Reapply "Build post chat and attachment workflows"

This reverts commit 5bc4a551af.
2026-06-10 09:24:44 -03:00
parent 5bc4a551af
commit 3314c2e863
30 changed files with 3021 additions and 204 deletions
--- a/.env.example
+++ b/.env.example
@@ -1,5 +1,5 @@
 APP_ENV=production
-APP_PUBLIC_URL=https://app.example.com.br
+APP_PUBLIC_URL=http://localhost:5173
 APP_TIMEZONE=America/Sao_Paulo
 HTTP_ADDR=:8080
 LOG_LEVEL=info
@@ -15,7 +15,7 @@ POSTGRES_PASSWORD=change-me-secure-password
 DATABASE_URL=postgres://mira:change-me-secure-password@postgres:5432/mira?sslmode=disable

 JWT_SECRET=change-me-with-a-long-random-secret
-JWT_ACCESS_TOKEN_TTL_MINUTES=15
+JWT_ACCESS_TOKEN_TTL_MINUTES=480
 JWT_REFRESH_TOKEN_TTL_DAYS=7

 CORS_ALLOWED_ORIGINS=https://app.example.com.br
@@ -25,15 +25,15 @@ CALENDAR_API_BASE_URL=https://brasilapi.com.br
 CALENDAR_API_KEY=
 CALENDAR_CACHE_TTL_HOURS=24

-SMTP_HOST=smtp.example.com.br
-SMTP_PORT=587
+SMTP_HOST=
+SMTP_PORT=
 SMTP_USER=
-SMTP_PASSWORD=
-SMTP_FROM_EMAIL=no-reply@example.com.br
+SMTP_PASS=
+MAIL_FROM=
 SMTP_FROM_NAME=Mira

 UPLOAD_MAX_SIZE_MB=10
-UPLOAD_ALLOWED_MIME_TYPES=image/jpeg,image/png,image/webp,application/pdf
+UPLOAD_ALLOWED_MIME_TYPES=image/jpeg,image/png,image/webp,application/pdf,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document
 STORAGE_DRIVER=local
 STORAGE_LOCAL_PATH=/var/lib/mira/uploads

--- a/backend/internal/auth/rate_limit.go
+++ b/backend/internal/auth/rate_limit.go
@@ -0,0 +1,68 @@
+package auth
+
+import (
+	"strings"
+	"sync"
+	"time"
+)
+
+type LoginRateLimiter struct {
+	mu       sync.Mutex
+	attempts map[string]loginAttempt
+	limit    int
+	window   time.Duration
+}
+
+type loginAttempt struct {
+	Count     int
+	ExpiresAt time.Time
+}
+
+func NewLoginRateLimiter(limit int, window time.Duration) *LoginRateLimiter {
+	return &LoginRateLimiter{
+		attempts: map[string]loginAttempt{},
+		limit:    limit,
+		window:   window,
+	}
+}
+
+func (l *LoginRateLimiter) IsBlocked(key string) bool {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	attempt, ok := l.attempts[key]
+	if !ok || time.Now().After(attempt.ExpiresAt) {
+		delete(l.attempts, key)
+		return false
+	}
+
+	return attempt.Count >= l.limit
+}
+
+func (l *LoginRateLimiter) RecordFailure(key string) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	now := time.Now()
+	attempt, ok := l.attempts[key]
+	if !ok || now.After(attempt.ExpiresAt) {
+		l.attempts[key] = loginAttempt{
+			Count:     1,
+			ExpiresAt: now.Add(l.window),
+		}
+		return
+	}
+
+	attempt.Count++
+	l.attempts[key] = attempt
+}
+
+func (l *LoginRateLimiter) Clear(key string) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	delete(l.attempts, key)
+}
+
+func LoginRateLimitKey(ip string, email string) string {
+	return strings.TrimSpace(ip) + ":" + strings.ToLower(strings.TrimSpace(email))
+}
--- a/backend/internal/auth/routes.go
+++ b/backend/internal/auth/routes.go
@@ -4,35 +4,40 @@ import (
 	"errors"
 	"net/http"
 	"strings"
+	"time"

 	"mira/backend/internal/users"

