diff --git a/internal/repos/actions_repo/repo.go b/internal/repos/actions_repo/repo.go
index 8448e31..4b45088 100644
--- a/internal/repos/actions_repo/repo.go
+++ b/internal/repos/actions_repo/repo.go
@@ -9,24 +9,29 @@ import (
 )
 
 var (
+	// ErrActionsNotFound indicates that no actions were found.
 	ErrActionsNotFound = errors.New("Ход не найден")
 )
 
+// ActionsRepo persists team actions.
 type ActionsRepo struct {
 	pool *pgxpool.Pool
 }
 
+// Action describes a team action.
 type Action struct {
 	Code   string
 	ViaMCP bool
 }
 
+// NewActionsRepo creates an actions repository.
 func NewActionsRepo(pool *pgxpool.Pool) *ActionsRepo {
 	return &ActionsRepo{
 		pool: pool,
 	}
 }
 
+// AddAction stores an action for a team.
 func (r *ActionsRepo) AddAction(ctx context.Context, teamID int, code string, viaMCP bool) (int, error) {
 	id := 0
 	err := r.pool.QueryRow(
@@ -45,6 +50,7 @@ func (r *ActionsRepo) AddAction(ctx context.Context, teamID int, code string, vi
 	return id, nil
 }
 
+// GetActionsByTeamID returns actions for a team.
 func (r *ActionsRepo) GetActionsByTeamID(ctx context.Context, teamID int) ([]Action, error) {
 	rows, err := r.pool.Query(
 		ctx,
@@ -80,6 +86,7 @@ func (r *ActionsRepo) GetActionsByTeamID(ctx context.Context, teamID int) ([]Act
 	return actions, nil
 }
 
+// GetActionsCountByTeamIDs returns action counts for teams.
 func (r *ActionsRepo) GetActionsCountByTeamIDs(ctx context.Context, teamIDs []int) (map[int]int, error) {
 	rows, err := r.pool.Query(
 		ctx,
@@ -116,6 +123,7 @@ func (r *ActionsRepo) GetActionsCountByTeamIDs(ctx context.Context, teamIDs []in
 	return res, nil
 }
 
+// DeleteLastActionByTeamID removes the latest action for a team.
 func (r *ActionsRepo) DeleteLastActionByTeamID(ctx context.Context, teamID int) error {
 	tag, err := r.pool.Exec(
 		ctx,
diff --git a/internal/repos/applications_repo/repo.go b/internal/repos/applications_repo/repo.go
index 80cd4b7..786031f 100644
--- a/internal/repos/applications_repo/repo.go
+++ b/internal/repos/applications_repo/repo.go
@@ -10,19 +10,23 @@ import (
 )
 
 var (
+	// ErrApplicationNotFound indicates that an application was not found.
 	ErrApplicationNotFound = errors.New("Улика не найдена")
 )
 
+// ApplicationsRepo persists team applications.
 type ApplicationsRepo struct {
 	pool *pgxpool.Pool
 }
 
+// NewApplicationsRepo creates an applications repository.
 func NewApplicationsRepo(pool *pgxpool.Pool) *ApplicationsRepo {
 	return &ApplicationsRepo{
 		pool: pool,
 	}
 }
 
+// AddApplication stores an application for a team.
 func (r *ApplicationsRepo) AddApplication(
 	ctx context.Context,
 	teamID int,
@@ -48,6 +52,7 @@ func (r *ApplicationsRepo) AddApplication(
 	return id, nil
 }
 
+// GetApplicationsByTeamIDsAndState returns applications matching team IDs and state.
 func (r *ApplicationsRepo) GetApplicationsByTeamIDsAndState(
 	ctx context.Context,
 	teamIDs []int,
@@ -91,6 +96,7 @@ func (r *ApplicationsRepo) GetApplicationsByTeamIDsAndState(
 	return res, nil
 }
 
+// UpdateApplicationStatus changes an application's status.
 func (r *ApplicationsRepo) UpdateApplicationStatus(
 	ctx context.Context,
 	teamID int,
@@ -116,6 +122,7 @@ func (r *ApplicationsRepo) UpdateApplicationStatus(
 	return nil
 }
 
+// DeleteApplicationByTeamIDAndName removes an application by team and name.
 func (r *ApplicationsRepo) DeleteApplicationByTeamIDAndName(ctx context.Context, teamID int, name string) error {
 	tag, err := r.pool.Exec(
 		ctx,
diff --git a/internal/repos/game_reviews_repo/repo.go b/internal/repos/game_reviews_repo/repo.go
index d11e287..8495eb3 100644
--- a/internal/repos/game_reviews_repo/repo.go
+++ b/internal/repos/game_reviews_repo/repo.go
@@ -11,12 +11,17 @@ import (
 )
 
 var (
+	// ErrReviewNotFound indicates that a review was not found.
 	ErrReviewNotFound = errors.New("Отзыв не найден")
-	ErrReviewExists   = errors.New("Отзыв от команды уже оставлен")
-	ErrTeamNotFound   = errors.New("Команда не найдена")
-	ErrInvalidStatus  = errors.New("Недопустимый статус модерации")
+	// ErrReviewExists indicates that a team already submitted a review.
+	ErrReviewExists = errors.New("Отзыв от команды уже оставлен")
+	// ErrTeamNotFound indicates that a team was not found.
+	ErrTeamNotFound = errors.New("Команда не найдена")
+	// ErrInvalidStatus indicates that a moderation status is invalid.
+	ErrInvalidStatus = errors.New("Недопустимый статус модерации")
 )
 
+// Review describes a game review.
 type Review struct {
 	ID        int
 	GameID    int
@@ -29,10 +34,13 @@ type Review struct {
 	CreatedAt time.Time
 }
 
+// Repo persists game reviews.
 type Repo struct{ pool *pgxpool.Pool }
 
+// NewGameReviewsRepo creates a game reviews repository.
 func NewGameReviewsRepo(pool *pgxpool.Pool) *Repo { return &Repo{pool: pool} }
 
+// Create stores a review.
 func (r *Repo) Create(ctx context.Context, gameID, teamID int, rating int32, text string) (*Review, error) {
 	review := &Review{}
 	err := r.pool.QueryRow(
@@ -72,10 +80,12 @@ func (r *Repo) Create(ctx context.Context, gameID, teamID int, rating int32, tex
 	return review, err
 }
 
+// GetByID returns a review by ID.
 func (r *Repo) GetByID(ctx context.Context, id int) (*Review, error) {
 	return r.queryOne(ctx, id)
 }
 
+// List returns reviews for a game and aggregate rating data.
 func (r *Repo) List(ctx context.Context, gameID int, all bool) ([]*Review, float64, int32, error) {
 	rows, err := r.pool.Query(
 		ctx,
@@ -117,6 +127,7 @@ func (r *Repo) List(ctx context.Context, gameID int, all bool) ([]*Review, float
 	return reviews, average, int32(count), nil
 }
 
+// ListForModeration returns reviews awaiting moderation.
 func (r *Repo) ListForModeration(ctx context.Context) ([]*Review, error) {
 	rows, err := r.pool.Query(
 		ctx,
@@ -141,6 +152,7 @@ func (r *Repo) ListForModeration(ctx context.Context) ([]*Review, error) {
 	return reviews, rows.Err()
 }
 
