,
     editor_id: &str,
     paragraphs: &[ParagraphRender],
     direction_hint: Option<SnapDirection>,
@@ -133,7 +135,7 @@ pub fn sync_cursor_from_dom_with_direction(
 
 #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
 pub fn sync_cursor_from_dom(
-    _document: &mut EditorDocument,
+    _document: &mut SignalEditorDocument,
     _editor_id: &str,
     _paragraphs: &[ParagraphRender],
 ) {
@@ -141,7 +143,7 @@ pub fn sync_cursor_from_dom(
 
 #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
 pub fn sync_cursor_from_dom_with_direction(
-    _document: &mut EditorDocument,
+    _document: &mut SignalEditorDocument,
     _editor_id: &str,
     _paragraphs: &[ParagraphRender],
     _direction_hint: Option<SnapDirection>,
@@ -332,11 +334,9 @@ pub fn update_paragraph_dom(
                     if is_cursor_para {
                         // Restore cursor synchronously - don't wait for rAF
                         // This prevents race conditions with fast typing
-                        if let Err(e) = restore_cursor_position(
-                            cursor_offset,
-                            &new_para.offset_map,
-                            None,
-                        ) {
+                        if let Err(e) =
+                            restore_cursor_position(cursor_offset, &new_para.offset_map, None)
+                        {
                             tracing::warn!("Synchronous cursor restore failed: {:?}", e);
                         }
                         cursor_para_updated = true;
diff --git a/crates/weaver-app/src/components/editor/formatting.rs b/crates/weaver-app/src/components/editor/formatting.rs
index 338c632..bf7525c 100644
--- a/crates/weaver-app/src/components/editor/formatting.rs
+++ b/crates/weaver-app/src/components/editor/formatting.rs
@@ -1,6 +1,7 @@
 //! Formatting actions and utilities for applying markdown formatting.
 
-use super::document::EditorDocument;
+use crate::components::editor::SignalEditorDocument;
+
 #[allow(unused_imports)]
 use super::input::{ListContext, detect_list_context, find_line_end};
 use dioxus::prelude::*;
@@ -47,7 +48,7 @@ pub fn find_word_boundaries(text: &loro::LoroText, offset: usize) -> (usize, usi
 /// Apply formatting to document.
 ///
 /// If there's a selection, wrap it. Otherwise, expand to word boundaries and wrap.
-pub fn apply_formatting(doc: &mut EditorDocument, action: FormatAction) {
+pub fn apply_formatting(doc: &mut SignalEditorDocument, action: FormatAction) {
     let cursor_offset = doc.cursor.read().offset;
     let (start, end) = if let Some(sel) = *doc.selection.read() {
         // Use selection
diff --git a/crates/weaver-app/src/components/editor/input.rs b/crates/weaver-app/src/components/editor/input.rs
index 19f7ab6..b2953ed 100644
--- a/crates/weaver-app/src/components/editor/input.rs
+++ b/crates/weaver-app/src/components/editor/input.rs
@@ -4,7 +4,7 @@
 
 use dioxus::prelude::*;
 
-use super::document::EditorDocument;
+use super::document::SignalEditorDocument;
 use super::formatting::{self, FormatAction};
 use weaver_editor_core::SnapDirection;
 
@@ -52,7 +52,7 @@ pub fn should_intercept_key(evt: &Event<KeyboardData>) -> bool {
 
 /// Handle keyboard events and update document state.
 #[allow(unused)]
-pub fn handle_keydown(evt: Event<KeyboardData>, doc: &mut EditorDocument) {
+pub fn handle_keydown(evt: Event<KeyboardData>, doc: &mut SignalEditorDocument) {
     use dioxus::prelude::keyboard_types::Key;
 
     let key = evt.key();
@@ -326,18 +326,13 @@ pub fn handle_keydown(evt: Event<KeyboardData>, doc: &mut EditorDocument) {
 
