diff --git a/_check_ts_progress.sh b/_check_ts_progress.sh
index 424760125..7332a6054 100755
--- a/_check_ts_progress.sh
+++ b/_check_ts_progress.sh
@@ -10,4 +10,4 @@ echo By file
 cloc HEAD \
     --git --md \
     --include-lang=javascript,typescript \
-    --by-file
\ No newline at end of file
+    --by-file | grep \.js\|
\ No newline at end of file
diff --git a/bin/copy-dist.ts b/bin/copy-dist.ts
index 093a3a375..9e272d222 100644
--- a/bin/copy-dist.ts
+++ b/bin/copy-dist.ts
@@ -29,7 +29,7 @@ const copy = async () => {
     fs.copySync(path.join("build", srcFile), destFile, { recursive: true });
   }
 
-  const filesToCopy = ["config-sample.ini"];
+  const filesToCopy = ["config-sample.ini", "tsconfig.webpack.json"];
   for (const file of filesToCopy) {
     log(`Copying ${file}`);
     await fs.copy(file, path.join(DEST_DIR, file));
diff --git a/src/public/app/components/app_context.ts b/src/public/app/components/app_context.ts
index 6372d43ce..549f465bf 100644
--- a/src/public/app/components/app_context.ts
+++ b/src/public/app/components/app_context.ts
@@ -14,6 +14,10 @@ import MainTreeExecutors from "./main_tree_executors.js";
 import toast from "../services/toast.js";
 import ShortcutComponent from "./shortcut_component.js";
 import { t, initLocale } from "../services/i18n.js";
+import NoteDetailWidget from "../widgets/note_detail.js";
+import { ResolveOptions } from "../widgets/dialogs/delete_notes.js";
+import { PromptDialogOptions } from "../widgets/dialogs/prompt.js";
+import { ConfirmWithMessageOptions, ConfirmWithTitleOptions } from "../widgets/dialogs/confirm.js";
 
 interface Layout {
     getRootWidget: (appContext: AppContext) => RootWidget;
@@ -27,13 +31,72 @@ interface BeforeUploadListener extends Component {
     beforeUnloadEvent(): boolean;
 }
 
-interface TriggerData {
-    noteId?: string;
-    noteIds?: string[];
-    messages?: unknown[];
-    callback?: () => void;
+interface CommandData {
+    ntxId?: string;
 }
 
+type CommandMappings = {
+    "api-log-messages": CommandData;
+    focusOnDetail: Required<CommandData>;
+    searchNotes: CommandData & {
+        searchString: string | undefined;
+    };
+    showDeleteNotesDialog: CommandData & {
+        branchIdsToDelete: string[];
+        callback: (value: ResolveOptions) => void;
+        forceDeleteAllClones: boolean;
+    };
+    showConfirmDeleteNoteBoxWithNoteDialog: ConfirmWithTitleOptions;
+    openedFileUpdated: CommandData & {
+        entityType: string;
+        entityId: string;
+        lastModifiedMs: number;
+        filePath: string;
+    };
+    focusAndSelectTitle: CommandData & {
+        isNewNote: boolean;
+    };
+    showPromptDialog: PromptDialogOptions;
+    showInfoDialog: ConfirmWithMessageOptions;
+    showConfirmDialog: ConfirmWithMessageOptions;
+    openNewNoteSplit: CommandData & {
+        ntxId: string;
+        notePath: string;   
+    };
+    executeInActiveNoteDetailWidget: CommandData & {
+        callback: (value: NoteDetailWidget | PromiseLike<NoteDetailWidget>) => void
+    };
+    addTextToActiveEditor: CommandData & {
+        text: string;
+    };
+    
+    importMarkdownInline: CommandData;
+    showPasswordNotSet: CommandData;
+    showProtectedSessionPasswordDialog: CommandData;
+    closeProtectedSessionPasswordDialog: CommandData;
+}
+
+type EventMappings = {
+    initialRenderComplete: {};
+    frocaReloaded: {};
+    protectedSessionStarted: {};
+    notesReloaded: {
+        noteIds: string[];
+    };
+    refreshIncludedNote: {
+        noteId: string;
+    };
+    apiLogMessages: {
+        noteId: string;
+        messages: string[];
+    };
+}
+
+type CommandAndEventMappings = (CommandMappings & EventMappings);
+
+export type CommandNames = keyof CommandMappings;
+type EventNames = keyof EventMappings;
+
 class AppContext extends Component {
 
     isMainWindow: boolean;
@@ -127,11 +190,15 @@ class AppContext extends Component {
         this.triggerEvent('initialRenderComplete');
     }
 
-    triggerEvent(name: string, data: TriggerData = {}) {
+    // TODO: Remove ignore once all commands are mapped out.
+    //@ts-ignore
+    triggerEvent<K extends EventNames | CommandNames>(name: K, data: CommandAndEventMappings[K] = {}) {
         return this.handleEvent(name, data);
     }
 
-    triggerCommand(name: string, data: TriggerData = {}) {
+    // TODO: Remove ignore once all commands are mapped out.
+    //@ts-ignore
+    triggerCommand<K extends CommandNames>(name: K, data: CommandMappings[K] = {}) {
         for (const executor of this.components) {
             const fun = (executor as any)[`${name}Command`];
 
@@ -144,7 +211,7 @@ class AppContext extends Component {
         // in the component tree to communicate with each other
         console.debug(`Unhandled command ${name}, converting to event.`);
 
-        return this.triggerEvent(name, data);
+        return this.triggerEvent(name, data as CommandAndEventMappings[K]);
     }
 
     getComponentByEl(el: HTMLElement) {
diff --git a/src/public/app/components/component.ts b/src/public/app/components/component.ts
index 0156bdfc2..f8205e0b2 100644
--- a/src/public/app/components/component.ts
+++ b/src/public/app/components/component.ts
@@ -16,6 +16,7 @@ export default class Component {
     children: Component[];
     initialized: Promise<void> | null;
     parent?: Component;
+    position!: number;
 
     constructor() {
         this.componentId = `${this.sanitizedClassName}-${utils.randomString(8)}`;
diff --git a/src/public/app/entities/fattachment.ts b/src/public/app/entities/fattachment.ts
index 704a53ba7..20ba79c94 100644
--- a/src/public/app/entities/fattachment.ts
+++ b/src/public/app/entities/fattachment.ts
@@ -21,10 +21,11 @@ class FAttachment {
     attachmentId!: string;
     private ownerId!: string;
     role!: string;
-    private mime!: string;
-    private title!: string;
+    mime!: string;
+    title!: string;
+    isProtected!: boolean;  // TODO: Is this used?
     private dateModified!: string;
-    private utcDateModified!: string;
+    utcDateModified!: string;
     private utcDateScheduledForErasureSince!: string;
     /**
      * optionally added to the entity 
diff --git a/src/public/app/server_types.ts b/src/public/app/server_types.ts
new file mode 100644
index 000000000..cdbb1c9ec
--- /dev/null
+++ b/src/public/app/server_types.ts
@@ -0,0 +1,18 @@
+// TODO: Deduplicate with src/services/entity_changes_interface.ts
+export interface EntityChange {
+	id?: number | null;
+	noteId?: string;
+	entityName: string;
+	entityId: string;
+	entity?: any;
+	positions?: Record<string, number>;
+	hash: string;
+	utcDateChanged?: string;
+	utcDateModified?: string;
+	utcDateCreated?: string;
+	isSynced: boolean | 1 | 0;
+	isErased: boolean | 1 | 0;
+	componentId?: string | null;
+	changeId?: string | null;
+	instanceId?: string | null;
+}
\ No newline at end of file
diff --git a/src/public/app/services/attribute_autocomplete.js b/src/public/app/services/attribute_autocomplete.ts
similarity index 83%
rename from src/public/app/services/attribute_autocomplete.js
rename to src/public/app/services/attribute_autocomplete.ts
index 761d5dbeb..041129974 100644
--- a/src/public/app/services/attribute_autocomplete.js
+++ b/src/public/app/services/attribute_autocomplete.ts
@@ -1,11 +1,19 @@
+import { AttributeType } from "../entities/fattribute.js";
 import server from "./server.js";
 
+interface InitOptions {
+    $el: JQuery<HTMLElement>;
+    attributeType: AttributeType | (() => AttributeType);
+    open: boolean;
+    nameCallback: () => string;
+}
+
 /**
  * @param $el - element on which to init autocomplete
  * @param attributeType - "relation" or "label" or callback providing one of those values as a type of autocompleted attributes
  * @param open - should the autocomplete be opened after init?
  */
-function initAttributeNameAutocomplete({ $el, attributeType, open }) {
+function initAttributeNameAutocomplete({ $el, attributeType, open }: InitOptions) {
     if (!$el.hasClass("aa-input")) {
         $el.autocomplete({
             appendTo: document.querySelector('body'),
@@ -20,7 +28,7 @@ function initAttributeNameAutocomplete({ $el, attributeType, open }) {
             source: async (term, cb) => {
                 const type = typeof attributeType === "function" ? attributeType() : attributeType;
 
-                const names = await server.get(`attribute-names/?type=${type}&query=${encodeURIComponent(term)}`);
+                const names = await server.get<string[]>(`attribute-names/?type=${type}&query=${encodeURIComponent(term)}`);
                 const result = names.map(name => ({name}));
 
                 cb(result);
@@ -39,7 +47,7 @@ function initAttributeNameAutocomplete({ $el, attributeType, open }) {
     }
 }
 
-async function initLabelValueAutocomplete({ $el, open, nameCallback }) {
+async function initLabelValueAutocomplete({ $el, open, nameCallback }: InitOptions) {
     if ($el.hasClass("aa-input")) {
         // we reinit every time because autocomplete seems to have a bug where it retains state from last
         // open even though the value was reset
@@ -52,7 +60,7 @@ async function initLabelValueAutocomplete({ $el, open, nameCallback }) {
         return;
     }
 
-    const attributeValues = (await server.get(`attribute-values/${encodeURIComponent(attributeName)}`))
+    const attributeValues = (await server.get<string[]>(`attribute-values/${encodeURIComponent(attributeName)}`))
         .map(attribute => ({ value: attribute }));
 
     if (attributeValues.length === 0) {
diff --git a/src/public/app/services/attribute_parser.d.ts b/src/public/app/services/attribute_parser.d.ts
deleted file mode 100644
index 58fe9b916..000000000
--- a/src/public/app/services/attribute_parser.d.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-declare module 'attribute_parser';
-
-
-export function lex(str: string): any[]
-export function parse(tokens: any[], str?: string, allowEmptyRelations?: boolean): any[]
-export function lexAndParse(str: string, allowEmptyRelations?: boolean): any[]
-
diff --git a/src/public/app/services/attribute_parser.js b/src/public/app/services/attribute_parser.ts
similarity index 86%
rename from src/public/app/services/attribute_parser.js
rename to src/public/app/services/attribute_parser.ts
index fc032a252..07677a1e5 100644
--- a/src/public/app/services/attribute_parser.js
+++ b/src/public/app/services/attribute_parser.ts
@@ -1,14 +1,30 @@
+import FAttribute, { AttributeType, FAttributeRow } from "../entities/fattribute.js";
 import utils from "./utils.js";
 
-function lex(str) {
+interface Token {
+    text: string;
+    startIndex: number;
+    endIndex: number;
+}
+
+interface Attribute {
+    type: AttributeType;
+    name: string;
+    isInheritable: boolean;
+    value?: string;
+    startIndex: number;
+    endIndex: number;
+}
+
+function lex(str: string) {
     str = str.trim();
 
-    const tokens = [];
+    const tokens: Token[] = [];
 
-    let quotes = false;
+    let quotes: boolean | string = false;
     let currentWord = '';
 
-    function isOperatorSymbol(chr) {
+    function isOperatorSymbol(chr: string) {
         return ['=', '*', '>', '<', '!'].includes(chr);
     }
 
@@ -24,7 +40,7 @@ function lex(str) {
     /**
      * @param endIndex - index of the last character of the token
      */
-    function finishWord(endIndex) {
+    function finishWord(endIndex: number) {
         if (currentWord === '') {
             return;
         }
@@ -107,7 +123,7 @@ function lex(str) {
     return tokens;
 }
 
-function checkAttributeName(attrName) {
+function checkAttributeName(attrName: string) {
     if (attrName.length === 0) {
         throw new Error("Attribute name is empty, please fill the name.");
     }
@@ -117,10 +133,10 @@ function checkAttributeName(attrName) {
     }
 }
 
-function parse(tokens, str, allowEmptyRelations = false) {
-    const attrs = [];
+function parse(tokens: Token[], str: string, allowEmptyRelations = false) {
+    const attrs: Attribute[] = [];
 
-    function context(i) {
+    function context(i: number) {
         let { startIndex, endIndex } = tokens[i];
         startIndex = Math.max(0, startIndex - 20);
         endIndex = Math.min(str.length, endIndex + 20);
@@ -151,7 +167,7 @@ function parse(tokens, str, allowEmptyRelations = false) {
 
             checkAttributeName(labelName);
 
-            const attr = {
+            const attr: Attribute = {
                 type: 'label',
                 name: labelName,
                 isInheritable: isInheritable(),
@@ -177,7 +193,7 @@ function parse(tokens, str, allowEmptyRelations = false) {
 
             checkAttributeName(relationName);
 
-            const attr = {
+            const attr: Attribute = {
                 type: 'relation',
                 name: relationName,
                 isInheritable: isInheritable(),
@@ -216,7 +232,7 @@ function parse(tokens, str, allowEmptyRelations = false) {
     return attrs;
 }
 
-function lexAndParse(str, allowEmptyRelations = false) {
+function lexAndParse(str: string, allowEmptyRelations = false) {
     const tokens = lex(str);
 
     return parse(tokens, str, allowEmptyRelations);
diff --git a/src/public/app/services/attribute_renderer.js b/src/public/app/services/attribute_renderer.ts
similarity index 84%
rename from src/public/app/services/attribute_renderer.js
rename to src/public/app/services/attribute_renderer.ts
index 8916665a3..b5f8477ec 100644
--- a/src/public/app/services/attribute_renderer.js
+++ b/src/public/app/services/attribute_renderer.ts
@@ -1,7 +1,9 @@
 import ws from "./ws.js";
 import froca from "./froca.js";
+import FAttribute from "../entities/fattribute.js";
+import FNote from "../entities/fnote.js";
 
-async function renderAttribute(attribute, renderIsInheritable) {
+async function renderAttribute(attribute: FAttribute, renderIsInheritable: boolean) {
     const isInheritable = renderIsInheritable && attribute.isInheritable ? `(inheritable)` : '';
     const $attr = $("<span>");
 
@@ -20,7 +22,11 @@ async function renderAttribute(attribute, renderIsInheritable) {
         // when the relation has just been created, then it might not have a value
         if (attribute.value) {
             $attr.append(document.createTextNode(`~${attribute.name}${isInheritable}=`));
-            $attr.append(await createLink(attribute.value));
+
+            const link = await createLink(attribute.value);
+            if (link) {
+                $attr.append(link);
+            }
         }
     } else {
         ws.logError(`Unknown attr type: ${attribute.type}`);
@@ -29,7 +35,7 @@ async function renderAttribute(attribute, renderIsInheritable) {
     return $attr;
 }
 
-function formatValue(val) {
+function formatValue(val: string) {
     if (/^[\p{L}\p{N}\-_,.]+$/u.test(val)) {
         return val;
     }
@@ -47,7 +53,7 @@ function formatValue(val) {
     }
 }
 
-async function createLink(noteId) {
+async function createLink(noteId: string) {
     const note = await froca.getNote(noteId);
 
     if (!note) {
@@ -61,7 +67,7 @@ async function createLink(noteId) {
         .text(note.title);
 }
 
-async function renderAttributes(attributes, renderIsInheritable) {
+async function renderAttributes(attributes: FAttribute[], renderIsInheritable: boolean) {
     const $container = $('<span class="rendered-note-attributes">');
 
     for (let i = 0; i < attributes.length; i++) {
@@ -89,7 +95,7 @@ const HIDDEN_ATTRIBUTES = [
     'viewType'
 ];
 
-async function renderNormalAttributes(note) {
+async function renderNormalAttributes(note: FNote) {
     const promotedDefinitionAttributes = note.getPromotedDefinitionAttributes();
     let attrs = note.getAttributes();
 
diff --git a/src/public/app/services/attributes.js b/src/public/app/services/attributes.ts
similarity index 79%
rename from src/public/app/services/attributes.js
rename to src/public/app/services/attributes.ts
index 7267d9bb8..e8dbcb89e 100644
--- a/src/public/app/services/attributes.js
+++ b/src/public/app/services/attributes.ts
@@ -1,7 +1,8 @@
 import server from './server.js';
 import froca from './froca.js';
+import FNote from '../entities/fnote.js';
 
-async function addLabel(noteId, name, value = "") {
+async function addLabel(noteId: string, name: string, value: string = "") {
     await server.put(`notes/${noteId}/attribute`, {
         type: 'label',
         name: name,
@@ -9,7 +10,7 @@ async function addLabel(noteId, name, value = "") {
     });
 }
 
-async function setLabel(noteId, name, value = "") {
+async function setLabel(noteId: string, name: string, value: string = "") {
     await server.put(`notes/${noteId}/set-attribute`, {
         type: 'label',
         name: name,
@@ -17,7 +18,7 @@ async function setLabel(noteId, name, value = "") {
     });
 }
 
-async function removeAttributeById(noteId, attributeId) {
+async function removeAttributeById(noteId: string, attributeId: string) {
     await server.remove(`notes/${noteId}/attributes/${attributeId}`);
 }
 
@@ -28,7 +29,7 @@ async function removeAttributeById(noteId, attributeId) {
  *         2. attribute is owned by the template of the note
  *         3. attribute is owned by some note's ancestor and is inheritable
  */
-function isAffecting(attrRow, affectedNote) {
+function isAffecting(this: { isInheritable: boolean }, attrRow: { noteId: string }, affectedNote: FNote) {
     if (!affectedNote || !attrRow) {
         return false;
     }
@@ -48,6 +49,7 @@ function isAffecting(attrRow, affectedNote) {
         }
     }
 
+    // TODO: This doesn't seem right.
     if (this.isInheritable) {
         for (const owningNote of owningNotes) {
             if (owningNote.hasAncestor(attrNote.noteId, true)) {
diff --git a/src/public/app/services/branches.js b/src/public/app/services/branches.ts
similarity index 74%
rename from src/public/app/services/branches.js
rename to src/public/app/services/branches.ts
index 803c59147..6eb5c07ff 100644
--- a/src/public/app/services/branches.js
+++ b/src/public/app/services/branches.ts
@@ -1,17 +1,28 @@
 import utils from './utils.js';
 import server from './server.js';
-import toastService from "./toast.js";
+import toastService, { ToastOptions } from "./toast.js";
 import froca from "./froca.js";
 import hoistedNoteService from "./hoisted_note.js";
 import ws from "./ws.js";
 import appContext from "../components/app_context.js";
 import { t } from './i18n.js';
+import { Node } from './tree.js';
+import { ResolveOptions } from '../widgets/dialogs/delete_notes.js';
 
-async function moveBeforeBranch(branchIdsToMove, beforeBranchId) {
+// TODO: Deduplicate type with server
+interface Response {
+    success: boolean;
+    message: string;
+}
+
+async function moveBeforeBranch(branchIdsToMove: string[], beforeBranchId: string) {
     branchIdsToMove = filterRootNote(branchIdsToMove);
     branchIdsToMove = filterSearchBranches(branchIdsToMove);
 
     const beforeBranch = froca.getBranch(beforeBranchId);
+    if (!beforeBranch) {
+        return;
+    }
 
     if (['root', '_lbRoot', '_lbAvailableLaunchers', '_lbVisibleLaunchers'].includes(beforeBranch.noteId)) {
         toastService.showError(t("branches.cannot-move-notes-here"));
@@ -19,7 +30,7 @@ async function moveBeforeBranch(branchIdsToMove, beforeBranchId) {
     }
 
     for (const branchIdToMove of branchIdsToMove) {
-        const resp = await server.put(`branches/${branchIdToMove}/move-before/${beforeBranchId}`);
+        const resp = await server.put<Response>(`branches/${branchIdToMove}/move-before/${beforeBranchId}`);
 
         if (!resp.success) {
             toastService.showError(resp.message);
@@ -28,11 +39,14 @@ async function moveBeforeBranch(branchIdsToMove, beforeBranchId) {
     }
 }
 
-async function moveAfterBranch(branchIdsToMove, afterBranchId) {
+async function moveAfterBranch(branchIdsToMove: string[], afterBranchId: string) {
     branchIdsToMove = filterRootNote(branchIdsToMove);
     branchIdsToMove = filterSearchBranches(branchIdsToMove);
 
-    const afterNote = froca.getBranch(afterBranchId).getNote();
+    const afterNote = await froca.getBranch(afterBranchId)?.getNote();
+    if (!afterNote) {
+        return;
+    }
 
     const forbiddenNoteIds = [
         'root',
@@ -50,7 +64,7 @@ async function moveAfterBranch(branchIdsToMove, afterBranchId) {
     branchIdsToMove.reverse(); // need to reverse to keep the note order
 
     for (const branchIdToMove of branchIdsToMove) {
-        const resp = await server.put(`branches/${branchIdToMove}/move-after/${afterBranchId}`);
+        const resp = await server.put<Response>(`branches/${branchIdToMove}/move-after/${afterBranchId}`);
 
         if (!resp.success) {
             toastService.showError(resp.message);
@@ -59,8 +73,11 @@ async function moveAfterBranch(branchIdsToMove, afterBranchId) {
     }
 }
 
-async function moveToParentNote(branchIdsToMove, newParentBranchId) {
+async function moveToParentNote(branchIdsToMove: string[], newParentBranchId: string) {
     const newParentBranch = froca.getBranch(newParentBranchId);
+    if (!newParentBranch) {
+        return;
+    }
 
     if (newParentBranch.noteId === '_lbRoot') {
         toastService.showError(t("branches.cannot-move-notes-here"));
@@ -72,12 +89,13 @@ async function moveToParentNote(branchIdsToMove, newParentBranchId) {
     for (const branchIdToMove of branchIdsToMove) {
         const branchToMove = froca.getBranch(branchIdToMove);
 
-        if (branchToMove.noteId === hoistedNoteService.getHoistedNoteId()
-            || (await branchToMove.getParentNote()).type === 'search') {
+        if (!branchToMove
+            || branchToMove.noteId === hoistedNoteService.getHoistedNoteId()
+            || (await branchToMove.getParentNote())?.type === 'search') {
             continue;
         }
 