 	"github.com/gin-gonic/gin"
 )

+const refreshCookieName = "mira_refresh_token"
+
 type Routes struct {
-	users  users.Store
-	tokens TokenService
+	users            users.Store
+	sessions         SessionStore
+	tokens           TokenService
+	refreshTTL       time.Duration
+	secureCookies    bool
+	loginRateLimiter *LoginRateLimiter
 }

-func NewRoutes(users users.Store, tokens TokenService) Routes {
+func NewRoutes(users users.Store, sessions SessionStore, tokens TokenService, refreshTTL time.Duration, secureCookies bool) Routes {
 	return Routes{
-		users:  users,
-		tokens: tokens,
+		users:            users,
+		sessions:         sessions,
+		tokens:           tokens,
+		refreshTTL:       refreshTTL,
+		secureCookies:    secureCookies,
+		loginRateLimiter: NewLoginRateLimiter(5, 15*time.Minute),
 	}
 }

 func (r Routes) Register(router *gin.RouterGroup) {
 	router.POST("/login", r.login)
 	router.POST("/invitations/accept", r.acceptInvitation)
-
-	router.POST("/logout", func(c *gin.Context) {
-		c.JSON(http.StatusOK, gin.H{"message": "Sessao encerrada."})
-	})
-
-	router.POST("/refresh", func(c *gin.Context) {
-		c.JSON(http.StatusNotImplemented, gin.H{"message": "Renovacao de sessao ainda nao implementada."})
-	})
+	router.POST("/logout", r.logout)
+	router.POST("/refresh", r.refresh)
 }

 type loginRequest struct {
@@ -47,8 +52,16 @@ func (r Routes) login(c *gin.Context) {
 		return
 	}

-	user, err := r.users.FindByEmail(c.Request.Context(), strings.TrimSpace(input.Email))
+	email := strings.TrimSpace(input.Email)
+	rateLimitKey := LoginRateLimitKey(c.ClientIP(), email)
+	if r.loginRateLimiter.IsBlocked(rateLimitKey) {
+		c.JSON(http.StatusTooManyRequests, gin.H{"message": "Muitas tentativas de login. Tente novamente em alguns minutos."})
+		return
+	}
+
+	user, err := r.users.FindByEmail(c.Request.Context(), email)
 	if errors.Is(err, users.ErrNotFound) {
+		r.loginRateLimiter.RecordFailure(rateLimitKey)
 		c.JSON(http.StatusUnauthorized, gin.H{"message": "E-mail ou senha invalidos."})
 		return
 	}
@@ -57,15 +70,17 @@ func (r Routes) login(c *gin.Context) {
 		return
 	}
 	if !CheckPassword(input.Password, user.PasswordHash) || user.Status != "active" {
+		r.loginRateLimiter.RecordFailure(rateLimitKey)
 		c.JSON(http.StatusUnauthorized, gin.H{"message": "E-mail ou senha invalidos."})
 		return
 	}

-	token, err := r.tokens.IssueAccessToken(user.ID, user.Email, user.Role)
+	token, err := r.createSession(c, user)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel criar a sessao."})
 		return
 	}
+	r.loginRateLimiter.Clear(rateLimitKey)

 	c.JSON(http.StatusOK, gin.H{
 		"access_token": token,
@@ -114,15 +129,8 @@ func (r Routes) acceptInvitation(c *gin.Context) {
 		return
 	}