     // Sync Loro cursor when edits affect paragraph boundaries
     // This ensures cursor position is tracked correctly through structural changes
-    if doc
-        .last_edit
-        .read()
-        .as_ref()
-        .is_some_and(|e| e.contains_newline)
-    {
+    if doc.last_edit().is_some_and(|e| e.contains_newline) {
         doc.sync_loro_cursor();
     }
 }
 
 /// Handle paste events and insert text at cursor.
-pub fn handle_paste(evt: Event<ClipboardData>, doc: &mut EditorDocument) {
+pub fn handle_paste(evt: Event<ClipboardData>, doc: &mut SignalEditorDocument) {
     evt.prevent_default();
     #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
     let _ = doc;
@@ -379,7 +374,7 @@ pub fn handle_paste(evt: Event<ClipboardData>, doc: &mut EditorDocument) {
 }
 
 /// Handle cut events - extract text, write to clipboard, then delete.
-pub fn handle_cut(evt: Event<ClipboardData>, doc: &mut EditorDocument) {
+pub fn handle_cut(evt: Event<ClipboardData>, doc: &mut SignalEditorDocument) {
     evt.prevent_default();
     #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
     let _ = doc;
@@ -440,7 +435,7 @@ pub fn handle_cut(evt: Event<ClipboardData>, doc: &mut EditorDocument) {
 }
 
 /// Handle copy events - extract text, clean it up, write to clipboard.
-pub fn handle_copy(evt: Event<ClipboardData>, doc: &EditorDocument) {
+pub fn handle_copy(evt: Event<ClipboardData>, doc: &SignalEditorDocument) {
     #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
     {
         use dioxus::web::WebEventExt;
diff --git a/crates/weaver-app/src/components/editor/mod.rs b/crates/weaver-app/src/components/editor/mod.rs
index 56c48a1..1200f91 100644
--- a/crates/weaver-app/src/components/editor/mod.rs
+++ b/crates/weaver-app/src/components/editor/mod.rs
@@ -44,7 +44,7 @@ pub use component::MarkdownEditor;
 // Document types
 #[allow(unused_imports)]
 pub use document::{
-    Affinity, CompositionState, CursorState, EditorDocument, LoadedDocState, Selection,
+    Affinity, CompositionState, CursorState, LoadedDocState, Selection, SignalEditorDocument,
 };
 
 // Formatting
diff --git a/crates/weaver-app/src/components/editor/publish.rs b/crates/weaver-app/src/components/editor/publish.rs
index 16eae86..5763376 100644
--- a/crates/weaver-app/src/components/editor/publish.rs
+++ b/crates/weaver-app/src/components/editor/publish.rs
@@ -55,9 +55,9 @@ fn rewrite_draft_paths_for_notebook(content: &str, notebook_key: &str) -> String
 }
 
 use crate::auth::AuthState;
+use crate::components::editor::SignalEditorDocument;
 use crate::fetch::Fetcher;
 
-use super::document::EditorDocument;
 use super::storage::{delete_draft, save_to_storage};
 
 /// Result of a publish operation.
@@ -161,7 +161,7 @@ pub async fn load_entry_for_editing(
 /// On successful create, sets `doc.entry_uri` so subsequent publishes update the same record.
 pub async fn publish_entry(
     fetcher: &Fetcher,
-    doc: &mut EditorDocument,
+    doc: &mut SignalEditorDocument,
     notebook_title: Option<&str>,
     draft_key: &str,
 ) -> Result<PublishResult, WeaverError> {
@@ -484,7 +484,7 @@ fn slugify(title: &str) -> String {
 #[derive(Props, Clone, PartialEq)]
 pub struct PublishButtonProps {
     /// The editor document
-    pub document: EditorDocument,
+    pub document: SignalEditorDocument,
     /// Storage key for the draft
     pub draft_key: String,
     /// Pre-selected notebook (from URL param)
diff --git a/crates/weaver-app/src/components/editor/render.rs b/crates/weaver-app/src/components/editor/render.rs
index 14b3bd2..d69d1b1 100644
--- a/crates/weaver-app/src/components/editor/render.rs
+++ b/crates/weaver-app/src/components/editor/render.rs
@@ -3,78 +3,23 @@
 //! Phase 2: Paragraph-level incremental rendering with formatting characters visible.
 //!
 //! This module provides a thin wrapper around the core rendering logic,
-//! adapting it to LoroText and adding app-specific features like timing.
+//! adding app-specific features like timing instrumentation.
 