-        const resp = await server.put(`branches/${branchIdToMove}/move-to/${newParentBranchId}`);
+        const resp = await server.put<Response>(`branches/${branchIdToMove}/move-to/${newParentBranchId}`);
 
         if (!resp.success) {
             toastService.showError(resp.message);
@@ -86,7 +104,7 @@ async function moveToParentNote(branchIdsToMove, newParentBranchId) {
     }
 }
 
-async function deleteNotes(branchIdsToDelete, forceDeleteAllClones = false) {
+async function deleteNotes(branchIdsToDelete: string[], forceDeleteAllClones = false) {
     branchIdsToDelete = filterRootNote(branchIdsToDelete);
 
     if (branchIdsToDelete.length === 0) {
@@ -100,7 +118,7 @@ async function deleteNotes(branchIdsToDelete, forceDeleteAllClones = false) {
         deleteAllClones = false;
     }
     else {
-        ({proceed, deleteAllClones, eraseNotes} = await new Promise(res =>
+        ({proceed, deleteAllClones, eraseNotes} = await new Promise<ResolveOptions>(res =>
             appContext.triggerCommand('showDeleteNotesDialog', {branchIdsToDelete, callback: res, forceDeleteAllClones})));
     }
 
@@ -127,10 +145,9 @@ async function deleteNotes(branchIdsToDelete, forceDeleteAllClones = false) {
 
         const branch = froca.getBranch(branchIdToDelete);
 
-        if (deleteAllClones) {
+        if (deleteAllClones && branch) {
             await server.remove(`notes/${branch.noteId}${query}`);
-        }
-        else {
+        } else {
             await server.remove(`branches/${branchIdToDelete}${query}`);
         }
     }
@@ -152,7 +169,7 @@ async function activateParentNotePath() {
     }
 }
 
-async function moveNodeUpInHierarchy(node) {
+async function moveNodeUpInHierarchy(node: Node) {
     if (hoistedNoteService.isHoistedNode(node)
         || hoistedNoteService.isTopLevelNode(node)
         || node.getParent().data.noteType === 'search') {
@@ -162,7 +179,7 @@ async function moveNodeUpInHierarchy(node) {
     const targetBranchId = node.getParent().data.branchId;
     const branchIdToMove = node.data.branchId;
 
-    const resp = await server.put(`branches/${branchIdToMove}/move-after/${targetBranchId}`);
+    const resp = await server.put<Response>(`branches/${branchIdToMove}/move-after/${targetBranchId}`);
 
     if (!resp.success) {
         toastService.showError(resp.message);
@@ -175,22 +192,25 @@ async function moveNodeUpInHierarchy(node) {
     }
 }
 
-function filterSearchBranches(branchIds) {
+function filterSearchBranches(branchIds: string[]) {
     return branchIds.filter(branchId => !branchId.startsWith('virt-'));
 }
 
-function filterRootNote(branchIds) {
+function filterRootNote(branchIds: string[]) {
     const hoistedNoteId = hoistedNoteService.getHoistedNoteId();
 
     return branchIds.filter(branchId => {
         const branch = froca.getBranch(branchId);
+        if (!branch) {
+            return false;
+        }
 
         return branch.noteId !== 'root'
             && branch.noteId !== hoistedNoteId;
     });
 }
 
-function makeToast(id, message) {
+function makeToast(id: string, message: string): ToastOptions {
     return {
         id: id,
         title: t("branches.delete-status"),
@@ -235,8 +255,8 @@ ws.subscribeToMessages(async message => {
     }
 });
 
-async function cloneNoteToBranch(childNoteId, parentBranchId, prefix) {
-    const resp = await server.put(`notes/${childNoteId}/clone-to-branch/${parentBranchId}`, {
+async function cloneNoteToBranch(childNoteId: string, parentBranchId: string, prefix?: string) {
+    const resp = await server.put<Response>(`notes/${childNoteId}/clone-to-branch/${parentBranchId}`, {
         prefix: prefix
     });
 
@@ -245,8 +265,8 @@ async function cloneNoteToBranch(childNoteId, parentBranchId, prefix) {
     }
 }
 
-async function cloneNoteToParentNote(childNoteId, parentNoteId, prefix) {
-    const resp = await server.put(`notes/${childNoteId}/clone-to-note/${parentNoteId}`, {
+async function cloneNoteToParentNote(childNoteId: string, parentNoteId: string, prefix: string) {
+    const resp = await server.put<Response>(`notes/${childNoteId}/clone-to-note/${parentNoteId}`, {
         prefix: prefix
     });
 
@@ -256,8 +276,8 @@ async function cloneNoteToParentNote(childNoteId, parentNoteId, prefix) {
 }
 
 // beware that the first arg is noteId and the second is branchId!
-async function cloneNoteAfter(noteId, afterBranchId) {
-    const resp = await server.put(`notes/${noteId}/clone-after/${afterBranchId}`);
+async function cloneNoteAfter(noteId: string, afterBranchId: string) {
+    const resp = await server.put<Response>(`notes/${noteId}/clone-after/${afterBranchId}`);
 
     if (!resp.success) {
         toastService.showError(resp.message);
diff --git a/src/public/app/services/bulk_action.js b/src/public/app/services/bulk_action.ts
similarity index 95%
rename from src/public/app/services/bulk_action.js
rename to src/public/app/services/bulk_action.ts
index 313f36a8f..5a039ea4f 100644
--- a/src/public/app/services/bulk_action.js
+++ b/src/public/app/services/bulk_action.ts
@@ -14,6 +14,7 @@ import AddLabelBulkAction from "../widgets/bulk_actions/label/add_label.js";
 import AddRelationBulkAction from "../widgets/bulk_actions/relation/add_relation.js";
 import RenameNoteBulkAction from "../widgets/bulk_actions/note/rename_note.js";
 import { t } from "./i18n.js";
+import FNote from "../entities/fnote.js";
 
 const ACTION_GROUPS = [
     {
@@ -50,7 +51,7 @@ const ACTION_CLASSES = [
     ExecuteScriptBulkAction
 ];
 
-async function addAction(noteId, actionName) {
+async function addAction(noteId: string, actionName: string) {
     await server.post(`notes/${noteId}/attributes`, {
         type: 'label',
         name: 'action',
@@ -62,7 +63,7 @@ async function addAction(noteId, actionName) {
     await ws.waitForMaxKnownEntityChangeId();
 }
 
-function parseActions(note) {
+function parseActions(note: FNote) {
     const actionLabels = note.getLabels('action');
 
     return actionLabels.map(actionAttr => {
@@ -70,7 +71,7 @@ function parseActions(note) {
 
         try {
             actionDef = JSON.parse(actionAttr.value);
-        } catch (e) {
+        } catch (e: any) {
             logError(`Parsing of attribute: '${actionAttr.value}' failed with error: ${e.message}`);
             return null;
         }
diff --git a/src/public/app/services/bundle.js b/src/public/app/services/bundle.ts
similarity index 72%
rename from src/public/app/services/bundle.js
rename to src/public/app/services/bundle.ts
index e0a81eee4..071d89458 100644
--- a/src/public/app/services/bundle.js
+++ b/src/public/app/services/bundle.ts
@@ -4,9 +4,22 @@ import toastService from "./toast.js";
 import froca from "./froca.js";
 import utils from "./utils.js";
 import { t } from "./i18n.js";
+import { Entity } from "./frontend_script_api.js";
 
-async function getAndExecuteBundle(noteId, originEntity = null, script = null, params = null) {
-    const bundle = await server.post(`script/bundle/${noteId}`, {
+// TODO: Deduplicate with server.
+export interface Bundle {
+    script: string;
+    html: string;
+    noteId: string;
+    allNoteIds: string[];
+}
+
+interface Widget {
+    parentWidget?: string;
+}
+
+async function getAndExecuteBundle(noteId: string, originEntity = null, script = null, params = null) {
+    const bundle = await server.post<Bundle>(`script/bundle/${noteId}`, {
         script,
         params
     });
@@ -14,24 +27,23 @@ async function getAndExecuteBundle(noteId, originEntity = null, script = null, p
     return await executeBundle(bundle, originEntity);
 }
 
-async function executeBundle(bundle, originEntity, $container) {
+async function executeBundle(bundle: Bundle, originEntity?: Entity | null, $container?: JQuery<HTMLElement>) {
     const apiContext = await ScriptContext(bundle.noteId, bundle.allNoteIds, originEntity, $container);
 
     try {
         return await (function () {
             return eval(`const apiContext = this; (async function() { ${bundle.script}\r\n})()`);
         }.call(apiContext));
-    }
-    catch (e) {
+    } catch (e: any) {
         const note = await froca.getNote(bundle.noteId);
 
-        toastService.showAndLogError(`Execution of JS note "${note.title}" with ID ${bundle.noteId} failed with error: ${e.message}`);
+        toastService.showAndLogError(`Execution of JS note "${note?.title}" with ID ${bundle.noteId} failed with error: ${e?.message}`);
     }
 }
 
 async function executeStartupBundles() {
     const isMobile = utils.isMobile();
-    const scriptBundles = await server.get("script/startup" + (isMobile ? "?mobile=true" : ""));
+    const scriptBundles = await server.get<Bundle[]>("script/startup" + (isMobile ? "?mobile=true" : ""));
 
     for (const bundle of scriptBundles) {
         await executeBundle(bundle);
@@ -39,11 +51,14 @@ async function executeStartupBundles() {
 }
 
 class WidgetsByParent {
+
+    private byParent: Record<string, Widget[]>;
+
     constructor() {
         this.byParent = {};
     }
 
-    add(widget) {
+    add(widget: Widget) {
         if (!widget.parentWidget) {
             console.log(`Custom widget does not have mandatory 'parentWidget' property defined`);
             return;
@@ -53,7 +68,7 @@ class WidgetsByParent {
         this.byParent[widget.parentWidget].push(widget);
     }
 
-    get(parentName) {
+    get(parentName: string) {
         if (!this.byParent[parentName]) {
             return [];
         }
@@ -62,12 +77,12 @@ class WidgetsByParent {
             // previously, custom widgets were provided as a single instance, but that has the disadvantage
             // for splits where we actually need multiple instaces and thus having a class to instantiate is better
             // https://github.com/zadam/trilium/issues/4274
-            .map(w => w.prototype ? new w() : w);
+            .map((w: any) => w.prototype ? new w() : w);
     }
 }
 
 async function getWidgetBundlesByParent() {
-    const scriptBundles = await server.get("script/widgets");
+    const scriptBundles = await server.get<Bundle[]>("script/widgets");
 
     const widgetsByParent = new WidgetsByParent();
 
@@ -80,7 +95,7 @@ async function getWidgetBundlesByParent() {
                 widget._noteId = bundle.noteId;
                 widgetsByParent.add(widget);
             }
-        } catch (e) {
+        } catch (e: any) {
             const noteId = bundle.noteId;
             const note = await froca.getNote(noteId);
             toastService.showPersistent({
@@ -88,7 +103,7 @@ async function getWidgetBundlesByParent() {
                 icon: "alert",
                 message: t("toast.bundle-error.message", {
                     id: noteId,
-                    title: note.title,
+                    title: note?.title,
                     message: e.message
                 })
             });
diff --git a/src/public/app/services/clipboard.js b/src/public/app/services/clipboard.ts
similarity index 83%
rename from src/public/app/services/clipboard.js
rename to src/public/app/services/clipboard.ts
index dda27f598..d1cb708e3 100644
--- a/src/public/app/services/clipboard.js
+++ b/src/public/app/services/clipboard.ts
@@ -5,10 +5,10 @@ import linkService from "./link.js";
 import utils from "./utils.js";
 import { t } from "./i18n.js";
 
-let clipboardBranchIds = [];
-let clipboardMode = null;
+let clipboardBranchIds: string[] = [];
+let clipboardMode: string | null = null;
 
-async function pasteAfter(afterBranchId) {
+async function pasteAfter(afterBranchId: string) {
     if (isClipboardEmpty()) {
         return;
     }
@@ -23,7 +23,14 @@ async function pasteAfter(afterBranchId) {
         const clipboardBranches = clipboardBranchIds.map(branchId => froca.getBranch(branchId));
 
         for (const clipboardBranch of clipboardBranches) {
+            if (!clipboardBranch) {
+                continue;
+            }
+
             const clipboardNote = await clipboardBranch.getNote();
+            if (!clipboardNote) {
+                continue;
+            }
 
             await branchService.cloneNoteAfter(clipboardNote.noteId, afterBranchId);
         }
@@ -35,7 +42,7 @@ async function pasteAfter(afterBranchId) {
     }
 }
 
-async function pasteInto(parentBranchId) {
+async function pasteInto(parentBranchId: string) {
     if (isClipboardEmpty()) {
         return;
     }
@@ -50,7 +57,14 @@ async function pasteInto(parentBranchId) {
         const clipboardBranches = clipboardBranchIds.map(branchId => froca.getBranch(branchId));
 
         for (const clipboardBranch of clipboardBranches) {
+            if (!clipboardBranch) {
+                continue;
+            }
+
             const clipboardNote = await clipboardBranch.getNote();
+            if (!clipboardNote) {
+                continue;
+            }
 
             await branchService.cloneNoteToBranch(clipboardNote.noteId, parentBranchId);
         }
@@ -62,7 +76,7 @@ async function pasteInto(parentBranchId) {
     }
 }
 
-async function copy(branchIds) {
+async function copy(branchIds: string[]) {
     clipboardBranchIds = branchIds;
     clipboardMode = 'copy';
 
@@ -82,7 +96,7 @@ async function copy(branchIds) {
     toastService.showMessage(t("clipboard.copied"));
 }
 
-function cut(branchIds) {
+function cut(branchIds: string[]) {
     clipboardBranchIds = branchIds;
 
     if (clipboardBranchIds.length > 0) {
diff --git a/src/public/app/services/content_renderer.js b/src/public/app/services/content_renderer.ts
similarity index 84%
rename from src/public/app/services/content_renderer.js
rename to src/public/app/services/content_renderer.ts
index ec0bee7f5..2ff796b4c 100644
--- a/src/public/app/services/content_renderer.js
+++ b/src/public/app/services/content_renderer.ts
@@ -16,12 +16,13 @@ import { loadElkIfNeeded } from "./mermaid.js";
 
 let idCounter = 1;
 
-/**
- * @param {FNote|FAttachment} entity
- * @param {object} options
- * @return {Promise<{type: string, $renderedContent: jQuery}>}
- */
-async function getRenderedContent(entity, options = {}) {
+interface Options {
+    tooltip?: boolean;
+    trim?: boolean;
+    imageHasZoom?: boolean;
+}
+
+async function getRenderedContent(this: {} | { ctx: string }, entity: FNote, options: Options = {}) {
     options = Object.assign({
         tooltip: false
     }, options);
@@ -49,7 +50,7 @@ async function getRenderedContent(entity, options = {}) {
     else if (type === 'render') {
         const $content = $('<div>');
 
-        await renderService.render(entity, $content, this.ctx);
+        await renderService.render(entity, $content);
 
         $renderedContent.append($content);
     }
@@ -86,12 +87,11 @@ async function getRenderedContent(entity, options = {}) {
     };
 }
 
-/** @param {FNote} note */
-async function renderText(note, $renderedContent) {
+async function renderText(note: FNote, $renderedContent: JQuery<HTMLElement>) {
     // entity must be FNote
     const blob = await note.getBlob();
 
-    if (!utils.isHtmlEmpty(blob.content)) {
+    if (blob && !utils.isHtmlEmpty(blob.content)) {
         $renderedContent.append($('<div class="ck-content">').html(blob.content));
 
         if ($renderedContent.find('span.math-tex').length > 0) {
@@ -100,9 +100,9 @@ async function renderText(note, $renderedContent) {
             renderMathInElement($renderedContent[0], {trust: true});
         }
 
-        const getNoteIdFromLink = el => treeService.getNoteIdFromUrl($(el).attr('href'));
+        const getNoteIdFromLink = (el: HTMLElement) => treeService.getNoteIdFromUrl($(el).attr('href') || "");
         const referenceLinks = $renderedContent.find("a.reference-link");
-        const noteIdsToPrefetch = referenceLinks.map(el => getNoteIdFromLink(el));
+        const noteIdsToPrefetch = referenceLinks.map((i, el) => getNoteIdFromLink(el));
         await froca.getNotes(noteIdsToPrefetch);
 
         for (const el of referenceLinks) {
@@ -117,19 +117,17 @@ async function renderText(note, $renderedContent) {
 
 /**
  * Renders a code note, by displaying its content and applying syntax highlighting based on the selected MIME type.
- * 
- * @param {FNote} note
  */
-async function renderCode(note, $renderedContent) {
+async function renderCode(note: FNote, $renderedContent: JQuery<HTMLElement>) {
     const blob = await note.getBlob();
 
     const $codeBlock = $("<code>");
-    $codeBlock.text(blob.content);
+    $codeBlock.text(blob?.content || "");
     $renderedContent.append($("<pre>").append($codeBlock));
     await applySingleBlockSyntaxHighlight($codeBlock, mime_types.normalizeMimeTypeForCKEditor(note.mime));
 }
 
-function renderImage(entity, $renderedContent, options = {}) {
+function renderImage(entity: FNote | FAttachment, $renderedContent: JQuery<HTMLElement>, options: Options = {}) {
     const encodedTitle = encodeURIComponent(entity.title);
 
     let url;
@@ -146,7 +144,7 @@ function renderImage(entity, $renderedContent, options = {}) {
         .css('justify-content', 'center');
 
     const $img = $("<img>")
-        .attr("src", url)
+        .attr("src", url || "")
         .attr("id", "attachment-image-" + idCounter++)
         .css("max-width", "100%");
 
@@ -165,7 +163,7 @@ function renderImage(entity, $renderedContent, options = {}) {
     imageContextMenuService.setupContextMenu($img);
 }
 
-function renderFile(entity, type, $renderedContent) {
+function renderFile(entity: FNote | FAttachment, type: string, $renderedContent: JQuery<HTMLElement>) {
     let entityType, entityId;
 
     if (entity instanceof FNote) {
@@ -201,7 +199,7 @@ function renderFile(entity, type, $renderedContent) {
         $content.append($videoPreview);
     }
 
-    if (entityType === 'notes') {
+    if (entityType === 'notes' && "noteId" in entity) {
         // TODO: we should make this available also for attachments, but there's a problem with "Open externally" support
         //       in attachment list
         const $downloadButton = $('<button class="file-download btn btn-primary" type="button">Download</button>');
@@ -222,11 +220,11 @@ function renderFile(entity, type, $renderedContent) {
     $renderedContent.append($content);
 }
 
-async function renderMermaid(note, $renderedContent) {
+async function renderMermaid(note: FNote, $renderedContent: JQuery<HTMLElement>) {
     await libraryLoader.requireLibrary(libraryLoader.MERMAID);
 
     const blob = await note.getBlob();
-    const content = blob.content || "";
+    const content = blob?.content || "";
 
     $renderedContent
         .css("display", "flex")
@@ -254,7 +252,7 @@ async function renderMermaid(note, $renderedContent) {
  * @param {FNote} note
  * @returns {Promise<void>}
  */
-async function renderChildrenList($renderedContent, note) {
+async function renderChildrenList($renderedContent: JQuery<HTMLElement>, note: FNote) {
     $renderedContent.css("padding", "10px");
     $renderedContent.addClass("text-with-ellipsis");
 
@@ -277,15 +275,21 @@ async function renderChildrenList($renderedContent, note) {
     }
 }
 
-function getRenderingType(entity) {
-    let type = entity.type || entity.role;
-    const mime = entity.mime;
+function getRenderingType(entity: FNote | FAttachment) {
+    let type: string = "";
+    if ("type" in entity) {
+        type = entity.type;
+    } else if ("role" in entity) {
+        type = entity.role;
+    }
+
+    const mime = ("mime" in entity && entity.mime);
 
     if (type === 'file' && mime === 'application/pdf') {
         type = 'pdf';
-    } else if (type === 'file' && mime.startsWith('audio/')) {
+    } else if (type === 'file' && mime && mime.startsWith('audio/')) {
         type = 'audio';
-    } else if (type === 'file' && mime.startsWith('video/')) {
+    } else if (type === 'file' && mime && mime.startsWith('video/')) {
         type = 'video';
     }
 
diff --git a/src/public/app/services/debounce.js b/src/public/app/services/debounce.ts
similarity index 70%
rename from src/public/app/services/debounce.js
rename to src/public/app/services/debounce.ts
index 4e5429a32..4f9972a7b 100644
--- a/src/public/app/services/debounce.js
+++ b/src/public/app/services/debounce.ts
@@ -7,13 +7,17 @@
  *
  * @source underscore.js
  * @see http://unscriptable.com/2009/03/20/debouncing-javascript-methods/
- * @param {Function} func to wrap
- * @param {Number} waitMs in ms (`100`)
- * @param {Boolean} [immediate=false] whether to execute at the beginning (`false`)
+ * @param func to wrap
+ * @param waitMs in ms (`100`)
+ * @param whether to execute at the beginning (`false`)
  * @api public
  */
-function debounce(func, waitMs, immediate = false) {
-    let timeout, args, context, timestamp, result;
+function debounce<T>(func: (...args: unknown[]) => T, waitMs: number, immediate: boolean = false) {
+    let timeout: any; // TODO: fix once we split client and server.
+    let args: unknown[] | null;
+    let context: unknown;
+    let timestamp: number;
+    let result: T;
     if (null == waitMs) waitMs = 100;
 
     function later() {
@@ -24,20 +28,20 @@ function debounce(func, waitMs, immediate = false) {
         } else {
             timeout = null;
             if (!immediate) {
-                result = func.apply(context, args);
+                result = func.apply(context, args || []);
                 context = args = null;
             }
         }
     }
 
-    const debounced = function () {
+    const debounced = function (this: any) {
         context = this;
-        args = arguments;
+        args = arguments as unknown as unknown[];
         timestamp = Date.now();
         const callNow = immediate && !timeout;
         if (!timeout) timeout = setTimeout(later, waitMs);
         if (callNow) {
-            result = func.apply(context, args);
+            result = func.apply(context, args || []);
             context = args = null;
         }
 
@@ -53,7 +57,7 @@ function debounce(func, waitMs, immediate = false) {
 
     debounced.flush = function() {
         if (timeout) {
-            result = func.apply(context, args);
+            result = func.apply(context, args || []);
             context = args = null;
 
             clearTimeout(timeout);
diff --git a/src/public/app/services/dialog.js b/src/public/app/services/dialog.ts
similarity index 52%
rename from src/public/app/services/dialog.js
rename to src/public/app/services/dialog.ts
index 325a65146..18db1df40 100644
--- a/src/public/app/services/dialog.js
+++ b/src/public/app/services/dialog.ts
@@ -1,24 +1,26 @@
 import appContext from "../components/app_context.js";
+import { ConfirmDialogOptions, ConfirmWithMessageOptions } from "../widgets/dialogs/confirm.js";
+import { PromptDialogOptions } from "../widgets/dialogs/prompt.js";
 