-	token, err := r.tokens.IssueAccessToken(user.ID, user.Email, user.Role)
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel criar a sessao."})
-		return
-	}
-
 	c.JSON(http.StatusOK, gin.H{
-		"access_token": token,
-		"token_type":   "Bearer",
+		"message": "Senha criada com sucesso. Faca login para acessar o Mira.",
 		"user": gin.H{
 			"id":     user.ID,
 			"email":  user.Email,
@@ -132,3 +140,84 @@ func (r Routes) acceptInvitation(c *gin.Context) {
 		},
 	})
 }
+
+func (r Routes) refresh(c *gin.Context) {
+	refreshToken, err := c.Cookie(refreshCookieName)
+	if err != nil || strings.TrimSpace(refreshToken) == "" {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Sessao expirada."})
+		return
+	}
+
+	tokenHash := HashRefreshToken(refreshToken)
+	session, err := r.sessions.FindValidRefreshSession(c.Request.Context(), tokenHash)
+	if errors.Is(err, ErrRefreshTokenNotFound) {
+		r.clearRefreshCookie(c)
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Sessao expirada."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel renovar a sessao."})
+		return
+	}
+
+	if err := r.sessions.RevokeRefreshSession(c.Request.Context(), tokenHash); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel renovar a sessao."})
+		return
+	}
+
+	accessToken, err := r.createSession(c, session.User)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel renovar a sessao."})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"access_token": accessToken,
+		"token_type":   "Bearer",
+		"user": gin.H{
+			"id":     session.User.ID,
+			"email":  session.User.Email,
+			"name":   session.User.Name,
+			"role":   session.User.Role,
+			"status": session.User.Status,
+		},
+	})
+}
+
+func (r Routes) logout(c *gin.Context) {
+	refreshToken, err := c.Cookie(refreshCookieName)
+	if err == nil && strings.TrimSpace(refreshToken) != "" {
+		_ = r.sessions.RevokeRefreshSession(c.Request.Context(), HashRefreshToken(refreshToken))
+	}
+	r.clearRefreshCookie(c)
+	c.JSON(http.StatusOK, gin.H{"message": "Sessao encerrada."})
+}
+
+func (r Routes) createSession(c *gin.Context, user users.User) (string, error) {
+	refreshToken, err := GenerateRefreshToken()
+	if err != nil {
+		return "", err
+	}
+
+	if err := r.sessions.CreateRefreshSession(
+		c.Request.Context(),
+		user.ID,
+		HashRefreshToken(refreshToken),
+		time.Now().Add(r.refreshTTL),
+	); err != nil {
+		return "", err
+	}
+
+	r.setRefreshCookie(c, refreshToken)
+	return r.tokens.IssueAccessToken(user.ID, user.Email, user.Role)
+}
+
+func (r Routes) setRefreshCookie(c *gin.Context, token string) {
+	c.SetSameSite(http.SameSiteLaxMode)
+	c.SetCookie(refreshCookieName, token, int(r.refreshTTL.Seconds()), "/api/v1/auth", "", r.secureCookies, true)
+}
+
+func (r Routes) clearRefreshCookie(c *gin.Context) {
+	c.SetSameSite(http.SameSiteLaxMode)
+	c.SetCookie(refreshCookieName, "", 0, "/api/v1/auth", "", r.secureCookies, true)
