From 434201c657d54d69360c4576fe64bf37e4797c53 Mon Sep 17 00:00:00 2001
From: Niko PLP <niko@nextgraph.org>
Date: Mon, 5 Aug 2024 00:27:20 +0300
Subject: [PATCH] discrete doc: Codemirror+Yjs

---
 Cargo.lock                              |   4 +-
 ng-app/package.json                     |   5 +-
 ng-app/src/api.ts                       |   7 +
 ng-app/src/apps/CodeMirrorEditor.svelte |  72 +++++++++++
 ng-app/src/apps/ContainerView.svelte    |   1 -
 ng-app/src/apps/PreTextViewer.svelte    |   0
 ng-app/src/lib/Document.svelte          |   3 +-
 ng-app/src/lib/FullLayout.svelte        |   4 +-
 ng-app/src/lib/components/NavBar.svelte |  19 +--
 ng-app/src/routes/NURI.svelte           |   5 +-
 ng-app/src/store.ts                     |  34 ++++-
 ng-app/src/tab.ts                       |  50 ++++++--
 ng-app/src/zeras.ts                     |   2 +-
 ng-net/src/app_protocol.rs              |  72 +++++++++--
 ng-repo/src/errors.rs                   |   3 +
 ng-repo/src/types.rs                    |   6 +
 ng-sdk-js/src/lib.rs                    |  43 +++++++
 ng-verifier/Cargo.toml                  |   2 +-
 ng-verifier/src/commits/mod.rs          |   2 +
 ng-verifier/src/commits/transaction.rs  | 164 +++++++++++++++++-------
 ng-verifier/src/request_processor.rs    |  69 +++++++++-
 ng-verifier/src/rocksdb_user_storage.rs |  16 +++
 ng-verifier/src/types.rs                |  71 +++++++++-
 ng-verifier/src/user_storage/branch.rs  |  24 +++-
 ng-verifier/src/user_storage/storage.rs |  29 +++++
 ng-verifier/src/verifier.rs             |  29 ++++-
 pnpm-lock.yaml                          |  58 +++++++++
 27 files changed, 702 insertions(+), 92 deletions(-)
 create mode 100644 ng-app/src/apps/CodeMirrorEditor.svelte
 create mode 100644 ng-app/src/apps/PreTextViewer.svelte

diff --git a/Cargo.lock b/Cargo.lock
index 6deb20d..a327cd0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7216,9 +7216,9 @@ dependencies = [
 
 [[package]]
 name = "yrs"
-version = "0.18.2"
+version = "0.19.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4058d69bbbc97181d53d9d093a4b892001b84601f2fc4e27f48c8862bc8b369"
+checksum = "a8ca5126331b9a5ef5bb10f3f1c3d01b05f298d348c66f8fb15497d83ee73176"
 dependencies = [
  "arc-swap",
  "atomic_refcell",
diff --git a/ng-app/package.json b/ng-app/package.json
index e0fcff2..f461975 100644
--- a/ng-app/package.json
+++ b/ng-app/package.json
@@ -18,6 +18,7 @@
   "dependencies": {
     "@codemirror/autocomplete": "^6.17.0",
     "@codemirror/commands": "^6.6.0",
+    "@codemirror/lang-javascript": "^6.2.2",
     "@codemirror/language": "^6.10.2",
     "@codemirror/legacy-modes": "^6.4.0",
     "@codemirror/lint": "^6.8.1",
@@ -39,7 +40,9 @@
     "svelte-i18n": "^4.0.0",
     "svelte-inview": "^4.0.2",
     "svelte-spa-router": "^3.3.0",
-    "vite-plugin-top-level-await": "^1.3.1"
+    "vite-plugin-top-level-await": "^1.3.1",
+    "y-codemirror.next": "^0.3.5",
+    "yjs": "^13.6.18"
   },
   "devDependencies": {
     "@sveltejs/vite-plugin-svelte": "^2.0.0",
diff --git a/ng-app/src/api.ts b/ng-app/src/api.ts
index 5d582d0..36350cd 100644
--- a/ng-app/src/api.ts
+++ b/ng-app/src/api.ts
@@ -222,6 +222,13 @@ const handler = {
                         let removes_json_str = new TextDecoder().decode(Uint8Array.from(event.payload.V0.Patch.graph.removes));
                         event.payload.V0.Patch.graph.removes = JSON.parse(removes_json_str);
                     }
+                    if (event.payload.V0.State?.discrete) {
+                        let crdt = Object.getOwnPropertyNames(event.payload.V0.State.discrete)[0];
+                        event.payload.V0.State.discrete[crdt] = Uint8Array.from(event.payload.V0.State.discrete[crdt]);
+                    } else if (event.payload.V0.Patch?.discrete) { 
+                        let crdt = Object.getOwnPropertyNames(event.payload.V0.Patch.discrete)[0];
+                        event.payload.V0.Patch.discrete[crdt] = Uint8Array.from(event.payload.V0.Patch.discrete[crdt]);
+                    }
                     let ret = callback(event.payload);
                     if (ret === true) {
                         await tauri.invoke("cancel_stream", {stream_id});
diff --git a/ng-app/src/apps/CodeMirrorEditor.svelte b/ng-app/src/apps/CodeMirrorEditor.svelte
new file mode 100644
index 0000000..ad690f2
--- /dev/null
+++ b/ng-app/src/apps/CodeMirrorEditor.svelte
@@ -0,0 +1,72 @@
+<!--
+// Copyright (c) 2022-2024 Niko Bonnieure, Par le Peuple, NextGraph.org developers
+// All rights reserved.
+// Licensed under the Apache License, Version 2.0
+// <LICENSE-APACHE2 or http://www.apache.org/licenses/LICENSE-2.0>
+// or the MIT license <LICENSE-MIT or http://opensource.org/licenses/MIT>,
+// at your option. All files in the project carrying such
+// notice may not be copied, modified, or distributed except
+// according to those terms.
+-->
+
+<script lang="ts">
+    import { onMount, tick, onDestroy } from "svelte";
+    import { 
+      sparql_query,
+      toast_error,
+      toast_success,
+      reset_toasts,
+      display_error,
+      live_discrete_update
+    } from "../store";
+    
+    import * as Y from 'yjs'
+    // @ts-ignore
+    import { yCollab } from 'y-codemirror.next'
+
+    import CodeMirror from "svelte-codemirror-editor";
+    import { javascript } from '@codemirror/lang-javascript'
+    import {basicSetup} from "codemirror"
+
+    export let commits = {};
+
+    const ydoc = new Y.Doc()
+    const ytext = ydoc.getText('ng')
+
+    ydoc.on('update', async (update, origin) => {
+      if (!origin.local) {
+        try {
+            await live_discrete_update(update, "YText", commits.heads);
+        } catch (e){
+            toast_error(display_error(e));
+        }
+      }
+    })
+
+    ydoc.on('destroy', () => {
+        commits.discrete?.deregisterOnUpdate();
+    })
+
+    onMount(()=>{
+        let history = commits.discrete?.registerOnUpdate((update) => {
+            Y.applyUpdate(ydoc, update.YText, {local:true})
+        });
+        for (const h of history) {
+            Y.applyUpdate(ydoc, h.YText, {local:true})
+        }
+    });
+
+    onDestroy(()=>{
+        ydoc.destroy();
+    });
+  
+  </script>
+  <div class="flex-col">
+    
+    <CodeMirror lang={javascript()} lineWrapping useTab={false} extensions={[basicSetup, yCollab(ytext, false, { undoManager: false })]} styles={{
+      "&": {
+          maxWidth: "100%",
+      },
+    }}/>
+    
+  </div>
\ No newline at end of file
diff --git a/ng-app/src/apps/ContainerView.svelte b/ng-app/src/apps/ContainerView.svelte
index bbeed74..95981cd 100644
--- a/ng-app/src/apps/ContainerView.svelte
+++ b/ng-app/src/apps/ContainerView.svelte
@@ -21,7 +21,6 @@
     function contained(graph) {
         let ret = [];
         for (const g of graph) {
-            console.log(g)
             if (g.substring(104,137) === "http://www.w3.org/ns/ldp#contains") {
                 let nuri = g.substring(140,240);
                 let hash = nuri.substring(9,16);
diff --git a/ng-app/src/apps/PreTextViewer.svelte b/ng-app/src/apps/PreTextViewer.svelte
new file mode 100644
index 0000000..e69de29
diff --git a/ng-app/src/lib/Document.svelte b/ng-app/src/lib/Document.svelte
index f0919ec..f51fecf 100644
--- a/ng-app/src/lib/Document.svelte
+++ b/ng-app/src/lib/Document.svelte
@@ -24,7 +24,7 @@
   import { t } from "svelte-i18n";
   import { Button, Progressbar, Spinner, Alert } from "flowbite-svelte";
   import { inview } from 'svelte-inview';
-  import { cur_tab_doc_can_edit, nav_bar, can_have_header, header_icon, header_title, header_description, cur_branch, set_header_in_view, edit_header_button, cur_app, load_official_app, nav_bar_reset_newest } from "../tab";
+  import { cur_tab, cur_tab_doc_can_edit, nav_bar, can_have_header, header_icon, header_title, header_description, cur_branch, set_header_in_view, edit_header_button, cur_app, load_official_app, nav_bar_reset_newest } from "../tab";
   import NavIcon from "./icons/NavIcon.svelte";
 