-async function info(message) {
+async function info(message: string) {
     return new Promise(res =>
         appContext.triggerCommand("showInfoDialog", {message, callback: res}));
 }
 
-async function confirm(message) {
+async function confirm(message: string) {
     return new Promise(res =>
-        appContext.triggerCommand("showConfirmDialog", {
+        appContext.triggerCommand("showConfirmDialog", <ConfirmWithMessageOptions>{
             message,
-            callback: x => res(x.confirmed)
+            callback: (x: false | ConfirmDialogOptions) => res(x && x.confirmed)
         }));
 }
 
-async function confirmDeleteNoteBoxWithNote(title) {
+async function confirmDeleteNoteBoxWithNote(title: string) {
     return new Promise(res =>
         appContext.triggerCommand("showConfirmDeleteNoteBoxWithNoteDialog", {title, callback: res}));
 }
 
-async function prompt(props) {
+async function prompt(props: PromptDialogOptions) {
     return new Promise(res =>
         appContext.triggerCommand("showPromptDialog", {...props, callback: res}));
 }
diff --git a/src/public/app/services/file_watcher.js b/src/public/app/services/file_watcher.ts
similarity index 66%
rename from src/public/app/services/file_watcher.js
rename to src/public/app/services/file_watcher.ts
index a0db524cc..0f9ec3bb5 100644
--- a/src/public/app/services/file_watcher.js
+++ b/src/public/app/services/file_watcher.ts
@@ -1,36 +1,45 @@
 import ws from "./ws.js";
 import appContext from "../components/app_context.js";
 
-const fileModificationStatus = {
+// TODO: Deduplicate
+interface Message {
+    type: string;
+    entityType: string;
+    entityId: string;
+    lastModifiedMs: number;
+    filePath: string;
+}
+
+const fileModificationStatus: Record<string, Record<string, Message>> = {
     notes: {},
     attachments: {}
 };
 
-function checkType(type) {
+function checkType(type: string) {
     if (type !== 'notes' && type !== 'attachments') {
         throw new Error(`Unrecognized type '${type}', should be 'notes' or 'attachments'`);
     }
 }
 
-function getFileModificationStatus(entityType, entityId) {
+function getFileModificationStatus(entityType: string, entityId: string) {
     checkType(entityType);
 
     return fileModificationStatus[entityType][entityId];
 }
 
-function fileModificationUploaded(entityType, entityId) {
+function fileModificationUploaded(entityType: string, entityId: string) {
     checkType(entityType);
 
     delete fileModificationStatus[entityType][entityId];
 }
 
-function ignoreModification(entityType, entityId) {
+function ignoreModification(entityType: string, entityId: string) {
     checkType(entityType);
 
     delete fileModificationStatus[entityType][entityId];
 }
 
-ws.subscribeToMessages(async message => {
+ws.subscribeToMessages(async (message: Message) => {
     if (message.type !== 'openedFileUpdated') {
         return;
     }
diff --git a/src/public/app/services/froca.ts b/src/public/app/services/froca.ts
index 5bc1191e3..f84dc37ea 100644
--- a/src/public/app/services/froca.ts
+++ b/src/public/app/services/froca.ts
@@ -243,7 +243,7 @@ class FrocaImpl implements Froca {
         }).filter(note => !!note) as FNote[];
     }
 
-    async getNotes(noteIds: string[], silentNotFoundError = false): Promise<FNote[]> {
+    async getNotes(noteIds: string[] | JQuery<string>, silentNotFoundError = false): Promise<FNote[]> {
         noteIds = Array.from(new Set(noteIds)); // make unique
         const missingNoteIds = noteIds.filter(noteId => !this.notes[noteId]);
 
diff --git a/src/public/app/services/froca_updater.ts b/src/public/app/services/froca_updater.ts
index 2c850881d..d936a5495 100644
--- a/src/public/app/services/froca_updater.ts
+++ b/src/public/app/services/froca_updater.ts
@@ -7,7 +7,7 @@ import FBranch, { FBranchRow } from "../entities/fbranch.js";
 import FAttribute, { FAttributeRow } from "../entities/fattribute.js";
 import FAttachment, { FAttachmentRow } from "../entities/fattachment.js";
 import FNote, { FNoteRow } from "../entities/fnote.js";
-import { EntityChange } from "../../../services/entity_changes_interface.js";
+import type { EntityChange } from "../server_types.js"
 
 async function processEntityChanges(entityChanges: EntityChange[]) {
     const loadResults = new LoadResults(entityChanges);
diff --git a/src/public/app/services/frontend_script_api.js b/src/public/app/services/frontend_script_api.ts
similarity index 65%
rename from src/public/app/services/frontend_script_api.js
rename to src/public/app/services/frontend_script_api.ts
index 5af37876a..1cbab4a0f 100644
--- a/src/public/app/services/frontend_script_api.js
+++ b/src/public/app/services/frontend_script_api.ts
@@ -15,6 +15,11 @@ import BasicWidget from "../widgets/basic_widget.js";
 import SpacedUpdate from "./spaced_update.js";
 import shortcutService from "./shortcuts.js";
 import dialogService from "./dialog.js";
+import FNote from '../entities/fnote.js';
+import { t } from './i18n.js';
+import NoteContext from '../components/note_context.js';
+import NoteDetailWidget from '../widgets/note_detail.js';
+import Component from '../components/component.js';
 
 
 /**
@@ -28,71 +33,434 @@ import dialogService from "./dialog.js";
  * @var {FrontendScriptApi} api
  */
 
-/**
- * <p>This is the main frontend API interface for scripts. All the properties and methods are published in the "api" object
- * available in the JS frontend notes. You can use e.g. <code>api.showMessage(api.startNote.title);</code></p>
- *
- * @constructor
- */
-function FrontendScriptApi(startNote, currentNote, originEntity = null, $container = null) {
+interface AddToToolbarOpts {
+    title: string;
+    /** callback handling the click on the button */
+    action: () => void;
+    /** id of the button, used to identify the old instances of this button to be replaced
+     * ID is optional because of BC, but not specifying it is deprecated. ID can be alphanumeric only. */
+    id: string;    
+    /** name of the boxicon to be used (e.g. "time" for "bx-time" icon) */
+    icon: string;
+    /** keyboard shortcut for the button, e.g. "alt+t" */
+    shortcut: string;
+}
+
+// TODO: Deduplicate me with the server.
+interface ExecResult {
+    success: boolean;
+    executionResult: unknown;
+    error?: string;
+}
+
+export interface Entity {
+    noteId: string;
+}
+
+type Func = ((...args: unknown[]) => unknown) | string;
+
+interface Api {
     /**
      * Container of all the rendered script content
-     * @type {jQuery}
      * */
-    this.$container = $container;
+    $container: JQuery<HTMLElement> | null;
 
     /**
      * Note where the script started executing, i.e., the (event) entrypoint of the current script execution.
-     * @type {FNote}
      */
-    this.startNote = startNote;
+    startNote: FNote;
 
     /**
      * Note where the script is currently executing, i.e. the note where the currently executing source code is written.
-     * @type {FNote}
      */
-    this.currentNote = currentNote;
+    currentNote: FNote;
 
     /**
      * Entity whose event triggered this execution.
-     * @type {object|null}
      */
-    this.originEntity = originEntity;
+    originEntity: unknown | null;
 
     /**
      * day.js library for date manipulation.
      * See {@link https://day.js.org} for documentation
      * @see https://day.js.org
-     * @type {dayjs}
      */
-    this.dayjs = dayjs;
+    dayjs: typeof window.dayjs;
 
-    /** @type {RightPanelWidget} */
-    this.RightPanelWidget = RightPanelWidget;
-
-    /** @type {NoteContextAwareWidget} */
-    this.NoteContextAwareWidget = NoteContextAwareWidget;
-
-    /** @type {BasicWidget} */
-    this.BasicWidget = BasicWidget;
+    RightPanelWidget: typeof RightPanelWidget;
+    NoteContextAwareWidget: typeof NoteContextAwareWidget;
+    BasicWidget: typeof BasicWidget;
 
     /**
      * Activates note in the tree and in the note detail.
      *
-     * @method
-     * @param {string} notePath (or noteId)
-     * @returns {Promise<void>}
+     * @param notePath (or noteId)
      */
-    this.activateNote = async notePath => {
-        await appContext.tabManager.getActiveContext().setNote(notePath);
-    };
+    activateNote(notePath: string): Promise<void>;
 
     /**
      * Activates newly created note. Compared to this.activateNote() also makes sure that frontend has been fully synced.
      *
-     * @param {string} notePath (or noteId)
-     * @returns {Promise<void>}
+     * @param notePath (or noteId)
      */
+    activateNewNote(notePath: string): Promise<void>;
+
+     /**
+     * Open a note in a new tab.
+     *
+     * @method
+     * @param notePath (or noteId)
+     * @param activate - set to true to activate the new tab, false to stay on the current tab
+     */
+    openTabWithNote(notePath: string, activate: boolean): Promise<void>;
+
+    /**
+     * Open a note in a new split.
+     *
+     * @param notePath (or noteId)
+     * @param activate - set to true to activate the new split, false to stay on the current split
+     */
+    openSplitWithNote(notePath: string, activate: boolean): Promise<void>;
+
+    /**
+     * Adds a new launcher to the launchbar. If the launcher (id) already exists, it will be updated.
+     *
+     * @method
+     * @deprecated you can now create/modify launchers in the top-left Menu -> Configure Launchbar
+     *             for special needs there's also backend API's createOrUpdateLauncher()
+     */
+    addButtonToToolbar(opts: AddToToolbarOpts): void;
+
+     /**
+     * @private
+     */
+    __runOnBackendInner(func: unknown, params: unknown[], transactional: boolean): unknown;
+
+    /**
+     * Executes given anonymous function on the backend.
+     * Internally this serializes the anonymous function into string and sends it to backend via AJAX.
+     * Please make sure that the supplied function is synchronous. Only sync functions will work correctly
+     * with transaction management. If you really know what you're doing, you can call api.runAsyncOnBackendWithManualTransactionHandling()
+     *
+     * @method
+     * @param func - (synchronous) function to be executed on the backend
+     * @param params - list of parameters to the anonymous function to be sent to backend
+     * @returns return value of the executed function on the backend
+     */
+    runOnBackend(func: Func, params: unknown[]): unknown;
+
+    /**
+     * Executes given anonymous function on the backend.
+     * Internally this serializes the anonymous function into string and sends it to backend via AJAX.
+     * This function is meant for advanced needs where an async function is necessary.
+     * In this case, the automatic request-scoped transaction management is not applied,
+     * and you need to manually define transaction via api.transactional().
+     *
+     * If you have a synchronous function, please use api.runOnBackend().
+     *
+     * @method
+     * @param func - (synchronous) function to be executed on the backend
+     * @param params - list of parameters to the anonymous function to be sent to backend
+     * @returns return value of the executed function on the backend
+     */
+    runAsyncOnBackendWithManualTransactionHandling(func: Func, params: unknown[]): unknown;
+
+    /**
+     * This is a powerful search method - you can search by attributes and their values, e.g.:
+     * "#dateModified =* MONTH AND #log". See full documentation for all options at: https://triliumnext.github.io/Docs/Wiki/search.html
+     */
+    searchForNotes(searchString: string): Promise<FNote[]>;
+
+    /**
+     * This is a powerful search method - you can search by attributes and their values, e.g.:
+     * "#dateModified =* MONTH AND #log". See full documentation for all options at: https://triliumnext.github.io/Docs/Wiki/search.html
+     */
+    searchForNote(searchString: string): Promise<FNote | null>;
+
+    /**
+     * Returns note by given noteId. If note is missing from the cache, it's loaded.
+     */
+    getNote(noteId: string): Promise<FNote | null>;
+
+    /**
+     * Returns list of notes. If note is missing from the cache, it's loaded.
+     *
+     * This is often used to bulk-fill the cache with notes which would have to be picked one by one
+     * otherwise (by e.g. createLink())
+     *
+     * @param [silentNotFoundError] - don't report error if the note is not found
+     */
+    getNotes(noteIds: string[], silentNotFoundError: boolean): Promise<FNote[]>;
+
+    /**
+     * Update frontend tree (note) cache from the backend.
+     */
+    reloadNotes(noteIds: string[]): Promise<void>;
+
+    /**
+     * Instance name identifies particular Trilium instance. It can be useful for scripts
+     * if some action needs to happen on only one specific instance.
+     */
+    getInstanceName(): string;
+
+    /**
+     * @returns date in YYYY-MM-DD format
+     */
+    formatDateISO: typeof utils.formatDateISO;
+
+    parseDate: typeof utils.parseDate;
+
+    /**
+     * Show an info toast message to the user.
+     */
+    showMessage: typeof toastService.showMessage;
+
+    /**
+     * Show an error toast message to the user.
+     */
+    showError: typeof toastService.showError;
+
+    /**
+     * Show an info dialog to the user.
+     */
+    showInfoDialog: typeof dialogService.info;
+
+    /**
+     * Show confirm dialog to the user.
+     * @returns promise resolving to true if the user confirmed
+     */
+    showConfirmDialog: typeof dialogService.confirm;
+
+    /**
+     * Show prompt dialog to the user.
+     *
+     * @returns promise resolving to the answer provided by the user
+     */
+    showPromptDialog: typeof dialogService.prompt;
+
+    /**
+     * Trigger command. This is a very low-level API which should be avoided if possible.
+     */
+    triggerCommand: typeof appContext.triggerCommand;
+
+    /**
+     * Trigger event. This is a very low-level API which should be avoided if possible.
+     */
+    triggerEvent: typeof appContext.triggerEvent;
+
+     /**
+     * Create a note link (jQuery object) for given note.
+     *
+     * @param {string} notePath (or noteId)
+     * @param {object} [params]
+     * @param {boolean} [params.showTooltip] - enable/disable tooltip on the link
+     * @param {boolean} [params.showNotePath] - show also whole note's path as part of the link
+     * @param {boolean} [params.showNoteIcon] - show also note icon before the title
+     * @param {string} [params.title] - custom link tile with note's title as default
+     * @param {string} [params.title=] - custom link tile with note's title as default
+     * @returns {jQuery} - jQuery element with the link (wrapped in <span>)
+     */
+    createLink: typeof linkService.createLink;
+
+    /** @deprecated - use api.createLink() instead */
+    createNoteLink: typeof linkService.createLink;
+
+    /**
+     * Adds given text to the editor cursor
+     *
+     * @param text - this must be clear text, HTML is not supported.
+     */
+    addTextToActiveContextEditor(text: string): void;
+
+    /**
+     * @returns active note (loaded into center pane)
+     */
+    getActiveContextNote(): FNote;
+
+    /**
+     * @returns returns active context (split)
+     */
+    getActiveContext(): NoteContext;
+
+    /**
+     * @returns returns active main context (first split in a tab, represents the tab as a whole)
+     */
+    getActiveMainContext(): NoteContext;
+
+    /**
+     * @returns returns all note contexts (splits) in all tabs
+     */
+    getNoteContexts(): NoteContext[];
+
+    /**
+     * @returns returns all main contexts representing tabs
+     */
+    getMainNoteContexts(): NoteContext[];
+
+    /**
+     * See https://ckeditor.com/docs/ckeditor5/latest/api/module_core_editor_editor-Editor.html for documentation on the returned instance.
+     *
+     * @returns {Promise<BalloonEditor>} instance of CKEditor
+     */
+    getActiveContextTextEditor(): Promise<unknown>;
+
+    /**
+     * See https://codemirror.net/doc/manual.html#api
+     *
+     * @method
+     * @returns instance of CodeMirror
+     */
+    getActiveContextCodeEditor(): Promise<unknown>;
+
+    /**
+     * Get access to the widget handling note detail. Methods like `getWidgetType()` and `getTypeWidget()` to get to the
+     * implementation of actual widget type.
+     */
+    getActiveNoteDetailWidget(): Promise<NoteDetailWidget>;
+    /**
+     * @returns returns a note path of active note or null if there isn't active note
+     */
+    getActiveContextNotePath(): string | null;
+
+    /**
+     * Returns component which owns the given DOM element (the nearest parent component in DOM tree)
+     *
+     * @method
+     * @param el DOM element
+     */
+    getComponentByEl(el: HTMLElement): Component;
+
+    /**
+     * @param {object} $el - jquery object on which to set up the tooltip
+     */
+    setupElementTooltip: typeof noteTooltipService.setupElementTooltip;
+
+    /**
+     * @param {boolean} protect - true to protect note, false to unprotect
+     */
+    protectNote: typeof protectedSessionService.protectNote;
+
+    /**
+     * @param noteId
+     * @param protect - true to protect subtree, false to unprotect
+     */
+    protectSubTree: typeof protectedSessionService.protectNote;
+
+    /**
+     * Returns date-note for today. If it doesn't exist, it is automatically created.
+     */
+    getTodayNote: typeof dateNotesService.getTodayNote;
+
+    /**
+     * Returns day note for a given date. If it doesn't exist, it is automatically created.
+     *
+     * @param date - e.g. "2019-04-29"
+     */
+    getDayNote: typeof dateNotesService.getDayNote;
+
+    /**
+     * Returns day note for the first date of the week of the given date. If it doesn't exist, it is automatically created.
+     *
+     * @param date - e.g. "2019-04-29"
+     */
+    getWeekNote: typeof dateNotesService.getWeekNote;
+
+    /**
+     * Returns month-note. If it doesn't exist, it is automatically created.
+     *
+     * @param month - e.g. "2019-04"
+     */
+    getMonthNote: typeof dateNotesService.getMonthNote;
+
+    /**
+     * Returns year-note. If it doesn't exist, it is automatically created.
+     *
+     * @method
+     * @param {string} year - e.g. "2019"
+     * @returns {Promise<FNote>}
+     */
+    getYearNote: typeof dateNotesService.getYearNote;
+
+    /**
+     * Hoist note in the current tab. See https://triliumnext.github.io/Docs/Wiki/note-hoisting.html
+     *
+     * @param {string} noteId - set hoisted note. 'root' will effectively unhoist
+     */
+    setHoistedNoteId(noteId: string): void;
+
+     /**
+     * @param keyboardShortcut - e.g. "ctrl+shift+a"
+     * @param [namespace] specify namespace of the handler for the cases where call for bind may be repeated.
+     *                               If a handler with this ID exists, it's replaced by the new handler.
+     */
+    bindGlobalShortcut: typeof shortcutService.bindGlobalShortcut;
+
+    /**
+     * Trilium runs in a backend and frontend process, when something is changed on the backend from a script,
+     * frontend will get asynchronously synchronized.
+     *
+     * This method returns a promise which resolves once all the backend -> frontend synchronization is finished.
+     * Typical use case is when a new note has been created, we should wait until it is synced into frontend and only then activate it.
+     */
+    waitUntilSynced: typeof ws.waitForMaxKnownEntityChangeId;
+
+    /**
+     * This will refresh all currently opened notes which have included note specified in the parameter
+     *
+     * @param includedNoteId - noteId of the included note
+     */
+    refreshIncludedNote(includedNoteId: string): void;
+
+    /**
+     * Return randomly generated string of given length. This random string generation is NOT cryptographically secure.
+     *
+     * @method
+     * @param length of the string
+     * @returns random string
+     */
+    randomString: typeof utils.randomString;
+
+    /**
+     * @param size in bytes
+     * @return formatted string
+     */
+    formatSize: typeof utils.formatSize;
+
+    /**
+     * @param size in bytes
+     * @return formatted string
+     * @deprecated - use api.formatSize()
+     */
+    formatNoteSize: typeof utils.formatSize;
+
+    logMessages: Record<string, string[]>;
+    logSpacedUpdates: Record<string, SpacedUpdate>;
+
+    /**
+     * Log given message to the log pane in UI
+     */
+    log(message: string): void;
+}
+
+/**
+ * <p>This is the main frontend API interface for scripts. All the properties and methods are published in the "api" object
+ * available in the JS frontend notes. You can use e.g. <code>api.showMessage(api.startNote.title);</code></p>
+ */
+function FrontendScriptApi(this: Api, startNote: FNote, currentNote: FNote, originEntity: Entity | null = null, $container: JQuery<HTMLElement> | null = null) {
+    
+    this.$container = $container;
+    this.startNote = startNote;
+    this.currentNote = currentNote;    
+    this.originEntity = originEntity;
+    this.dayjs = dayjs;
+    this.RightPanelWidget = RightPanelWidget;
+    this.NoteContextAwareWidget = NoteContextAwareWidget;
+    this.BasicWidget = BasicWidget;
+    
+    this.activateNote = async notePath => {
+        await appContext.tabManager.getActiveContext().setNote(notePath);
+    };
+
     this.activateNewNote = async notePath => {
         await ws.waitForMaxKnownEntityChangeId();
 
@@ -100,14 +468,7 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
         await appContext.triggerEvent('focusAndSelectTitle');
     };
 
-    /**
-     * Open a note in a new tab.
-     *
-     * @method
-     * @param {string} notePath (or noteId)
-     * @param {boolean} activate - set to true to activate the new tab, false to stay on the current tab
-     * @returns {Promise<void>}
-     */
+   
     this.openTabWithNote = async (notePath, activate) => {
         await ws.waitForMaxKnownEntityChangeId();
 
@@ -117,15 +478,7 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
             await appContext.triggerEvent('focusAndSelectTitle');
         }
     };
-
-    /**
-     * Open a note in a new split.
-     *
-     * @method
-     * @param {string} notePath (or noteId)
-     * @param {boolean} activate - set to true to activate the new split, false to stay on the current split
-     * @returns {Promise<void>}
-     */
+    
     this.openSplitWithNote = async (notePath, activate) => {
         await ws.waitForMaxKnownEntityChangeId();
 
@@ -138,31 +491,19 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
             await appContext.triggerEvent('focusAndSelectTitle');
         }
     };
-
-    /**
-     * Adds a new launcher to the launchbar. If the launcher (id) already exists, it will be updated.
-     *
-     * @method
-     * @deprecated you can now create/modify launchers in the top-left Menu -> Configure Launchbar
-     *             for special needs there's also backend API's createOrUpdateLauncher()
-     * @param {object} opts
-     * @param {string} opts.title
-     * @param {function} opts.action - callback handling the click on the button
-     * @param {string} [opts.id] - id of the button, used to identify the old instances of this button to be replaced
-     *                          ID is optional because of BC, but not specifying it is deprecated. ID can be alphanumeric only.
-     * @param {string} [opts.icon] - name of the boxicon to be used (e.g. "time" for "bx-time" icon)
-     * @param {string} [opts.shortcut] - keyboard shortcut for the button, e.g. "alt+t"
-     */
+    
     this.addButtonToToolbar = async opts => {
         console.warn("api.addButtonToToolbar() has been deprecated since v0.58 and may be removed in the future. Use  Menu -> Configure Launchbar to create/update launchers instead.");
 
         const {action, ...reqBody} = opts;
-        reqBody.action = action.toString();
-
-        await server.put('special-notes/api-script-launcher', reqBody);
+        
+        await server.put('special-notes/api-script-launcher', {
+            action: action.toString(),
+            ...reqBody
+        });
     };
 