+}
--- a/backend/internal/auth/sessions.go
+++ b/backend/internal/auth/sessions.go
@@ -0,0 +1,112 @@
+package auth
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"time"
+
+	"mira/backend/internal/users"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+var ErrRefreshTokenNotFound = errors.New("refresh token not found")
+
+type RefreshSession struct {
+	ID        string
+	TokenHash string
+	User      users.User
+	ExpiresAt time.Time
+	RevokedAt *time.Time
+}
+
+type SessionStore struct {
+	db *pgxpool.Pool
+}
+
+func NewSessionStore(db *pgxpool.Pool) SessionStore {
+	return SessionStore{db: db}
+}
+
+func GenerateRefreshToken() (string, error) {
+	bytes := make([]byte, 32)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(bytes), nil
+}
+
+func HashRefreshToken(token string) string {
+	hash := sha256.Sum256([]byte(token))
+	return hex.EncodeToString(hash[:])
+}
+
+func (s SessionStore) CreateRefreshSession(ctx context.Context, userID string, tokenHash string, expiresAt time.Time) error {
+	_, err := s.db.Exec(ctx, `
+		INSERT INTO refresh_tokens (user_id, token_hash, expires_at)
+		VALUES ($1::uuid, $2, $3)
+	`, userID, tokenHash, expiresAt)
+	return err
+}
+
+func (s SessionStore) FindValidRefreshSession(ctx context.Context, tokenHash string) (RefreshSession, error) {
+	row := s.db.QueryRow(ctx, `
+		SELECT
+			refresh_tokens.id::text,
+			refresh_tokens.token_hash,
+			users.id::text,
+			users.email,
+			users.name,
+			users.password_hash,
+			users.role,
+			users.status,
+			users.created_at,
+			users.updated_at,
+			refresh_tokens.expires_at,
+			refresh_tokens.revoked_at
+		FROM refresh_tokens
+		INNER JOIN users ON users.id = refresh_tokens.user_id
+		WHERE refresh_tokens.token_hash = $1
+		AND refresh_tokens.revoked_at IS NULL
+		AND refresh_tokens.expires_at > now()
+		AND users.status = 'active'
+	`, tokenHash)
+
+	var session RefreshSession
+	err := row.Scan(
+		&session.ID,
+		&session.TokenHash,
+		&session.User.ID,
+		&session.User.Email,
+		&session.User.Name,
+		&session.User.PasswordHash,
+		&session.User.Role,
+		&session.User.Status,
+		&session.User.CreatedAt,
+		&session.User.UpdatedAt,
+		&session.ExpiresAt,
+		&session.RevokedAt,
+	)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return RefreshSession{}, ErrRefreshTokenNotFound
+	}
+	if err != nil {
+		return RefreshSession{}, err
+	}
+	return session, nil
+}
+
+func (s SessionStore) RevokeRefreshSession(ctx context.Context, tokenHash string) error {
+	_, err := s.db.Exec(ctx, `
+		UPDATE refresh_tokens
+		SET revoked_at = now()
+		WHERE token_hash = $1
+		AND revoked_at IS NULL
+	`, tokenHash)
+	return err
+}
--- a/backend/internal/calendar/attachments.go
+++ b/backend/internal/calendar/attachments.go
@@ -137,6 +137,26 @@ func (s Store) FindAttachment(ctx context.Context, id string, viewerUserID strin
 	return scanAttachment(row)
 }