 use super::paragraph::ParagraphRender;
 use super::writer::embed::EditorImageResolver;
-use loro::LoroText;
 use weaver_common::{EntryIndex, ResolvedContent};
-use weaver_editor_core::{EditInfo, SmolStr, TextBuffer};
+use weaver_editor_core::{EditInfo, TextBuffer};
 
 // Re-export core types.
 pub use weaver_editor_core::RenderCache;
 
-/// Adapter to make LoroText implement TextBuffer-like interface for core.
-/// temporary until weaver-editor-crdt crate complete
-struct LoroTextAdapter<'a>(&'a LoroText);
-
-impl TextBuffer for LoroTextAdapter<'_> {
-    fn len_chars(&self) -> usize {
-        self.0.len_unicode()
-    }
-
-    fn len_bytes(&self) -> usize {
-        self.0.len_utf8()
-    }
-
-    fn slice(&self, range: std::ops::Range<usize>) -> Option<SmolStr> {
-        self.0
-            .slice(range.start, range.end)
-            .ok()
-            .map(|s| SmolStr::new(&s))
-    }
-
-    fn char_at(&self, offset: usize) -> Option<char> {
-        self.0
-            .slice(offset, offset + 1)
-            .ok()
-            .and_then(|s| s.chars().next())
-    }
-
-    fn char_to_byte(&self, char_offset: usize) -> usize {
-        // LoroText doesn't expose this directly, so we compute it.
-        let slice = self.0.slice(0, char_offset).unwrap_or_default();
-        slice.len()
-    }
-
-    fn byte_to_char(&self, byte_offset: usize) -> usize {
-        // LoroText doesn't expose this directly, so we compute it.
-        let full = self.0.to_string();
-        full[..byte_offset.min(full.len())].chars().count()
-    }
-
-    fn insert(&mut self, _offset: usize, _text: &str) {
-        // Read-only adapter - this should never be called during rendering.
-        panic!("LoroTextAdapter is read-only");
-    }
-
-    fn delete(&mut self, _range: std::ops::Range<usize>) {
-        // Read-only adapter - this should never be called during rendering.
-        panic!("LoroTextAdapter is read-only");
-    }
-
-    fn to_string(&self) -> String {
-        self.0.to_string()
-    }
-}
-
 /// Render markdown with incremental caching.
 ///
 /// Uses cached paragraph renders when possible, only re-rendering changed paragraphs.
 /// This is a thin wrapper around the core rendering logic that adds timing.
 ///
 /// # Parameters
-/// - `text`: The LoroText to render
+/// - `text`: Any TextBuffer implementation (LoroTextBuffer, EditorRope, etc.)
 /// - `cache`: Optional previous render cache
 /// - `cursor_offset`: Current cursor position
 /// - `edit`: Edit info for stable ID assignment
@@ -84,8 +29,8 @@ impl TextBuffer for LoroTextAdapter<'_> {
 ///
 /// # Returns
 /// (paragraphs, cache, collected_refs) - collected_refs contains wikilinks and AT embeds found during render
-pub fn render_paragraphs_incremental(
-    text: &LoroText,
+pub fn render_paragraphs_incremental<T: TextBuffer>(
+    text: &T,
     cache: Option<&RenderCache>,
     cursor_offset: usize,
     edit: Option<&EditInfo>,
@@ -99,12 +44,8 @@ pub fn render_paragraphs_incremental(
 ) {
     let fn_start = crate::perf::now();
 