-    function prepareParams(params) {
+    function prepareParams(params: unknown[]) {
         if (!params) {
             return params;
         }
@@ -177,15 +518,13 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
         });
     }
 
-    /**
-     * @private
-     */
+   
     this.__runOnBackendInner = async (func, params, transactional) => {
         if (typeof func === "function") {
             func = func.toString();
         }
 
-        const ret = await server.post('script/exec', {
+        const ret = await server.post<ExecResult>('script/exec', {
             script: func,
             params: prepareParams(params),
             startNoteId: startNote.noteId,
@@ -204,364 +543,91 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
         }
     }
 
-    /**
-     * Executes given anonymous function on the backend.
-     * Internally this serializes the anonymous function into string and sends it to backend via AJAX.
-     * Please make sure that the supplied function is synchronous. Only sync functions will work correctly
-     * with transaction management. If you really know what you're doing, you can call api.runAsyncOnBackendWithManualTransactionHandling()
-     *
-     * @method
-     * @param {function|string} func - (synchronous) function to be executed on the backend
-     * @param {Array.<?>} params - list of parameters to the anonymous function to be sent to backend
-     * @returns {Promise<*>} return value of the executed function on the backend
-     */
     this.runOnBackend = async (func, params = []) => {
-        if (func?.constructor.name === "AsyncFunction" || func?.startsWith?.("async ")) {
+        if (func?.constructor.name === "AsyncFunction" || (typeof func === "string" && func?.startsWith?.("async "))) {
             toastService.showError(t("frontend_script_api.async_warning"));
         }
 
         return await this.__runOnBackendInner(func, params, true);
     };
 
-    /**
-     * Executes given anonymous function on the backend.
-     * Internally this serializes the anonymous function into string and sends it to backend via AJAX.
-     * This function is meant for advanced needs where an async function is necessary.
-     * In this case, the automatic request-scoped transaction management is not applied,
-     * and you need to manually define transaction via api.transactional().
-     *
-     * If you have a synchronous function, please use api.runOnBackend().
-     *
-     * @method
-     * @param {function|string} func - (synchronous) function to be executed on the backend
-     * @param {Array.<?>} params - list of parameters to the anonymous function to be sent to backend
-     * @returns {Promise<*>} return value of the executed function on the backend
-     */
+    
     this.runAsyncOnBackendWithManualTransactionHandling = async (func, params = []) => {
-        if (func?.constructor.name === "Function" || func?.startsWith?.("function")) {
+        if (func?.constructor.name === "Function" || (typeof func === "string" && func?.startsWith?.("function"))) {
             toastService.showError(t("frontend_script_api.sync_warning"));
         }
 
         return await this.__runOnBackendInner(func, params, false);
     };
-
-    /**
-     * This is a powerful search method - you can search by attributes and their values, e.g.:
-     * "#dateModified =* MONTH AND #log". See full documentation for all options at: https://triliumnext.github.io/Docs/Wiki/search.html
-     *
-     * @method
-     * @param {string} searchString
-     * @returns {Promise<FNote[]>}
-     */
+    
     this.searchForNotes = async searchString => {
         return await searchService.searchForNotes(searchString);
     };
 
-    /**
-     * This is a powerful search method - you can search by attributes and their values, e.g.:
-     * "#dateModified =* MONTH AND #log". See full documentation for all options at: https://triliumnext.github.io/Docs/Wiki/search.html
-     *
-     * @method
-     * @param {string} searchString
-     * @returns {Promise<FNote|null>}
-     */
+    
     this.searchForNote = async searchString => {
         const notes = await this.searchForNotes(searchString);
 
         return notes.length > 0 ? notes[0] : null;
     };
 
-    /**
-     * Returns note by given noteId. If note is missing from the cache, it's loaded.
-     **
-     * @method
-     * @param {string} noteId
-     * @returns {Promise<FNote>}
-     */
+    
     this.getNote = async noteId => await froca.getNote(noteId);
-
-    /**
-     * Returns list of notes. If note is missing from the cache, it's loaded.
-     *
-     * This is often used to bulk-fill the cache with notes which would have to be picked one by one
-     * otherwise (by e.g. createLink())
-     *
-     * @method
-     * @param {string[]} noteIds
-     * @param {boolean} [silentNotFoundError] - don't report error if the note is not found
-     * @returns {Promise<FNote[]>}
-     */
-    this.getNotes = async (noteIds, silentNotFoundError = false) => await froca.getNotes(noteIds, silentNotFoundError);
-
-    /**
-     * Update frontend tree (note) cache from the backend.
-     *
-     * @method
-     * @param {string[]} noteIds
-     */
-    this.reloadNotes = async noteIds => await froca.reloadNotes(noteIds);
-
-    /**
-     * Instance name identifies particular Trilium instance. It can be useful for scripts
-     * if some action needs to happen on only one specific instance.
-     *
-     * @method
-     * @returns {string}
-     */
-    this.getInstanceName = () => window.glob.instanceName;
-
-    /**
-     * @method
-     * @param {Date} date
-     * @returns {string} date in YYYY-MM-DD format
-     */
+    this.getNotes = async (noteIds, silentNotFoundError = false) => await froca.getNotes(noteIds, silentNotFoundError);    
+    this.reloadNotes = async noteIds => await froca.reloadNotes(noteIds);    
+    this.getInstanceName = () => window.glob.instanceName;    
     this.formatDateISO = utils.formatDateISO;
-
-    /**
-     * @method
-     * @param {string} str
-     * @returns {Date} parsed object
-     */
     this.parseDate = utils.parseDate;
 
-    /**
-     * Show an info toast message to the user.
-     *
-     * @method
-     * @param {string} message
-     */
     this.showMessage = toastService.showMessage;
-
-    /**
-     * Show an error toast message to the user.
-     *
-     * @method
-     * @param {string} message
-     */
     this.showError = toastService.showError;
-
-    /**
-     * Show an info dialog to the user.
-     *
-     * @method
-     * @param {string} message
-     * @returns {Promise}
-     */
-    this.showInfoDialog = dialogService.info;
-
-    /**
-     * Show confirm dialog to the user.
-     *
-     * @method
-     * @param {string} message
-     * @returns {Promise<boolean>} promise resolving to true if the user confirmed
-     */
+    this.showInfoDialog = dialogService.info;    
     this.showConfirmDialog = dialogService.confirm;
 
-    /**
-     * Show prompt dialog to the user.
-     *
-     * @method
-     * @param {object} props
-     * @param {string} props.title
-     * @param {string} props.message
-     * @param {string} props.defaultValue
-     * @returns {Promise<string>} promise resolving to the answer provided by the user
-     */
+    
     this.showPromptDialog = dialogService.prompt;
-
-    /**
-     * Trigger command. This is a very low-level API which should be avoided if possible.
-     *
-     * @method
-     * @param {string} name
-     * @param {object} data
-     */
-    this.triggerCommand = (name, data) => appContext.triggerCommand(name, data);
-
-    /**
-     * Trigger event. This is a very low-level API which should be avoided if possible.
-     *
-     * @method
-     * @param {string} name
-     * @param {object} data
-     */
+    
+    this.triggerCommand = (name, data) => appContext.triggerCommand(name, data);    
     this.triggerEvent = (name, data) => appContext.triggerEvent(name, data);
 
-    /**
-     * Create a note link (jQuery object) for given note.
-     *
-     * @method
-     * @param {string} notePath (or noteId)
-     * @param {object} [params]
-     * @param {boolean} [params.showTooltip=true] - enable/disable tooltip on the link
-     * @param {boolean} [params.showNotePath=false] - show also whole note's path as part of the link
-     * @param {boolean} [params.showNoteIcon=false] - show also note icon before the title
-     * @param {string} [params.title] - custom link tile with note's title as default
-     * @param {string} [params.title=] - custom link tile with note's title as default
-     * @returns {jQuery} - jQuery element with the link (wrapped in <span>)
-     */
+   
     this.createLink = linkService.createLink;
-
-    /** @deprecated - use api.createLink() instead */
     this.createNoteLink = linkService.createLink;
-
-    /**
-     * Adds given text to the editor cursor
-     *
-     * @method
-     * @param {string} text - this must be clear text, HTML is not supported.
-     */
+    
     this.addTextToActiveContextEditor = text => appContext.triggerCommand('addTextToActiveEditor', {text});
 
-    /**
-     * @method
-     * @returns {FNote} active note (loaded into center pane)
-     */
     this.getActiveContextNote = () => appContext.tabManager.getActiveContextNote();
-
-    /**
-     * @method
-     * @returns {NoteContext} - returns active context (split)
-     */
     this.getActiveContext = () => appContext.tabManager.getActiveContext();
-
-    /**
-     * @method
-     * @returns {NoteContext} - returns active main context (first split in a tab, represents the tab as a whole)
-     */
     this.getActiveMainContext = () => appContext.tabManager.getActiveMainContext();
-
-    /**
-     * @method
-     * @returns {NoteContext[]} - returns all note contexts (splits) in all tabs
-     */
-    this.getNoteContexts = () => appContext.tabManager.getNoteContexts();
-
-    /**
-     * @method
-     * @returns {NoteContext[]} - returns all main contexts representing tabs
-     */
+    
+    this.getNoteContexts = () => appContext.tabManager.getNoteContexts();    
     this.getMainNoteContexts = () => appContext.tabManager.getMainNoteContexts();
 
-    /**
-     * See https://ckeditor.com/docs/ckeditor5/latest/api/module_core_editor_editor-Editor.html for documentation on the returned instance.
-     *
-     * @method
-     * @returns {Promise<BalloonEditor>} instance of CKEditor
-     */
-    this.getActiveContextTextEditor = () => appContext.tabManager.getActiveContext()?.getTextEditor();
-
-    /**
-     * See https://codemirror.net/doc/manual.html#api
-     *
-     * @method
-     * @returns {Promise<CodeMirror>} instance of CodeMirror
-     */
+    
+    this.getActiveContextTextEditor = () => appContext.tabManager.getActiveContext()?.getTextEditor();    
     this.getActiveContextCodeEditor = () => appContext.tabManager.getActiveContext()?.getCodeEditor();
-
-    /**
-     * Get access to the widget handling note detail. Methods like `getWidgetType()` and `getTypeWidget()` to get to the
-     * implementation of actual widget type.
-     *
-     * @method
-     * @returns {Promise<NoteDetailWidget>}
-     */
-    this.getActiveNoteDetailWidget = () => new Promise(resolve => appContext.triggerCommand('executeInActiveNoteDetailWidget', {callback: resolve}));
-
-    /**
-     * @method
-     * @returns {Promise<string|null>} returns a note path of active note or null if there isn't active note
-     */
+    
+    this.getActiveNoteDetailWidget = () => new Promise(resolve => appContext.triggerCommand('executeInActiveNoteDetailWidget', {callback: resolve}));    
     this.getActiveContextNotePath = () => appContext.tabManager.getActiveContextNotePath();
-
-    /**
-     * Returns component which owns the given DOM element (the nearest parent component in DOM tree)
-     *
-     * @method
-     * @param {Element} el - DOM element
-     * @returns {Component}
-     */
+    
     this.getComponentByEl = el => appContext.getComponentByEl(el);
-
-    /**
-     * @method
-     * @param {object} $el - jquery object on which to set up the tooltip
-     * @returns {Promise<void>}
-     */
+    
     this.setupElementTooltip = noteTooltipService.setupElementTooltip;
-
-    /**
-     * @method
-     * @param {string} noteId
-     * @param {boolean} protect - true to protect note, false to unprotect
-     * @returns {Promise<void>}
-     */
+    
     this.protectNote = async (noteId, protect) => {
         await protectedSessionService.protectNote(noteId, protect, false);
     };
-
-    /**
-     * @method
-     * @param {string} noteId
-     * @param {boolean} protect - true to protect subtree, false to unprotect
-     * @returns {Promise<void>}
-     */
+    
     this.protectSubTree = async (noteId, protect) => {
         await protectedSessionService.protectNote(noteId, protect, true);
     };
-
-    /**
-     * Returns date-note for today. If it doesn't exist, it is automatically created.
-     *
-     * @method
-     * @returns {Promise<FNote>}
-     */
-    this.getTodayNote = dateNotesService.getTodayNote;
-
-    /**
-     * Returns day note for a given date. If it doesn't exist, it is automatically created.
-     *
-     * @method
-     * @param {string} date - e.g. "2019-04-29"
-     * @returns {Promise<FNote>}
-     */
+    
+    this.getTodayNote = dateNotesService.getTodayNote;    
     this.getDayNote = dateNotesService.getDayNote;
-
-    /**
-     * Returns day note for the first date of the week of the given date. If it doesn't exist, it is automatically created.
-     *
-     * @method
-     * @param {string} date - e.g. "2019-04-29"
-     * @returns {Promise<FNote>}
-     */
-    this.getWeekNote = dateNotesService.getWeekNote;
-
-    /**
-     * Returns month-note. If it doesn't exist, it is automatically created.
-     *
-     * @method
-     * @param {string} month - e.g. "2019-04"
-     * @returns {Promise<FNote>}
-     */
+    this.getWeekNote = dateNotesService.getWeekNote;    
     this.getMonthNote = dateNotesService.getMonthNote;
-
-    /**
-     * Returns year-note. If it doesn't exist, it is automatically created.
-     *
-     * @method
-     * @param {string} year - e.g. "2019"
-     * @returns {Promise<FNote>}
-     */
     this.getYearNote = dateNotesService.getYearNote;
 
-    /**
-     * Hoist note in the current tab. See https://triliumnext.github.io/Docs/Wiki/note-hoisting.html
-     *
-     * @method
-     * @param {string} noteId - set hoisted note. 'root' will effectively unhoist
-     * @returns {Promise<void>}
-     */
     this.setHoistedNoteId = (noteId) => {
         const activeNoteContext = appContext.tabManager.getActiveContext();
 
@@ -570,69 +636,19 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
         }
     };
 
-    /**
-     * @method
-     * @param {string} keyboardShortcut - e.g. "ctrl+shift+a"
-     * @param {function} handler
-     * @param {string} [namespace] - specify namespace of the handler for the cases where call for bind may be repeated.
-     *                               If a handler with this ID exists, it's replaced by the new handler.
-     * @returns {Promise<void>}
-     */
     this.bindGlobalShortcut = shortcutService.bindGlobalShortcut;
-
-    /**
-     * Trilium runs in a backend and frontend process, when something is changed on the backend from a script,
-     * frontend will get asynchronously synchronized.
-     *
-     * This method returns a promise which resolves once all the backend -> frontend synchronization is finished.
-     * Typical use case is when a new note has been created, we should wait until it is synced into frontend and only then activate it.
-     *
-     * @method
-     * @returns {Promise<void>}
-     */
+    
     this.waitUntilSynced = ws.waitForMaxKnownEntityChangeId;
-
-    /**
-     * This will refresh all currently opened notes which have included note specified in the parameter
-     *
-     * @param includedNoteId - noteId of the included note
-     * @returns {Promise<void>}
-     */
+    
     this.refreshIncludedNote = includedNoteId => appContext.triggerEvent('refreshIncludedNote', {noteId: includedNoteId});
 
-    /**
-     * Return randomly generated string of given length. This random string generation is NOT cryptographically secure.
-     *
-     * @method
-     * @param {int} length of the string
-     * @returns {string} random string
-     */
+    
     this.randomString = utils.randomString;
-
-    /**
-     * @method
-     * @param {int} size in bytes
-     * @return {string} formatted string
-     */
     this.formatSize = utils.formatSize;
-
-    /**
-     * @method
-     * @param {int} size in bytes
-     * @return {string} formatted string
-     * @deprecated - use api.formatSize()
-     */
     this.formatNoteSize = utils.formatSize;
 
     this.logMessages = {};
-    this.logSpacedUpdates = {};
-
-    /**
-     * Log given message to the log pane in UI
-     *
-     * @param message
-     * @returns {void}
-     */
+    this.logSpacedUpdates = {};    
     this.log = message => {
         const {noteId} = this.startNote;
 
@@ -653,4 +669,6 @@ function FrontendScriptApi(startNote, currentNote, originEntity = null, $contain
     };
 }
 
-export default FrontendScriptApi;
+export default FrontendScriptApi as any as {
+    new (startNote: FNote, currentNote: FNote, originEntity: Entity | null, $container: JQuery<HTMLElement> | null): Api
+};
diff --git a/src/public/app/services/glob.js b/src/public/app/services/glob.ts
similarity index 98%
rename from src/public/app/services/glob.js
rename to src/public/app/services/glob.ts
index f523a677e..e5f9e744d 100644
--- a/src/public/app/services/glob.js
+++ b/src/public/app/services/glob.ts
@@ -27,7 +27,7 @@ function setupGlobs() {
     window.glob.importMarkdownInline = async () => appContext.triggerCommand("importMarkdownInline");
 
     window.onerror = function (msg, url, lineNo, columnNo, error) {
-        const string = msg.toLowerCase();
+        const string = String(msg).toLowerCase();
 
         let message = "Uncaught error: ";
 
diff --git a/src/public/app/services/i18n.js b/src/public/app/services/i18n.ts
similarity index 89%
rename from src/public/app/services/i18n.js
rename to src/public/app/services/i18n.ts
index 7e9be3a09..3d82c0e1d 100644
--- a/src/public/app/services/i18n.js
+++ b/src/public/app/services/i18n.ts
@@ -4,7 +4,7 @@ import options from "./options.js";
 await library_loader.requireLibrary(library_loader.I18NEXT);
 
 export async function initLocale() {
-    const locale = options.get("locale") || "en";
+    const locale = (options.get("locale") as string) || "en";
 
     await i18next
         .use(i18nextHttpBackend)
diff --git a/src/public/app/services/image.js b/src/public/app/services/image.ts
similarity index 66%
rename from src/public/app/services/image.js
rename to src/public/app/services/image.ts
index f732e843c..deedc7c0e 100644
--- a/src/public/app/services/image.js
+++ b/src/public/app/services/image.ts
@@ -1,6 +1,7 @@
+import { t } from "./i18n.js";
 import toastService from "./toast.js";
 
-function copyImageReferenceToClipboard($imageWrapper) {
+function copyImageReferenceToClipboard($imageWrapper: JQuery<HTMLElement>) {
     try {
         $imageWrapper.attr('contenteditable', 'true');
         selectImage($imageWrapper.get(0));
@@ -14,17 +15,21 @@ function copyImageReferenceToClipboard($imageWrapper) {
         }
     }
     finally {
-        window.getSelection().removeAllRanges();
+        window.getSelection()?.removeAllRanges();
         $imageWrapper.removeAttr('contenteditable');
     }
 }
 
-function selectImage(element) {
+function selectImage(element: HTMLElement | undefined) {
+    if (!element) {
+        return;
+    }
+    
     const selection = window.getSelection();
     const range = document.createRange();
     range.selectNodeContents(element);
-    selection.removeAllRanges();
-    selection.addRange(range);
+    selection?.removeAllRanges();
+    selection?.addRange(range);
 }
 
 export default {
diff --git a/src/public/app/services/import.js b/src/public/app/services/import.ts
similarity index 92%
rename from src/public/app/services/import.js
rename to src/public/app/services/import.ts
index 6cc3aebe7..b63fde8de 100644
--- a/src/public/app/services/import.js
+++ b/src/public/app/services/import.ts
@@ -1,11 +1,11 @@
-import toastService from "./toast.js";
+import toastService, { ToastOptions } from "./toast.js";
 import server from "./server.js";
 import ws from "./ws.js";
 import utils from "./utils.js";
 import appContext from "../components/app_context.js";
 import { t } from "./i18n.js";
 
-export async function uploadFiles(entityType, parentNoteId, files, options) {
+export async function uploadFiles(entityType: string, parentNoteId: string, files: string[], options: Record<string, string | Blob>) {
     if (!['notes', 'attachments'].includes(entityType)) {
         throw new Error(`Unrecognized import entity type '${entityType}'.`);
     }
@@ -45,7 +45,7 @@ export async function uploadFiles(entityType, parentNoteId, files, options) {
     }
 }
 
-function makeToast(id, message) {
+function makeToast(id: string, message: string): ToastOptions {
     return {
         id: id,
         title: t("import.import-status"),
diff --git a/src/public/app/services/keyboard_actions.js b/src/public/app/services/keyboard_actions.ts
similarity index 72%
rename from src/public/app/services/keyboard_actions.js
rename to src/public/app/services/keyboard_actions.ts
index d4f88db6e..630ec03a9 100644
--- a/src/public/app/services/keyboard_actions.js
+++ b/src/public/app/services/keyboard_actions.ts
@@ -1,10 +1,18 @@
 import server from "./server.js";
-import appContext from "../components/app_context.js";
+import appContext, { CommandNames } from "../components/app_context.js";
 import shortcutService from "./shortcuts.js";
+import Component from "../components/component.js";
 
-const keyboardActionRepo = {};
+const keyboardActionRepo: Record<string, Action> = {};
 
-const keyboardActionsLoaded = server.get('keyboard-actions').then(actions => {
+// TODO: Deduplicate with server.
+interface Action {
+	actionName: CommandNames;
+	effectiveShortcuts: string[];
+	scope: string;
+}
+
+const keyboardActionsLoaded = server.get<Action[]>('keyboard-actions').then(actions => {
 	actions = actions.filter(a => !!a.actionName); // filter out separators
 
 	for (const action of actions) {
@@ -20,13 +28,13 @@ async function getActions() {
 	return await keyboardActionsLoaded;
 }
 
-async function getActionsForScope(scope) {
+async function getActionsForScope(scope: string) {
 	const actions = await keyboardActionsLoaded;
 
 	return actions.filter(action => action.scope === scope);
 }
 
-async function setupActionsForElement(scope, $el, component) {
+async function setupActionsForElement(scope: string, $el: JQuery<HTMLElement>, component: Component) {
 	const actions = await getActionsForScope(scope);
 
 	for (const action of actions) {
@@ -44,7 +52,7 @@ getActionsForScope("window").then(actions => {
 	}
 });
 