+func (s Store) DeleteAttachment(ctx context.Context, id string) (Attachment, error) {
+	row := s.db.QueryRow(ctx, `
+		DELETE FROM calendar_item_attachments
+		WHERE id = $1::uuid
+		RETURNING
+			id::text,
+			calendar_item_id::text,
+			original_filename,
+			stored_filename,
+			mime_type,
+			size_bytes,
+			storage_driver,
+			storage_path,
+			created_by::text,
+			created_at
+	`, id)
+
+	return scanAttachment(row)
+}
+
 type attachmentScanner interface {
 	Scan(dest ...any) error
 }
--- a/backend/internal/calendar/chat.go
+++ b/backend/internal/calendar/chat.go
@@ -0,0 +1,377 @@
+package calendar
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+)
+
+var ErrChatMessageNotFound = errors.New("chat message not found")
+
+const (
+	ChatChannelExternal = "external"
+	ChatChannelInternal = "internal"
+)
+
+type ChatMessage struct {
+	ID             string           `json:"id"`
+	CalendarItemID string           `json:"calendar_item_id"`
+	Channel        string           `json:"channel"`
+	Body           string           `json:"body"`
+	CreatedBy      *string          `json:"created_by"`
+	AuthorName     string           `json:"author_name"`
+	AuthorRole     string           `json:"author_role"`
+	CreatedAt      time.Time        `json:"created_at"`
+	EditedAt       *time.Time       `json:"edited_at"`
+	DeletedAt      *time.Time       `json:"deleted_at"`
+	Attachments    []ChatAttachment `json:"attachments"`
+}
+
+type ChatAttachment struct {
+	ID               string    `json:"id"`
+	ChatMessageID    string    `json:"chat_message_id"`
+	OriginalFilename string    `json:"original_filename"`
+	StoredFilename   string    `json:"stored_filename"`
+	MimeType         string    `json:"mime_type"`
+	SizeBytes        int64     `json:"size_bytes"`
+	StorageDriver    string    `json:"storage_driver"`
+	StoragePath      string    `json:"-"`
+	CreatedBy        *string   `json:"created_by"`
+	CreatedAt        time.Time `json:"created_at"`
+}
+
+type CreateChatMessageInput struct {
+	CalendarItemID string
+	Channel        string
+	Body           string
+	CreatedBy      string
+}
+
+type CreateChatAttachmentInput struct {
+	ChatMessageID    string
+	OriginalFilename string
+	StoredFilename   string
+	MimeType         string
+	SizeBytes        int64
+	StorageDriver    string
+	StoragePath      string
+	CreatedBy        string
+}
+
+func (s Store) ListChatMessages(ctx context.Context, calendarItemID string, channel string) ([]ChatMessage, error) {
+	rows, err := s.db.Query(ctx, `
+		SELECT
+			calendar_item_chat_messages.id::text,
+			calendar_item_chat_messages.calendar_item_id::text,
+			calendar_item_chat_messages.channel,
+			calendar_item_chat_messages.body,
+			calendar_item_chat_messages.created_by::text,
+			COALESCE(users.name, 'Usuario removido'),
+			COALESCE(users.role, ''),
+			calendar_item_chat_messages.created_at,
+			calendar_item_chat_messages.edited_at,
+			calendar_item_chat_messages.deleted_at
+		FROM calendar_item_chat_messages
+		LEFT JOIN users ON users.id = calendar_item_chat_messages.created_by
+		WHERE calendar_item_chat_messages.calendar_item_id = $1::uuid
+		AND calendar_item_chat_messages.channel = $2
+		ORDER BY calendar_item_chat_messages.created_at ASC
+	`, calendarItemID, channel)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	messages := []ChatMessage{}
+	for rows.Next() {
+		message, err := scanChatMessage(rows)
+		if err != nil {
+			return nil, err
+		}
+		messages = append(messages, message)
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
+	if err := s.attachChatAttachments(ctx, messages); err != nil {
+		return nil, err
+	}
+
+	return messages, nil
+}
+
+func (s Store) CreateChatMessage(ctx context.Context, input CreateChatMessageInput) (ChatMessage, error) {
+	row := s.db.QueryRow(ctx, `
+		INSERT INTO calendar_item_chat_messages (
+			calendar_item_id,
+			channel,
+			body,
+			created_by
+		)
+		VALUES ($1::uuid, $2, $3, NULLIF($4, '')::uuid)
+		RETURNING
+			calendar_item_chat_messages.id::text,
+			calendar_item_chat_messages.calendar_item_id::text,
+			calendar_item_chat_messages.channel,
+			calendar_item_chat_messages.body,
+			calendar_item_chat_messages.created_by::text,