-    // Create adapter for LoroText to use with core rendering.
-    let adapter = LoroTextAdapter(text);
-
-    // Call the core rendering function.
     let result = weaver_editor_core::render_paragraphs_incremental(
-        &adapter,
+        text,
         cache,
         cursor_offset,
         edit,
diff --git a/crates/weaver-app/src/components/editor/storage.rs b/crates/weaver-app/src/components/editor/storage.rs
index bf5080e..144f905 100644
--- a/crates/weaver-app/src/components/editor/storage.rs
+++ b/crates/weaver-app/src/components/editor/storage.rs
@@ -29,7 +29,7 @@ use loro::cursor::Cursor;
 use serde::{Deserialize, Serialize};
 use weaver_api::com_atproto::repo::strong_ref::StrongRef;
 
-use super::document::EditorDocument;
+use super::document::SignalEditorDocument;
 
 /// Prefix for all draft storage keys.
 pub const DRAFT_KEY_PREFIX: &str = "weaver_draft:";
@@ -89,7 +89,7 @@ fn storage_key(key: &str) -> String {
 /// Save editor state to LocalStorage (WASM only).
 #[cfg(all(target_family = "wasm", target_os = "unknown"))]
 pub fn save_to_storage(
-    doc: &EditorDocument,
+    doc: &SignalEditorDocument,
     key: &str,
 ) -> Result<(), gloo_storage::errors::StorageError> {
     let export_start = crate::perf::now();
@@ -108,7 +108,7 @@ pub fn save_to_storage(
         content: doc.content(),
         title: doc.title().into(),
         snapshot: snapshot_b64,
-        cursor: doc.loro_cursor().cloned(),
+        cursor: doc.loro_cursor(),
         cursor_offset: doc.cursor.read().offset,
         editing_uri: doc.entry_ref().map(|r| r.uri.to_smolstr()),
         editing_cid: doc.entry_ref().map(|r| r.cid.to_smolstr()),
@@ -132,10 +132,10 @@ pub fn save_to_storage(
 
 /// Load editor state from LocalStorage (WASM only).
 ///
-/// Returns an EditorDocument restored from CRDT snapshot if available,
+/// Returns an SignalEditorDocument restored from CRDT snapshot if available,
 /// otherwise falls back to just the text content.
 #[cfg(all(target_family = "wasm", target_os = "unknown"))]
-pub fn load_from_storage(key: &str) -> Option<EditorDocument> {
+pub fn load_from_storage(key: &str) -> Option<SignalEditorDocument> {
     let snapshot: EditorSnapshot = LocalStorage::get(storage_key(key)).ok()?;
 
     // Parse entry_ref from the snapshot (requires both URI and CID)
@@ -152,7 +152,7 @@ pub fn load_from_storage(key: &str) -> Option<EditorDocument> {
     // Try to restore from CRDT snapshot first
     if let Some(ref snapshot_b64) = snapshot.snapshot {
         if let Ok(snapshot_bytes) = BASE64.decode(snapshot_b64) {
-            let mut doc = EditorDocument::from_snapshot(
+            let mut doc = SignalEditorDocument::from_snapshot(
                 &snapshot_bytes,
                 snapshot.cursor.clone(),
                 snapshot.cursor_offset,
@@ -170,7 +170,7 @@ pub fn load_from_storage(key: &str) -> Option<EditorDocument> {
     }
 
     // Fallback: create new doc from text content
-    let mut doc = EditorDocument::new(snapshot.content);
+    let mut doc = SignalEditorDocument::new(snapshot.content);
     doc.cursor.write().offset = snapshot.cursor_offset.min(doc.len_chars());
     doc.sync_loro_cursor();
     doc.set_entry_ref(entry_ref);
@@ -192,7 +192,7 @@ pub struct LocalSnapshotData {
 