+// Moderate updates a review moderation status.
 func (r *Repo) Moderate(ctx context.Context, id int, status string) (*Review, error) {
 	if status != "approved" && status != "rejected" && status != "hidden" {
 		return nil, ErrInvalidStatus
@@ -162,6 +174,7 @@ func (r *Repo) Moderate(ctx context.Context, id int, status string) (*Review, er
 	return r.queryOne(ctx, id)
 }
 
+// ScenarioRating returns aggregate ratings for a scenario.
 func (r *Repo) ScenarioRating(ctx context.Context, scenarioID int) (float64, int32, error) {
 	var average float64
 	var count int64
@@ -176,6 +189,7 @@ func (r *Repo) ScenarioRating(ctx context.Context, scenarioID int) (float64, int
 	return average, int32(count), err
 }
 
+// ListByScenario returns reviews and aggregate ratings for a scenario.
 func (r *Repo) ListByScenario(ctx context.Context, scenarioID int) ([]*Review, float64, int32, error) {
 	rows, err := r.pool.Query(
 		ctx,
diff --git a/internal/repos/games_repo/repo.go b/internal/repos/games_repo/repo.go
index f5ca639..33b089e 100644
--- a/internal/repos/games_repo/repo.go
+++ b/internal/repos/games_repo/repo.go
@@ -12,19 +12,23 @@ import (
 )
 
 var (
+	// ErrGameNotFound indicates that a game was not found.
 	ErrGameNotFound = errors.New("Игра не найдена")
 )
 
+// GamesRepo persists games.
 type GamesRepo struct {
 	pool *pgxpool.Pool
 }
 
+// NewGamesRepo creates a games repository.
 func NewGamesRepo(pool *pgxpool.Pool) *GamesRepo {
 	return &GamesRepo{
 		pool: pool,
 	}
 }
 
+// AddGame stores a game.
 func (r *GamesRepo) AddGame(
 	ctx context.Context,
 	name string,
@@ -54,6 +58,7 @@ func (r *GamesRepo) AddGame(
 	return id, nil
 }
 
+// GetGameByID returns a game by ID.
 func (r *GamesRepo) GetGameByID(
 	ctx context.Context,
 	id int,
@@ -98,6 +103,7 @@ func (r *GamesRepo) GetGameByID(
 	return game, nil
 }
 
+// DeleteGameByID removes a game by ID.
 func (r *GamesRepo) DeleteGameByID(
 	ctx context.Context,
 	id int,
@@ -117,6 +123,7 @@ func (r *GamesRepo) DeleteGameByID(
 	return nil
 }
 
+// GetGames returns games matching the requested filters.
 func (r *GamesRepo) GetGames(
 	ctx context.Context,
 ) ([]*repos.Game, error) {
@@ -162,6 +169,7 @@ func (r *GamesRepo) GetGames(
 	return games, nil
 }
 
+// UpdateGame updates a game's editable fields.
 func (r *GamesRepo) UpdateGame(
 	ctx context.Context,
 	id int,
@@ -201,6 +209,7 @@ func (r *GamesRepo) UpdateGame(
 	return nil
 }
 
+// StartGame marks a game as started.
 func (r *GamesRepo) StartGame(ctx context.Context, id int) error {
 	tag, err := r.pool.Exec(
 		ctx,
@@ -221,6 +230,7 @@ func (r *GamesRepo) StartGame(ctx context.Context, id int) error {
 	return nil
 }
 
+// PauseGame marks a game as paused.
 func (r *GamesRepo) PauseGame(ctx context.Context, id int) error {
 	tag, err := r.pool.Exec(
 		ctx,
@@ -240,6 +250,7 @@ func (r *GamesRepo) PauseGame(ctx context.Context, id int) error {
 	return nil
 }
 
+// PlayGame resumes a paused game.
 func (r *GamesRepo) PlayGame(ctx context.Context, id int) error {
 	tag, err := r.pool.Exec(
 		ctx,
@@ -259,6 +270,7 @@ func (r *GamesRepo) PlayGame(ctx context.Context, id int) error {
 	return nil
 }
 
+// FinishGame marks a game as finished.
 func (r *GamesRepo) FinishGame(ctx context.Context, id int) error {
 	tag, err := r.pool.Exec(
 		ctx,
@@ -279,6 +291,7 @@ func (r *GamesRepo) FinishGame(ctx context.Context, id int) error {
 	return nil
 }
 
+// ResetGame resets a game's state.
 func (r *GamesRepo) ResetGame(ctx context.Context, id int) error {
 	tag, err := r.pool.Exec(
 		ctx,
diff --git a/internal/repos/screen_sessions_repo/repo.go b/internal/repos/screen_sessions_repo/repo.go
index 77498ed..a939157 100644
--- a/internal/repos/screen_sessions_repo/repo.go
+++ b/internal/repos/screen_sessions_repo/repo.go
@@ -10,8 +10,10 @@ import (
 	"github.com/jackc/pgx/v5/pgxpool"
 )
 
+// ErrScreenNotFound indicates that a screen session was not found.
 var ErrScreenNotFound = errors.New("Экран не найден")
 
+// ScreenSession describes a screen session.
 type ScreenSession struct {
 	ID                    int
 	GameID                *int
@@ -29,14 +31,17 @@ type ScreenSession struct {
 	TimerEndsAt           *time.Time
 }
 
+// ScreenSessionsRepo persists screen sessions.
 type ScreenSessionsRepo struct {
 	pool *pgxpool.Pool
 }
 
+// NewScreenSessionsRepo creates a screen sessions repository.
 func NewScreenSessionsRepo(pool *pgxpool.Pool) *ScreenSessionsRepo {
 	return &ScreenSessionsRepo{pool: pool}
 }
 
+// Create creates a screen session.
 func (r *ScreenSessionsRepo) Create(ctx context.Context, tokenHash string) (int, error) {
 	var id int
 	err := r.pool.QueryRow(ctx, `
@@ -46,6 +51,7 @@ func (r *ScreenSessionsRepo) Create(ctx context.Context, tokenHash string) (int,
 	return id, err
 }
 
+// Get returns a screen session by ID and token hash.
 func (r *ScreenSessionsRepo) Get(ctx context.Context, id int, tokenHash string) (*ScreenSession, error) {
 	session := &ScreenSession{ID: id}
 	err := r.pool.QueryRow(ctx, `
@@ -69,6 +75,7 @@ func (r *ScreenSessionsRepo) Get(ctx context.Context, id int, tokenHash string)
 	return session, nil
 }
 
+// ListByGame returns screen sessions for a game.
 func (r *ScreenSessionsRepo) ListByGame(ctx context.Context, gameID int) ([]*ScreenSession, error) {
 	rows, err := r.pool.Query(ctx, `
 		SELECT id, game_id, sound_enabled, last_seen_at, mode, state_version, position_ms, command, volume,
@@ -93,21 +100,25 @@ func (r *ScreenSessionsRepo) ListByGame(ctx context.Context, gameID int) ([]*Scr
 	return sessions, rows.Err()
 }
 
+// SetMode updates the display mode for a game.
 func (r *ScreenSessionsRepo) SetMode(ctx context.Context, gameID int, mode int32) error {
 	_, err := r.pool.Exec(ctx, `UPDATE screen_sessions SET mode = $2, command = 0, state_version = state_version + 1, updated_at = NOW() WHERE game_id = $1`, gameID, mode)
 	return err
 }
 