   export let nuri = ""; 
@@ -68,6 +68,7 @@
                         class:"w-8 h-8 mr-2 mb-2 flex-none focus:outline-none"
                     }}/>
                     {/if}
+                    {#if !$header_title} <span class="font-mono h-8 py-1 inline-block align-middle mr-3"> {$cur_tab.doc.nuri.substring(2,9)} </span>  {/if}
                     {#if $cur_tab_doc_can_edit}
                     <button class="p-1 mr-2 mb-2 w-8 h-8 flex-none" on:click={openEditHeader} title={$t($edit_header_button)}>
                         <Pencil tabindex=-1 class="w-5 h-5 focus:outline-none" />
diff --git a/ng-app/src/lib/FullLayout.svelte b/ng-app/src/lib/FullLayout.svelte
index 82ec14a..7452a78 100644
--- a/ng-app/src/lib/FullLayout.svelte
+++ b/ng-app/src/lib/FullLayout.svelte
@@ -689,7 +689,7 @@
                     </MenuItem>
                   {/each}
                 {/if}
-                {#if open_edit_with}
+                {#if open_edit_with || $available_editors.length === 1}
                   <MenuItem title={get_app("n:g:z:upload_file")["ng:a"]} extraClass="submenu" clickable={ () => {openPane("files")} }>
                     <ZeraIcon
                       zera={get_app("n:g:z:upload_file")["ng:u"]}
@@ -701,7 +701,7 @@
                     <span class="ml-3">{get_app("n:g:z:upload_file")["ng:n"]}</span>  
                   </MenuItem>
                 {/if}
-                {#if !$cur_tab_view_or_edit || open_edit_with }
+                {#if (!$cur_tab_view_or_edit || open_edit_with) && !$cur_tab_graph_or_discrete }
                   <li title={$t("doc.menu.live_editing_description")} style="margin: 7px 0; padding-left: 32px;" class="toggle">
                     <Toggle
                       on:change={ toggle_live_edit }
diff --git a/ng-app/src/lib/components/NavBar.svelte b/ng-app/src/lib/components/NavBar.svelte
index 347a402..c93182e 100644
--- a/ng-app/src/lib/components/NavBar.svelte
+++ b/ng-app/src/lib/components/NavBar.svelte
@@ -24,7 +24,8 @@
     Popover,
   } from "flowbite-svelte";
 
-  import {nav_bar_newest, save, nav_bar, showMenu, cur_tab_header_in_view, cur_tab_store_name_override, cur_tab_store_icon_override, cur_tab_persistent_error} from "../../tab";
+  import {nav_bar_newest, save, nav_bar, showMenu, cur_tab_header_in_view, cur_tab_store_name_override, cur_tab_store_icon_override, cur_tab_persistent_error, nav_bar_save,
+    cur_tab_view_or_edit, cur_tab_graph_or_discrete, nav_bar_back, nav_bar_title, nav_bar_icon} from "../../tab";
 
   export let scrollToTop = () => {};
 
@@ -40,21 +41,21 @@
 </script>
   
 <div style="background-color: #fbfbfb;" class="h-11 pb-1 flex text-center text-gray-700 dark:text-white">
-    {#if $nav_bar.back}
+    {#if $nav_bar_back}
         <div role="button" tabindex="0" on:click={back} on:keypress={back} class="flex-none w-10 flex justify-center items-center">
         <ArrowLeft tabindex="-1" class="w-8 h-8 focus:outline-none"/>
         </div>
     {/if}
-    {#if $cur_tab_store_icon_override || $nav_bar.icon}
-        <div style="cursor:pointer;" class:w-10={!$nav_bar.back} class:ml-3={!$nav_bar.back} class="flex-none w-8 m-1 " on:click={scrollToTop} on:keypress={scrollToTop}>
-        <NavIcon img={$cur_tab_store_icon_override || $nav_bar.icon} config={{
+    {#if $cur_tab_store_icon_override || $nav_bar_icon}
+        <div style="cursor:pointer;" class:w-10={!$nav_bar_back} class:ml-3={!$nav_bar_back} class="flex-none w-8 m-1 " on:click={scrollToTop} on:keypress={scrollToTop}>
+        <NavIcon img={$cur_tab_store_icon_override || $nav_bar_icon} config={{
             tabindex:"-1",
             class:"w-8 h-8 focus:outline-none"
         }}/>
         </div>
     {/if}
-    <div style="cursor:pointer;" class:pl-3={!$nav_bar.back && !$nav_bar.icon} class="grow w-10 items-center flex px-1" on:click={scrollToTop} on:keypress={scrollToTop}>
-        <span class="inline-block truncate" > {$cur_tab_store_name_override || $nav_bar.title} </span>
+    <div style="cursor:pointer;" class:pl-3={!$nav_bar_back && !$nav_bar_icon} class="grow w-10 items-center flex px-1" on:click={scrollToTop} on:keypress={scrollToTop}>
+        <span class="inline-block truncate" > {$cur_tab_store_name_override || $nav_bar_title} </span>
     </div>
     {#if $nav_bar_newest && !$cur_tab_header_in_view}
         <div role="button" tabindex="0" class="flex-none m-1 rounded-full bg-primary-700 text-white dark:bg-primary-700" on:click={scrollToTop} on:keypress={scrollToTop}>
@@ -74,9 +75,9 @@
             >{@html $cur_tab_persistent_error.desc}
             <br/><br/><span class="text-primary-700" on:click={closeErrorPopup} on:keypress={closeErrorPopup} role="button" tabindex="0">Dismiss</span>
         </Popover>
-    {:else if $nav_bar.save !== undefined}
+    {:else if $nav_bar_save !== undefined && !$cur_tab_view_or_edit && !$cur_tab_graph_or_discrete}
         