-async function getAction(actionName, silent = false) {
+async function getAction(actionName: string, silent = false) {
 	await keyboardActionsLoaded;
 
 	const action = keyboardActionRepo[actionName];
@@ -61,9 +69,15 @@ async function getAction(actionName, silent = false) {
 	return action;
 }
 
-function updateDisplayedShortcuts($container) {
+function updateDisplayedShortcuts($container: JQuery<HTMLElement>) {
+	//@ts-ignore
+	//TODO: each() does not support async callbacks.
 	$container.find('kbd[data-command]').each(async (i, el) => {
 		const actionName = $(el).attr('data-command');
+		if (!actionName) {
+			return;
+		}
+
 		const action = await getAction(actionName, true);
 
 		if (action) {
@@ -75,8 +89,13 @@ function updateDisplayedShortcuts($container) {
 		}
 	});
 
+	//@ts-ignore
+	//TODO: each() does not support async callbacks.
 	$container.find('[data-trigger-command]').each(async (i, el) => {
 		const actionName = $(el).attr('data-trigger-command');
+		if (!actionName) {
+			return;
+		}
 		const action = await getAction(actionName, true);
 
 		if (action) {
diff --git a/src/public/app/services/library_loader.js b/src/public/app/services/library_loader.ts
similarity index 79%
rename from src/public/app/services/library_loader.js
rename to src/public/app/services/library_loader.ts
index b5507d1d6..a3e79e8c9 100644
--- a/src/public/app/services/library_loader.js
+++ b/src/public/app/services/library_loader.ts
@@ -2,9 +2,16 @@ import mimeTypesService from "./mime_types.js";
 import optionsService from "./options.js";
 import { getStylesheetUrl } from "./syntax_highlight.js";
 
-const CKEDITOR = {"js": ["libraries/ckeditor/ckeditor.js"]};
+export interface Library {
+    js?: string[] | (() => string[]);
+    css?: string[];
+}
 
-const CODE_MIRROR = {
+const CKEDITOR: Library = {
+    js: ["libraries/ckeditor/ckeditor.js"]
+};
+
+const CODE_MIRROR: Library = {
     js: [
         "node_modules/codemirror/lib/codemirror.js",
         "node_modules/codemirror/addon/display/placeholder.js",
@@ -26,9 +33,13 @@ const CODE_MIRROR = {
     ]
 };
 
-const ESLINT = {js: ["node_modules/eslint/bin/eslint.js"]};
+const ESLINT: Library = {
+    js: [
+        "node_modules/eslint/bin/eslint.js"
+    ]
+};
 
-const RELATION_MAP = {
+const RELATION_MAP: Library = {
     js: [
         "node_modules/jsplumb/dist/js/jsplumb.min.js",
         "node_modules/panzoom/dist/panzoom.min.js"
@@ -38,26 +49,30 @@ const RELATION_MAP = {
     ]
 };
 
-const PRINT_THIS = {js: ["node_modules/print-this/printThis.js"]};
+const PRINT_THIS: Library = {
+    js: ["node_modules/print-this/printThis.js"]
+};
 
-const CALENDAR_WIDGET = {css: ["stylesheets/calendar.css"]};
+const CALENDAR_WIDGET: Library = {
+    css: ["stylesheets/calendar.css"]
+};
 
-const KATEX = {
+const KATEX: Library = {
     js: [ "node_modules/katex/dist/katex.min.js",
         "node_modules/katex/dist/contrib/mhchem.min.js",
         "node_modules/katex/dist/contrib/auto-render.min.js" ],
     css: [ "node_modules/katex/dist/katex.min.css" ]
 };
 
-const WHEEL_ZOOM = {
+const WHEEL_ZOOM: Library = {
     js: [ "node_modules/vanilla-js-wheel-zoom/dist/wheel-zoom.min.js"]
 };
 
-const FORCE_GRAPH = {
+const FORCE_GRAPH: Library = {
     js: [ "node_modules/force-graph/dist/force-graph.min.js"]
 };
 
-const MERMAID = {
+const MERMAID: Library = {
     js: [
         "node_modules/mermaid/dist/mermaid.min.js"        
     ]
@@ -67,13 +82,13 @@ const MERMAID = {
  * The ELK extension of Mermaid.js, which supports more advanced layouts.
  * See https://www.npmjs.com/package/@mermaid-js/layout-elk for more information.
  */
-const MERMAID_ELK = {
+const MERMAID_ELK: Library = {
     js: [
         "libraries/mermaid-elk/elk.min.js"
     ]
 }
 
-const EXCALIDRAW = {
+const EXCALIDRAW: Library = {
     js: [
         "node_modules/react/umd/react.production.min.js",
         "node_modules/react-dom/umd/react-dom.production.min.js",
@@ -81,30 +96,30 @@ const EXCALIDRAW = {
     ]
 };
 
-const MARKJS = {
+const MARKJS: Library = {
     js: [
         "node_modules/mark.js/dist/jquery.mark.es6.min.js"
     ]
 };
 
-const I18NEXT = {
+const I18NEXT: Library = {
     js: [
         "node_modules/i18next/i18next.min.js",
         "node_modules/i18next-http-backend/i18nextHttpBackend.min.js"
     ]
 };
 
-const MIND_ELIXIR = {
+const MIND_ELIXIR: Library = {
     js: [
         "node_modules/mind-elixir/dist/MindElixir.iife.js",
         "node_modules/@mind-elixir/node-menu/dist/node-menu.umd.cjs"
     ]
 };
 
-const HIGHLIGHT_JS = {
+const HIGHLIGHT_JS: Library = {
     js: () => {
         const mimeTypes = mimeTypesService.getMimeTypes();
-        const scriptsToLoad = new Set();
+        const scriptsToLoad = new Set<string>();
         scriptsToLoad.add("node_modules/@highlightjs/cdn-assets/highlight.min.js");
         for (const mimeType of mimeTypes) {
             const id = mimeType.highlightJs;
@@ -120,14 +135,14 @@ const HIGHLIGHT_JS = {
             }
         }
         
-        const currentTheme = optionsService.get("codeBlockTheme");
+        const currentTheme = String(optionsService.get("codeBlockTheme"));
         loadHighlightingTheme(currentTheme);
 
         return Array.from(scriptsToLoad);
     }
 };
 
-async function requireLibrary(library) {
+async function requireLibrary(library: Library) {
     if (library.css) {
         library.css.map(cssUrl => requireCss(cssUrl));
     }
@@ -139,18 +154,18 @@ async function requireLibrary(library) {
     }
 }
 
-function unwrapValue(value) {
+function unwrapValue<T>(value: T | (() => T)) {
     if (typeof value === "function") {
-        return value();
+        return (value as () => T)();
     }
 
     return value;
 }
 
 // we save the promises in case of the same script being required concurrently multiple times
-const loadedScriptPromises = {};
+const loadedScriptPromises: Record<string, JQuery.jqXHR> = {};
 
-async function requireScript(url) {
+async function requireScript(url: string) {
     url = `${window.glob.assetPath}/${url}`;
 
     if (!loadedScriptPromises[url]) {
@@ -164,7 +179,7 @@ async function requireScript(url) {
     await loadedScriptPromises[url];
 }
 
-async function requireCss(url, prependAssetPath = true) {
+async function requireCss(url: string, prependAssetPath = true) {
     const cssLinks = Array
         .from(document.querySelectorAll('link'))
         .map(el => el.href);
@@ -178,8 +193,8 @@ async function requireCss(url, prependAssetPath = true) {
     }
 }
 
-let highlightingThemeEl = null;
-function loadHighlightingTheme(theme) {
+let highlightingThemeEl: JQuery<HTMLElement> | null = null;
+function loadHighlightingTheme(theme: string) {
     if (!theme) {        
         return;
     }
diff --git a/src/public/app/services/link.js b/src/public/app/services/link.ts
similarity index 83%
rename from src/public/app/services/link.js
rename to src/public/app/services/link.ts
index b7e236be5..a4d6a6d6e 100644
--- a/src/public/app/services/link.js
+++ b/src/public/app/services/link.ts
@@ -4,19 +4,19 @@ import appContext from "../components/app_context.js";
 import froca from "./froca.js";
 import utils from "./utils.js";
 
-function getNotePathFromUrl(url) {
+function getNotePathFromUrl(url: string) {
     const notePathMatch = /#(root[A-Za-z0-9_/]*)$/.exec(url);
 
     return notePathMatch === null ? null : notePathMatch[1];
 }
 
-async function getLinkIcon(noteId, viewMode) {
+async function getLinkIcon(noteId: string, viewMode: ViewMode | undefined) {
     let icon;
 
-    if (viewMode === 'default') {
+    if (!viewMode || viewMode === 'default') {
         const note = await froca.getNote(noteId);
 
-        icon = note.getIcon();
+        icon = note?.getIcon();
     } else if (viewMode === 'source') {
         icon = 'bx bx-code-curly';
     } else if (viewMode === 'attachments') {
@@ -25,7 +25,24 @@ async function getLinkIcon(noteId, viewMode) {
     return icon;
 }
 
-async function createLink(notePath, options = {}) {
+type ViewMode = "default" | "source" | "attachments" | string;
+
+interface ViewScope {
+    viewMode?: ViewMode;
+    attachmentId?: string;
+}
+
+interface CreateLinkOptions {
+    title?: string;
+    showTooltip?: boolean;
+    showNotePath?: boolean;
+    showNoteIcon?: boolean;
+    referenceLink?: boolean;
+    autoConvertToImage?: boolean;
+    viewScope?: ViewScope;
+}
+
+async function createLink(notePath: string, options: CreateLinkOptions = {}) {
     if (!notePath || !notePath.trim()) {
         logError("Missing note path");
 
@@ -45,6 +62,12 @@ async function createLink(notePath, options = {}) {
     const autoConvertToImage = options.autoConvertToImage === undefined ? false : options.autoConvertToImage;
 
     const { noteId, parentNoteId } = treeService.getNoteIdAndParentIdFromUrl(notePath);
+    if (!noteId) {
+        logError("Missing note ID");
+
+        return $("<span>").text("[missing note]");
+    }
+
     const viewScope = options.viewScope || {};
     const viewMode = viewScope.viewMode || 'default';
     let linkTitle = options.title;
@@ -54,19 +77,19 @@ async function createLink(notePath, options = {}) {
             const attachment = await froca.getAttachment(viewScope.attachmentId);
 
             linkTitle = attachment ? attachment.title : '[missing attachment]';
-        } else {
+        } else if (noteId) {
             linkTitle = await treeService.getNoteTitle(noteId, parentNoteId);
         }
     }
 
     const note = await froca.getNote(noteId);
 
-    if (autoConvertToImage && ['image', 'canvas', 'mermaid'].includes(note.type) && viewMode === 'default') {
-        const encodedTitle = encodeURIComponent(linkTitle);
+    if (autoConvertToImage && (note?.type && ['image', 'canvas', 'mermaid'].includes(note.type)) && viewMode === 'default') {
+        const encodedTitle = encodeURIComponent(linkTitle || "");
 
         return $("<img>")
             .attr("src", `api/images/${noteId}/${encodedTitle}?${Math.random()}`)
-            .attr("alt", linkTitle);
+            .attr("alt", linkTitle || "");
     }
 
     const $container = $("<span>");
@@ -102,7 +125,7 @@ async function createLink(notePath, options = {}) {
     $container.append($noteLink);
 
     if (showNotePath) {
-        const resolvedPathSegments = await treeService.resolveNotePathToSegments(notePath);
+        const resolvedPathSegments = await treeService.resolveNotePathToSegments(notePath) || [];
         resolvedPathSegments.pop(); // Remove last element
 
         const resolvedPath = resolvedPathSegments.join("/");
@@ -118,7 +141,14 @@ async function createLink(notePath, options = {}) {
     return $container;
 }
 
-function calculateHash({notePath, ntxId, hoistedNoteId, viewScope = {}}) {
+interface CalculateHashOpts {
+    notePath: string;
+    ntxId?: string;
+    hoistedNoteId?: string;
+    viewScope: ViewScope;
+}
+
+function calculateHash({notePath, ntxId, hoistedNoteId, viewScope = {}}: CalculateHashOpts) {
     notePath = notePath || "";
     const params = [
         ntxId ? { ntxId: ntxId } : null,
@@ -129,9 +159,9 @@ function calculateHash({notePath, ntxId, hoistedNoteId, viewScope = {}}) {
 
     const paramStr = params.map(pair => {
         const name = Object.keys(pair)[0];
-        const value = pair[name];
+        const value = (pair as Record<string, string | undefined>)[name];
 
-        return `${encodeURIComponent(name)}=${encodeURIComponent(value)}`;
+        return `${encodeURIComponent(name)}=${encodeURIComponent(value || "")}`;
     }).join("&");
 
     if (!notePath && !paramStr) {
@@ -147,7 +177,7 @@ function calculateHash({notePath, ntxId, hoistedNoteId, viewScope = {}}) {
     return hash;
 }
 
-function parseNavigationStateFromUrl(url) {
+function parseNavigationStateFromUrl(url: string | undefined) {
     if (!url) {
         return {};
     }
@@ -164,7 +194,7 @@ function parseNavigationStateFromUrl(url) {
         return {};
     }
 
-    const viewScope = {
+    const viewScope: ViewScope = {
         viewMode: 'default'
     };
     let ntxId = null;
@@ -184,7 +214,7 @@ function parseNavigationStateFromUrl(url) {
             } else if (name === 'searchString') {
                 searchString = value; // supports triggering search from URL, e.g. #?searchString=blabla
             } else if (['viewMode', 'attachmentId'].includes(name)) {
-                viewScope[name] = value;
+                (viewScope as any)[name] = value;
             } else {
                 console.warn(`Unrecognized hash parameter '${name}'.`);
             }
@@ -201,14 +231,14 @@ function parseNavigationStateFromUrl(url) {
     };
 }
 
-function goToLink(evt) {
-    const $link = $(evt.target).closest("a,.block-link");
+function goToLink(evt: MouseEvent) {
+    const $link = $(evt.target as any).closest("a,.block-link");
     const hrefLink = $link.attr('href') || $link.attr('data-href');
 
     return goToLinkExt(evt, hrefLink, $link);
 }
 
-function goToLinkExt(evt, hrefLink, $link) {
+function goToLinkExt(evt: MouseEvent, hrefLink: string | undefined, $link: JQuery<HTMLElement>) {
     if (hrefLink?.startsWith("data:")) {
         return true;
     }
@@ -230,7 +260,7 @@ function goToLinkExt(evt, hrefLink, $link) {
         if (openInNewTab) {
             appContext.tabManager.openTabWithNoteWithHoisting(notePath, {viewScope});
         } else if (isLeftClick) {
-            const ntxId = $(evt.target).closest("[data-ntx-id]").attr("data-ntx-id");
+            const ntxId = $(evt.target as any).closest("[data-ntx-id]").attr("data-ntx-id");
 
             const noteContext = ntxId
                 ? appContext.tabManager.getNoteContextById(ntxId)
@@ -275,8 +305,8 @@ function goToLinkExt(evt, hrefLink, $link) {
     return true;
 }
 
-function linkContextMenu(e) {
-    const $link = $(e.target).closest("a");
+function linkContextMenu(e: Event) {
+    const $link = $(e.target as any).closest("a");
     const url = $link.attr("href") || $link.attr("data-href");
 
     const { notePath, viewScope } = parseNavigationStateFromUrl(url);
@@ -290,7 +320,7 @@ function linkContextMenu(e) {
     linkContextMenuService.openContextMenu(notePath, e, viewScope, null);
 }
 
-async function loadReferenceLinkTitle($el, href = null) {
+async function loadReferenceLinkTitle($el: JQuery<HTMLElement>, href: string | null | undefined = null) {
     const $link = $el[0].tagName === 'A' ? $el : $el.find("a");
 
     href = href || $link.attr("href");
@@ -300,6 +330,11 @@ async function loadReferenceLinkTitle($el, href = null) {
     }
 
     const {noteId, viewScope} = parseNavigationStateFromUrl(href);
+    if (!noteId) {
+        console.warn("Missing note ID.");
+        return;
+    }
+    
     const note = await froca.getNote(noteId, true);
 
     if (note) {
@@ -312,11 +347,13 @@ async function loadReferenceLinkTitle($el, href = null) {
     if (note) {
         const icon = await getLinkIcon(noteId, viewScope.viewMode);
 
-        $el.prepend($("<span>").addClass(icon));
+        if (icon) {
+            $el.prepend($("<span>").addClass(icon));
+        }
     }
 }
 
-async function getReferenceLinkTitle(href) {
+async function getReferenceLinkTitle(href: string) {
     const {noteId, viewScope} = parseNavigationStateFromUrl(href);
     if (!noteId) {
         return "[missing note]";
@@ -336,7 +373,7 @@ async function getReferenceLinkTitle(href) {
     }
 }
 
-function getReferenceLinkTitleSync(href) {
+function getReferenceLinkTitleSync(href: string) {
     const {noteId, viewScope} = parseNavigationStateFromUrl(href);
     if (!noteId) {
         return "[missing note]";
@@ -360,7 +397,11 @@ function getReferenceLinkTitleSync(href) {
     }
 }
 
+// TODO: Check why the event is not supported.
+//@ts-ignore
 $(document).on('click', "a", goToLink);
+// TODO: Check why the event is not supported.
+//@ts-ignore
 $(document).on('auxclick', "a", goToLink); // to handle the middle button
 $(document).on('contextmenu', 'a', linkContextMenu);
 $(document).on('dblclick', "a", e => {
diff --git a/src/public/app/services/load_results.ts b/src/public/app/services/load_results.ts
index 7945a943e..7627fc2c8 100644
--- a/src/public/app/services/load_results.ts
+++ b/src/public/app/services/load_results.ts
@@ -1,4 +1,4 @@
-import { EntityChange } from "../../../services/entity_changes_interface.js";
+import { EntityChange } from "../server_types.js";
 
 interface BranchRow {
     branchId: string;
diff --git a/src/public/app/services/mac_init.js b/src/public/app/services/mac_init.ts
similarity index 96%
rename from src/public/app/services/mac_init.js
rename to src/public/app/services/mac_init.ts
index 10fba8cbb..259b412f1 100644
--- a/src/public/app/services/mac_init.js
+++ b/src/public/app/services/mac_init.ts
@@ -15,7 +15,7 @@ function init() {
     }
 }
 
-function exec(cmd) {
+function exec(cmd: string) {
     document.execCommand(cmd);
 
     return false;
diff --git a/src/public/app/services/mermaid.js b/src/public/app/services/mermaid.ts
similarity index 93%
rename from src/public/app/services/mermaid.js
rename to src/public/app/services/mermaid.ts
index 152f14252..e553e89e2 100644
--- a/src/public/app/services/mermaid.js
+++ b/src/public/app/services/mermaid.ts
@@ -11,7 +11,7 @@ let elkLoaded = false;
  * 
  * @param mermaidContent the plain text of the mermaid diagram, potentially including a frontmatter.
  */
-export async function loadElkIfNeeded(mermaidContent) {
+export async function loadElkIfNeeded(mermaidContent: string) {
     if (elkLoaded) {
         // Exit immediately since the ELK library is already loaded.
         return;
diff --git a/src/public/app/services/mime_types.js b/src/public/app/services/mime_types.ts
similarity index 89%
rename from src/public/app/services/mime_types.js
rename to src/public/app/services/mime_types.ts
index adb863673..44e3e72d8 100644
--- a/src/public/app/services/mime_types.js
+++ b/src/public/app/services/mime_types.ts
@@ -9,7 +9,21 @@ const MIME_TYPE_AUTO = "text-x-trilium-auto";
  * For highlight.js-supported languages, see https://github.com/highlightjs/highlight.js/blob/main/SUPPORTED_LANGUAGES.md.
  */
 
-const MIME_TYPES_DICT = [
+interface MimeTypeDefinition {
+    default?: boolean;
+    title: string;
+    mime: string;
+    /** The name of the language/mime type as defined by highlight.js (or one of the aliases), in order to be used for syntax highlighting such as inside code blocks. */
+    highlightJs?: string;
+    /** If specified, will load the corresponding highlight.js file from the `libraries/highlightjs/${id}.js` instead of `node_modules/@highlightjs/cdn-assets/languages/${id}.min.js`. */
+    highlightJsSource?: "libraries";
+}
+
+interface MimeType extends MimeTypeDefinition {
+    enabled: boolean
+}
+
+const MIME_TYPES_DICT: MimeTypeDefinition[] = [
     { default: true, title: "Plain text", mime: "text/plain", highlightJs: "plaintext" },
     { title: "APL", mime: "text/apl" },
     { title: "ASN.1", mime: "text/x-ttcn-asn" },
@@ -170,10 +184,10 @@ const MIME_TYPES_DICT = [
     { title: "Z80", mime: "text/x-z80" }
 ];
 
-let mimeTypes = null;
+let mimeTypes: MimeType[] | null = null;
 
 function loadMimeTypes() {
-    mimeTypes = JSON.parse(JSON.stringify(MIME_TYPES_DICT)); // clone
+    mimeTypes = JSON.parse(JSON.stringify(MIME_TYPES_DICT)) as MimeType[]; // clone
 
     const enabledMimeTypes = options.getJson('codeNotesMimeTypes')
         || MIME_TYPES_DICT.filter(mt => mt.default).map(mt => mt.mime);
@@ -183,32 +197,34 @@ function loadMimeTypes() {
     }
 }
 
-function getMimeTypes() {
+function getMimeTypes(): MimeType[] {
     if (mimeTypes === null) {
         loadMimeTypes();
     }
 
-    return mimeTypes;
+    return mimeTypes as MimeType[];
 }
 
-let mimeToHighlightJsMapping = null;
+let mimeToHighlightJsMapping: Record<string, string> | null = null;
 
 /**
  * Obtains the corresponding language tag for highlight.js for a given MIME type.
  * 
  * The mapping is built the first time this method is built and then the results are cached for better performance.
  * 
- * @param {string} mimeType The MIME type of the code block, in the CKEditor-normalized format (e.g. `text-c-src` instead of `text/c-src`).
+ * @param mimeType The MIME type of the code block, in the CKEditor-normalized format (e.g. `text-c-src` instead of `text/c-src`).
  * @returns the corresponding highlight.js tag, for example `c` for `text-c-src`.
  */
-function getHighlightJsNameForMime(mimeType) {    
+function getHighlightJsNameForMime(mimeType: string) {    
     if (!mimeToHighlightJsMapping) {
         const mimeTypes = getMimeTypes();
         mimeToHighlightJsMapping = {};
         for (const mimeType of mimeTypes) {
             // The mime stored by CKEditor is text-x-csrc instead of text/x-csrc so we keep this format for faster lookup.
             const normalizedMime = normalizeMimeTypeForCKEditor(mimeType.mime);
-            mimeToHighlightJsMapping[normalizedMime] = mimeType.highlightJs;
+            if (mimeType.highlightJs) {
+                mimeToHighlightJsMapping[normalizedMime] = mimeType.highlightJs;
+            }
         }
     }
 
