diff --git a/src/history/history.service.ts b/src/history/history.service.ts
index aef7bc389..04f70eadc 100644
--- a/src/history/history.service.ts
+++ b/src/history/history.service.ts
@@ -29,6 +29,12 @@ export class HistoryService {
     this.logger.setContext(HistoryService.name);
   }
 
+  /**
+   * @async
+   * Get all entries of a user
+   * @param {User} user - the user the entries should be from
+   * @return {HistoryEntry[]} an array of history entries of the specified user
+   */
   async getEntriesByUser(user: User): Promise<HistoryEntry[]> {
     return await this.historyEntryRepository.find({
       where: { user: user },
@@ -36,7 +42,15 @@ export class HistoryService {
     });
   }
 
-  private async getEntryByNoteIdOrAlias(
+  /**
+   * @async
+   * Get a history entry by the user and note, which is specified via id or alias
+   * @param {string} noteIdOrAlias - the id or alias specifying the note
+   * @param {User} user - the user that the note belongs to
+   * @throws {NotInDBError} the specified note does not exist
+   * @return {HistoryEntry} the requested history entry
+   */
+  async getEntryByNoteIdOrAlias(
     noteIdOrAlias: string,
     user: User,
   ): Promise<HistoryEntry> {
@@ -44,6 +58,13 @@ export class HistoryService {
     return await this.getEntryByNote(note, user);
   }
 
+  /**
+   * @async
+   * Get a history entry by the user and note
+   * @param {Note} note - the note that the history entry belongs to
+   * @param {User} user - the user that the history entry belongs to
+   * @return {HistoryEntry} the requested history entry
+   */
   private async getEntryByNote(note: Note, user: User): Promise<HistoryEntry> {
     return await this.historyEntryRepository.findOne({
       where: {
@@ -54,6 +75,13 @@ export class HistoryService {
     });
   }
 
+  /**
+   * @async
+   * Create or update a history entry by the user and note. If the entry is merely updated the updatedAt date is set to the current date.
+   * @param {Note} note - the note that the history entry belongs to
+   * @param {User} user - the user that the history entry belongs to
+   * @return {HistoryEntry} the requested history entry
+   */
   async createOrUpdateHistoryEntry(
     note: Note,
     user: User,
@@ -67,6 +95,14 @@ export class HistoryService {
     return await this.historyEntryRepository.save(entry);
   }
 
+  /**
+   * @async
+   * Update a history entry identified by the user and a note id or alias
+   * @param {string} noteIdOrAlias - the note that the history entry belongs to
+   * @param {User} user - the user that the history entry belongs to
+   * @param {HistoryEntryUpdateDto} updateDto - the change that should be applied to the history entry
+   * @return {HistoryEntry} the requested history entry
+   */
   async updateHistoryEntry(
     noteIdOrAlias: string,
     user: User,
@@ -82,6 +118,13 @@ export class HistoryService {
     return await this.historyEntryRepository.save(entry);
   }
 
+  /**
+   * @async
+   * Delete the history entry identified by the user and a note id or alias
+   * @param {string} noteIdOrAlias - the note that the history entry belongs to
+   * @param {User} user - the user that the history entry belongs to
+   * @throws {NotInDBError} the specified history entry does not exist
+   */
   async deleteHistoryEntry(noteIdOrAlias: string, user: User): Promise<void> {
     const entry = await this.getEntryByNoteIdOrAlias(noteIdOrAlias, user);
     if (!entry) {
@@ -93,6 +136,11 @@ export class HistoryService {
     return;
   }
 
+  /**
+   * Build HistoryEntryDto from a history entry.
+   * @param {HistoryEntry} entry - the history entry to use
+   * @return {HistoryEntryDto} the built HistoryEntryDto
+   */
   toHistoryEntryDto(entry: HistoryEntry): HistoryEntryDto {
     return {
       identifier: entry.note.alias ? entry.note.alias : entry.note.id,