-        {#if $nav_bar.save }
+        {#if $nav_bar_save }
         <div tabindex="0" class="flex-none w-10" role="button" on:click={save} on:keypress={save} title="Save">
             <CheckCircle variation="solid" tabindex="-1" strokeWidth="3" class="w-10 h-10  text-primary-400 focus:outline-none"/>
         </div>
diff --git a/ng-app/src/routes/NURI.svelte b/ng-app/src/routes/NURI.svelte
index 9827ee9..8bdfaf2 100644
--- a/ng-app/src/routes/NURI.svelte
+++ b/ng-app/src/routes/NURI.svelte
@@ -36,7 +36,10 @@
                 else if (params[1].startsWith("o:"+$active_session.protected_store_id)) push("#/shared"); 
                 else if (params[1].startsWith("o:"+$active_session.public_store_id)) push("#/site"); else nuri = params[1]; } 
   onMount(() => {
-    change_nav_bar("nav:unknown_doc",$t("doc.doc"), true);
+    if ($cur_tab.store.store_type) 
+      change_nav_bar(`nav:${$cur_tab.store.store_type}`,$t(`doc.${$cur_tab.store.store_type}_store`), true); 
+    else 
+      change_nav_bar("nav:unknown_doc",$t("doc.doc"), true);
     reset_in_memory();
   });
 </script>
diff --git a/ng-app/src/store.ts b/ng-app/src/store.ts
index 672450a..92c9520 100644
--- a/ng-app/src/store.ts
+++ b/ng-app/src/store.ts
@@ -395,6 +395,28 @@ export const digest_to_string = function(digest) {
     return encode(buffer.buffer);
 };
 
+export const discrete_update = async (update) => {
+    // if cur_tab.doc.live_edit => send directly to verifier (with live_discrete_update)
+    // else, save the update locally with the API. 
+    // and nav_bar.update((o) => { o.save = true; return o; });
+    // once save button is pressed, we call OnSave with all the updates that we retrieve from local storage (via API). and we set nav_bar.update((o) => { o.save = false; return o; });
+    // the editor then process those updates and calls live_discrete_update
+}
+
+export const live_discrete_update = async (update, crdt, heads) => {
+    // send directly to verifier with AppRequest Update
+    let session = get(active_session);
+    if (!session) {
+        persistent_error(get(cur_branch), {
+            title: get(format)("doc.errors.no_session"),
+            desc: get(format)("doc.errors_details.no_session")
+        });
+        throw new Error("no session");
+    }
+    let nuri = "did:ng:"+get(cur_tab).branch.nuri;
+    await ng.discrete_update(session.session_id, update, heads, crdt, nuri);
+}
+
 export const sparql_query = async function(sparql:string, union:boolean) {
     let session = get(active_session);
     if (!session) {
@@ -472,10 +494,12 @@ export const branch_subscribe = function(nuri:string, in_tab:boolean) {
             //console.log("sub");
             let already_subscribed = all_branches[nuri];
             if (!already_subscribed) {
-                const { subscribe, set, update } = writable({graph:[], discrete:[], files:[], history: {start:()=>{}, stop:()=>{}, commits:false}, heads: []}); // create the underlying writable store // take:()=>{},
+                let onUpdate = (update) => {};
+                const { subscribe, set, update } = writable({graph:[], discrete:{updates:[], deregisterOnUpdate:()=>{ onUpdate=()=>{};},registerOnUpdate:(f)=>{ }}, files:[], history: {start:()=>{}, stop:()=>{}, commits:false}, heads: []}); // create the underlying writable store // take:()=>{},
                 update((old)=> {
                     old.history.start = () => update((o) => {o.history.commits = true; return o;}) ;
                     old.history.stop = () => update((o) => {o.history.commits = false; return o;}) ;
+                    old.discrete.registerOnUpdate = (f) => { onUpdate = f; return get({subscribe}).discrete.updates; };
                     //old.history.take = () => { let res: boolean | Array<{}> = false; update((o) => {res = o.history.commits; o.history.commits = []; return o;});  return res;}
                     return old;});
                 let count = 0;
@@ -562,6 +586,10 @@ export const branch_subscribe = function(nuri:string, in_tab:boolean) {
                                                 }
                                                 old.graph.sort();
                                             }
+                                            if (response.V0.State.discrete) {
+                                                old.discrete.updates.push(response.V0.State.discrete);
+                                                onUpdate(response.V0.State.discrete);
+                                            }
                                             tab_update(nuri, ($cur_tab) => {
                                                 $cur_tab.branch.files = old.files.length;
                                                 return $cur_tab;
@@ -582,6 +610,10 @@ export const branch_subscribe = function(nuri:string, in_tab:boolean) {
                                                     old.history.commits.push(commit);
                                                 }
                                             }
+                                            if (response.V0.Patch.discrete) {
+                                                old.discrete.updates.push(response.V0.Patch.discrete);
+                                                onUpdate(response.V0.Patch.discrete);
+                                            }
                                             if (response.V0.Patch.graph) {
                                                 let duplicates = [];
                                                 for (let i = 0; i < old.graph.length; i++) {
diff --git a/ng-app/src/tab.ts b/ng-app/src/tab.ts
index cb0b6b2..2135c21 100644
--- a/ng-app/src/tab.ts
+++ b/ng-app/src/tab.ts
@@ -260,6 +260,8 @@ export const all_tabs = writable({
             description: "",
     
             app: "", // current app being used
+            onSave: (updates) => {},
+            updates: [],
         },
         view_or_edit: true, // true=> view, false=> edit
         graph_viewer: "", // selected viewer
@@ -304,6 +306,13 @@ export const all_tabs = writable({
     }
 });
 
+export const cur_tab_register_on_save = (f:(updates) => {}) => {
+    cur_tab_update((old)=>{
+        old.branch.onSave = f;
+        return old;
+    });
+}
+
 export const set_header_in_view = function(val) {
     cur_tab_update((old) => { old.header_in_view = val; return old;});
 }
@@ -427,13 +436,6 @@ export const cur_tab_update = function( fn ) {
 
 export const live_editing = writable(false);
 
-live_editing.subscribe((val) => {
-    cur_tab_update((old)=> {
-        old.doc.live_edit = val;
-        return old;
-    });
-});
-
 export const showMenu = () => {
     show_modal_menu.set(true);
     cur_tab_update(ct => {
@@ -458,13 +460,42 @@ export const nav_bar = writable({
     back: false,
     newest: 0,
     save: undefined,
-    toasts: [],
+});
+
+live_editing.subscribe((val) => {
+    cur_tab_update((old)=> {
+        old.doc.live_edit = val;
+        if (val) {
+            //TODO: send all the updates with live_discrete_update
+        }
+        nav_bar.update((o) => {
+            o.save = old.doc.live_edit ? undefined : ( old.branch.updates.length > 0 ? true : false )
+            return o;
+        });
+        return old;
+    });
 });
 
 export const nav_bar_newest = derived(nav_bar, ($nav_bar) => {
     return $nav_bar.newest;
 });
 
+export const nav_bar_save = derived(nav_bar, ($nav_bar) => {
+    return $nav_bar.save;
+});
+
+export const nav_bar_back = derived(nav_bar, ($nav_bar) => {
+    return $nav_bar.back;
+});
+
+export const nav_bar_title = derived(nav_bar, ($nav_bar) => {
+    return $nav_bar.title;
+});
+
+export const nav_bar_icon = derived(nav_bar, ($nav_bar) => {
+    return $nav_bar.icon;
+});
+
 export const nav_bar_reset_newest = () => {
     nav_bar.update((old) => {
         old.newest = 0;
@@ -496,6 +527,8 @@ export const persistent_error = (nuri, pe) => {
 
 export const save = async () => {
     // saving the doc
+    // fetch updates from local storage
+    get(cur_tab).branch.onSave([]);
 }
 