@@ -219,10 +235,10 @@ function getHighlightJsNameForMime(mimeType) {
  * Given a MIME type in the usual format (e.g. `text/csrc`), it returns a MIME type that can be passed down to the CKEditor
  * code plugin.
  * 
- * @param {string} mimeType The MIME type to normalize, in the usual format (e.g. `text/c-src`).
+ * @param mimeType The MIME type to normalize, in the usual format (e.g. `text/c-src`).
  * @returns the normalized MIME type (e.g. `text-c-src`).
  */
-function normalizeMimeTypeForCKEditor(mimeType) {
+function normalizeMimeTypeForCKEditor(mimeType: string) {
     return mimeType.toLowerCase()
         .replace(/[\W_]+/g,"-");
 }
diff --git a/src/public/app/services/note_autocomplete.js b/src/public/app/services/note_autocomplete.ts
similarity index 83%
rename from src/public/app/services/note_autocomplete.js
rename to src/public/app/services/note_autocomplete.ts
index 7fb29de46..d83d83f62 100644
--- a/src/public/app/services/note_autocomplete.js
+++ b/src/public/app/services/note_autocomplete.ts
@@ -10,7 +10,26 @@ const SELECTED_NOTE_PATH_KEY = "data-note-path";
 
 const SELECTED_EXTERNAL_LINK_KEY = "data-external-link";
 
-async function autocompleteSourceForCKEditor(queryText) {
+export interface Suggestion {
+    noteTitle?: string;
+    externalLink?: string;
+    notePathTitle?: string;
+    notePath?: string;
+    highlightedNotePathTitle?: string;
+    action?: string | "create-note" | "search-notes" | "external-link";
+    parentNoteId?: string;
+}
+
+interface Options {
+    container?: HTMLElement;
+    fastSearch?: boolean;
+    allowCreatingNotes?: boolean;
+    allowJumpToSearchNotes?: boolean;
+    allowExternalLinks?: boolean;
+    hideGoToSelectedNoteButton?: boolean;
+}
+
+async function autocompleteSourceForCKEditor(queryText: string) {
     return await new Promise((res, rej) => {
         autocompleteSource(queryText, rows => {
             res(rows.map(row => {
@@ -30,7 +49,7 @@ async function autocompleteSourceForCKEditor(queryText) {
     });
 }
 
-async function autocompleteSource(term, cb, options = {}) {
+async function autocompleteSource(term: string, cb: (rows: Suggestion[]) => void, options: Options = {}) {
     const fastSearch = options.fastSearch === false ? false : true;
     if (fastSearch === false) {
         if (term.trim().length === 0){
@@ -46,7 +65,7 @@ async function autocompleteSource(term, cb, options = {}) {
     
     const activeNoteId = appContext.tabManager.getActiveContextNoteId();
 
-    let results = await server.get(`autocomplete?query=${encodeURIComponent(term)}&activeNoteId=${activeNoteId}&fastSearch=${fastSearch}`);
+    let results: Suggestion[] = await server.get<Suggestion[]>(`autocomplete?query=${encodeURIComponent(term)}&activeNoteId=${activeNoteId}&fastSearch=${fastSearch}`);
     if (term.trim().length >= 1 && options.allowCreatingNotes) {
         results = [
             {
@@ -54,7 +73,7 @@ async function autocompleteSource(term, cb, options = {}) {
                 noteTitle: term,
                 parentNoteId: activeNoteId || 'root',
                 highlightedNotePathTitle: t("note_autocomplete.create-note", { term })
-            }
+            } as Suggestion
         ].concat(results);
     }
 
@@ -74,14 +93,14 @@ async function autocompleteSource(term, cb, options = {}) {
                 action: 'external-link',
                 externalLink: term,
                 highlightedNotePathTitle: t("note_autocomplete.insert-external-link", { term })
-            }
+            } as Suggestion
         ].concat(results);
     }
 
     cb(results);
 }
 
-function clearText($el) {
+function clearText($el: JQuery<HTMLElement>) {
     if (utils.isMobile()) {
         return;
     }
@@ -90,7 +109,7 @@ function clearText($el) {
     $el.autocomplete("val", "").trigger('change');
 }
 
-function setText($el, text) {
+function setText($el: JQuery<HTMLElement>, text: string) {
     if (utils.isMobile()) {
         return;
     }
@@ -101,7 +120,7 @@ function setText($el, text) {
         .autocomplete("open");
 }
 
-function showRecentNotes($el) {
+function showRecentNotes($el:JQuery<HTMLElement>) {
     if (utils.isMobile()) {
         return;
     }
@@ -112,21 +131,22 @@ function showRecentNotes($el) {
     $el.trigger('focus');
 }
 
-function fullTextSearch($el, options){
-    const searchString = $el.autocomplete('val');
-    if (options.fastSearch === false || searchString.trim().length === 0) {
+function fullTextSearch($el: JQuery<HTMLElement>, options: Options){
+    const searchString = $el.autocomplete('val') as unknown as string;
+    if (options.fastSearch === false || searchString?.trim().length === 0) {
         return;
     }    
     $el.trigger('focus');
     options.fastSearch = false;
     $el.autocomplete('val', '');
+    $el.autocomplete()
     $el.setSelectedNotePath("");
     $el.autocomplete('val', searchString);
     // Set a delay to avoid resetting to true before full text search (await server.get) is called.
     setTimeout(() => { options.fastSearch = true; }, 100);
 }
 
-function initNoteAutocomplete($el, options) {
+function initNoteAutocomplete($el: JQuery<HTMLElement>, options?: Options) {
     if ($el.hasClass("note-autocomplete-input") || utils.isMobile()) {
         // clear any event listener added in previous invocation of this function
         $el.off('autocomplete:noteselected');
@@ -174,7 +194,7 @@ function initNoteAutocomplete($el, options) {
         return false;
     });
 
-    let autocompleteOptions = {};
+    let autocompleteOptions: AutoCompleteConfig = {};
     if (options.container) {
         autocompleteOptions.dropdownMenuContainer = options.container;
         autocompleteOptions.debug = true;   // don't close on blur
@@ -221,7 +241,8 @@ function initNoteAutocomplete($el, options) {
         }
     ]);
 
-    $el.on('autocomplete:selected', async (event, suggestion) => {
+    // TODO: Types fail due to "autocomplete:selected" not being registered in type definitions.
+    ($el as any).on('autocomplete:selected', async (event: Event, suggestion: Suggestion) => {
         if (suggestion.action === 'external-link') {
             $el.setSelectedNotePath(null);
             $el.setSelectedExternalLink(suggestion.externalLink);
@@ -250,7 +271,7 @@ function initNoteAutocomplete($el, options) {
             });
 
             const hoistedNoteId = appContext.tabManager.getActiveContext()?.hoistedNoteId;
-            suggestion.notePath = note.getBestNotePathString(hoistedNoteId);
+            suggestion.notePath = note?.getBestNotePathString(hoistedNoteId);
         }
 
         if (suggestion.action === 'search-notes') {
@@ -270,7 +291,7 @@ function initNoteAutocomplete($el, options) {
     });
 
     $el.on('autocomplete:closed', () => {
-        if (!$el.val().trim()) {
+        if (!String($el.val())?.trim()) {
             clearText($el);
         }
     });
@@ -289,7 +310,7 @@ function initNoteAutocomplete($el, options) {
 
 function init() {
     $.fn.getSelectedNotePath = function () {
-        if (!$(this).val().trim()) {
+        if (!String($(this).val())?.trim()) {
             return "";
         } else {
             return $(this).attr(SELECTED_NOTE_PATH_KEY);
@@ -297,7 +318,8 @@ function init() {
     };
 
     $.fn.getSelectedNoteId = function () {
-        const notePath = $(this).getSelectedNotePath();
+        const $el = $(this as unknown as HTMLElement);
+        const notePath = $el.getSelectedNotePath();
         if (!notePath) {
             return null;
         }
@@ -320,7 +342,7 @@ function init() {
     };
 
     $.fn.getSelectedExternalLink = function () {
-        if (!$(this).val().trim()) {
+        if (!String($(this).val())?.trim()) {
             return "";
         } else {
             return $(this).attr(SELECTED_EXTERNAL_LINK_KEY);
@@ -329,6 +351,7 @@ function init() {
 
     $.fn.setSelectedExternalLink = function (externalLink) {
         if (externalLink) {
+            // TODO: This doesn't seem to do anything with the external link, is it normal?
             $(this)
                 .closest(".input-group")
                 .find(".go-to-selected-note-button")
diff --git a/src/public/app/services/note_create.js b/src/public/app/services/note_create.ts
similarity index 64%
rename from src/public/app/services/note_create.js
rename to src/public/app/services/note_create.ts
index cc3bbb42f..b44bbcabb 100644
--- a/src/public/app/services/note_create.js
+++ b/src/public/app/services/note_create.ts
@@ -6,8 +6,41 @@ import froca from "./froca.js";
 import treeService from "./tree.js";
 import toastService from "./toast.js";
 import { t } from "./i18n.js";
+import FNote from "../entities/fnote.js";
+import FBranch from "../entities/fbranch.js";
+import { ChooseNoteTypeResponse } from "../widgets/dialogs/note_type_chooser.js";
 
-async function createNote(parentNotePath, options = {}) {
+interface CreateNoteOpts {
+    isProtected?: boolean;
+    saveSelection?: boolean;
+    title?: string | null;
+    content?: string | null;
+    type?: string;
+    mime?: string;
+    templateNoteId?: string;
+    activate?: boolean;
+    focus?: "title" | "content";
+    target?: string;
+    targetBranchId?: string;
+    textEditor?: {
+        // TODO: Replace with interface once note_context.js is converted.
+        getSelectedHtml(): string;
+        removeSelection(): void;
+    }
+}
+
+interface Response {
+    // TODO: Deduplicate with server once we have client/server architecture.
+    note: FNote;
+    branch: FBranch;
+}
+
+interface DuplicateResponse {
+    // TODO: Deduplicate with server once we have client/server architecture.
+    note: FNote;
+}
+
+async function createNote(parentNotePath: string | undefined, options: CreateNoteOpts = {}) {
     options = Object.assign({
         activate: true,
         focus: 'title',
@@ -24,7 +57,7 @@ async function createNote(parentNotePath, options = {}) {
         options.saveSelection = false;
     }
 
-    if (options.saveSelection) {
+    if (options.saveSelection && options.textEditor) {        
         [options.title, options.content] = parseSelectedHtml(options.textEditor.getSelectedHtml());
     }
 
@@ -38,7 +71,7 @@ async function createNote(parentNotePath, options = {}) {
     C-->D;`
     }
 
-    const {note, branch} = await server.post(`notes/${parentNoteId}/children?target=${options.target}&targetBranchId=${options.targetBranchId || ""}`, {
+    const {note, branch} = await server.post<Response>(`notes/${parentNoteId}/children?target=${options.target}&targetBranchId=${options.targetBranchId || ""}`, {
         title: options.title,
         content: options.content || "",
         isProtected: options.isProtected,
@@ -49,7 +82,7 @@ async function createNote(parentNotePath, options = {}) {
 
     if (options.saveSelection) {
         // we remove the selection only after it was saved to server to make sure we don't lose anything
-        options.textEditor.removeSelection();
+        options.textEditor?.removeSelection();
     }
 
     await ws.waitForMaxKnownEntityChangeId();
@@ -76,12 +109,14 @@ async function createNote(parentNotePath, options = {}) {
 }
 
 async function chooseNoteType() {
-    return new Promise(res => {
+    return new Promise<ChooseNoteTypeResponse>(res => {
+        // TODO: Remove ignore after callback for chooseNoteType is defined in app_context.ts
+        //@ts-ignore
         appContext.triggerCommand("chooseNoteType", {callback: res});
     });
 }
 
-async function createNoteWithTypePrompt(parentNotePath, options = {}) {
+async function createNoteWithTypePrompt(parentNotePath: string, options: CreateNoteOpts = {}) {
     const {success, noteType, templateNoteId} = await chooseNoteType();
 
     if (!success) {
@@ -95,12 +130,16 @@ async function createNoteWithTypePrompt(parentNotePath, options = {}) {
 }
 
 /* If the first element is heading, parse it out and use it as a new heading. */
-function parseSelectedHtml(selectedHtml) {
+function parseSelectedHtml(selectedHtml: string) {
     const dom = $.parseHTML(selectedHtml);
 
+    // TODO: tagName and outerHTML appear to be missing.
+    //@ts-ignore
     if (dom.length > 0 && dom[0].tagName && dom[0].tagName.match(/h[1-6]/i)) {
         const title = $(dom[0]).text();
         // remove the title from content (only first occurrence)
+        // TODO: tagName and outerHTML appear to be missing.
+        //@ts-ignore
         const content = selectedHtml.replace(dom[0].outerHTML, "");
 
         return [title, content];
@@ -110,9 +149,9 @@ function parseSelectedHtml(selectedHtml) {
     }
 }
 
-async function duplicateSubtree(noteId, parentNotePath) {
+async function duplicateSubtree(noteId: string, parentNotePath: string) {
     const parentNoteId = treeService.getNoteIdFromUrl(parentNotePath);
-    const {note} = await server.post(`notes/${noteId}/duplicate/${parentNoteId}`);
+    const {note} = await server.post<DuplicateResponse>(`notes/${noteId}/duplicate/${parentNoteId}`);
 
     await ws.waitForMaxKnownEntityChangeId();
 
@@ -120,7 +159,7 @@ async function duplicateSubtree(noteId, parentNotePath) {
     activeNoteContext.setNote(`${parentNotePath}/${note.noteId}`);
 
     const origNote = await froca.getNote(noteId);
-    toastService.showMessage(t("note_create.duplicated", { title: origNote.title }));
+    toastService.showMessage(t("note_create.duplicated", { title: origNote?.title }));
 }
 
 export default {
diff --git a/src/public/app/services/note_tooltip.js b/src/public/app/services/note_tooltip.ts
similarity index 87%
rename from src/public/app/services/note_tooltip.js
rename to src/public/app/services/note_tooltip.ts
index 3aecc7d8e..be0f2dd80 100644
--- a/src/public/app/services/note_tooltip.js
+++ b/src/public/app/services/note_tooltip.ts
@@ -5,6 +5,7 @@ import utils from "./utils.js";
 import attributeRenderer from "./attribute_renderer.js";
 import contentRenderer from "./content_renderer.js";
 import appContext from "../components/app_context.js";
+import FNote from "../entities/fnote.js";
 
 function setupGlobalTooltip() {
     $(document).on("mouseenter", "a", mouseEnterHandler);
@@ -24,11 +25,11 @@ function cleanUpTooltips() {
     $('.note-tooltip').remove();
 }
 
-function setupElementTooltip($el) {
+function setupElementTooltip($el: JQuery<HTMLElement>) {
     $el.on('mouseenter', mouseEnterHandler);
 }
 
-async function mouseEnterHandler() {
+async function mouseEnterHandler(this: HTMLElement) {
     const $link = $(this);
 
     if ($link.hasClass("no-tooltip-preview") || $link.hasClass("disabled")) {
@@ -44,7 +45,7 @@ async function mouseEnterHandler() {
     const url = $link.attr("href") || $link.attr("data-href");
     const { notePath, noteId, viewScope } = linkService.parseNavigationStateFromUrl(url);
 
-    if (!notePath || viewScope.viewMode !== 'default') {
+    if (!notePath || !noteId || viewScope?.viewMode !== 'default') {
         return;
     }
 
@@ -64,7 +65,7 @@ async function mouseEnterHandler() {
         new Promise(res => setTimeout(res, 500))
     ]);
 
-    if (utils.isHtmlEmpty(content)) {
+    if (!content || utils.isHtmlEmpty(content)) {
         return;
     }
 
@@ -81,7 +82,8 @@ async function mouseEnterHandler() {
             // with bottom this flickering happens a bit less
             placement: 'bottom',
             trigger: 'manual',
-            boundary: 'window',
+            //TODO: boundary No longer applicable?
+            //boundary: 'window',
             title: html,
             html: true,
             template: `<div class="tooltip note-tooltip ${tooltipClass}" role="tooltip"><div class="arrow"></div><div class="tooltip-inner"></div></div>`,
@@ -114,7 +116,7 @@ async function mouseEnterHandler() {
     }
 }
 
-async function renderTooltip(note) {
+async function renderTooltip(note: FNote | null) {
     if (!note) {
         return '<div>Note has been deleted.</div>';
     }
@@ -126,7 +128,11 @@ async function renderTooltip(note) {
         return;
     }
 
-    let content = `<h5 class="note-tooltip-title">${(await treeService.getNoteTitleWithPathAsSuffix(bestNotePath)).prop('outerHTML')}</h5>`;
+    const noteTitleWithPathAsSuffix = await treeService.getNoteTitleWithPathAsSuffix(bestNotePath);
+    let content = "";
+    if (noteTitleWithPathAsSuffix) {
+        content = `<h5 class="note-tooltip-title">${noteTitleWithPathAsSuffix.prop('outerHTML')}</h5>`;
+    }
 
     const {$renderedAttributes} = await attributeRenderer.renderNormalAttributes(note);
 
diff --git a/src/public/app/services/note_types.js b/src/public/app/services/note_types.ts
similarity index 81%
rename from src/public/app/services/note_types.js
rename to src/public/app/services/note_types.ts
index 8bc30af6b..472004dab 100644
--- a/src/public/app/services/note_types.js
+++ b/src/public/app/services/note_types.ts
@@ -2,8 +2,22 @@ import server from "./server.js";
 import froca from "./froca.js";
 import { t } from "./i18n.js";
 
-async function getNoteTypeItems(command) {
-    const items = [
+interface NoteTypeSeparator {
+    title: "----"
+}
+
+export interface NoteType {
+    title: string;
+    command?: string;
+    type: string;
+    uiIcon: string;
+    templateNoteId?: string;
+}
+
+type NoteTypeItem = NoteType | NoteTypeSeparator;
+
+async function getNoteTypeItems(command?: string) {
+    const items: NoteTypeItem[] = [
         { title: t("note_types.text"), command: command, type: "text", uiIcon: "bx bx-note" },
         { title: t("note_types.code"), command: command, type: "code", uiIcon: "bx bx-code" },
         { title: t("note_types.saved-search"), command: command, type: "search", uiIcon: "bx bx-file-find" },
@@ -17,7 +31,7 @@ async function getNoteTypeItems(command) {
         { title: t("note_types.mind-map"), command, type: "mindMap", uiIcon: "bx bx-sitemap" }
     ];
 
-    const templateNoteIds = await server.get("search-templates");
+    const templateNoteIds = await server.get<string[]>("search-templates");
     const templateNotes = await froca.getNotes(templateNoteIds);
 
     if (templateNotes.length > 0) {
diff --git a/src/public/app/services/options.ts b/src/public/app/services/options.ts
index 4f7e15f79..138c0402a 100644
--- a/src/public/app/services/options.ts
+++ b/src/public/app/services/options.ts
@@ -1,7 +1,7 @@
 
 import server from "./server.js";
 
-type OptionValue = string | number;
+type OptionValue = number | string;
 
 class Options {
     initializedPromise: Promise<void>;
diff --git a/src/public/app/services/protected_session.js b/src/public/app/services/protected_session.ts
similarity index 85%
rename from src/public/app/services/protected_session.js
rename to src/public/app/services/protected_session.ts
index e221e0d20..0b6b03c9d 100644
--- a/src/public/app/services/protected_session.js
+++ b/src/public/app/services/protected_session.ts
@@ -1,6 +1,7 @@
 import server from './server.js';
 import protectedSessionHolder from './protected_session_holder.js';
 import toastService from "./toast.js";
+import type { ToastOptions } from "./toast.js";
 import ws from "./ws.js";
 import appContext from "../components/app_context.js";
 import froca from "./froca.js";
@@ -8,7 +9,19 @@ import utils from "./utils.js";
 import options from "./options.js";
 import { t } from './i18n.js';
 
-let protectedSessionDeferred = null;
+let protectedSessionDeferred: JQuery.Deferred<any, any, any> | null = null;
+
+// TODO: Deduplicate with server when possible.
+interface Response {
+    success: boolean;
+}
+
+interface Message {
+    taskId: string;
+    data: {
+        protect: boolean
+    }
+}
 
 async function leaveProtectedSession() {
     if (protectedSessionHolder.isProtectedSessionAvailable()) {
@@ -44,11 +57,11 @@ async function reloadData() {
     await froca.loadInitialTree();
 
     // make sure that all notes used in the application are loaded, including the ones not shown in the tree
-    await froca.reloadNotes(allNoteIds, true);
+    await froca.reloadNotes(allNoteIds);
 }
 
-async function setupProtectedSession(password) {
-    const response = await server.post('login/protected', { password: password });
+async function setupProtectedSession(password: string) {
+    const response = await server.post<Response>('login/protected', { password: password });
 
     if (!response.success) {
         toastService.showError(t("protected_session.wrong_password"), 3000);
@@ -80,13 +93,13 @@ ws.subscribeToMessages(async message => {
     }
 });
 
-async function protectNote(noteId, protect, includingSubtree) {
+async function protectNote(noteId: string, protect: boolean, includingSubtree: boolean) {
     await enterProtectedSession();
 
     await server.put(`notes/${noteId}/protect/${protect ? 1 : 0}?subtree=${includingSubtree ? 1 : 0}`);
 }
 
-function makeToast(message, title, text) {
+function makeToast(message: Message, title: string, text: string): ToastOptions {
     return {
         id: message.taskId,
         title,
diff --git a/src/public/app/services/render.js b/src/public/app/services/render.ts
similarity index 72%
rename from src/public/app/services/render.js
rename to src/public/app/services/render.ts
index e7ecf8d28..9a998b573 100644
--- a/src/public/app/services/render.js
+++ b/src/public/app/services/render.ts
@@ -1,7 +1,8 @@
 import server from "./server.js";
-import bundleService from "./bundle.js";
+import bundleService, { Bundle } from "./bundle.js";
+import FNote from "../entities/fnote.js";
 