+// SetPosition updates the display position for a game.
 func (r *ScreenSessionsRepo) SetPosition(ctx context.Context, gameID int, position int64) error {
 	_, err := r.pool.Exec(ctx, `UPDATE screen_sessions SET position_ms = $2, state_version = state_version + 1, updated_at = NOW() WHERE game_id = $1`, gameID, position)
 	return err
 }
 
+// SetCommand updates the display command for a game.
 func (r *ScreenSessionsRepo) SetCommand(ctx context.Context, gameID int, command int32, position int64, volume int32) error {
 	_, err := r.pool.Exec(ctx, `UPDATE screen_sessions SET command = $2, position_ms = $3, volume = $4, state_version = state_version + 1, updated_at = NOW() WHERE game_id = $1`, gameID, command, position, volume)
 	return err
 }
 
+// SetTimer updates the display timer for a game.
 func (r *ScreenSessionsRepo) SetTimer(ctx context.Context, gameID int, duration int64, label string) error {
 	_, err := r.pool.Exec(ctx, `
 		UPDATE screen_sessions
@@ -124,6 +135,7 @@ func (r *ScreenSessionsRepo) SetTimer(ctx context.Context, gameID int, duration
 	return err
 }
 
+// SetTimerCommand updates the timer command for a game.
 func (r *ScreenSessionsRepo) SetTimerCommand(ctx context.Context, gameID int, command int32) error {
 	_, err := r.pool.Exec(ctx, `
 		UPDATE screen_sessions
@@ -154,6 +166,7 @@ func (r *ScreenSessionsRepo) SetTimerCommand(ctx context.Context, gameID int, co
 	return err
 }
 
+// Bind attaches a screen session to a game.
 func (r *ScreenSessionsRepo) Bind(ctx context.Context, id, gameID int, tokenHash string) error {
 	result, err := r.pool.Exec(ctx, `
 		UPDATE screen_sessions
@@ -168,6 +181,7 @@ func (r *ScreenSessionsRepo) Bind(ctx context.Context, id, gameID int, tokenHash
 	return nil
 }
 
+// Unbind detaches a screen session from its game.
 func (r *ScreenSessionsRepo) Unbind(ctx context.Context, id int) error {
 	result, err := r.pool.Exec(ctx, `
 		UPDATE screen_sessions
@@ -192,6 +206,7 @@ func (r *ScreenSessionsRepo) Unbind(ctx context.Context, id int) error {
 	return nil
 }
 
+// SetSound enables or disables sound for a screen session.
 func (r *ScreenSessionsRepo) SetSound(ctx context.Context, id int, enabled bool) error {
 	query := `UPDATE screen_sessions SET sound_enabled = FALSE, updated_at = NOW() WHERE id = $1`
 	args := []any{id}
diff --git a/internal/repos/teams_repo/participation.go b/internal/repos/teams_repo/participation.go
index e123820..d8ebe4f 100644
--- a/internal/repos/teams_repo/participation.go
+++ b/internal/repos/teams_repo/participation.go
@@ -11,14 +11,20 @@ import (
 	"github.com/jackc/pgx/v5"
 )
 
+// ErrParticipationLink indicates that a participation link is invalid.
 var ErrParticipationLink = errors.New("Ссылка недействительна")
+
+// ErrParticipationClosed indicates that participation answers are closed.
 var ErrParticipationClosed = errors.New("Приём ответов закрыт")
+
+// ErrParticipationFinal indicates that a final answer cannot be changed.
 var ErrParticipationFinal = errors.New("Решение уже принято и не может быть изменено")
 
 const maxParticipationEmailAttempts = 8
 
 const maxReviewReminderAttempts = 8
 
+// Participation describes a team's participation state.
 type Participation struct {
 	TeamID            int
 	TeamName          string
@@ -31,6 +37,7 @@ type Participation struct {
 	Attempts          int
 }
 
+// ReviewReminder describes a pending review reminder.
 type ReviewReminder struct {
 	TeamID   int
 	TeamName string
@@ -53,6 +60,7 @@ func tokenHash(token string) ([]byte, error) {
 	return hash[:], nil
 }
 
+// GetParticipation returns participation data by token.
 func (r *TeamsRepo) GetParticipation(ctx context.Context, token string) (*Participation, error) {
 	hash, err := tokenHash(token)
 	if err != nil {
@@ -69,6 +77,7 @@ func (r *TeamsRepo) GetParticipation(ctx context.Context, token string) (*Partic
 	return p, err
 }
 
+// AnswerParticipation stores a team's final answer.
 func (r *TeamsRepo) AnswerParticipation(ctx context.Context, token, answer string) (*Participation, error) {
 	if answer != "confirmed" && answer != "cancelled" {
 		return nil, errors.New("Выберите подтверждение или отмену участия")
@@ -102,6 +111,7 @@ func (r *TeamsRepo) AnswerParticipation(ctx context.Context, token, answer strin
 
 // Пятиминутная аренда переживает перезапуски и не позволяет рабочим процессам
 // отправить одну задачу повторно.
+// ClaimParticipationEmail claims the next participation email job.
 func (r *TeamsRepo) ClaimParticipationEmail(ctx context.Context) (*Participation, error) {
 	p := &Participation{}
 	err := r.pool.QueryRow(ctx, `WITH candidate AS (
@@ -122,6 +132,7 @@ func (r *TeamsRepo) ClaimParticipationEmail(ctx context.Context) (*Participation
 	return p, err
 }
 
+// SetParticipationToken stores a participation token.
 func (r *TeamsRepo) SetParticipationToken(ctx context.Context, id int, token string) error {
 	hash, err := tokenHash(token)
 	if err != nil {
@@ -131,6 +142,7 @@ func (r *TeamsRepo) SetParticipationToken(ctx context.Context, id int, token str
 	return err
 }
 
+// ConfirmParticipationByFirstAction confirms participation after the first action.
 func (r *TeamsRepo) ConfirmParticipationByFirstAction(ctx context.Context, teamID int) error {
 	_, err := r.pool.Exec(ctx, `UPDATE teams SET participation_status='confirmed',
  participation_source='first_action', participation_answered_at=NOW()
@@ -138,6 +150,7 @@ func (r *TeamsRepo) ConfirmParticipationByFirstAction(ctx context.Context, teamI
 	return err
 }
 
+// FinishParticipationEmail completes a participation email job.
 func (r *TeamsRepo) FinishParticipationEmail(ctx context.Context, id, attempt int, sendErr error) error {
 	message := ""
 	if sendErr != nil {
@@ -149,6 +162,7 @@ func (r *TeamsRepo) FinishParticipationEmail(ctx context.Context, id, attempt in
 	return err
 }
 
+// ClaimReviewReminder claims the next review reminder job.
 func (r *TeamsRepo) ClaimReviewReminder(ctx context.Context) (*ReviewReminder, error) {
 	job := &ReviewReminder{}
 	err := r.pool.QueryRow(ctx, `WITH candidate AS (
@@ -168,6 +182,7 @@ func (r *TeamsRepo) ClaimReviewReminder(ctx context.Context) (*ReviewReminder, e
 	return job, err
 }
 