 /// Load snapshot data from LocalStorage (WASM only).
 ///
-/// Unlike `load_from_storage`, this doesn't create an EditorDocument and is safe
+/// Unlike `load_from_storage`, this doesn't create an SignalEditorDocument and is safe
 /// to call outside of reactive context. Use with `load_and_merge_document`.
 #[cfg(all(target_family = "wasm", target_os = "unknown"))]
 pub fn load_snapshot_from_storage(key: &str) -> Option<LocalSnapshotData> {
@@ -344,12 +344,12 @@ pub fn clear_all_drafts() {
 
 // Stub implementations for non-WASM targets
 #[cfg(not(all(target_family = "wasm", target_os = "unknown")))]
-pub fn save_to_storage(_doc: &EditorDocument, _key: &str) -> Result<(), String> {
+pub fn save_to_storage(_doc: &SignalEditorDocument, _key: &str) -> Result<(), String> {
     Ok(())
 }
 
 #[cfg(not(all(target_family = "wasm", target_os = "unknown")))]
-pub fn load_from_storage(_key: &str) -> Option<EditorDocument> {
+pub fn load_from_storage(_key: &str) -> Option<SignalEditorDocument> {
     None
 }
 
diff --git a/crates/weaver-app/src/components/editor/sync.rs b/crates/weaver-app/src/components/editor/sync.rs
index 518d4c2..5b6d7b1 100644
--- a/crates/weaver-app/src/components/editor/sync.rs
+++ b/crates/weaver-app/src/components/editor/sync.rs
@@ -9,7 +9,7 @@
 
 use std::collections::HashMap;
 
-use super::document::{EditorDocument, LoadedDocState};
+use super::document::{LoadedDocState, SignalEditorDocument};
 use crate::fetch::Fetcher;
 use jacquard::IntoStatic;
 use jacquard::prelude::*;
@@ -214,7 +214,7 @@ pub async fn list_drafts_from_pds(fetcher: &Fetcher) -> Result<Vec<RemoteDraft>,
 /// Wraps the crdt crate's create_edit_root with Fetcher support.
 pub async fn create_edit_root(
     fetcher: &Fetcher,
-    doc: &EditorDocument,
+    doc: &SignalEditorDocument,
     draft_key: &str,
     entry_uri: Option<&AtUri<'_>>,
     entry_cid: Option<&Cid<'_>>,
@@ -235,7 +235,7 @@ pub async fn create_edit_root(
 /// Wraps the crdt crate's create_diff with Fetcher support.
 pub async fn create_diff(
     fetcher: &Fetcher,
-    doc: &EditorDocument,
+    doc: &SignalEditorDocument,
     root_uri: &AtUri<'_>,
     root_cid: &Cid<'_>,
     prev_diff: Option<(&AtUri<'_>, &Cid<'_>)>,
@@ -264,7 +264,7 @@ pub async fn create_diff(
 /// Updates the document's sync state on success.
 pub async fn sync_to_pds(
     fetcher: &Fetcher,
-    doc: &mut EditorDocument,
+    doc: &mut SignalEditorDocument,
     draft_key: &str,
 ) -> Result<SyncResult, WeaverError> {
     let fn_start = crate::perf::now();
@@ -415,7 +415,7 @@ pub async fn load_all_edit_states_from_pds(
 ///
 /// Loads from localStorage and PDS (if available), then merges both using Loro's
 /// CRDT merge. The result is a pre-merged LoroDoc that can be converted to an
-/// EditorDocument inside a reactive context using `use_hook`.
+/// SignalEditorDocument inside a reactive context using `use_hook`.
 ///
 /// For unpublished drafts, attempts to discover edit state via Constellation
 /// using the synthetic draft URI.
@@ -603,7 +603,7 @@ pub enum SyncState {
 #[derive(Props, Clone, PartialEq)]
 pub struct SyncStatusProps {
     /// The editor document to sync
-    pub document: EditorDocument,
+    pub document: SignalEditorDocument,
     /// Draft key for this document
     pub draft_key: String,
     /// Auto-sync interval in milliseconds (0 to disable, default disabled)
@@ -707,8 +707,8 @@ pub fn SyncStatus(props: SyncStatusProps) -> Element {
     // Note: We use peek() to avoid creating a reactive dependency on sync_state
     let doc_for_effect = doc.clone();
     use_effect(move || {
-        // Check for unsynced changes (reads last_edit signal for reactivity)
-        let _edit = doc_for_effect.last_edit();
+        // Read content_changed to create reactive dependency on document changes
+        let _ = doc_for_effect.content_changed.read();
 