-async function render(note, $el) {
+async function render(note: FNote, $el: JQuery<HTMLElement>) {
     const relations = note.getRelations('renderNote');
     const renderNoteIds = relations
         .map(rel => rel.value)
@@ -10,7 +11,7 @@ async function render(note, $el) {
     $el.empty().toggle(renderNoteIds.length > 0);
 
     for (const renderNoteId of renderNoteIds) {
-        const bundle = await server.post(`script/bundle/${renderNoteId}`);
+        const bundle = await server.post<Bundle>(`script/bundle/${renderNoteId}`);
 
         const $scriptContainer = $('<div>');
         $el.append($scriptContainer);
diff --git a/src/public/app/services/resizer.js b/src/public/app/services/resizer.ts
similarity index 90%
rename from src/public/app/services/resizer.js
rename to src/public/app/services/resizer.ts
index 72c90de6c..6acea693a 100644
--- a/src/public/app/services/resizer.js
+++ b/src/public/app/services/resizer.ts
@@ -1,9 +1,9 @@
 import options from "./options.js";
 
-let leftInstance;
-let rightInstance;
+let leftInstance: ReturnType<typeof Split> | null;
+let rightInstance: ReturnType<typeof Split> | null;
 
-function setupLeftPaneResizer(leftPaneVisible) {
+function setupLeftPaneResizer(leftPaneVisible: boolean) {
     if (leftInstance) {
         leftInstance.destroy();
         leftInstance = null;
diff --git a/src/public/app/services/script_context.js b/src/public/app/services/script_context.ts
similarity index 64%
rename from src/public/app/services/script_context.js
rename to src/public/app/services/script_context.ts
index f47380704..7d76c12a7 100644
--- a/src/public/app/services/script_context.js
+++ b/src/public/app/services/script_context.ts
@@ -1,21 +1,25 @@
-import FrontendScriptApi from './frontend_script_api.js';
+import FrontendScriptApi, { Entity } from './frontend_script_api.js';
 import utils from './utils.js';
 import froca from './froca.js';
 
-async function ScriptContext(startNoteId, allNoteIds, originEntity = null, $container = null) {
-    const modules = {};
+async function ScriptContext(startNoteId: string, allNoteIds: string[], originEntity: Entity | null = null, $container: JQuery<HTMLElement> | null = null) {
+    const modules: Record<string, { exports: unknown }> = {};
 
     await froca.initializedPromise;
 
     const startNote = await froca.getNote(startNoteId);
     const allNotes = await froca.getNotes(allNoteIds);
 
+    if (!startNote) {
+        throw new Error(`Could not find start note ${startNoteId}.`);
+    }
+
     return {
         modules: modules,
         notes: utils.toObject(allNotes, note => [note.noteId, note]),
         apis: utils.toObject(allNotes, note => [note.noteId, new FrontendScriptApi(startNote, note, originEntity, $container)]),
-        require: moduleNoteIds => {
-            return moduleName => {
+        require: (moduleNoteIds: string) => {
+            return (moduleName: string) => {
                 const candidates = allNotes.filter(note => moduleNoteIds.includes(note.noteId));
                 const note = candidates.find(c => c.title === moduleName);
 
diff --git a/src/public/app/services/search.js b/src/public/app/services/search.ts
similarity index 54%
rename from src/public/app/services/search.js
rename to src/public/app/services/search.ts
index 9a6cd61fc..f3ca50d75 100644
--- a/src/public/app/services/search.js
+++ b/src/public/app/services/search.ts
@@ -1,11 +1,11 @@
 import server from "./server.js";
 import froca from "./froca.js";
 
-async function searchForNoteIds(searchString) {
-    return await server.get(`search/${encodeURIComponent(searchString)}`);
+async function searchForNoteIds(searchString: string) {
+    return await server.get<string[]>(`search/${encodeURIComponent(searchString)}`);
 }
 
-async function searchForNotes(searchString) {
+async function searchForNotes(searchString: string) {
     const noteIds = await searchForNoteIds(searchString);
 
     return await froca.getNotes(noteIds);
diff --git a/src/public/app/services/shortcuts.js b/src/public/app/services/shortcuts.ts
similarity index 68%
rename from src/public/app/services/shortcuts.js
rename to src/public/app/services/shortcuts.ts
index 9c99ef0d1..05886bac2 100644
--- a/src/public/app/services/shortcuts.js
+++ b/src/public/app/services/shortcuts.ts
@@ -1,14 +1,17 @@
 import utils from "./utils.js";
 
-function removeGlobalShortcut(namespace) {
+type ElementType = HTMLElement | Document;
+type Handler = (e: JQuery.TriggeredEvent<ElementType, string, ElementType, ElementType>) => void;
+
+function removeGlobalShortcut(namespace: string) {
     bindGlobalShortcut('', null, namespace);
 }
 
-function bindGlobalShortcut(keyboardShortcut, handler, namespace = null) {
+function bindGlobalShortcut(keyboardShortcut: string, handler: Handler | null, namespace: string | null = null) {
     bindElShortcut($(document), keyboardShortcut, handler, namespace);
 }
 
-function bindElShortcut($el, keyboardShortcut, handler, namespace = null) {
+function bindElShortcut($el: JQuery<ElementType>, keyboardShortcut: string, handler: Handler | null, namespace: string | null = null) {
     if (utils.isDesktop()) {
         keyboardShortcut = normalizeShortcut(keyboardShortcut);
 
@@ -24,7 +27,9 @@ function bindElShortcut($el, keyboardShortcut, handler, namespace = null) {
         // method can be called to remove the shortcut (e.g. when keyboardShortcut label is deleted)
         if (keyboardShortcut) {
             $el.bind(eventName, keyboardShortcut, e => {
-                handler(e);
+                if (handler) {
+                    handler(e);
+                }
 
                 e.preventDefault();
                 e.stopPropagation();
@@ -36,7 +41,7 @@ function bindElShortcut($el, keyboardShortcut, handler, namespace = null) {
 /**
  * Normalize to the form expected by the jquery.hotkeys.js
  */
-function normalizeShortcut(shortcut) {
+function normalizeShortcut(shortcut: string): string {
     if (!shortcut) {
         return shortcut;
     }
diff --git a/src/public/app/services/spaced_update.ts b/src/public/app/services/spaced_update.ts
index 4ac0fdd23..991320423 100644
--- a/src/public/app/services/spaced_update.ts
+++ b/src/public/app/services/spaced_update.ts
@@ -1,4 +1,4 @@
-type Callback = () => Promise<void>;
+type Callback = () => Promise<void> | void;
 
 export default class SpacedUpdate {
     private updater: Callback;
diff --git a/src/public/app/services/sync.js b/src/public/app/services/sync.ts
similarity index 73%
rename from src/public/app/services/sync.js
rename to src/public/app/services/sync.ts
index 181f04933..7c953fb84 100644
--- a/src/public/app/services/sync.js
+++ b/src/public/app/services/sync.ts
@@ -2,8 +2,15 @@ import { t } from './i18n.js';
 import server from './server.js';
 import toastService from "./toast.js";
 
+// TODO: De-duplicate with server once we have a commons.
+interface SyncResult {
+    success: boolean;
+    message: string;
+    errorCode?: string;
+}
+
 async function syncNow(ignoreNotConfigured = false) {
-    const result = await server.post('sync/now');
+    const result = await server.post<SyncResult>('sync/now');
 
     if (result.success) {
         toastService.showMessage(t("sync.finished-successfully"));
diff --git a/src/public/app/services/syntax_highlight.js b/src/public/app/services/syntax_highlight.ts
similarity index 90%
rename from src/public/app/services/syntax_highlight.js
rename to src/public/app/services/syntax_highlight.ts
index c9f9449eb..68ca07ced 100644
--- a/src/public/app/services/syntax_highlight.js
+++ b/src/public/app/services/syntax_highlight.ts
@@ -2,7 +2,7 @@ import library_loader from "./library_loader.js";
 import mime_types from "./mime_types.js";
 import options from "./options.js";
 
-export function getStylesheetUrl(theme) {
+export function getStylesheetUrl(theme: string) {
     if (!theme) {
         return null;
     }
@@ -20,7 +20,7 @@ export function getStylesheetUrl(theme) {
  * 
  * @param $container the container under which to look for code blocks and to apply syntax highlighting to them.
  */
-export async function applySyntaxHighlight($container) {
+export async function applySyntaxHighlight($container: JQuery<HTMLElement>) {
     if (!isSyntaxHighlightEnabled()) {
         return;
     }    
@@ -38,11 +38,8 @@ export async function applySyntaxHighlight($container) {
 
 /**
  * Applies syntax highlight to the given code block (assumed to be <pre><code>), using highlight.js.
- * 
- * @param {*} $codeBlock 
- * @param {*} normalizedMimeType 
  */
-export async function applySingleBlockSyntaxHighlight($codeBlock, normalizedMimeType) {
+export async function applySingleBlockSyntaxHighlight($codeBlock: JQuery<HTMLElement>, normalizedMimeType: string) {
     $codeBlock.parent().toggleClass("hljs");
     const text = $codeBlock.text();
 
@@ -79,10 +76,10 @@ export function isSyntaxHighlightEnabled() {
 /**
  * Given a HTML element, tries to extract the `language-` class name out of it.
  * 
- * @param {string} el the HTML element from which to extract the language tag.
+ * @param el the HTML element from which to extract the language tag.
  * @returns the normalized MIME type (e.g. `text-css` instead of `language-text-css`).
  */
-function extractLanguageFromClassList(el) {
+function extractLanguageFromClassList(el: HTMLElement) {
     const prefix = "language-";
     for (const className of el.classList) {
         if (className.startsWith(prefix)) {
diff --git a/src/public/app/services/toast.ts b/src/public/app/services/toast.ts
index ba1cde259..9b6e4f64c 100644
--- a/src/public/app/services/toast.ts
+++ b/src/public/app/services/toast.ts
@@ -1,7 +1,7 @@
 import ws from "./ws.js";
 import utils from "./utils.js";
 
-interface ToastOptions {
+export interface ToastOptions {
     id?: string;
     icon: string;
     title: string;
diff --git a/src/public/app/services/tree.ts b/src/public/app/services/tree.ts
index 3a5cc9952..f2490278e 100644
--- a/src/public/app/services/tree.ts
+++ b/src/public/app/services/tree.ts
@@ -6,9 +6,14 @@ import appContext from "../components/app_context.js";
 
 export interface Node {
     getParent(): Node;
+    getChildren(): Node[];
+    folder: boolean;
+    renderTitle(): void,
     data: {
         noteId?: string;
         isProtected?: boolean;
+        branchId: string;
+        noteType: string;
     }
 }
 
@@ -144,7 +149,7 @@ function getParentProtectedStatus(node: Node) {
     return hoistedNoteService.isHoistedNode(node) ? false : node.getParent().data.isProtected;
 }
 
-function getNoteIdFromUrl(urlOrNotePath: string) {
+function getNoteIdFromUrl(urlOrNotePath: string | undefined) {
     if (!urlOrNotePath) {
         return null;
     }
diff --git a/src/public/app/services/utils.ts b/src/public/app/services/utils.ts
index 4addc1d1f..13539a635 100644
--- a/src/public/app/services/utils.ts
+++ b/src/public/app/services/utils.ts
@@ -1,5 +1,4 @@
 import dayjs from "dayjs";
-import { Modal } from "bootstrap";
 
 function reloadFrontendApp(reason?: string) {
     if (reason) {
@@ -99,7 +98,7 @@ function isMac() {
     return navigator.platform.indexOf('Mac') > -1;
 }
 
-function isCtrlKey(evt: KeyboardEvent) {
+function isCtrlKey(evt: KeyboardEvent | MouseEvent) {
     return (!isMac() && evt.ctrlKey)
         || (isMac() && evt.metaKey);
 }
@@ -138,8 +137,8 @@ function formatSize(size: number) {
     }
 }
 
-function toObject<T>(array: T[], fn: (arg0: T) => [key: string, value: T]) {
-    const obj: Record<string, T> = {};
+function toObject<T, R>(array: T[], fn: (arg0: T) => [key: string, value: R]) {
+    const obj: Record<string, R> = {};
 
     for (const item of array) {
         const [key, value] = fn(item);
@@ -205,7 +204,9 @@ function getMimeTypeClass(mime: string) {
 
 function closeActiveDialog() {
     if (glob.activeDialog) {
-        Modal.getOrCreateInstance(glob.activeDialog[0]).hide();
+        // TODO: Fix once we use proper ES imports.
+        //@ts-ignore
+        bootstrap.Modal.getOrCreateInstance(glob.activeDialog[0]).hide();
         glob.activeDialog = null;
     }
 }
@@ -249,7 +250,9 @@ async function openDialog($dialog: JQuery<HTMLElement>, closeActDialog = true) {
     }
 
     saveFocusedElement();
-    Modal.getOrCreateInstance($dialog[0]).show();
+    // TODO: Fix once we use proper ES imports.
+    //@ts-ignore
+    bootstrap.Modal.getOrCreateInstance($dialog[0]).show();
 
     $dialog.on('hidden.bs.modal', () => {
         $(".aa-input").autocomplete("close");
@@ -350,7 +353,7 @@ function openHelp($button: JQuery<HTMLElement>) {
     }
 }
 
-function initHelpButtons($el: JQuery<HTMLElement>) {
+function initHelpButtons($el: JQuery<HTMLElement> | JQuery<Window>) {
     // for some reason, the .on(event, listener, handler) does not work here (e.g. Options -> Sync -> Help button)
     // so we do it manually
     $el.on("click", e => {
diff --git a/src/public/app/services/ws.ts b/src/public/app/services/ws.ts
index 86f047dae..061673470 100644
--- a/src/public/app/services/ws.ts
+++ b/src/public/app/services/ws.ts
@@ -4,8 +4,8 @@ import server from "./server.js";
 import options from "./options.js";
 import frocaUpdater from "./froca_updater.js";
 import appContext from "../components/app_context.js";
-import { EntityChange } from '../../../services/entity_changes_interface.js';
 import { t } from './i18n.js';
+import { EntityChange } from '../server_types.js';
 
 type MessageHandler = (message: any) => void;
 const messageHandlers: MessageHandler[] = [];
diff --git a/src/public/app/types.d.ts b/src/public/app/types.d.ts
index f80a3fbec..147ca34d6 100644
--- a/src/public/app/types.d.ts
+++ b/src/public/app/types.d.ts
@@ -1,4 +1,12 @@
-import FNote from "./entities/fnote";
+import type FNote from "./entities/fnote";
+import type { BackendModule, i18n } from "i18next";
+import type { Froca } from "./services/froca-interface";
+import type { HttpBackendOptions } from "i18next-http-backend";
+import { Suggestion } from "./services/note_autocomplete.ts";
+import utils from "./services/utils.ts";
+import appContext from "./components/app_context.ts";
+import server from "./services/server.ts";
+import library_loader, { Library } from "./services/library_loader.ts";
 
 interface ElectronProcess {
     type: string;
@@ -6,16 +14,16 @@ interface ElectronProcess {
 }
 
 interface CustomGlobals {
-    isDesktop: boolean;
-    isMobile: boolean;
+    isDesktop: typeof utils.isDesktop;
+    isMobile: typeof utils.isMobile;
     device: "mobile" | "desktop";
-    getComponentsByEl: (el: unknown) => unknown;
-    getHeaders: Promise<Record<string, string>>;
+    getComponentByEl: typeof appContext.getComponentByEl;
+    getHeaders: typeof server.getHeaders;
     getReferenceLinkTitle: (href: string) => Promise<string>;
     getReferenceLinkTitleSync: (href: string) => string;
     getActiveContextNote: FNote;
-    requireLibrary: (library: string) => Promise<void>;
-    ESLINT: { js: string[]; };
+    requireLibrary: typeof library_loader.requireLibrary;
+    ESLINT: Library;
     appContext: AppContext;
     froca: Froca;
     treeCache: Froca;
@@ -30,6 +38,9 @@ interface CustomGlobals {
     isMainWindow: boolean;
     maxEntityChangeIdAtLoad: number;
     maxEntityChangeSyncIdAtLoad: number;
+    assetPath: string;
+    instanceName: string;
+    appCssNoteIds: string[];
 }
 
 type RequireMethod = (moduleName: string) => any;
@@ -37,19 +48,100 @@ type RequireMethod = (moduleName: string) => any;
 declare global {
     interface Window {
         logError(message: string);
-        logInfo(message: string);
+        logInfo(message: string);        
     
         process?: ElectronProcess;
         glob?: CustomGlobals;
     }
 
-    interface JQuery {
-        autocomplete: (action: "close") => void;
+    interface AutoCompleteConfig {
+        appendTo?: HTMLElement | null;
+        hint?: boolean;
+        openOnFocus?: boolean;
+        minLength?: number;
+        tabAutocomplete?: boolean;
+        autoselect?: boolean;
+        dropdownMenuContainer?: HTMLElement;
+        debug?: boolean;
     }
 
-    declare var logError: (message: string) => void;
-    declare var logInfo: (message: string) => void;
-    declare var glob: CustomGlobals;
-    declare var require: RequireMethod;
-    declare var __non_webpack_require__: RequireMethod | undefined;
+    type AutoCompleteCallback = (values: AutoCompleteCallbackArg[]) => void;
+
+    interface AutoCompleteArg {
+        displayKey: "name" | "value" | "notePathTitle";
+        cache: boolean;
+        source: (term: string, cb: AutoCompleteCallback) => void,
+        templates?: {
+            suggestion: (suggestion: Suggestion) => string | undefined
+        }
+    };
+    
+    interface JQuery {
+        autocomplete: (action?: "close" | "open" | "destroy" | "val" | AutoCompleteConfig, args?: AutoCompleteArg[] | string) => JQuery<?>;
+        
+        getSelectedNotePath(): string | undefined;
+        getSelectedNoteId(): string | null;
+        setSelectedNotePath(notePath: string | null | undefined);
+        getSelectedExternalLink(this: HTMLElement): string | undefined;
+        setSelectedExternalLink(externalLink: string | null | undefined);
+        setNote(noteId: string);
+    }
+
+    var logError: (message: string, e?: Error) => void;
+    var logInfo: (message: string) => void;    
+    var glob: CustomGlobals;
+    var require: RequireMethod;
+    var __non_webpack_require__: RequireMethod | undefined;
+
+    // Libraries
+    // TODO: Replace once library loader is replaced with webpack.
+    var i18next: i18n;
+    var i18nextHttpBackend: BackendModule<HttpBackendOptions>;
+    var hljs: {
+        highlightAuto(text: string);
+        highlight(text: string, {
+            language: string
+        });
+    };
+    var dayjs: {};
+    var Split: (selectors: string[], config: {
+        sizes: [ number, number ];
+        gutterSize: number;
+        onDragEnd: (sizes: [ number, number ]) => void;
+    }) => {
+        destroy();
+    };
+    var renderMathInElement: (element: HTMLElement, options: {
+        trust: boolean;
+    }) => void;
+    var WZoom = {
+        create(selector: string, opts: {
+            maxScale: number;
+            speed: number;
+            zoomOnClick: boolean
+        })
+    };
+    interface MermaidApi {
+        initialize(opts: {
+            startOnLoad: boolean,
+            theme: string,
+            securityLevel: "antiscript"
+        }): void;
+        render(selector: string, data: string);
+    }
+    interface MermaidLoader {
+
+    }
+    var mermaid: {        
+        mermaidAPI: MermaidApi;
+        registerLayoutLoaders(loader: MermaidLoader);
+        parse(content: string, opts: {
+            suppressErrors: true
+        }): {
+            config: {
+                layout: string;
+            }            
+        }
+    };
+    var MERMAID_ELK: MermaidLoader;
 }
diff --git a/src/public/app/widgets/basic_widget.js b/src/public/app/widgets/basic_widget.ts
similarity index 81%
rename from src/public/app/widgets/basic_widget.js
rename to src/public/app/widgets/basic_widget.ts
index 54b0b92a7..6d4f587f5 100644
--- a/src/public/app/widgets/basic_widget.js
+++ b/src/public/app/widgets/basic_widget.ts
@@ -9,6 +9,13 @@ import toastService from "../services/toast.js";
  * For information on using widgets, see the tutorial {@tutorial widget_basics}.
  */
 class BasicWidget extends Component {
+    private attrs: Record<string, string>;
+    private classes: string[];
+    private childPositionCounter: number;
+    private cssEl?: string;
+    protected $widget!: JQuery<HTMLElement>;
+    _noteId!: string;
+
     constructor() {
         super();
 
@@ -21,7 +28,7 @@ class BasicWidget extends Component {
         this.childPositionCounter = 10;
     }
 
-    child(...components) {
+    child(...components: Component[]) {
         if (!components) {
             return this;
         }
@@ -43,11 +50,11 @@ class BasicWidget extends Component {
     /**
      * Conditionally adds the given components as children to this component.
      * 
-     * @param {boolean} condition whether to add the components.
-     * @param  {...any} components the components to be added as children to this component provided the condition is truthy. 
+     * @param condition whether to add the components.
+     * @param components the components to be added as children to this component provided the condition is truthy. 
      * @returns self for chaining.
      */
-    optChild(condition, ...components) {
+    optChild(condition: boolean, ...components: Component[]) {
         if (condition) {
             return this.child(...components);
         } else {
@@ -55,12 +62,12 @@ class BasicWidget extends Component {
         }
     }
 
-    id(id) {
+    id(id: string) {
         this.attrs.id = id;
         return this;
     }
 
-    class(className) {
+    class(className: string) {
         this.classes.push(className);
         return this;
     }
@@ -68,11 +75,11 @@ class BasicWidget extends Component {
     /**
      * Sets the CSS attribute of the given name to the given value.
      * 
-     * @param {string} name the name of the CSS attribute to set (e.g. `padding-left`).
-     * @param {string} value the value of the CSS attribute to set (e.g. `12px`).
+     * @param name the name of the CSS attribute to set (e.g. `padding-left`).
+     * @param value the value of the CSS attribute to set (e.g. `12px`).
      * @returns self for chaining.
      */
-    css(name, value) {
+    css(name: string, value: string) {
         this.attrs.style += `${name}: ${value};`;
         return this;
     }
@@ -80,12 +87,12 @@ class BasicWidget extends Component {
     /**
      * Sets the CSS attribute of the given name to the given value, but only if the condition provided is truthy.
      * 
-     * @param {boolean} condition `true` in order to apply the CSS, `false` to ignore it.
-     * @param {string} name the name of the CSS attribute to set (e.g. `padding-left`).
-     * @param {string} value the value of the CSS attribute to set (e.g. `12px`).
+     * @param condition `true` in order to apply the CSS, `false` to ignore it.
+     * @param name the name of the CSS attribute to set (e.g. `padding-left`).
+     * @param value the value of the CSS attribute to set (e.g. `12px`).
      * @returns self for chaining.
      */
-    optCss(condition, name, value) {
+    optCss(condition: boolean, name: string, value: string) {
         if (condition) {
             return this.css(name, value);
         }
@@ -112,10 +119,9 @@ class BasicWidget extends Component {
 