+// FinishReviewReminder completes a review reminder job.
 func (r *TeamsRepo) FinishReviewReminder(ctx context.Context, id, attempt int, sendErr error) error {
 	message := ""
 	if sendErr != nil {
diff --git a/internal/repos/teams_repo/repo.go b/internal/repos/teams_repo/repo.go
index cb4a29c..68c27fe 100644
--- a/internal/repos/teams_repo/repo.go
+++ b/internal/repos/teams_repo/repo.go
@@ -10,19 +10,23 @@ import (
 )
 
 var (
+	// ErrTeamNotFound indicates that a team was not found.
 	ErrTeamNotFound = errors.New("Команда не найдена")
 )
 
+// TeamsRepo persists teams and their game membership.
 type TeamsRepo struct {
 	pool *pgxpool.Pool
 }
 
+// NewTeamsRepo creates a teams repository.
 func NewTeamsRepo(pool *pgxpool.Pool) *TeamsRepo {
 	return &TeamsRepo{
 		pool: pool,
 	}
 }
 
+// GetTeamByID returns a team by ID.
 func (r *TeamsRepo) GetTeamByID(ctx context.Context, id int) (*repos.Team, error) {
 	team := &repos.Team{}
 	row := r.pool.QueryRow(
@@ -60,6 +64,7 @@ func (r *TeamsRepo) GetTeamByID(ctx context.Context, id int) (*repos.Team, error
 	return team, nil
 }
 
+// GetTeamsByGameID returns teams registered for a game.
 func (r *TeamsRepo) GetTeamsByGameID(
 	ctx context.Context,
 	gameID int,
@@ -108,6 +113,7 @@ func (r *TeamsRepo) GetTeamsByGameID(
 	return teams, nil
 }
 
+// AddTeam creates a team.
 func (r *TeamsRepo) AddTeam(
 	ctx context.Context,
 	creatorID int,
@@ -118,6 +124,7 @@ func (r *TeamsRepo) AddTeam(
 	return r.AddTeamWithParticipation(ctx, creatorID, gameID, name, password, "", false)
 }
 
+// AddTeamWithParticipation creates a team with participation data.
 func (r *TeamsRepo) AddTeamWithParticipation(ctx context.Context, creatorID, gameID int, name, password, captainEmail string, autoConfirm bool) (int, error) {
 	id := 0
 	status, source := "pending", ""
@@ -144,6 +151,7 @@ func (r *TeamsRepo) AddTeamWithParticipation(ctx context.Context, creatorID, gam
 	return id, nil
 }
 
+// UpdateTeam changes a team's name.
 func (r *TeamsRepo) UpdateTeam(ctx context.Context, teamID int, name string) error {
 	tag, err := r.pool.Exec(
 		ctx,
@@ -163,6 +171,7 @@ func (r *TeamsRepo) UpdateTeam(ctx context.Context, teamID int, name string) err
 	return nil
 }
 
+// DeleteTeam removes a team.
 func (r *TeamsRepo) DeleteTeam(ctx context.Context, teamID int) error {
 	tag, err := r.pool.Exec(
 		ctx,
@@ -179,6 +188,7 @@ func (r *TeamsRepo) DeleteTeam(ctx context.Context, teamID int) error {
 	return nil
 }
 
+// ErrRegistrationClosed indicates that team registration is unavailable.
 var ErrRegistrationClosed = errors.New("Игра не найдена или регистрация уже закрыта")
 
 // RegisterTeam сохраняет одну команду на доставку, включая одновременные повторы.
@@ -186,6 +196,7 @@ func (r *TeamsRepo) RegisterTeam(ctx context.Context, gameID int, deliveryID, na
 	return r.RegisterTeamWithParticipation(ctx, gameID, deliveryID, name, email, participantsCount, password, false)
 }
 
+// RegisterTeamWithParticipation registers a team and its participation data.
 func (r *TeamsRepo) RegisterTeamWithParticipation(ctx context.Context, gameID int, deliveryID, name, email string, participantsCount int32, password string, autoConfirm bool) (int, error) {
 	var id int
 	// Повтор уже принятой доставки успешен и после старта игры.
diff --git a/internal/repos/users_repo/repo.go b/internal/repos/users_repo/repo.go
index bcef54e..fd4af8b 100644
--- a/internal/repos/users_repo/repo.go
+++ b/internal/repos/users_repo/repo.go
@@ -14,13 +14,16 @@ import (
 )
 
 var (
+	// ErrUserNotFound indicates that a user was not found.
 	ErrUserNotFound = errors.New("Пользователь не найден")
 )
 
+// UsersRepo persists users and their roles.
 type UsersRepo struct {
 	pool *pgxpool.Pool
 }
 
+// NewUserRepo creates a users repository.
 func NewUserRepo(pool *pgxpool.Pool) *UsersRepo {
 	return &UsersRepo{
 		pool: pool,
@@ -105,6 +108,7 @@ func (s *UsersRepo) AddUserWithAgreements(
 	return id, nil
 }
 
+// UpdateUserPassword changes a user's password hash.
 func (s *UsersRepo) UpdateUserPassword(
 	ctx context.Context,
 	email string,
@@ -128,6 +132,7 @@ func (s *UsersRepo) UpdateUserPassword(
 	return nil
 }
 
+// GetUserByEmail returns a user by email.
 func (s *UsersRepo) GetUserByEmail(
 	ctx context.Context,
 	email string,
@@ -158,6 +163,7 @@ func (s *UsersRepo) GetUserByEmail(
 	return user, nil
 }
 
+// GetUserByID returns a user by ID.
 func (s *UsersRepo) GetUserByID(
 	ctx context.Context,
 	id int,
@@ -188,6 +194,7 @@ func (s *UsersRepo) GetUserByID(
 	return user, nil
 }
 
+// GetUsers returns users matching the requested filters.
 func (s *UsersRepo) GetUsers(
 	ctx context.Context,
 ) ([]*repos.User, error) {
@@ -225,6 +232,7 @@ func (s *UsersRepo) GetUsers(
 	return users, nil
 }
 
+// AddUserRole assigns a role to a user.
 func (s *UsersRepo) AddUserRole(
 	ctx context.Context,
 	userID int,
@@ -241,6 +249,7 @@ func (s *UsersRepo) AddUserRole(
 	return err
 }
 
+// DeleteUserRole removes a role from a user.
 func (s *UsersRepo) DeleteUserRole(
 	ctx context.Context,
 	userID int,
diff --git a/internal/services/answer_service/service.go b/internal/services/answer_service/service.go
index 838416d..0bb671b 100644
--- a/internal/services/answer_service/service.go
+++ b/internal/services/answer_service/service.go
@@ -13,6 +13,7 @@ import (
 	"evening_detective_server/internal/services/scenarios_service"
 )
 
+// AnswerService handles game answers.
 type AnswerService struct {
 	gamesRepo       *games_repo.GamesRepo
 	teamsRepo       *teams_repo.TeamsRepo
@@ -21,6 +22,7 @@ type AnswerService struct {
 	actionsRepo     *actions_repo.ActionsRepo
 }
 
+// NewAnswerService creates an answer service.
 func NewAnswerService(
 	gamesRepo *games_repo.GamesRepo,
 	teamsRepo *teams_repo.TeamsRepo,
diff --git a/internal/services/file_service/service.go b/internal/services/file_service/service.go
index 7a2502b..19de7ba 100644
--- a/internal/services/file_service/service.go
+++ b/internal/services/file_service/service.go
@@ -41,11 +41,13 @@ var allowedExtensions = map[string]struct{}{
 	".webm": {},
 }
 
+// FileService handles file downloads.
 type FileService struct {
 	fileStorage file_storage.IFileStorage
 	maxFileSize int
 }
 