 export const all_files_count = derived(cur_tab, ($cur_tab) => {
@@ -515,6 +548,7 @@ export const has_editor_chat = derived(cur_tab, ($cur_tab) => {
 export const toggle_live_edit = () => {
     cur_tab_update(ct => {
         ct.doc.live_edit = !ct.doc.live_edit;
+        live_editing.set(ct.doc.live_edit);
         return ct;
     });
 }
diff --git a/ng-app/src/zeras.ts b/ng-app/src/zeras.ts
index f9918c8..609d15e 100644
--- a/ng-app/src/zeras.ts
+++ b/ng-app/src/zeras.ts
@@ -226,7 +226,7 @@ export const official_apps = {
         "ng:w": ["post:md"],
     },
     "n:g:z:code_editor": {
-        "ng:n": "Code and Text Editor",
+        "ng:n": "Text Editor",
         "ng:a": "Edit the code/text with CodeMirror",
         "ng:c": "app", 
         "ng:u": "edit",//favicon. can be a did:ng:j 
diff --git a/ng-net/src/app_protocol.rs b/ng-net/src/app_protocol.rs
index b553617..b9f61d8 100644
--- a/ng-net/src/app_protocol.rs
+++ b/ng-net/src/app_protocol.rs
@@ -43,12 +43,12 @@ lazy_static! {
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub enum AppFetchContentV0 {
-    Get,       // does not subscribe. more to be detailed
-    Subscribe, // more to be detailed
+    Get, // does not subscribe.
+    Subscribe,
     Update,
     //Invoke,
-    ReadQuery,  // more to be detailed
-    WriteQuery, // more to be detailed
+    ReadQuery,
+    WriteQuery,
     RdfDump,
     History,
 }
@@ -92,6 +92,13 @@ impl TargetBranchV0 {
             _ => true,
         }
     }
+    pub fn is_valid_for_discrete_update(&self) -> bool {
+        match self {
+            Self::BranchId(_) => true,
+            //TODO: add Named(s) is s is a branch => true
+            _ => false,
+        }
+    }
     pub fn branch_id(&self) -> &BranchId {
         match self {
             Self::BranchId(id) => id,
@@ -124,6 +131,12 @@ impl NuriTargetV0 {
             _ => true,
         }
     }
+    pub fn is_valid_for_discrete_update(&self) -> bool {
+        match self {
+            Self::UserSite | Self::AllDialogs | Self::AllGroups | Self::None => false,
+            _ => true,
+        }
+    }
     pub fn is_repo_id(&self) -> bool {
         match self {
             Self::Repo(_) => true,
@@ -276,6 +289,15 @@ impl NuriV0 {
                 .as_ref()
                 .map_or(true, |b| b.is_valid_for_sparql_update())
     }
+    pub fn is_valid_for_discrete_update(&self) -> bool {
+        self.object.is_none()
+            && self.entire_store == false
+            && self.target.is_valid_for_discrete_update()
+            && self
+                .branch
+                .as_ref()
+                .map_or(true, |b| b.is_valid_for_discrete_update())
+    }
     pub fn new_repo_target_from_string(repo_id_string: String) -> Result<Self, NgError> {
         let repo_id: RepoId = repo_id_string.as_str().try_into()?;
         Ok(Self {
@@ -460,6 +482,9 @@ impl AppRequestCommandV0 {
     pub fn new_write_query() -> Self {
         AppRequestCommandV0::Fetch(AppFetchContentV0::WriteQuery)
     }
+    pub fn new_update() -> Self {
+        AppRequestCommandV0::Fetch(AppFetchContentV0::Update)
+    }
     pub fn new_rdf_dump() -> Self {
         AppRequestCommandV0::Fetch(AppFetchContentV0::RdfDump)
     }
@@ -616,11 +641,24 @@ pub enum DiscreteUpdate {
     Automerge(Vec<u8>),
 }
 
+impl DiscreteUpdate {
+    pub fn from(crdt: String, update: Vec<u8>) -> Self {
+        match crdt.as_str() {
+            "YMap" => Self::YMap(update),
+            "YArray" => Self::YArray(update),
+            "YXml" => Self::YXml(update),
+            "YText" => Self::YText(update),
+            "Automerge" => Self::Automerge(update),
+            _ => panic!("wrong crdt type"),
+        }
+    }
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct DocUpdate {
-    heads: Vec<ObjectId>,
-    graph: Option<GraphUpdate>,
-    discrete: Option<DiscreteUpdate>,
+    pub heads: Vec<ObjectId>,
+    pub graph: Option<GraphUpdate>,
+    pub discrete: Option<DiscreteUpdate>,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
@@ -683,6 +721,24 @@ impl AppRequestPayload {
     pub fn new_sparql_query(query: String) -> Self {
         AppRequestPayload::V0(AppRequestPayloadV0::Query(DocQuery::V0(query)))
     }
+    pub fn new_discrete_update(
+        head_strings: Vec<String>,
+        crdt: String,
+        update: Vec<u8>,
+    ) -> Result<Self, NgError> {
+        let mut heads = Vec::with_capacity(head_strings.len());
+        for head in head_strings {
+            heads.push(decode_digest(&head)?);
+        }
+        let discrete = Some(DiscreteUpdate::from(crdt, update));
+        Ok(AppRequestPayload::V0(AppRequestPayloadV0::Update(
+            DocUpdate {
+                heads,
+                graph: None,
+                discrete,
+            },
+        )))
+    }
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
@@ -713,7 +769,7 @@ pub struct GraphPatch {
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub enum DiscreteState {
-    /// A yrs::StateVector
+    /// A yrs::Update
     #[serde(with = "serde_bytes")]
     YMap(Vec<u8>),
     #[serde(with = "serde_bytes")]
diff --git a/ng-repo/src/errors.rs b/ng-repo/src/errors.rs
index 9e860ae..9f4743e 100644
--- a/ng-repo/src/errors.rs
+++ b/ng-repo/src/errors.rs
@@ -226,6 +226,7 @@ pub enum StorageError {
     NotEmpty,
     ServerAlreadyRunningInOtherProcess,
     NgError(String),
+    NoDiscreteState,
 }
 
 impl core::fmt::Display for StorageError {
@@ -367,6 +368,8 @@ pub enum VerifierError {
     OxigraphError(String),
     CannotRemoveTriplesWhenNewBranch,
     PermissionDenied,
+    YrsError(String),
+    InvalidNuri,
 }
 
 impl Error for VerifierError {}
diff --git a/ng-repo/src/types.rs b/ng-repo/src/types.rs
index 16abb96..901c2d5 100644
--- a/ng-repo/src/types.rs
+++ b/ng-repo/src/types.rs
@@ -1366,6 +1366,12 @@ pub enum BranchCrdt {
 }
 
 impl BranchCrdt {
+    pub fn is_graph(&self) -> bool {
+        match self {
+            BranchCrdt::Graph(_) => true,
+            _ => false,
+        }
+    }
     pub fn name(&self) -> String {
         match self {
             BranchCrdt::Graph(_) => "Graph",
diff --git a/ng-sdk-js/src/lib.rs b/ng-sdk-js/src/lib.rs
index d6e407a..891636c 100644
--- a/ng-sdk-js/src/lib.rs
+++ b/ng-sdk-js/src/lib.rs
@@ -314,6 +314,49 @@ pub async fn sparql_query(
     }
 }
 