     /**
      * Accepts a string of CSS to add with the widget.
-     * @param {string} block
-     * @returns {this} for chaining
+     * @returns for chaining
      */
-    cssBlock(block) {
+    cssBlock(block: string) {
         this.cssEl = block;
         return this;
     }
@@ -123,7 +129,7 @@ class BasicWidget extends Component {
     render() {
         try {
             this.doRender();
-        } catch (e) {                        
+        } catch (e: any) {                        
             this.logRenderingError(e);
         }
 
@@ -163,7 +169,7 @@ class BasicWidget extends Component {
         return this.$widget;
     }
 
-    logRenderingError(e) {
+    logRenderingError(e: Error) {
         console.log("Got issue in widget ", this);
         console.error(e);
 
@@ -175,7 +181,7 @@ class BasicWidget extends Component {
                     icon: "alert",
                     message: t("toast.widget-error.message-custom", {
                         id: noteId,
-                        title: note.title,
+                        title: note?.title,
                         message: e.message
                     })
                 });
@@ -208,7 +214,7 @@ class BasicWidget extends Component {
      */
     doRender() {}
 
-    toggleInt(show) {
+    toggleInt(show: boolean) {
         this.$widget.toggleClass('hidden-int', !show);
     }
 
@@ -216,7 +222,7 @@ class BasicWidget extends Component {
         return this.$widget.hasClass('hidden-int');
     }
 
-    toggleExt(show) {
+    toggleExt(show: boolean) {
         this.$widget.toggleClass('hidden-ext', !show);
     }
 
diff --git a/src/public/app/widgets/bulk_actions/abstract_bulk_action.js b/src/public/app/widgets/bulk_actions/abstract_bulk_action.ts
similarity index 61%
rename from src/public/app/widgets/bulk_actions/abstract_bulk_action.js
rename to src/public/app/widgets/bulk_actions/abstract_bulk_action.ts
index 634f3d073..d1cf333b5 100644
--- a/src/public/app/widgets/bulk_actions/abstract_bulk_action.js
+++ b/src/public/app/widgets/bulk_actions/abstract_bulk_action.ts
@@ -2,9 +2,27 @@ import { t } from "../../services/i18n.js";
 import server from "../../services/server.js";
 import ws from "../../services/ws.js";
 import utils from "../../services/utils.js";
+import FAttribute from "../../entities/fattribute.js";
 
-export default class AbstractBulkAction {
-    constructor(attribute, actionDef) {
+interface ActionDefinition {
+    script: string;
+    relationName: string;
+    targetNoteId: string;
+    targetParentNoteId: string;
+    oldRelationName?: string;
+    newRelationName?: string;
+    newTitle?: string;
+    labelName?: string;
+    labelValue?: string;
+    oldLabelName?: string;
+    newLabelName?: string;
+}
+
+export default abstract class AbstractBulkAction {
+    attribute: FAttribute;
+    actionDef: ActionDefinition;
+
+    constructor(attribute: FAttribute, actionDef: ActionDefinition) {
         this.attribute = attribute;
         this.actionDef = actionDef;
     }
@@ -20,18 +38,18 @@ export default class AbstractBulkAction {
             utils.initHelpDropdown($rendered);
 
             return $rendered;
-        }
-        catch (e) {
+        } catch (e: any) {
             logError(`Failed rendering search action: ${JSON.stringify(this.attribute.dto)} with error: ${e.message} ${e.stack}`);
             return null;
         }
     }
 
     // to be overridden
-    doRender() {}
+    abstract doRender(): JQuery<HTMLElement>;
+    static get actionName() { return ""; }
 
-    async saveAction(data) {
-        const actionObject = Object.assign({ name: this.constructor.actionName }, data);
+    async saveAction(data: {}) {
+        const actionObject = Object.assign({ name: (this.constructor as typeof AbstractBulkAction).actionName }, data);
 
         await server.put(`notes/${this.attribute.noteId}/attribute`, {
             attributeId: this.attribute.attributeId,
diff --git a/src/public/app/widgets/bulk_actions/execute_script.js b/src/public/app/widgets/bulk_actions/execute_script.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/execute_script.js
rename to src/public/app/widgets/bulk_actions/execute_script.ts
diff --git a/src/public/app/widgets/bulk_actions/label/add_label.js b/src/public/app/widgets/bulk_actions/label/add_label.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/label/add_label.js
rename to src/public/app/widgets/bulk_actions/label/add_label.ts
diff --git a/src/public/app/widgets/bulk_actions/label/delete_label.js b/src/public/app/widgets/bulk_actions/label/delete_label.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/label/delete_label.js
rename to src/public/app/widgets/bulk_actions/label/delete_label.ts
diff --git a/src/public/app/widgets/bulk_actions/label/rename_label.js b/src/public/app/widgets/bulk_actions/label/rename_label.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/label/rename_label.js
rename to src/public/app/widgets/bulk_actions/label/rename_label.ts
diff --git a/src/public/app/widgets/bulk_actions/label/update_label_value.js b/src/public/app/widgets/bulk_actions/label/update_label_value.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/label/update_label_value.js
rename to src/public/app/widgets/bulk_actions/label/update_label_value.ts
diff --git a/src/public/app/widgets/bulk_actions/note/delete_note.js b/src/public/app/widgets/bulk_actions/note/delete_note.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/note/delete_note.js
rename to src/public/app/widgets/bulk_actions/note/delete_note.ts
diff --git a/src/public/app/widgets/bulk_actions/note/delete_revisions.js b/src/public/app/widgets/bulk_actions/note/delete_revisions.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/note/delete_revisions.js
rename to src/public/app/widgets/bulk_actions/note/delete_revisions.ts
diff --git a/src/public/app/widgets/bulk_actions/note/move_note.js b/src/public/app/widgets/bulk_actions/note/move_note.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/note/move_note.js
rename to src/public/app/widgets/bulk_actions/note/move_note.ts
diff --git a/src/public/app/widgets/bulk_actions/note/rename_note.js b/src/public/app/widgets/bulk_actions/note/rename_note.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/note/rename_note.js
rename to src/public/app/widgets/bulk_actions/note/rename_note.ts
diff --git a/src/public/app/widgets/bulk_actions/relation/add_relation.js b/src/public/app/widgets/bulk_actions/relation/add_relation.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/relation/add_relation.js
rename to src/public/app/widgets/bulk_actions/relation/add_relation.ts
diff --git a/src/public/app/widgets/bulk_actions/relation/delete_relation.js b/src/public/app/widgets/bulk_actions/relation/delete_relation.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/relation/delete_relation.js
rename to src/public/app/widgets/bulk_actions/relation/delete_relation.ts
diff --git a/src/public/app/widgets/bulk_actions/relation/rename_relation.js b/src/public/app/widgets/bulk_actions/relation/rename_relation.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/relation/rename_relation.js
rename to src/public/app/widgets/bulk_actions/relation/rename_relation.ts
diff --git a/src/public/app/widgets/bulk_actions/relation/update_relation_target.js b/src/public/app/widgets/bulk_actions/relation/update_relation_target.ts
similarity index 100%
rename from src/public/app/widgets/bulk_actions/relation/update_relation_target.js
rename to src/public/app/widgets/bulk_actions/relation/update_relation_target.ts
diff --git a/src/public/app/widgets/dialogs/confirm.js b/src/public/app/widgets/dialogs/confirm.ts
similarity index 75%
rename from src/public/app/widgets/dialogs/confirm.js
rename to src/public/app/widgets/dialogs/confirm.ts
index 041342c51..9ccda11ee 100644
--- a/src/public/app/widgets/dialogs/confirm.js
+++ b/src/public/app/widgets/dialogs/confirm.ts
@@ -27,7 +27,36 @@ const TPL = `
     </div>
 </div>`;
 
+type ConfirmDialogCallback = (val: false | ConfirmDialogOptions) => void;
+
+export interface ConfirmDialogOptions {
+    confirmed: boolean;
+    isDeleteNoteChecked: boolean
+}
+
+// For "showConfirmDialog"
+
+export interface ConfirmWithMessageOptions {
+    message: string | HTMLElement | JQuery<HTMLElement>;
+    callback: ConfirmDialogCallback;
+}
+
+export interface ConfirmWithTitleOptions {
+    title: string;
+    callback: ConfirmDialogCallback;       
+}
+
 export default class ConfirmDialog extends BasicWidget {
+
+    private resolve: ConfirmDialogCallback | null;
+
+    private modal!: bootstrap.Modal;
+    private $originallyFocused!: JQuery<HTMLElement> | null;
+    private $confirmContent!: JQuery<HTMLElement>;
+    private $okButton!: JQuery<HTMLElement>;
+    private $cancelButton!: JQuery<HTMLElement>;
+    private $custom!: JQuery<HTMLElement>;
+
     constructor() {
         super();
 
@@ -37,6 +66,8 @@ export default class ConfirmDialog extends BasicWidget {
 
     doRender() {
         this.$widget = $(TPL);
+        // TODO: Fix once we use proper ES imports.
+        //@ts-ignore
         this.modal = bootstrap.Modal.getOrCreateInstance(this.$widget);
         this.$confirmContent = this.$widget.find(".confirm-dialog-content");
         this.$okButton = this.$widget.find(".confirm-dialog-ok-button");
@@ -60,7 +91,7 @@ export default class ConfirmDialog extends BasicWidget {
         this.$okButton.on('click', () => this.doResolve(true));
     }
 
-    showConfirmDialogEvent({ message, callback }) {
+    showConfirmDialogEvent({ message, callback }: ConfirmWithMessageOptions) {
         this.$originallyFocused = $(':focus');
 
         this.$custom.hide();
@@ -77,8 +108,8 @@ export default class ConfirmDialog extends BasicWidget {
 
         this.resolve = callback;
     }
-
-    showConfirmDeleteNoteBoxWithNoteDialogEvent({ title, callback }) {
+    
+    showConfirmDeleteNoteBoxWithNoteDialogEvent({ title, callback }: ConfirmWithTitleOptions) {
         glob.activeDialog = this.$widget;
 
         this.$confirmContent.text(`${t('confirm.are_you_sure_remove_note', { title: title })}`);
@@ -107,11 +138,13 @@ export default class ConfirmDialog extends BasicWidget {
         this.resolve = callback;
     }
 
-    doResolve(ret) {
-        this.resolve({
-            confirmed: ret,
-            isDeleteNoteChecked: this.$widget.find(`.${DELETE_NOTE_BUTTON_CLASS}:checked`).length > 0
-        });
+    doResolve(ret: boolean) {
+        if (this.resolve) {
+            this.resolve({
+                confirmed: ret,
+                isDeleteNoteChecked: this.$widget.find(`.${DELETE_NOTE_BUTTON_CLASS}:checked`).length > 0
+            });
+        }
 
         this.resolve = null;
 
diff --git a/src/public/app/widgets/dialogs/delete_notes.js b/src/public/app/widgets/dialogs/delete_notes.ts
similarity index 82%
rename from src/public/app/widgets/dialogs/delete_notes.js
rename to src/public/app/widgets/dialogs/delete_notes.ts
index acfab51c4..c4aa28a75 100644
--- a/src/public/app/widgets/dialogs/delete_notes.js
+++ b/src/public/app/widgets/dialogs/delete_notes.ts
@@ -4,6 +4,25 @@ import linkService from "../../services/link.js";
 import utils from "../../services/utils.js";
 import BasicWidget from "../basic_widget.js";
 import { t } from "../../services/i18n.js";
+import FAttribute, { FAttributeRow } from "../../entities/fattribute.js";
+
+// TODO: Use common with server.
+interface Response {
+    noteIdsToBeDeleted: string[];
+    brokenRelations: FAttributeRow[];
+}
+
+export interface ResolveOptions {
+    proceed: boolean;
+    deleteAllClones?: boolean;    
+    eraseNotes?: boolean;
+}
+
+interface ShowDeleteNotesDialogOpts {
+    branchIdsToDelete: string[];
+    callback: (opts: ResolveOptions) => void;
+    forceDeleteAllClones: boolean;
+}
 
 const TPL = `
 <div class="delete-notes-dialog modal mx-auto" tabindex="-1" role="dialog">
@@ -54,11 +73,29 @@ const TPL = `
 </div>`;
 
 export default class DeleteNotesDialog extends BasicWidget {
+
+    private branchIds: string[] | null;
+    private resolve!: (options: ResolveOptions) => void;
+
+    private $content!: JQuery<HTMLElement>;
+    private $okButton!: JQuery<HTMLElement>;
+    private $cancelButton!: JQuery<HTMLElement>;
+    private $deleteNotesList!: JQuery<HTMLElement>;
+    private $brokenRelationsList!: JQuery<HTMLElement>;
+    private $deletedNotesCount!: JQuery<HTMLElement>;
+    private $noNoteToDeleteWrapper!: JQuery<HTMLElement>;
+    private $deleteNotesListWrapper!: JQuery<HTMLElement>;
+    private $brokenRelationsListWrapper!: JQuery<HTMLElement>;
+    private $brokenRelationsCount!: JQuery<HTMLElement>;
+    private $deleteAllClones!: JQuery<HTMLElement>;
+    private $eraseNotes!: JQuery<HTMLElement>;
+
+    private forceDeleteAllClones?: boolean;
+
     constructor() {
         super();
 
         this.branchIds = null;
-        this.resolve = null;
     }
 
     doRender() {
@@ -98,7 +135,7 @@ export default class DeleteNotesDialog extends BasicWidget {
     }
 
     async renderDeletePreview() {
-        const response = await server.post('delete-notes-preview', {
+        const response = await server.post<Response>('delete-notes-preview', {
             branchIdsToDelete: this.branchIds,
             deleteAllClones: this.forceDeleteAllClones || this.isDeleteAllClonesChecked()
         });
@@ -135,7 +172,7 @@ export default class DeleteNotesDialog extends BasicWidget {
         }
     }
 
-    async showDeleteNotesDialogEvent({branchIdsToDelete, callback, forceDeleteAllClones}) {
+    async showDeleteNotesDialogEvent({branchIdsToDelete, callback, forceDeleteAllClones}: ShowDeleteNotesDialogOpts) {
         this.branchIds = branchIdsToDelete;
         this.forceDeleteAllClones = forceDeleteAllClones;
 
diff --git a/src/public/app/widgets/dialogs/note_type_chooser.js b/src/public/app/widgets/dialogs/note_type_chooser.ts
similarity index 74%
rename from src/public/app/widgets/dialogs/note_type_chooser.js
rename to src/public/app/widgets/dialogs/note_type_chooser.ts
index 93fe69222..57995e315 100644
--- a/src/public/app/widgets/dialogs/note_type_chooser.js
+++ b/src/public/app/widgets/dialogs/note_type_chooser.ts
@@ -1,5 +1,5 @@
 import { t } from "../../services/i18n.js";
-import noteTypesService from "../../services/note_types.js";
+import noteTypesService, { NoteType } from "../../services/note_types.js";
 import BasicWidget from "../basic_widget.js";
 
 const TPL = `
@@ -41,9 +41,25 @@ const TPL = `
     </div>
 </div>`;
 
+export interface ChooseNoteTypeResponse {
+    success: boolean;
+    noteType?: string;
+    templateNoteId?: string;
+}
+
+type Callback = (data: ChooseNoteTypeResponse) => void;
+
 export default class NoteTypeChooserDialog extends BasicWidget {
-    constructor(props) {
-        super(props);
+
+    private resolve: Callback | null;
+    private dropdown!: bootstrap.Dropdown;
+    private modal!: JQuery<HTMLElement>;
+    private $noteTypeDropdown!: JQuery<HTMLElement>;
+    private $originalFocused: JQuery<HTMLElement> | null;
+    private $originalDialog: JQuery<HTMLElement> | null;
+
+    constructor(props: {}) {
+        super();
 
         this.resolve = null;
         this.$originalFocused = null; // element focused before the dialog was opened, so we can return to it afterward
@@ -51,10 +67,14 @@ export default class NoteTypeChooserDialog extends BasicWidget {
     }
 
     doRender() {
-        this.$widget = $(TPL);
+        this.$widget = $(TPL);        
+        // TODO: Remove once we import bootstrap the right way
+        //@ts-ignore
         this.modal = bootstrap.Modal.getOrCreateInstance(this.$widget);
 
         this.$noteTypeDropdown = this.$widget.find(".note-type-dropdown");
+        // TODO: Remove once we import bootstrap the right way
+        //@ts-ignore
         this.dropdown = bootstrap.Dropdown.getOrCreateInstance(this.$widget.find(".note-type-dropdown-trigger"));
 
         this.$widget.on("hidden.bs.modal", () => {
@@ -88,13 +108,15 @@ export default class NoteTypeChooserDialog extends BasicWidget {
 
         this.$noteTypeDropdown.parent().on('hide.bs.dropdown', e => {
             // prevent closing dropdown by clicking outside
+            // TODO: Check if this actually works.
+            //@ts-ignore
             if (e.clickEvent) {
                 e.preventDefault();
             }
         });
     }
 
-    async chooseNoteTypeEvent({ callback }) {
+    async chooseNoteTypeEvent({ callback }: { callback: Callback }) {
         this.$originalFocused = $(':focus');
 
         const noteTypes = await noteTypesService.getNoteTypeItems();
@@ -104,13 +126,12 @@ export default class NoteTypeChooserDialog extends BasicWidget {
         for (const noteType of noteTypes) {
             if (noteType.title === '----') {
                 this.$noteTypeDropdown.append($('<h6 class="dropdown-header">').append(t("note_type_chooser.templates")));
-            }
-            else {
+            } else {          
                 this.$noteTypeDropdown.append(
                     $('<a class="dropdown-item" tabindex="0">')
-                        .attr("data-note-type", noteType.type)
-                        .attr("data-template-note-id", noteType.templateNoteId)
-                        .append($("<span>").addClass(noteType.uiIcon))
+                        .attr("data-note-type", (noteType as NoteType).type)
+                        .attr("data-template-note-id", (noteType as NoteType).templateNoteId || "")
+                        .append($("<span>").addClass((noteType as NoteType).uiIcon))
                         .append(` ${noteType.title}`)
                 );
             }
@@ -127,16 +148,18 @@ export default class NoteTypeChooserDialog extends BasicWidget {
         this.resolve = callback;
     }
 
-    doResolve(e) {
+    doResolve(e: JQuery.KeyDownEvent | JQuery.ClickEvent) {
         const $item = $(e.target).closest(".dropdown-item");
         const noteType = $item.attr("data-note-type");
         const templateNoteId = $item.attr("data-template-note-id");
 
-        this.resolve({
-            success: true,
-            noteType,
-            templateNoteId
-        });
+        if (this.resolve) {
+            this.resolve({
+                success: true,
+                noteType,
+                templateNoteId
+            });
+        }
         this.resolve = null;
 
         this.modal.hide();
diff --git a/src/public/app/widgets/dialogs/prompt.js b/src/public/app/widgets/dialogs/prompt.ts
similarity index 71%
rename from src/public/app/widgets/dialogs/prompt.js
rename to src/public/app/widgets/dialogs/prompt.ts
index c8a1fa016..7bdc23956 100644
--- a/src/public/app/widgets/dialogs/prompt.js
+++ b/src/public/app/widgets/dialogs/prompt.ts
@@ -20,7 +20,34 @@ const TPL = `
     </div>
 </div>`;
 
+interface ShownCallbackData {
+    $dialog: JQuery<HTMLElement>;
+    $question: JQuery<HTMLElement> | null;
+    $answer: JQuery<HTMLElement> | null;
+    $form: JQuery<HTMLElement>;
+}
+
+export interface PromptDialogOptions {
+    title?: string;
+    message?: string;
+    defaultValue?: string;
+    shown: PromptShownDialogCallback;
+    callback: (value: unknown) => void;
+}
+
+export type PromptShownDialogCallback = ((callback: ShownCallbackData) => void) | null;
+
 export default class PromptDialog extends BasicWidget {
+
+    private resolve: ((val: string | null) => void) | null;
+    private shownCb: PromptShownDialogCallback;
+    
+    private modal!: bootstrap.Modal;
+    private $dialogBody!: JQuery<HTMLElement>;
+    private $question!: JQuery<HTMLElement> | null;
+    private $answer!: JQuery<HTMLElement> | null;
+    private $form!: JQuery<HTMLElement>;
+
     constructor() {
         super();
 
@@ -30,6 +57,8 @@ export default class PromptDialog extends BasicWidget {
 
     doRender() {
         this.$widget = $(TPL);
+        // TODO: Fix once we use proper ES imports.
+        //@ts-ignore
         this.modal = bootstrap.Modal.getOrCreateInstance(this.$widget);
         this.$dialogBody = this.$widget.find(".modal-body");
         this.$form = this.$widget.find(".prompt-dialog-form");
@@ -46,7 +75,7 @@ export default class PromptDialog extends BasicWidget {
                 });
             }
 
-            this.$answer.trigger('focus').select();
+            this.$answer?.trigger('focus').select();
         });
 
         this.$widget.on("hidden.bs.modal", () => {
@@ -57,13 +86,15 @@ export default class PromptDialog extends BasicWidget {
 
         this.$form.on('submit', e => {
             e.preventDefault();
-            this.resolve(this.$answer.val());
+            if (this.resolve) {
+                this.resolve(this.$answer?.val() as string);
+            }
 
             this.modal.hide();
         });
     }
 
-    showPromptDialogEvent({ title, message, defaultValue, shown, callback }) {
+    showPromptDialogEvent({ title, message, defaultValue, shown, callback }: PromptDialogOptions) {
         this.shownCb = shown;
         this.resolve = callback;
 
@@ -71,7 +102,7 @@ export default class PromptDialog extends BasicWidget {
 
         this.$question = $("<label>")
             .prop("for", "prompt-dialog-answer")
-            .text(message);
+            .text(message || "");
 
         this.$answer = $("<input>")
             .prop("type", "text")
diff --git a/tsconfig.json b/tsconfig.json
index cd4ea40e2..d1c25dd30 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -7,6 +7,7 @@
 		"strict": true,
 		"noImplicitAny": true,
 		"resolveJsonModule": true,
+		"allowJs": true,
 		"lib": [
 			"ES2022"
 		],
@@ -18,14 +19,14 @@
 		"./src/**/*.js",
 		"./src/**/*.ts",
 		"./*.ts",
-		"./spec/**/*.ts",
-		"./spec-es6/**/*.ts"
+		"./spec/**/*.ts"
 	],
 	"exclude": [
-		"./src/public/**/*",
-		"./node_modules/**/*"
+		"./node_modules/**/*",
+		"./spec-es6/**/*.ts"
 	],
 	"files": [
-		"src/types.d.ts"
+		"src/types.d.ts",
+		"src/public/app/types.d.ts"
 	]
 }
\ No newline at end of file