+// NewFileService creates a file service.
 func NewFileService(
 	fileStorage file_storage.IFileStorage,
 	maxFileSize int,
@@ -149,6 +151,7 @@ func contentTypeCategory(sniffed string) string {
 	}
 }
 
+// DownloadFile returns a file for download.
 func (s *FileService) DownloadFile(
 	ctx context.Context,
 	filename string,
diff --git a/internal/services/game_model/game.go b/internal/services/game_model/game.go
index e246809..483f23e 100644
--- a/internal/services/game_model/game.go
+++ b/internal/services/game_model/game.go
@@ -6,6 +6,7 @@ import (
 	"time"
 )
 
+// Game describes a game exposed by the service layer.
 type Game struct {
 	Format      string
 	ID          int
diff --git a/internal/services/game_model/game_mapper.go b/internal/services/game_model/game_mapper.go
index d3f8dfd..5c2101f 100644
--- a/internal/services/game_model/game_mapper.go
+++ b/internal/services/game_model/game_mapper.go
@@ -5,6 +5,7 @@ import (
 	"evening_detective_server/internal/services/scenarios_service"
 )
 
+// MapGame converts a repository game to a service model.
 func MapGame(
 	o *repos.Game,
 	domain string,
@@ -24,6 +25,7 @@ func MapGame(
 	}
 }
 
+// MapGames converts repository games to service models.
 func MapGames(
 	o []*repos.Game,
 	domain string,
diff --git a/internal/services/game_model/team.go b/internal/services/game_model/team.go
index 97151e7..b86321d 100644
--- a/internal/services/game_model/team.go
+++ b/internal/services/game_model/team.go
@@ -2,6 +2,7 @@ package game_model
 
 import "evening_detective_server/internal/modules/storytelling"
 
+// Team describes a team exposed by the service layer.
 type Team struct {
 	ParticipationStatus     string
 	ParticipationSource     string
diff --git a/internal/services/game_model/team_mapper.go b/internal/services/game_model/team_mapper.go
index 3a35061..2a4de6f 100644
--- a/internal/services/game_model/team_mapper.go
+++ b/internal/services/game_model/team_mapper.go
@@ -2,6 +2,7 @@ package game_model
 
 import "evening_detective_server/internal/repos"
 
+// MapTeam converts a repository team to a service model.
 func MapTeam(
 	o *repos.Team,
 ) *Team {
@@ -19,6 +20,7 @@ func MapTeam(
 	}
 }
 
+// MapTeams converts repository teams to service models.
 func MapTeams(
 	o []*repos.Team,
 ) []*Team {
diff --git a/internal/services/game_service/service.go b/internal/services/game_service/service.go
index c98fef6..fcc6ca3 100644
--- a/internal/services/game_service/service.go
+++ b/internal/services/game_service/service.go
@@ -13,6 +13,7 @@ import (
 	"time"
 )
 
+// GameService handles game lifecycle operations.
 type GameService struct {
 	gamesRepo        *games_repo.GamesRepo
 	teamsRepo        *teams_repo.TeamsRepo
@@ -30,6 +31,7 @@ var (
 	ErrInvalidGameFormat = errors.New("Формат игры должен быть online или offline")
 )
 
+// NewGameService creates a game service.
 func NewGameService(
 	gamesRepo *games_repo.GamesRepo,
 	teamsRepo *teams_repo.TeamsRepo,
@@ -50,6 +52,7 @@ func NewGameService(
 	}
 }
 
+// AddGame creates a game.
 func (s *GameService) AddGame(
 	ctx context.Context,
 	name string,
@@ -72,6 +75,7 @@ func (s *GameService) AddGame(
 	return id, nil
 }
 
+// GetGame returns a game by ID.
 func (s *GameService) GetGame(ctx context.Context, id int) (*game_model.Game, error) {
 	game, err := s.gamesRepo.GetGameByID(ctx, id)
 	if err != nil {
@@ -81,6 +85,7 @@ func (s *GameService) GetGame(ctx context.Context, id int) (*game_model.Game, er
 	return res, nil
 }
 
+// GetGameMedia returns a game with its media references.
 func (s *GameService) GetGameMedia(ctx context.Context, id int) (*game_model.Game, error) {
 	game, err := s.gamesRepo.GetGameByID(ctx, id)
 	if err != nil {
@@ -94,6 +99,7 @@ func (s *GameService) GetGameMedia(ctx context.Context, id int) (*game_model.Gam
 	return gameResult, nil
 }
 
+// GetFullGame returns a game with its full related data.
 func (s *GameService) GetFullGame(
 	ctx context.Context,
 	id int,
@@ -141,6 +147,7 @@ func (s *GameService) GetFullGame(
 	return res, nil
 }
 
+// DeleteGame removes a game.
 func (s *GameService) DeleteGame(
 	ctx context.Context,
 	id int,
@@ -148,6 +155,7 @@ func (s *GameService) DeleteGame(
 	return mapGameError(s.gamesRepo.DeleteGameByID(ctx, id))
 }
 
+// GetGames returns games matching the requested filters.
 func (s *GameService) GetGames(
 	ctx context.Context,
 ) ([]*game_model.Game, error) {
@@ -158,6 +166,7 @@ func (s *GameService) GetGames(
 	return game_model.MapGames(games, s.domain), nil
 }
 
+// UpdateGame updates a game's editable fields.
 func (s *GameService) UpdateGame(
 	ctx context.Context,
 	id int,
@@ -181,22 +190,27 @@ func (s *GameService) UpdateGame(
 	return mapGameError(s.gamesRepo.UpdateGame(ctx, id, name, description, location, startAt, scenarioID, format))
 }
 
+// StartGame marks a game as started.
 func (s *GameService) StartGame(ctx context.Context, id int) error {
 	return mapGameError(s.gamesRepo.StartGame(ctx, id))
 }
 
+// PauseGame marks a game as paused.
 func (s *GameService) PauseGame(ctx context.Context, id int) error {
 	return mapGameError(s.gamesRepo.PauseGame(ctx, id))
 }
 
+// PlayGame resumes a paused game.
 func (s *GameService) PlayGame(ctx context.Context, id int) error {
 	return mapGameError(s.gamesRepo.PlayGame(ctx, id))
 }
 
+// FinishGame marks a game as finished.
 func (s *GameService) FinishGame(ctx context.Context, id int) error {
 	return mapGameError(s.gamesRepo.FinishGame(ctx, id))
 }
 
+// ResetGame resets a game's state.
 func (s *GameService) ResetGame(ctx context.Context, id int) error {
 	return mapGameError(s.gamesRepo.ResetGame(ctx, id))
 }
diff --git a/internal/services/gameplay_service/service.go b/internal/services/gameplay_service/service.go
index 90f1b53..ca00c7d 100644
--- a/internal/services/gameplay_service/service.go
+++ b/internal/services/gameplay_service/service.go
@@ -15,10 +15,13 @@ import (
 )
 
 var (
+	// ErrTeamNotFound indicates that a team was not found.
 	ErrTeamNotFound = errors.New("Команда не найдена")
+	// ErrGameNotFound indicates that a game was not found.
 	ErrGameNotFound = errors.New("Игра не найдена")
 )
 