+#[wasm_bindgen]
+pub async fn discrete_update(
+    session_id: JsValue,
+    update: JsValue,
+    heads: Array,
+    crdt: String,
+    nuri: String,
+) -> Result<(), String> {
+    let session_id: u64 = serde_wasm_bindgen::from_value::<u64>(session_id)
+        .map_err(|_| "Invalid session_id".to_string())?;
+    let nuri = NuriV0::new_from(&nuri).map_err(|e| e.to_string())?;
+    let mut head_strings = Vec::with_capacity(heads.length() as usize);
+    for head in heads.iter() {
+        if let Some(s) = head.as_string() {
+            head_strings.push(s)
+        } else {
+            return Err("Invalid HEADS".to_string());
+        }
+    }
+    let update: serde_bytes::ByteBuf =
+        serde_wasm_bindgen::from_value::<serde_bytes::ByteBuf>(update)
+            .map_err(|_| "Deserialization error of update".to_string())?;
+
+    let request = AppRequest::V0(AppRequestV0 {
+        command: AppRequestCommandV0::new_update(),
+        nuri,
+        payload: Some(
+            AppRequestPayload::new_discrete_update(head_strings, crdt, update.into_vec())
+                .map_err(|e| format!("Deserialization error of heads: {e}"))?,
+        ),
+        session_id,
+    });
+
+    let res = nextgraph::local_broker::app_request(request)
+        .await
+        .map_err(|e: NgError| e.to_string())?;
+    if let AppResponse::V0(AppResponseV0::Error(e)) = res {
+        Err(e)
+    } else {
+        Ok(())
+    }
+}
+
 #[wasm_bindgen]
 pub async fn sparql_update(
     session_id: JsValue,
diff --git a/ng-verifier/Cargo.toml b/ng-verifier/Cargo.toml
index 4a1edcb..e3452f0 100644
--- a/ng-verifier/Cargo.toml
+++ b/ng-verifier/Cargo.toml
@@ -30,7 +30,7 @@ futures = "0.3.24"
 async-trait = "0.1.64"
 async-std = { version = "1.12.0", features = [ "attributes", "unstable" ] }
 automerge = "0.5.9"
-yrs = "0.18.2"
+yrs = "0.19.2"
 sbbf-rs-safe = "0.3.2"
 ng-repo = { path = "../ng-repo", version = "0.1.0-preview.1" }
 ng-net = { path = "../ng-net", version = "0.1.0-preview.1" }
diff --git a/ng-verifier/src/commits/mod.rs b/ng-verifier/src/commits/mod.rs
index 120ea80..9f1b120 100644
--- a/ng-verifier/src/commits/mod.rs
+++ b/ng-verifier/src/commits/mod.rs
@@ -574,9 +574,11 @@ impl CommitVerifier for AddRepo {
         let remote = (&verifier.connected_broker).into();
         let user = Some(verifier.user_id().clone());
         let read_cap = self.read_cap();
+        let overlay_id = store.overlay_id;
         verifier
             .load_repo_from_read_cap(read_cap, &broker, &user, &remote, store, true)
             .await?;
+        verifier.add_doc(repo_id, &overlay_id)?;
         Ok(())
     }
 }
diff --git a/ng-verifier/src/commits/transaction.rs b/ng-verifier/src/commits/transaction.rs
index e8d2d8f..c0d42bf 100644
--- a/ng-verifier/src/commits/transaction.rs
+++ b/ng-verifier/src/commits/transaction.rs
@@ -14,7 +14,10 @@ use std::sync::Arc;
 
 use ng_oxigraph::oxigraph::storage_ng::numeric_encoder::{EncodedQuad, EncodedTerm};
 use ng_oxigraph::oxigraph::storage_ng::*;
+use ng_repo::repo::Repo;
 use serde::{Deserialize, Serialize};
+use yrs::updates::decoder::Decode;
+use yrs::{ReadTxn, StateVector, Transact, Update};
 
 use ng_net::app_protocol::*;
 use ng_oxigraph::oxrdf::{GraphName, GraphNameRef, NamedNode, Quad, Triple, TripleRef};
@@ -23,53 +26,9 @@ use ng_repo::log::*;
 use ng_repo::store::Store;
 use ng_repo::types::*;
 
+use crate::types::*;
 use crate::verifier::Verifier;
 
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct GraphTransaction {
-    pub inserts: Vec<Triple>,
-    pub removes: Vec<Triple>,
-}
-
-impl GraphTransaction {
-    fn as_patch(&self) -> GraphPatch {
-        GraphPatch {
-            inserts: serde_bare::to_vec(&self.inserts).unwrap(),
-            removes: serde_bare::to_vec(&self.removes).unwrap(),
-        }
-    }
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub enum DiscreteTransaction {
-    /// A yrs::Update
-    #[serde(with = "serde_bytes")]
-    YMap(Vec<u8>),
-    #[serde(with = "serde_bytes")]
-    YArray(Vec<u8>),
-    #[serde(with = "serde_bytes")]
-    YXml(Vec<u8>),
-    #[serde(with = "serde_bytes")]
-    YText(Vec<u8>),
-    /// An automerge::Patch
-    #[serde(with = "serde_bytes")]
-    Automerge(Vec<u8>),
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub enum TransactionBodyType {
-    Graph,
-    Discrete,
-    Both,
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct TransactionBody {
-    body_type: TransactionBodyType,
-    graph: Option<GraphTransaction>,
-    discrete: Option<DiscreteTransaction>,
-}
-
 struct BranchUpdateInfo {
     branch_id: BranchId,
     branch_is_main: bool,
@@ -208,6 +167,77 @@ impl Verifier {
             .map_err(|e| VerifierError::OxigraphError(e.to_string()))
     }
 
+    pub(crate) async fn update_discrete(
+        &mut self,
+        patch: DiscreteTransaction,
+        crdt: &BranchCrdt,
+        branch_id: &BranchId,
+        commit_id: ObjectId,
+        commit_info: CommitInfoJs,
+    ) -> Result<(), VerifierError> {
+        let new_state = if let Ok(state) = self
+            .user_storage
+            .as_ref()
+            .unwrap()
+            .branch_get_discrete_state(branch_id)
+        {
+            match crdt {
+                BranchCrdt::Automerge(_) => {
+                    unimplemented!();
+                }
+                BranchCrdt::YArray(_)
+                | BranchCrdt::YMap(_)
+                | BranchCrdt::YText(_)
+                | BranchCrdt::YXml(_) => {
+                    let doc = yrs::Doc::new();
+                    {
+                        let mut txn = doc.transact_mut();
+                        let update = yrs::Update::decode_v1(&state)
+                            .map_err(|e| VerifierError::YrsError(e.to_string()))?;
+                        txn.apply_update(update);
+                        let update = yrs::Update::decode_v1(&patch.to_vec())
+                            .map_err(|e| VerifierError::YrsError(e.to_string()))?;
+                        txn.apply_update(update);
+                        txn.commit();
+                    }
+                    let empty_state_vector = yrs::StateVector::default();
+                    let transac = doc.transact();
+                    transac.encode_state_as_update_v1(&empty_state_vector)
+                }
+                _ => return Err(VerifierError::InvalidBranch),
+            }
+        } else {
+            patch.to_vec()
+        };
+        self.user_storage
+            .as_ref()
+            .unwrap()
+            .branch_set_discrete_state(*branch_id, new_state)?;
+
+        let patch = match (crdt, patch) {
+            (BranchCrdt::Automerge(_), DiscreteTransaction::Automerge(v)) => {
+                DiscretePatch::Automerge(v)
+            }
+            (BranchCrdt::YArray(_), DiscreteTransaction::YArray(v)) => DiscretePatch::YArray(v),
+            (BranchCrdt::YMap(_), DiscreteTransaction::YMap(v)) => DiscretePatch::YMap(v),
+            (BranchCrdt::YText(_), DiscreteTransaction::YText(v)) => DiscretePatch::YText(v),
+            (BranchCrdt::YXml(_), DiscreteTransaction::YXml(v)) => DiscretePatch::YXml(v),
+            _ => return Err(VerifierError::InvalidCommit),
+        };
+        self.push_app_response(
+            branch_id,
+            AppResponse::V0(AppResponseV0::Patch(AppPatch {
+                commit_id: commit_id.to_string(),
+                commit_info: commit_info,
+                graph: None,
+                discrete: Some(patch),
+                other: None,
+            })),
+        )
+        .await;
+        Ok(())
+    }
+
     pub(crate) async fn verify_async_transaction(
         &mut self,
         transaction: &Transaction,
@@ -239,12 +269,54 @@ impl Verifier {
                 commit_info,
             };
             self.update_graph(vec![info]).await?;
+        } else
+        //TODO: change the logic here. transaction commits can have both a discrete and graph update. Only one AppResponse should be sent in this case, containing both updates.
+        if body.discrete.is_some() {
+            let patch = body.discrete.unwrap();
+            let crdt = &repo.branch(branch_id)?.crdt.clone();
+            self.update_discrete(patch, &crdt, branch_id, commit_id, commit_info)
+                .await?;
         }
-        //TODO: discrete update
 