+			COALESCE((SELECT users.name FROM users WHERE users.id = calendar_item_chat_messages.created_by), 'Usuario removido'),
+			COALESCE((SELECT users.role FROM users WHERE users.id = calendar_item_chat_messages.created_by), ''),
+			calendar_item_chat_messages.created_at,
+			calendar_item_chat_messages.edited_at,
+			calendar_item_chat_messages.deleted_at
+	`, input.CalendarItemID, input.Channel, input.Body, input.CreatedBy)
+
+	return scanChatMessage(row)
+}
+
+func (s Store) FindChatMessage(ctx context.Context, id string) (ChatMessage, error) {
+	row := s.db.QueryRow(ctx, `
+		SELECT
+			calendar_item_chat_messages.id::text,
+			calendar_item_chat_messages.calendar_item_id::text,
+			calendar_item_chat_messages.channel,
+			calendar_item_chat_messages.body,
+			calendar_item_chat_messages.created_by::text,
+			COALESCE(users.name, 'Usuario removido'),
+			COALESCE(users.role, ''),
+			calendar_item_chat_messages.created_at,
+			calendar_item_chat_messages.edited_at,
+			calendar_item_chat_messages.deleted_at
+		FROM calendar_item_chat_messages
+		LEFT JOIN users ON users.id = calendar_item_chat_messages.created_by
+		WHERE calendar_item_chat_messages.id = $1::uuid
+	`, id)
+
+	message, err := scanChatMessage(row)
+	if err != nil {
+		return ChatMessage{}, err
+	}
+	messages := []ChatMessage{message}
+	if err := s.attachChatAttachments(ctx, messages); err != nil {
+		return ChatMessage{}, err
+	}
+	return messages[0], nil
+}
+
+func (s Store) UpdateChatMessage(ctx context.Context, id string, body string) (ChatMessage, error) {
+	row := s.db.QueryRow(ctx, `
+		UPDATE calendar_item_chat_messages
+		SET body = $2, edited_at = now()
+		WHERE id = $1::uuid
+		AND deleted_at IS NULL
+		RETURNING
+			calendar_item_chat_messages.id::text,
+			calendar_item_chat_messages.calendar_item_id::text,
+			calendar_item_chat_messages.channel,
+			calendar_item_chat_messages.body,
+			calendar_item_chat_messages.created_by::text,
+			COALESCE((SELECT users.name FROM users WHERE users.id = calendar_item_chat_messages.created_by), 'Usuario removido'),
+			COALESCE((SELECT users.role FROM users WHERE users.id = calendar_item_chat_messages.created_by), ''),
+			calendar_item_chat_messages.created_at,
+			calendar_item_chat_messages.edited_at,
+			calendar_item_chat_messages.deleted_at
+	`, id, body)
+
+	message, err := scanChatMessage(row)
+	if err != nil {
+		return ChatMessage{}, err
+	}
+	messages := []ChatMessage{message}
+	if err := s.attachChatAttachments(ctx, messages); err != nil {
+		return ChatMessage{}, err
+	}
+	return messages[0], nil
+}
+
+func (s Store) DeleteChatMessage(ctx context.Context, id string) (ChatMessage, error) {
+	row := s.db.QueryRow(ctx, `
+		UPDATE calendar_item_chat_messages
+		SET deleted_at = now(), body = ''
+		WHERE id = $1::uuid
+		AND deleted_at IS NULL
+		RETURNING
+			calendar_item_chat_messages.id::text,
+			calendar_item_chat_messages.calendar_item_id::text,
+			calendar_item_chat_messages.channel,
+			calendar_item_chat_messages.body,
+			calendar_item_chat_messages.created_by::text,
+			COALESCE((SELECT users.name FROM users WHERE users.id = calendar_item_chat_messages.created_by), 'Usuario removido'),
+			COALESCE((SELECT users.role FROM users WHERE users.id = calendar_item_chat_messages.created_by), ''),
+			calendar_item_chat_messages.created_at,
+			calendar_item_chat_messages.edited_at,
+			calendar_item_chat_messages.deleted_at
+	`, id)
+
+	return scanChatMessage(row)
+}
+
+func (s Store) CreateChatAttachment(ctx context.Context, input CreateChatAttachmentInput) (ChatAttachment, error) {
+	row := s.db.QueryRow(ctx, `
+		INSERT INTO calendar_item_chat_attachments (
+			chat_message_id,
+			original_filename,
+			stored_filename,
+			mime_type,
+			size_bytes,
+			storage_driver,
+			storage_path,
+			created_by
+		)
+		VALUES ($1::uuid, $2, $3, $4, $5, $6, $7, NULLIF($8, '')::uuid)
+		RETURNING
+			id::text,
+			chat_message_id::text,
+			original_filename,
+			stored_filename,
+			mime_type,
+			size_bytes,
+			storage_driver,
+			storage_path,
+			created_by::text,
+			created_at
+	`, input.ChatMessageID, input.OriginalFilename, input.StoredFilename, input.MimeType, input.SizeBytes, input.StorageDriver, input.StoragePath, input.CreatedBy)
+
+	return scanChatAttachment(row)
+}
+