+// GameplayService handles team gameplay operations.
 type GameplayService struct {
 	gamesRepo        *games_repo.GamesRepo
 	teamsRepo        *teams_repo.TeamsRepo
@@ -30,6 +33,7 @@ type GameplayService struct {
 	domain           string
 }
 
+// NewGameplayService creates a gameplay service.
 func NewGameplayService(
 	gamesRepo *games_repo.GamesRepo,
 	teamsRepo *teams_repo.TeamsRepo,
@@ -52,10 +56,12 @@ func NewGameplayService(
 	}
 }
 
+// GiveTeamApplications grants an application to a team.
 func (s *GameplayService) GiveTeamApplications(ctx context.Context, teamID int, name string) error {
 	return mapGameplayError(s.applicationsRepo.UpdateApplicationStatus(ctx, teamID, name, "done"))
 }
 
+// GetTeamActions returns the current story, game, and available team actions.
 func (s *GameplayService) GetTeamActions(ctx context.Context, teamID int, password string) (*storytelling.Story, *game_model.Game, []actions_repo.Action, error) {
 	team, err := s.teamsRepo.GetTeamByID(ctx, teamID)
 	if err != nil {
@@ -93,6 +99,7 @@ func (s *GameplayService) GetTeamActions(ctx context.Context, teamID int, passwo
 	return story, game_model.MapGame(game, s.domain), actions, nil
 }
 
+// AddTeamAction records an action performed by a team.
 func (s *GameplayService) AddTeamAction(ctx context.Context, teamID int, password string, actionCode string, viaMCP bool) error {
 	team, err := s.teamsRepo.GetTeamByID(ctx, teamID)
 	if err != nil {
@@ -147,6 +154,7 @@ func (s *GameplayService) AddTeamAction(ctx context.Context, teamID int, passwor
 	return nil
 }
 
+// DeleteLastTeamAction removes the latest action for a team.
 func (s *GameplayService) DeleteLastTeamAction(ctx context.Context, teamID int) error {
 	team, err := s.teamsRepo.GetTeamByID(ctx, teamID)
 	if err != nil {
diff --git a/internal/services/map_service/mapper.go b/internal/services/map_service/mapper.go
index b258f1f..aa4a3e8 100644
--- a/internal/services/map_service/mapper.go
+++ b/internal/services/map_service/mapper.go
@@ -3,6 +3,7 @@ package map_service
 
 import "evening_detective_server/internal/repos/game_map_repo"
 
+// MapItem describes an item placed on a game map.
 type MapItem struct {
 	GameID int
 	Kind   string
diff --git a/internal/services/map_service/service.go b/internal/services/map_service/service.go
index b93ceb3..fef0e2f 100644
--- a/internal/services/map_service/service.go
+++ b/internal/services/map_service/service.go
@@ -7,20 +7,25 @@ import (
 	"evening_detective_server/internal/repos/game_map_repo"
 )
 
+// ErrItemNotFound indicates that a map item was not found.
 var ErrItemNotFound = errors.New("объект карты не найден")
 
+// MapService handles game map items.
 type MapService struct {
 	repo *game_map_repo.Repo
 }
 
+// NewMapService creates a map service.
 func NewMapService(repo *game_map_repo.Repo) *MapService {
 	return &MapService{repo: repo}
 }
 
+// Ensure creates a map item if it does not exist.
 func (s *MapService) Ensure(ctx context.Context, gameID int, kind string, itemID int) error {
 	return s.repo.Ensure(ctx, gameID, kind, itemID)
 }
 
+// List returns map items for a game.
 func (s *MapService) List(ctx context.Context, gameID int) ([]*MapItem, error) {
 	items, err := s.repo.List(ctx, gameID)
 	if err != nil {
@@ -33,6 +38,7 @@ func (s *MapService) List(ctx context.Context, gameID int) ([]*MapItem, error) {
 	return result, nil
 }
 
+// Update changes a map item's position and visibility.
 func (s *MapService) Update(ctx context.Context, item *MapItem) error {
 	if err := s.repo.Update(ctx, toRepoItem(item)); err != nil {
 		if errors.Is(err, game_map_repo.ErrItemNotFound) {
@@ -43,6 +49,7 @@ func (s *MapService) Update(ctx context.Context, item *MapItem) error {
 	return nil
 }
 
+// Delete removes a map item.
 func (s *MapService) Delete(ctx context.Context, item *MapItem) error {
 	return s.repo.Delete(ctx, toRepoItem(item))
 }
diff --git a/internal/services/mcp_service/service.go b/internal/services/mcp_service/service.go
index 7063dad..c50dc07 100644
--- a/internal/services/mcp_service/service.go
+++ b/internal/services/mcp_service/service.go
@@ -1,8 +1,3 @@
-// Пакет mcp_service собирает MCP-сервер (Model Context Protocol) для
-// игры «Вечерний детектив»: инструменты MCP вызывают игровые сервисы
-// напрямую (через интерфейс GamePlayer), без HTTP-прослойки. MCP-сервер
-// монтируется в основной процесс как HTTP-эндпоинт /mcp (streamable HTTP)
-// на REST-gateway.
 // Package mcp_service exposes game operations through MCP.
 package mcp_service
 
@@ -50,10 +45,12 @@ type MCPService struct {
 	answers AnswerSubmitter
 }
 
+// NewMCPService creates an MCP service.
 func NewMCPService(game GamePlayer, answers AnswerSubmitter) *MCPService {
 	return &MCPService{game: game, answers: answers}
 }
 
+// Server returns the underlying MCP server.
 func (s *MCPService) Server() *server.MCPServer {
 	srv := server.NewMCPServer(
 		"evening-detective-mcp",
diff --git a/internal/services/participation_service/participation.go b/internal/services/participation_service/participation.go
index 0cf9755..bd539fe 100644
--- a/internal/services/participation_service/participation.go
+++ b/internal/services/participation_service/participation.go
@@ -19,8 +19,12 @@ type Participation struct {
 }
 
 var (
-	ErrParticipationLink   = errors.New("Ссылка недействительна")
+	// ErrParticipationLink indicates that a participation link is invalid.
+	ErrParticipationLink = errors.New("Ссылка недействительна")
+	// ErrParticipationClosed indicates that participation answers are closed.
 	ErrParticipationClosed = errors.New("Приём ответов закрыт")
-	ErrParticipationFinal  = errors.New("Решение уже принято и не может быть изменено")
-	ErrInvalidAnswer       = errors.New("Выберите подтверждение или отмену участия")
+	// ErrParticipationFinal indicates that a final answer cannot be changed.
+	ErrParticipationFinal = errors.New("Решение уже принято и не может быть изменено")
+	// ErrInvalidAnswer indicates that the participation answer is invalid.
+	ErrInvalidAnswer = errors.New("Выберите подтверждение или отмену участия")
 )
diff --git a/internal/services/participation_service/service.go b/internal/services/participation_service/service.go
index 5dec006..af053cc 100644
--- a/internal/services/participation_service/service.go
+++ b/internal/services/participation_service/service.go
@@ -20,19 +20,24 @@ import (
 	"github.com/jackc/pgx/v5"
 )
 
+// ParticipationService handles team participation.
 type ParticipationService struct {
 	teamsRepo  *teams_repo.TeamsRepo
 	appBaseURL string
 }
 
+// NewParticipationService creates a participation service.
 func NewParticipationService(teamsRepo *teams_repo.TeamsRepo, appBaseURL string) *ParticipationService {
 	return &ParticipationService{teamsRepo: teamsRepo, appBaseURL: appBaseURL}
 }
 