         // Use peek to avoid reactive loop
         let current_state = *sync_state.peek();
diff --git a/crates/weaver-app/src/components/editor/tests.rs b/crates/weaver-app/src/components/editor/tests.rs
index 081735a..fb80ff2 100644
--- a/crates/weaver-app/src/components/editor/tests.rs
+++ b/crates/weaver-app/src/components/editor/tests.rs
@@ -1,11 +1,11 @@
 //! Snapshot tests for the markdown editor rendering pipeline.
 
-use weaver_editor_core::{OffsetMapping, find_mapping_for_char};
 use super::paragraph::ParagraphRender;
 use super::render::render_paragraphs_incremental;
-use loro::LoroDoc;
 use serde::Serialize;
 use weaver_common::ResolvedContent;
+use weaver_editor_core::{OffsetMapping, TextBuffer, find_mapping_for_char};
+use weaver_editor_crdt::LoroTextBuffer;
 
 /// Serializable version of ParagraphRender for snapshot testing.
 #[derive(Debug, Serialize)]
@@ -55,11 +55,10 @@ impl From<&OffsetMapping> for TestOffsetMapping {
 
 /// Helper: render markdown and convert to serializable test output.
 fn render_test(input: &str) -> Vec<TestParagraph> {
-    let doc = LoroDoc::new();
-    let text = doc.get_text("content");
-    text.insert(0, input).unwrap();
+    let mut buffer = LoroTextBuffer::new();
+    buffer.insert(0, input);
     let (paragraphs, _cache, _refs) =
-        render_paragraphs_incremental(&text, None, 0, None, None, None, &ResolvedContent::default());
+        render_paragraphs_incremental(&buffer, None, 0, None, None, None, &ResolvedContent::default());
     paragraphs.iter().map(TestParagraph::from).collect()
 }
 
@@ -640,15 +639,13 @@ fn test_heading_to_non_heading_transition() {
     // Simulates typing: start with "#" (heading), then add "t" to make "#t" (not heading)
     // This tests that the syntax spans are correctly updated on content change.
     use super::render::render_paragraphs_incremental;
-    use loro::LoroDoc;
 
-    let doc = LoroDoc::new();
-    let text = doc.get_text("content");
+    let mut buffer = LoroTextBuffer::new();
 
     // Initial state: "#" is a valid empty heading
-    text.insert(0, "#").unwrap();
+    buffer.insert(0, "#");
     let (paras1, cache1, _refs1) =
-        render_paragraphs_incremental(&text, None, 0, None, None, None, &ResolvedContent::default());
+        render_paragraphs_incremental(&buffer, None, 0, None, None, None, &ResolvedContent::default());
 
     eprintln!("State 1 ('#'): {}", paras1[0].html);
     assert!(paras1[0].html.contains("<h1"), "# alone should be heading");
@@ -658,9 +655,9 @@ fn test_heading_to_non_heading_transition() {
     );
 
     // Transition: add "t" to make "#t" - no longer a heading
-    text.insert(1, "t").unwrap();
+    buffer.insert(1, "t");
     let (paras2, _cache2, _refs2) = render_paragraphs_incremental(
-        &text,
+        &buffer,
         Some(&cache1),
         0,
         None,
@@ -773,11 +770,10 @@ fn test_char_range_coverage_allows_paragraph_breaks() {
     // cursor snaps to adjacent paragraphs for standard breaks.
     // Only EXTRA whitespace beyond \n\n gets gap elements.
     let input = "Hello\n\nWorld";
-    let doc = LoroDoc::new();
-    let text = doc.get_text("content");
-    text.insert(0, input).unwrap();
+    let mut buffer = LoroTextBuffer::new();
+    buffer.insert(0, input);
     let (paragraphs, _cache, _refs) =
-        render_paragraphs_incremental(&text, None, 0, None, None, None, &ResolvedContent::default());
+        render_paragraphs_incremental(&buffer, None, 0, None, None, None, &ResolvedContent::default());
 