         Ok(())
     }
 
+    // pub(crate) fn find_branch_and_repo_for_nuri(
+    //     &self,
+    //     nuri: &NuriV0,
+    // ) -> Result<(RepoId, BranchId, StoreRepo), VerifierError> {
+    //     if !nuri.is_branch_identifier() {
+    //         return Err(VerifierError::InvalidNuri);
+    //     }
+    //     let store = self.get_store_by_overlay_id(&OverlayId::Outer(
+    //         nuri.overlay.as_ref().unwrap().outer().to_slice(),
+    //     ))?;
+    //     let repo = self.get_repo(nuri.target.repo_id(), store.get_store_repo())?;
+    //     Ok((
+    //         match nuri.branch {
+    //             None => {
+    //                 let b = repo.main_branch().ok_or(VerifierError::BranchNotFound)?;
+    //                 if b.topic_priv_key.is_none() {
+    //                     return Err(VerifierError::PermissionDenied);
+    //                 }
+    //                 b.id
+    //             }
+    //             Some(TargetBranchV0::BranchId(id)) => {
+    //                 let b = repo.branch(&id)?;
+    //                 //TODO: deal with named branch that is also the main branch
+    //                 if b.topic_priv_key.is_none() {
+    //                     return Err(VerifierError::PermissionDenied);
+    //                 }
+    //                 id
+    //             }
+    //             // TODO: implement TargetBranchV0::Named
+    //             _ => unimplemented!(),
+    //         },
+    //         repo.id,
+    //         store.get_store_repo().clone(),
+    //     ))
+    // }
+
     fn find_branch_and_repo_for_quad(
         &self,
         quad: &Quad,
diff --git a/ng-verifier/src/request_processor.rs b/ng-verifier/src/request_processor.rs
index 7aa6445..43a0197 100644
--- a/ng-verifier/src/request_processor.rs
+++ b/ng-verifier/src/request_processor.rs
@@ -266,12 +266,11 @@ impl Verifier {
                         .await?;
 
                     // adding an ldp:contains triple to the store main branch
-                    let nuri = NuriV0::repo_graph_name(&repo_id, &doc_create.store.outer_overlay());
+                    let overlay_id = doc_create.store.outer_overlay();
+                    let nuri = NuriV0::repo_graph_name(&repo_id, &overlay_id);
                     let store_nuri = NuriV0::from_store_repo(&doc_create.store);
-                    let store_nuri_string = NuriV0::repo_graph_name(
-                        doc_create.store.repo_id(),
-                        &doc_create.store.outer_overlay(),
-                    );
+                    let store_nuri_string =
+                        NuriV0::repo_graph_name(doc_create.store.repo_id(), &overlay_id);
                     let query = format!("INSERT DATA {{ <{store_nuri_string}> <http://www.w3.org/ns/ldp#contains> <{nuri}>. }}");
 
                     let ret = self.process_sparql_update(&store_nuri, &query).await;
@@ -279,6 +278,8 @@ impl Verifier {
                         return Ok(AppResponse::error(e));
                     }
 
+                    self.add_doc(&repo_id, &overlay_id)?;
+
                     return Ok(AppResponse::V0(AppResponseV0::Nuri(nuri)));
                 } else {
                     return Err(NgError::InvalidPayload);
@@ -333,6 +334,64 @@ impl Verifier {
                         Err(NgError::InvalidPayload)
                     };
                 }
+                AppFetchContentV0::Update => {
+                    if !nuri.is_valid_for_discrete_update() {
+                        return Err(NgError::InvalidNuri);
+                    }
+                    return if let Some(AppRequestPayload::V0(AppRequestPayloadV0::Update(update))) =
+                        payload
+                    {
+                        //TODO: deal with update.graph
+                        //TODO: verify that update.heads are the same as what the Verifier knows
+                        if let Some(discrete) = update.discrete {
+                            let (repo_id, branch_id, store_repo) =
+                                match self.resolve_target(&nuri.target) {
+                                    Err(e) => return Ok(AppResponse::error(e.to_string())),
+                                    Ok(a) => a,
+                                };
+
+                            let patch: DiscreteTransaction = discrete.into();
+
+                            let transac = TransactionBody {
+                                body_type: TransactionBodyType::Discrete,
+                                graph: None,
+                                discrete: Some(patch.clone()),
+                            };
+
+                            let transaction_commit_body = CommitBodyV0::AsyncTransaction(
+                                Transaction::V0(serde_bare::to_vec(&transac)?),
+                            );
+
+                            let commit = self
+                                .new_transaction_commit(
+                                    transaction_commit_body,
+                                    &repo_id,
+                                    &branch_id,
+                                    &store_repo,
+                                    vec![], //TODO deps
+                                    vec![],
+                                )
+                                .await?;
+
+                            let repo = self.get_repo(&repo_id, &store_repo)?;
+                            let commit_info: CommitInfoJs = (&commit.as_info(repo)).into();
+
+                            let crdt = &repo.branch(&branch_id)?.crdt.clone();
+                            self.update_discrete(
+                                patch,
+                                &crdt,
+                                &branch_id,
+                                commit.id().unwrap(),
+                                commit_info,
+                            )
+                            .await?;
+                        }
+
+                        Ok(AppResponse::ok())
+                    } else {
+                        Err(NgError::InvalidPayload)
+                    };
+                }
                 AppFetchContentV0::RdfDump => {
                     let store = self.graph_dataset.as_ref().unwrap();
 
diff --git a/ng-verifier/src/rocksdb_user_storage.rs b/ng-verifier/src/rocksdb_user_storage.rs
index 115f982..a514c09 100644
--- a/ng-verifier/src/rocksdb_user_storage.rs
+++ b/ng-verifier/src/rocksdb_user_storage.rs
@@ -95,6 +95,22 @@ impl UserStorage for RocksDbUserStorage {
         }
     }
 
+    fn branch_set_discrete_state(
+        &self,
+        branch: BranchId,
+        state: Vec<u8>,
+    ) -> Result<(), StorageError> {
+        let branch = BranchStorage::open(&branch, &self.user_storage)?;
+        branch.set_discrete_state(state)
+    }
+
+    fn branch_get_discrete_state(&self, branch: &BranchId) -> Result<Vec<u8>, StorageError> {
+        let branch = BranchStorage::new(&branch, &self.user_storage)?;
+        branch
+            .get_discrete_state()
+            .map_err(|_| StorageError::NoDiscreteState)
+    }
+
     fn branch_add_file(
         &self,
         commit_id: ObjectId,
diff --git a/ng-verifier/src/types.rs b/ng-verifier/src/types.rs
index 6de872c..2e1f6a4 100644
--- a/ng-verifier/src/types.rs
+++ b/ng-verifier/src/types.rs
@@ -18,9 +18,78 @@ use serde::{Deserialize, Serialize};
 //use oxigraph::model::GroundQuad;
 //use yrs::{StateVector, Update};
 
+use ng_net::{app_protocol::*, types::*};
+use ng_oxigraph::oxrdf::{GraphName, GraphNameRef, NamedNode, Quad, Triple, TripleRef};
 use ng_repo::{errors::*, types::*};
 