+// GetParticipation returns participation data by token.
 func (s *ParticipationService) GetParticipation(ctx context.Context, token string) (*Participation, error) {
 	p, err := s.teamsRepo.GetParticipation(ctx, token)
 	return mapParticipation(p), mapParticipationError(err)
 }
+
+// AnswerParticipation stores a team's final answer.
 func (s *ParticipationService) AnswerParticipation(ctx context.Context, token, answer string) (*Participation, error) {
 	p, err := s.teamsRepo.AnswerParticipation(ctx, token, answer)
 	return mapParticipation(p), mapParticipationError(err)
@@ -76,6 +81,7 @@ func participationEmail(p *Participation, baseURL, token string, location *time.
 	return email_sender.Message{To: p.Email, Subject: "Подтвердите участие в «Вечернем детективе»", Body: body, HTML: markup}
 }
 
+// RunParticipationEmails sends pending participation emails.
 func (s *ParticipationService) RunParticipationEmails(ctx context.Context, sender email_sender.IEmailSender, secret, timezone string) {
 	base, err := url.Parse(s.appBaseURL)
 	if err != nil || base.Host == "" || (base.Scheme != "https" && base.Scheme != "http") || base.User != nil || base.RawQuery != "" || base.Fragment != "" || secret == "" {
diff --git a/internal/services/scenarios_service/scenario.go b/internal/services/scenarios_service/scenario.go
index ae574cc..425ab2a 100644
--- a/internal/services/scenarios_service/scenario.go
+++ b/internal/services/scenarios_service/scenario.go
@@ -7,6 +7,7 @@ import (
 	"time"
 )
 
+// Scenario describes a scenario exposed by the service layer.
 type Scenario struct {
 	ID            int
 	Name          string
diff --git a/internal/services/scenarios_service/scenario_mapper.go b/internal/services/scenarios_service/scenario_mapper.go
index 329328e..90c1e1c 100644
--- a/internal/services/scenarios_service/scenario_mapper.go
+++ b/internal/services/scenarios_service/scenario_mapper.go
@@ -21,6 +21,7 @@ func mapScenariosLight(
 	return res
 }
 
+// MapScenarioLight converts a repository scenario to a lightweight model.
 func MapScenarioLight(
 	o *repos.Scenario,
 	domain string,
diff --git a/internal/services/scenarios_service/service.go b/internal/services/scenarios_service/service.go
index 8a84686..be224fd 100644
--- a/internal/services/scenarios_service/service.go
+++ b/internal/services/scenarios_service/service.go
@@ -28,6 +28,7 @@ type IScenariosRepository interface {
 	UpdateStoryByScenarioID(ctx context.Context, id int, story string) error
 }
 
+// ScenarioService handles scenario operations.
 type ScenarioService struct {
 	scenariosRepo   IScenariosRepository
 	cleaner         cleaner.ICleaner
@@ -36,6 +37,7 @@ type ScenarioService struct {
 	domain          string
 }
 
+// NewScenarioService creates a scenario service.
 func NewScenarioService(
 	scenariosRepo IScenariosRepository,
 	cleaner cleaner.ICleaner,
@@ -52,6 +54,7 @@ func NewScenarioService(
 	}
 }
 
+// AddScenario creates a scenario.
 func (s *ScenarioService) AddScenario(
 	ctx context.Context,
 	name string,
@@ -64,6 +67,7 @@ func (s *ScenarioService) AddScenario(
 	return id, nil
 }
 
+// GetScenariosByAuthorID returns scenarios created by an author.
 func (s *ScenarioService) GetScenariosByAuthorID(
 	ctx context.Context,
 	authorID int,
@@ -75,6 +79,7 @@ func (s *ScenarioService) GetScenariosByAuthorID(
 	return mapScenariosLight(scenarios, s.domain), nil
 }
 
+// GetScenariosCatalog returns scenarios available in the catalog.
 func (s *ScenarioService) GetScenariosCatalog(
 	ctx context.Context,
 ) ([]*Scenario, error) {
@@ -85,6 +90,7 @@ func (s *ScenarioService) GetScenariosCatalog(
 	return mapScenariosLight(scenarios, s.domain), nil
 }
 
+// GetFullScenarioByID returns a scenario with its full story.
 func (s *ScenarioService) GetFullScenarioByID(
 	ctx context.Context,
 	id int,
@@ -96,6 +102,7 @@ func (s *ScenarioService) GetFullScenarioByID(
 	return mapScenario(scenario, s.domain)
 }
 
+// GetScenarioByID returns a scenario by ID.
 func (s *ScenarioService) GetScenarioByID(
 	ctx context.Context,
 	id int,
@@ -107,6 +114,7 @@ func (s *ScenarioService) GetScenarioByID(
 	return MapScenarioLight(scenario, s.domain), nil
 }
 
+// UpdateScenarioByID updates a scenario's metadata.
 func (s *ScenarioService) UpdateScenarioByID(
 	ctx context.Context,
 	id int,
@@ -177,6 +185,7 @@ func mapScenarioError(err error) error {
 	return err
 }
 
+// UpdateScenarioStatusByID changes a scenario's publication status.
 func (s *ScenarioService) UpdateScenarioStatusByID(
 	ctx context.Context,
 	id int,
@@ -208,6 +217,7 @@ func (s *ScenarioService) UpdateScenarioStatusByID(
 	return nil
 }
 
+// DeleteScenarioByID removes a scenario.
 func (s *ScenarioService) DeleteScenarioByID(
 	ctx context.Context,
 	id int,
@@ -229,6 +239,7 @@ func (s *ScenarioService) DeleteScenarioByID(
 	return nil
 }
 
+// AddScenarioPlace adds a place to a scenario story.
 func (s *ScenarioService) AddScenarioPlace(
 	ctx context.Context,
 	id int,
@@ -250,6 +261,7 @@ func (s *ScenarioService) AddScenarioPlace(
 	return s.updateStory(ctx, id, story)
 }
 
+// UpdateScenarioPlace updates a place in a scenario story.
 func (s *ScenarioService) UpdateScenarioPlace(
 	ctx context.Context,
 	id int,
@@ -274,6 +286,7 @@ func (s *ScenarioService) UpdateScenarioPlace(
 	return s.updateStory(ctx, id, story)
 }
 
+// DeleteScenarioPlace removes a place from a scenario story.
 func (s *ScenarioService) DeleteScenarioPlace(
 	ctx context.Context,
 	id int,
@@ -332,6 +345,7 @@ func (s *ScenarioService) UpdateScenarioIntro(
 	return s.updateStory(ctx, id, story)
 }
 
+// UpdateScenarioConclusion updates a scenario conclusion.
 func (s *ScenarioService) UpdateScenarioConclusion(ctx context.Context, id int, conclusion *storytelling.Conclusion, actorID int, isAdmin bool) error {
 	if _, err := s.getScenarioForChange(ctx, id, actorID, isAdmin); err != nil {
 		return err
diff --git a/internal/services/screen_service/mapper.go b/internal/services/screen_service/mapper.go
index e1f66bd..e0714ce 100644
--- a/internal/services/screen_service/mapper.go
+++ b/internal/services/screen_service/mapper.go
@@ -7,6 +7,7 @@ import (
 	"evening_detective_server/internal/repos/screen_sessions_repo"
 )
 