     // With standard \n\n break, we expect 2 paragraphs (no gap element)
     // Paragraph ranges include some trailing whitespace from markdown parsing
@@ -803,11 +799,10 @@ fn test_char_range_coverage_with_extra_whitespace() {
     // Extra whitespace beyond MIN_PARAGRAPH_BREAK (2) gets gap elements
     // Plain paragraphs don't consume trailing newlines like headings do
     let input = "Hello\n\n\n\nWorld"; // 4 newlines = gap of 4 > 2
-    let doc = LoroDoc::new();
-    let text = doc.get_text("content");
-    text.insert(0, input).unwrap();
+    let mut buffer = LoroTextBuffer::new();
+    buffer.insert(0, input);
     let (paragraphs, _cache, _refs) =
-        render_paragraphs_incremental(&text, None, 0, None, None, None, &ResolvedContent::default());
+        render_paragraphs_incremental(&buffer, None, 0, None, None, None, &ResolvedContent::default());
 
     // With extra newlines, we expect 3 elements: para, gap, para
     assert_eq!(
@@ -903,17 +898,16 @@ fn test_offset_mappings_reference_own_paragraph() {
 fn test_incremental_cache_reuse() {
     // Verify cache is populated and can be reused
     let input = "First para\n\nSecond para";
-    let doc = LoroDoc::new();
-    let text = doc.get_text("content");
-    text.insert(0, input).unwrap();
+    let mut buffer = LoroTextBuffer::new();
+    buffer.insert(0, input);
 
     let (paras1, cache1, _refs1) =
-        render_paragraphs_incremental(&text, None, 0, None, None, None, &ResolvedContent::default());
+        render_paragraphs_incremental(&buffer, None, 0, None, None, None, &ResolvedContent::default());
     assert!(!cache1.paragraphs.is_empty(), "Cache should be populated");
 
     // Second render with same content should reuse cache
     let (paras2, _cache2, _refs2) = render_paragraphs_incremental(
-        &text,
+        &buffer,
         Some(&cache1),
         0,
         None,
diff --git a/crates/weaver-editor-crdt/src/buffer.rs b/crates/weaver-editor-crdt/src/buffer.rs
index 65438a4..4560e0d 100644
--- a/crates/weaver-editor-crdt/src/buffer.rs
+++ b/crates/weaver-editor-crdt/src/buffer.rs
@@ -227,6 +227,31 @@ impl TextBuffer for LoroTextBuffer {
         });
     }
 