-use ng_net::types::*;
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct GraphTransaction {
+    pub inserts: Vec<Triple>,
+    pub removes: Vec<Triple>,
+}
+
+impl GraphTransaction {
+    pub(crate) fn as_patch(&self) -> GraphPatch {
+        GraphPatch {
+            inserts: serde_bare::to_vec(&self.inserts).unwrap(),
+            removes: serde_bare::to_vec(&self.removes).unwrap(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum DiscreteTransaction {
+    /// A serialization of a yrs::Update
+    #[serde(with = "serde_bytes")]
+    YMap(Vec<u8>),
+    #[serde(with = "serde_bytes")]
+    YArray(Vec<u8>),
+    #[serde(with = "serde_bytes")]
+    YXml(Vec<u8>),
+    #[serde(with = "serde_bytes")]
+    YText(Vec<u8>),
+    /// An automerge::Patch
+    #[serde(with = "serde_bytes")]
+    Automerge(Vec<u8>),
+}
+
+impl From<DiscreteUpdate> for DiscreteTransaction {
+    fn from(update: DiscreteUpdate) -> Self {
+        match update {
+            DiscreteUpdate::Automerge(v) => DiscreteTransaction::Automerge(v),
+            DiscreteUpdate::YMap(v) => DiscreteTransaction::YMap(v),
+            DiscreteUpdate::YArray(v) => DiscreteTransaction::YArray(v),
+            DiscreteUpdate::YXml(v) => DiscreteTransaction::YXml(v),
+            DiscreteUpdate::YText(v) => DiscreteTransaction::YText(v),
+        }
+    }
+}
+
+impl DiscreteTransaction {
+    pub fn to_vec(&self) -> Vec<u8> {
+        match self {
+            Self::YMap(v)
+            | Self::YArray(v)
+            | Self::YXml(v)
+            | Self::YText(v)
+            | Self::Automerge(v) => v.to_vec(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum TransactionBodyType {
+    Graph,
+    Discrete,
+    Both,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct TransactionBody {
+    pub body_type: TransactionBodyType,
+    pub graph: Option<GraphTransaction>,
+    pub discrete: Option<DiscreteTransaction>,
+}
 
 #[doc(hidden)]
 #[derive(Clone, Debug, Serialize, Deserialize)]
diff --git a/ng-verifier/src/user_storage/branch.rs b/ng-verifier/src/user_storage/branch.rs
index 6b663e9..d0e1540 100644
--- a/ng-verifier/src/user_storage/branch.rs
+++ b/ng-verifier/src/user_storage/branch.rs
@@ -42,8 +42,9 @@ impl<'a> BranchStorage<'a> {
     const MERGED_IN: u8 = b'm';
     const CRDT: u8 = b'd';
     const CLASS: u8 = b'c';
+    const DISCRETE_STATE: u8 = b's';
 
-    const ALL_PROPERTIES: [u8; 9] = [
+    const ALL_PROPERTIES: [u8; 10] = [
         Self::TYPE,
         Self::PUBLISHER,
         Self::READ_CAP,
@@ -53,6 +54,7 @@ impl<'a> BranchStorage<'a> {
         Self::MERGED_IN,
         Self::CRDT,
         Self::CLASS,
+        Self::DISCRETE_STATE,
     ];
 
     const PREFIX_HEADS: u8 = b'h';
@@ -220,6 +222,26 @@ impl<'a> BranchStorage<'a> {
         Ok(res)
     }
 
+    pub fn set_discrete_state(&self, state: Vec<u8>) -> Result<(), StorageError> {
+        self.storage.write_transaction(&mut |tx| {
+            let id_ser = &to_vec(&self.id)?;
+            tx.put(
+                Self::PREFIX,
+                &id_ser,
+                Some(Self::DISCRETE_STATE),
+                &state,
+                &None,
+            )?;
+            Ok(())
+        })
+    }
+
+    pub fn get_discrete_state(&self) -> Result<Vec<u8>, StorageError> {
+        let id_ser = &to_vec(&self.id)?;
+        self.storage
+            .get(Self::PREFIX, &id_ser, Some(Self::DISCRETE_STATE), &None)
+    }
+
     pub fn add_file(&self, commit_id: &ObjectId, file: &FileName) -> Result<(), StorageError> {
         self.storage.write_transaction(&mut |tx| {
             let branch_id_ser = to_vec(&self.id)?;
diff --git a/ng-verifier/src/user_storage/storage.rs b/ng-verifier/src/user_storage/storage.rs
index 8fa8d5c..5b20556 100644
--- a/ng-verifier/src/user_storage/storage.rs
+++ b/ng-verifier/src/user_storage/storage.rs
@@ -51,6 +51,14 @@ pub trait UserStorage: Send + Sync {
 
     fn branch_get_all_files(&self, branch: &BranchId) -> Result<Vec<FileName>, StorageError>;
 
+    fn branch_set_discrete_state(
+        &self,
+        branch: BranchId,
+        state: Vec<u8>,
+    ) -> Result<(), StorageError>;
+
+    fn branch_get_discrete_state(&self, branch: &BranchId) -> Result<Vec<u8>, StorageError>;
+
     fn branch_get_tab_info(
         &self,
         branch: &BranchId,
@@ -68,12 +76,14 @@ pub trait UserStorage: Send + Sync {
 
 pub(crate) struct InMemoryUserStorage {
     branch_files: RwLock<HashMap<BranchId, Vec<FileName>>>,
+    branch_discrete_state: RwLock<HashMap<BranchId, Vec<u8>>>,
 }
 
 impl InMemoryUserStorage {
     pub fn new() -> Self {
         InMemoryUserStorage {
             branch_files: RwLock::new(HashMap::new()),
+            branch_discrete_state: RwLock::new(HashMap::new()),
         }
     }
 }
@@ -100,6 +110,25 @@ impl UserStorage for InMemoryUserStorage {
         }
     }
 
+    fn branch_set_discrete_state(
+        &self,
+        branch: BranchId,
+        state: Vec<u8>,
+    ) -> Result<(), StorageError> {
+        let mut lock = self.branch_discrete_state.write().unwrap();
+        let _ = lock.insert(branch, state);
+        Ok(())
+    }
+
+    fn branch_get_discrete_state(&self, branch: &BranchId) -> Result<Vec<u8>, StorageError> {
+        let lock = self.branch_discrete_state.read().unwrap();
+        if let Some(state) = lock.get(&branch) {
+            Ok(state.to_vec())
+        } else {
+            Err(StorageError::NoDiscreteState)
+        }
+    }
+
     fn branch_get_tab_info(
         &self,
         branch: &BranchId,
diff --git a/ng-verifier/src/verifier.rs b/ng-verifier/src/verifier.rs
index 87b1eb1..e736d42 100644
--- a/ng-verifier/src/verifier.rs
+++ b/ng-verifier/src/verifier.rs
@@ -261,7 +261,7 @@ impl Verifier {
 
         let store_tab_info = AppTabStoreInfo {
             repo: Some(repo.store.get_store_repo().clone()),
-            overlay: Some(format!("v:{}", repo.store.outer_overlay().to_string())),
+            overlay: Some(format!("v:{}", repo.store.overlay_id.to_string())),
             store_type: Some(repo.store.get_store_repo().store_type_for_app()),
             has_outer: None, //TODO
             inner: None,     //TODO
@@ -335,6 +335,29 @@ impl Verifier {
             }
         }
 
+        let crdt = &repo.branch(&branch_id)?.crdt;
+        let discrete = if crdt.is_graph() {
+            None
+        } else {
+            match self
+                .user_storage
+                .as_ref()
+                .unwrap()
+                .branch_get_discrete_state(&branch_id)
+            {
+                Ok(state) => Some(match repo.branch(&branch_id)?.crdt {
+                    BranchCrdt::Automerge(_) => DiscreteState::Automerge(state),
+                    BranchCrdt::YArray(_) => DiscreteState::YArray(state),
+                    BranchCrdt::YMap(_) => DiscreteState::YMap(state),
+                    BranchCrdt::YText(_) => DiscreteState::YText(state),
+                    BranchCrdt::YXml(_) => DiscreteState::YXml(state),
+                    _ => return Err(VerifierError::InvalidBranch),
+                }),
+                Err(StorageError::NoDiscreteState) => None,
+                Err(e) => return Err(e.into()),
+            }
+        };
+
         let state = AppState {
             heads: branch.current_heads.iter().map(|h| h.id.clone()).collect(),
             graph: if results.is_empty() {
@@ -344,7 +367,7 @@ impl Verifier {
                     triples: serde_bare::to_vec(&results).unwrap(),
                 })
             },
-            discrete: None,
+            discrete,
             files,
         };
 
