diff --git a/src/TodoistApi.ts b/src/TodoistApi.ts
index 84813bc..d48977a 100644
--- a/src/TodoistApi.ts
+++ b/src/TodoistApi.ts
@@ -9,12 +9,11 @@ import {
     Comment,
 } from './types/entities'
 import {
+    AddCommentArgs,
     AddLabelArgs,
     AddProjectArgs,
     AddSectionArgs,
-    AddProjectCommentArgs,
     AddTaskArgs,
-    AddTaskCommentArgs,
     GetProjectCommentsArgs,
     GetTaskCommentsArgs,
     GetTasksArgs,
@@ -24,6 +23,7 @@ import {
     UpdateSectionArgs,
     UpdateTaskArgs,
     QuickAddTaskArgs,
+    GetSharedLabelsArgs,
     RenameSharedLabelArgs,
     RemoveSharedLabelArgs,
 } from './types/requests'
@@ -398,12 +398,13 @@ export class TodoistApi {
         return isSuccess(response)
     }
 
-    async getSharedLabels(): Promise<string[]> {
+    async getSharedLabels(args?: GetSharedLabelsArgs): Promise<string[]> {
         const response = await request<string[]>(
             'GET',
             this.restApiBase,
             ENDPOINT_REST_LABELS_SHARED,
             this.authToken,
+            args,
         )
 
         return response.data
@@ -453,10 +454,7 @@ export class TodoistApi {
         return validateComment(response.data)
     }
 
-    async addComment(
-        args: AddTaskCommentArgs | AddProjectCommentArgs,
-        requestId?: string,
-    ): Promise<Comment> {
+    async addComment(args: AddCommentArgs, requestId?: string): Promise<Comment> {
         const response = await request<Comment>(
             'POST',
             this.restApiBase,
diff --git a/src/authentication.test.ts b/src/authentication.test.ts
index 64bcf82..0aa8b47 100644
--- a/src/authentication.test.ts
+++ b/src/authentication.test.ts
@@ -67,7 +67,7 @@ describe('authentication', () => {
 
         const successfulTokenResponse = {
             accessToken: 'AToken',
-            state: 'AState',
+            tokenType: 'Bearer',
         }
 
         test('calls request with expected values', async () => {
@@ -112,7 +112,7 @@ describe('authentication', () => {
         test('throws error if token not present in response', async () => {
             const missingTokenResponse = {
                 accessToken: undefined,
-                state: 'AState',
+                tokenType: undefined,
             }
 
             setupRestClientMock(missingTokenResponse)
diff --git a/src/authentication.ts b/src/authentication.ts
index 7020f8f..8728785 100644
--- a/src/authentication.ts
+++ b/src/authentication.ts
@@ -18,7 +18,7 @@ export type Permission =
 
 export type AuthTokenResponse = {
     accessToken: string
-    state: string
+    tokenType: string
 }
 
 export type AuthTokenRequestArgs = {
diff --git a/src/types/entities.ts b/src/types/entities.ts
index 2948d19..d00b6ee 100644
--- a/src/types/entities.ts
+++ b/src/types/entities.ts
@@ -35,6 +35,7 @@ export const DueDate = Record({
     Partial({
         datetime: String.Or(Null),
         timezone: String.Or(Null),
+        lang: String.Or(Null),
     }),
 )
 
@@ -93,6 +94,9 @@ export const Project = Record({
 
 export type Project = Static<typeof Project>
 
+// This allows us to accept any string during validation, but provide intellisense for the two possible values in request args
+export type ProjectViewStyle = 'list' | 'board'
+
 export const Section = Record({
     id: String,
     order: Int,
diff --git a/src/types/requests.ts b/src/types/requests.ts
index c31aa2a..d988184 100644
--- a/src/types/requests.ts
+++ b/src/types/requests.ts
@@ -1,5 +1,5 @@
-import type { RequireAllOrNone } from 'type-fest'
-import type { Duration } from './entities'
+import type { RequireAllOrNone, RequireOneOrNone, RequireExactlyOne } from 'type-fest'
+import type { Duration, ProjectViewStyle } from './entities'
 
 export type AddTaskArgs = {
     content: string
@@ -10,15 +10,17 @@ export type AddTaskArgs = {
     order?: number
     labels?: string[]
     priority?: number
-    dueString?: string
     dueLang?: string
+    assigneeId?: string
+    dueString?: string
+} & RequireOneOrNone<{
     dueDate?: string
     dueDatetime?: string
-    assigneeId?: string
-} & RequireAllOrNone<{
-    duration?: Duration['amount']
-    durationUnit?: Duration['unit']
-}>
+}> &
+    RequireAllOrNone<{
+        duration?: Duration['amount']
+        durationUnit?: Duration['unit']
+    }>
 
 export type QuickAddTaskArgs = {
     text: string
@@ -41,17 +43,17 @@ export type UpdateTaskArgs = {
     description?: string
     labels?: string[]
     priority?: number
-    dueString?: string | null
     dueLang?: string | null
-    dueDate?: string | null
-    dueDatetime?: string | null
     assigneeId?: string | null
-} & RequireAllOrNone<{
-    duration?: Duration['amount']
-    durationUnit?: Duration['unit']
-}>
-
-export type ProjectViewStyle = 'list' | 'board'
+    dueString?: string
+} & RequireOneOrNone<{
+    dueDate?: string
+    dueDatetime?: string
+}> &
+    RequireAllOrNone<{
+        duration?: Duration['amount']
+        durationUnit?: Duration['unit']
+    }>
 
 export type AddProjectArgs = {
     name: string
@@ -102,7 +104,7 @@ export type GetProjectCommentsArgs = {
     taskId?: never
 }
 
-type AddCommentArgs = {
+export type AddCommentArgs = {
     content: string
     attachment?: {
         fileName?: string
@@ -110,22 +112,19 @@ type AddCommentArgs = {
         fileType?: string
         resourceType?: string
     }
-}
-
-export type AddTaskCommentArgs = AddCommentArgs & {
-    taskId: string
-    projectId?: never
-}
-
-export type AddProjectCommentArgs = AddCommentArgs & {
-    projectId: string
-    taskId?: never
-}
+} & RequireExactlyOne<{
+    taskId?: string
+    projectId?: string
+}>
 
 export type UpdateCommentArgs = {
     content: string
 }
 
+export type GetSharedLabelsArgs = {
+    omitPersonal?: boolean
+}
+
 export type RenameSharedLabelArgs = {
     name: string
     newName: string