+// ScreenSession describes a screen session exposed by the service layer.
 type ScreenSession struct {
 	ID                    int
 	GameID                *int
diff --git a/internal/services/screen_service/service.go b/internal/services/screen_service/service.go
index 85e1189..78bb7e6 100644
--- a/internal/services/screen_service/service.go
+++ b/internal/services/screen_service/service.go
@@ -7,20 +7,25 @@ import (
 	"evening_detective_server/internal/repos/screen_sessions_repo"
 )
 
+// ErrScreenNotFound indicates that a screen session was not found.
 var ErrScreenNotFound = errors.New("Экран не найден")
 
+// ScreenService handles screen sessions.
 type ScreenService struct {
 	repo *screen_sessions_repo.ScreenSessionsRepo
 }
 
+// NewScreenService creates a screen service.
 func NewScreenService(repo *screen_sessions_repo.ScreenSessionsRepo) *ScreenService {
 	return &ScreenService{repo: repo}
 }
 
+// Create creates a screen session.
 func (s *ScreenService) Create(ctx context.Context, tokenHash string) (int, error) {
 	return s.repo.Create(ctx, tokenHash)
 }
 
+// Get returns a screen session.
 func (s *ScreenService) Get(ctx context.Context, id int, tokenHash string) (*ScreenSession, error) {
 	session, err := s.repo.Get(ctx, id, tokenHash)
 	if err != nil {
@@ -29,6 +34,7 @@ func (s *ScreenService) Get(ctx context.Context, id int, tokenHash string) (*Scr
 	return mapSession(session), nil
 }
 
+// ListByGame returns screen sessions for a game.
 func (s *ScreenService) ListByGame(ctx context.Context, gameID int) ([]*ScreenSession, error) {
 	sessions, err := s.repo.ListByGame(ctx, gameID)
 	if err != nil {
@@ -41,30 +47,37 @@ func (s *ScreenService) ListByGame(ctx context.Context, gameID int) ([]*ScreenSe
 	return result, nil
 }
 
+// SetMode updates the display mode for a game.
 func (s *ScreenService) SetMode(ctx context.Context, gameID int, mode int32) error {
 	return s.repo.SetMode(ctx, gameID, mode)
 }
 
+// SetTimer updates the display timer for a game.
 func (s *ScreenService) SetTimer(ctx context.Context, gameID int, duration int64, label string) error {
 	return s.repo.SetTimer(ctx, gameID, duration, label)
 }
 
+// SetTimerCommand updates the timer command for a game.
 func (s *ScreenService) SetTimerCommand(ctx context.Context, gameID int, command int32) error {
 	return s.repo.SetTimerCommand(ctx, gameID, command)
 }
 
+// SetCommand updates the display command for a game.
 func (s *ScreenService) SetCommand(ctx context.Context, gameID int, command int32, position int64, volume int32) error {
 	return s.repo.SetCommand(ctx, gameID, command, position, volume)
 }
 
+// Bind attaches a screen session to a game.
 func (s *ScreenService) Bind(ctx context.Context, id, gameID int, tokenHash string) error {
 	return mapError(s.repo.Bind(ctx, id, gameID, tokenHash))
 }
 
+// Unbind detaches a screen session from its game.
 func (s *ScreenService) Unbind(ctx context.Context, id int) error {
 	return mapError(s.repo.Unbind(ctx, id))
 }
 
+// SetSound enables or disables sound for a screen session.
 func (s *ScreenService) SetSound(ctx context.Context, id int, enabled bool) error {
 	return mapError(s.repo.SetSound(ctx, id, enabled))
 }
diff --git a/internal/services/team_service/registration.go b/internal/services/team_service/registration.go
index 90a9c80..4e8e95f 100644
--- a/internal/services/team_service/registration.go
+++ b/internal/services/team_service/registration.go
@@ -21,12 +21,14 @@ var (
 	ErrRegistrationClosed = errors.New("Игра не найдена или регистрация уже закрыта")
 )
 
+// Registration contains data required to register a team.
 type Registration struct {
 	Name              string `json:"name"`
 	Email             string `json:"email"`
 	ParticipantsCount int32  `json:"participantsCount"`
 }
 
+// UnmarshalJSON decodes and normalizes registration data.
 func (r *Registration) UnmarshalJSON(data []byte) error {
 	var payload struct {
 		Name              string          `json:"name"`
@@ -63,6 +65,7 @@ func validCaptainEmail(email string) bool {
 	return err == nil && address.Address == email && len(email) <= 254
 }
 
+// Validate checks registration data.
 func (r *Registration) Validate() error {
 	r.Name = strings.TrimSpace(r.Name)
 	r.Email = strings.TrimSpace(r.Email)
diff --git a/internal/services/team_service/service.go b/internal/services/team_service/service.go
index 9751d66..2985d73 100644
--- a/internal/services/team_service/service.go
+++ b/internal/services/team_service/service.go
@@ -17,6 +17,7 @@ import (
 	"evening_detective_server/internal/services/game_model"
 )
 
+// TeamService handles team operations.
 type TeamService struct {
 	gamesRepo         *games_repo.GamesRepo
 	teamsRepo         *teams_repo.TeamsRepo
@@ -25,6 +26,7 @@ type TeamService struct {
 	emailSender       email_sender.IEmailSender
 }
 
+// NewTeamService creates a team service.
 func NewTeamService(
 	gamesRepo *games_repo.GamesRepo,
 	teamsRepo *teams_repo.TeamsRepo,
@@ -41,6 +43,7 @@ func NewTeamService(
 	}
 }
 
+// AddTeam creates a team.
 func (s *TeamService) AddTeam(
 	ctx context.Context,
 	creatorID int,
@@ -73,6 +76,7 @@ func (s *TeamService) AddTeam(
 	}, nil
 }
 
+// UpdateTeam changes a team's name.
 func (s *TeamService) UpdateTeam(ctx context.Context, teamID int, name string) error {
 	err := s.teamsRepo.UpdateTeam(ctx, teamID, name)
 	if errors.Is(err, teams_repo.ErrTeamNotFound) {
@@ -81,6 +85,7 @@ func (s *TeamService) UpdateTeam(ctx context.Context, teamID int, name string) e
 	return err
 }
 
+// DeleteTeam removes a team.
 func (s *TeamService) DeleteTeam(ctx context.Context, teamID int) error {
 	err := s.teamsRepo.DeleteTeam(ctx, teamID)
 	if errors.Is(err, teams_repo.ErrTeamNotFound) {
@@ -89,6 +94,7 @@ func (s *TeamService) DeleteTeam(ctx context.Context, teamID int) error {
 	return err
 }
 
+// RegisterTeam registers a team for a game.
 func (s *TeamService) RegisterTeam(ctx context.Context, gameID int, deliveryID string, registration Registration) (int, error) {
 	if err := registration.Validate(); err != nil {
 		return 0, err
@@ -133,6 +139,7 @@ func registrationEmail(team *repos.Team, gameName, baseURL string) email_sender.
 	return email_sender.Message{To: team.CaptainEmail, Subject: "Регистрация команды в «Вечернем детективе»", Body: body, HTML: markup}
 }
 
+// DownloadTeamQR returns a PDF with team QR codes.
 func (s *TeamService) DownloadTeamQR(ctx context.Context, id int) ([]byte, string, error) {
 	game, err := s.gamesRepo.GetGameByID(ctx, id)
 	if err != nil {