@@ -2424,7 +2447,7 @@ impl Verifier {
         //TODO: improve the inner_to_outer insert. (should be done when store is created, not here. should work also for dialogs.)
         self.inner_to_outer.insert(
             repo.store.overlay_for_read_on_client_protocol(),
-            repo.store.outer_overlay(),
+            repo.store.overlay_id,
         );
         for sub in opened_repo {
             Self::branch_was_opened(&self.topics, repo, sub)?;
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 9e09bd4..6a2b467 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -33,6 +33,7 @@ importers:
     specifiers:
       '@codemirror/autocomplete': ^6.17.0
       '@codemirror/commands': ^6.6.0
+      '@codemirror/lang-javascript': ^6.2.2
       '@codemirror/language': ^6.10.2
       '@codemirror/legacy-modes': ^6.4.0
       '@codemirror/lint': ^6.8.1
@@ -81,9 +82,12 @@ importers:
       vite-plugin-svelte-svg: ^2.2.1
       vite-plugin-top-level-await: ^1.3.1
       vite-plugin-wasm: ^3.2.2
+      y-codemirror.next: ^0.3.5
+      yjs: ^13.6.18
     dependencies:
       '@codemirror/autocomplete': 6.17.0_77urojsfbrmvdrcps23icldzhi
       '@codemirror/commands': 6.6.0
+      '@codemirror/lang-javascript': 6.2.2
       '@codemirror/language': 6.10.2
       '@codemirror/legacy-modes': 6.4.0
       '@codemirror/lint': 6.8.1
@@ -106,6 +110,8 @@ importers:
       svelte-inview: 4.0.2_svelte@3.59.1
       svelte-spa-router: 3.3.0
       vite-plugin-top-level-await: 1.3.1_vite@4.3.9
+      y-codemirror.next: 0.3.5_2derscuhaavtzv2sogf3enfvaa
+      yjs: 13.6.18
     devDependencies:
       '@sveltejs/vite-plugin-svelte': 2.4.1_svelte@3.59.1+vite@4.3.9
       '@tauri-apps/cli': 2.0.0-alpha.14
@@ -195,6 +201,18 @@ packages:
       '@lezer/common': 1.2.1
     dev: false
 
+  /@codemirror/lang-javascript/6.2.2:
+    resolution: {integrity: sha512-VGQfY+FCc285AhWuwjYxQyUQcYurWlxdKYT4bqwr3Twnd5wP5WSeu52t4tvvuWmljT4EmgEgZCqSieokhtY8hg==}
+    dependencies:
+      '@codemirror/autocomplete': 6.17.0_77urojsfbrmvdrcps23icldzhi
+      '@codemirror/language': 6.10.2
+      '@codemirror/lint': 6.8.1
+      '@codemirror/state': 6.4.1
+      '@codemirror/view': 6.29.1
+      '@lezer/common': 1.2.1
+      '@lezer/javascript': 1.4.17
+    dev: false
+
   /@codemirror/language/6.10.2:
     resolution: {integrity: sha512-kgbTYTo0Au6dCSc/TFy7fK3fpJmgHDv1sG1KNQKJXVi+xBTEeBPY/M30YXiU6mMXeH+YIDLsbrT4ZwNRdtF+SA==}
     dependencies:
@@ -718,6 +736,14 @@ packages:
       '@lezer/common': 1.2.1
     dev: false
 
+  /@lezer/javascript/1.4.17:
+    resolution: {integrity: sha512-bYW4ctpyGK+JMumDApeUzuIezX01H76R1foD6LcRX224FWfyYit/HYxiPGDjXXe/wQWASjCvVGoukTH68+0HIA==}
+    dependencies:
+      '@lezer/common': 1.2.1
+      '@lezer/highlight': 1.2.0
+      '@lezer/lr': 1.4.1
+    dev: false
+
   /@lezer/lr/1.4.1:
     resolution: {integrity: sha512-CHsKq8DMKBf9b3yXPDIU4DbH+ZJd/sJdYOW2llbW/HudP5u0VS6Bfq1hLYfgU7uAYGFIyGGQIsSOXGPEErZiJw==}
     dependencies:
@@ -1756,6 +1782,10 @@ packages:
     resolution: {integrity: sha512-RHxMLp9lnKHGHRng9QFhRCMbYAcVpn69smSGcq3f36xjgVVWThj4qqLbTLlq7Ssj8B+fIQ1EuCEGI2lKsyQeIw==}
     dev: true
 
+  /isomorphic.js/0.2.5:
+    resolution: {integrity: sha512-PIeMbHqMt4DnUP3MA/Flc0HElYjMXArsw1qwJZcm9sqR8mq3l8NYizFMty0pWwE/tzIGH3EKK5+jes5mAr85yw==}
+    dev: false
+
   /jiti/1.18.2:
     resolution: {integrity: sha512-QAdOptna2NYiSSpv0O/BwoHBSmz4YhpzJHyi+fnMRTXFjp7B8i/YG5Z8IfusxB1ufjcD2Sre1F3R+nX3fvy7gg==}
     hasBin: true
@@ -1766,6 +1796,14 @@ packages:
     engines: {node: '>=6'}
     dev: true
 
+  /lib0/0.2.95:
+    resolution: {integrity: sha512-St5XGDh5omvNawGkAOa7CFRjxl4xEKLj9DxgT8Nl7rmrD6l2WRTngvmZGhJKRaniROterT0RDVdnwLlU9PiEOg==}
+    engines: {node: '>=16'}
+    hasBin: true
+    dependencies:
+      isomorphic.js: 0.2.5
+    dev: false
+
   /lilconfig/2.1.0:
     resolution: {integrity: sha512-utWOt/GHzuUxnLKxB6dk81RoOeoNeHgbrXiuGk4yyF5qlRz+iIVWu56E2fqGHFrXz0QNUhLB/8nKqvRH66JKGQ==}
     engines: {node: '>=10'}
@@ -2770,7 +2808,27 @@ packages:
     resolution: {integrity: sha512-l4Sp/DRseor9wL6EvV2+TuQn63dMkPjZ/sp9XkghTEbV9KlPS1xUsZ3u7/IQO4wxtcFB4bgpQPRcR3QCvezPcQ==}
     dev: true
 
+  /y-codemirror.next/0.3.5_2derscuhaavtzv2sogf3enfvaa:
+    resolution: {integrity: sha512-VluNu3e5HfEXybnypnsGwKAj+fKLd4iAnR7JuX1Sfyydmn1jCBS5wwEL/uS04Ch2ib0DnMAOF6ZRR/8kK3wyGw==}
+    peerDependencies:
+      '@codemirror/state': ^6.0.0
+      '@codemirror/view': ^6.0.0
+      yjs: ^13.5.6
+    dependencies:
+      '@codemirror/state': 6.4.1
+      '@codemirror/view': 6.29.1
+      lib0: 0.2.95
+      yjs: 13.6.18
+    dev: false
+
   /yaml/2.3.1:
     resolution: {integrity: sha512-2eHWfjaoXgTBC2jNM1LRef62VQa0umtvRiDSk6HSzW7RvS5YtkabJrwYLLEKWBc8a5U2PTSCs+dJjUTJdlHsWQ==}
     engines: {node: '>= 14'}
     dev: true
+
+  /yjs/13.6.18:
+    resolution: {integrity: sha512-GBTjO4QCmv2HFKFkYIJl7U77hIB1o22vSCSQD1Ge8ZxWbIbn8AltI4gyXbtL+g5/GJep67HCMq3Y5AmNwDSyEg==}
+    engines: {node: '>=16.0.0', npm: '>=8.0.0'}
+    dependencies:
+      lib0: 0.2.95
+    dev: false