+    fn replace(&mut self, char_range: Range<usize>, text: &str) {
+        let in_block_syntax_zone = self.is_in_block_syntax_zone(char_range.start);
+        let delete_has_newline = self
+            .slice(char_range.clone())
+            .map(|s| s.contains('\n'))
+            .unwrap_or(false);
+        let deleted_len = char_range.len();
+        let inserted_len = text.chars().count();
+
+        // Use Loro's atomic splice operation
+        self.content
+            .splice(char_range.start, deleted_len, text)
+            .ok();
+
+        self.inner.borrow_mut().last_edit = Some(EditInfo {
+            edit_char_pos: char_range.start,
+            inserted_len,
+            deleted_len,
+            contains_newline: delete_has_newline || text.contains('\n'),
+            in_block_syntax_zone,
+            doc_len_after: self.content.len_unicode(),
+            timestamp: Instant::now(),
+        });
+    }
+
     fn slice(&self, char_range: Range<usize>) -> Option<SmolStr> {
         if char_range.end > self.content.len_unicode() {
             return None;
diff --git a/docs/graph-data.json b/docs/graph-data.json
index 1839841..8c96b4c 100644
--- a/docs/graph-data.json
+++ b/docs/graph-data.json
@@ -1781,6 +1781,50 @@
       "created_at": "2026-01-06T15:54:32.396727943-05:00",
       "updated_at": "2026-01-06T15:54:32.396727943-05:00",
       "metadata_json": "{\"confidence\":95}"
+    },
+    {
+      "id": 164,
+      "change_id": "9f555968-9c6c-4db6-bda1-6223c92acbec",
+      "node_type": "goal",
+      "title": "Refactor EditorDocument to wrap LoroTextBuffer and impl TextBuffer+UndoManager",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T16:00:43.381698744-05:00",
+      "updated_at": "2026-01-06T16:00:43.381698744-05:00",
+      "metadata_json": "{\"confidence\":90,\"prompt\":\"User: refactor EditorDocument struct (rename it) to wrap LoroTextBuffer and implement EditorDocument trait. Replace EditInfo signal with Signal<()>. Migrate callers to trait methods. Remove LoroTextAdapter later.\"}"
+    },
+    {
+      "id": 165,
+      "change_id": "aded9525-4d0b-426a-a86a-39e28635dbbf",
+      "node_type": "action",
+      "title": "Analyze EditorDocument refactor scope",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T16:01:15.257884614-05:00",
+      "updated_at": "2026-01-06T16:01:15.257884614-05:00",
+      "metadata_json": "{\"confidence\":95}"
+    },
+    {
+      "id": 166,
+      "change_id": "8d2c762d-490e-4783-bb9e-ebcfa32f7be0",
+      "node_type": "action",
+      "title": "Rename EditorDocument to SignalEditorDocument and wrap LoroTextBuffer",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T16:01:49.255692341-05:00",
+      "updated_at": "2026-01-06T16:01:49.255692341-05:00",
+      "metadata_json": "{\"confidence\":90}"
+    },
+    {
+      "id": 167,
+      "change_id": "8921c6ea-9bf0-4c2a-8b1e-02fd290dde68",
+      "node_type": "outcome",
+      "title": "SignalEditorDocument refactor compiles - wraps LoroTextBuffer, uses content_changed signal",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T16:13:31.725544621-05:00",
+      "updated_at": "2026-01-06T16:13:31.725544621-05:00",
+      "metadata_json": "{\"confidence\":95}"
     }
   ],
   "edges": [
@@ -3620,6 +3664,39 @@
       "weight": 1.0,
       "rationale": "Refactoring complete with tests",
       "created_at": "2026-01-06T15:54:32.412922730-05:00"
+    },
+    {
+      "id": 169,
+      "from_node_id": 164,
+      "to_node_id": 165,
+      "from_change_id": "9f555968-9c6c-4db6-bda1-6223c92acbec",
+      "to_change_id": "aded9525-4d0b-426a-a86a-39e28635dbbf",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "Analysis step of refactor goal",
+      "created_at": "2026-01-06T16:01:15.381825313-05:00"
+    },
+    {
+      "id": 170,
+      "from_node_id": 165,
+      "to_node_id": 166,
+      "from_change_id": "aded9525-4d0b-426a-a86a-39e28635dbbf",
+      "to_change_id": "8d2c762d-490e-4783-bb9e-ebcfa32f7be0",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "Analysis complete, starting implementation",
+      "created_at": "2026-01-06T16:01:53.140032559-05:00"
+    },
+    {
+      "id": 171,
+      "from_node_id": 166,
+      "to_node_id": 167,
+      "from_change_id": "8d2c762d-490e-4783-bb9e-ebcfa32f7be0",
+      "to_change_id": "8921c6ea-9bf0-4c2a-8b1e-02fd290dde68",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "Refactor implementation complete",
+      "created_at": "2026-01-06T16:13:31.873150501-05:00"
     }
   ]
 }
\ No newline at end of file