+func (s Store) FindChatAttachment(ctx context.Context, id string, viewerUserID string) (ChatAttachment, error) {
+	row := s.db.QueryRow(ctx, `
+		SELECT
+			calendar_item_chat_attachments.id::text,
+			calendar_item_chat_attachments.chat_message_id::text,
+			calendar_item_chat_attachments.original_filename,
+			calendar_item_chat_attachments.stored_filename,
+			calendar_item_chat_attachments.mime_type,
+			calendar_item_chat_attachments.size_bytes,
+			calendar_item_chat_attachments.storage_driver,
+			calendar_item_chat_attachments.storage_path,
+			calendar_item_chat_attachments.created_by::text,
+			calendar_item_chat_attachments.created_at
+		FROM calendar_item_chat_attachments
+		INNER JOIN calendar_item_chat_messages ON calendar_item_chat_messages.id = calendar_item_chat_attachments.chat_message_id
+		INNER JOIN calendar_items ON calendar_items.id = calendar_item_chat_messages.calendar_item_id
+		WHERE calendar_item_chat_attachments.id = $1::uuid
+		AND calendar_item_chat_messages.deleted_at IS NULL
+		AND (
+			$2 = ''
+			OR (
+				calendar_item_chat_messages.channel = 'external'
+				AND EXISTS (
+					SELECT 1
+					FROM client_users
+					WHERE client_users.client_id = calendar_items.client_id
+					AND client_users.user_id = $2::uuid
+				)
+			)
+		)
+	`, id, viewerUserID)
+
+	return scanChatAttachment(row)
+}
+
+func (s Store) attachChatAttachments(ctx context.Context, messages []ChatMessage) error {
+	if len(messages) == 0 {
+		return nil
+	}
+
+	ids := make([]string, 0, len(messages))
+	indexByID := map[string]int{}
+	for index, message := range messages {
+		ids = append(ids, message.ID)
+		indexByID[message.ID] = index
+	}
+
+	rows, err := s.db.Query(ctx, `
+		SELECT
+			id::text,
+			chat_message_id::text,
+			original_filename,
+			stored_filename,
+			mime_type,
+			size_bytes,
+			storage_driver,
+			storage_path,
+			created_by::text,
+			created_at
+		FROM calendar_item_chat_attachments
+		WHERE chat_message_id::text = ANY($1)
+		ORDER BY created_at ASC
+	`, ids)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		attachment, err := scanChatAttachment(rows)
+		if err != nil {
+			return err
+		}
+		index, ok := indexByID[attachment.ChatMessageID]
+		if ok {
+			messages[index].Attachments = append(messages[index].Attachments, attachment)
+		}
+	}
+
+	return rows.Err()
+}
+
+type chatMessageScanner interface {
+	Scan(dest ...any) error
+}
+
+func scanChatMessage(row chatMessageScanner) (ChatMessage, error) {
+	var message ChatMessage
+	err := row.Scan(
+		&message.ID,
+		&message.CalendarItemID,
+		&message.Channel,
+		&message.Body,
+		&message.CreatedBy,
+		&message.AuthorName,
+		&message.AuthorRole,
+		&message.CreatedAt,
+		&message.EditedAt,
+		&message.DeletedAt,
+	)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return ChatMessage{}, ErrChatMessageNotFound
+	}
+	if err != nil {
+		return ChatMessage{}, err
+	}
+	message.Attachments = []ChatAttachment{}
+	return message, nil
+}
+
+type chatAttachmentScanner interface {
+	Scan(dest ...any) error
+}
+
+func scanChatAttachment(row chatAttachmentScanner) (ChatAttachment, error) {
+	var attachment ChatAttachment
+	err := row.Scan(
+		&attachment.ID,
+		&attachment.ChatMessageID,
+		&attachment.OriginalFilename,
+		&attachment.StoredFilename,
+		&attachment.MimeType,
+		&attachment.SizeBytes,
+		&attachment.StorageDriver,
+		&attachment.StoragePath,
+		&attachment.CreatedBy,
+		&attachment.CreatedAt,
+	)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return ChatAttachment{}, ErrAttachmentNotFound
+	}
+	if err != nil {
+		return ChatAttachment{}, err
+	}
+	return attachment, nil
+}
--- a/backend/internal/calendar/chat_events.go
+++ b/backend/internal/calendar/chat_events.go
@@ -0,0 +1,55 @@
+package calendar
+
+import "sync"
+
+type ChatEventHub struct {
+	mu          sync.Mutex
+	subscribers map[string]map[chan struct{}]struct{}
+}
+
+func NewChatEventHub() *ChatEventHub {
+	return &ChatEventHub{
+		subscribers: map[string]map[chan struct{}]struct{}{},
+	}
+}
+
+func (h *ChatEventHub) Subscribe(itemID string, channel string) (chan struct{}, func()) {
+	key := chatEventKey(itemID, channel)
+	events := make(chan struct{}, 1)
+
+	h.mu.Lock()
+	if h.subscribers[key] == nil {
+		h.subscribers[key] = map[chan struct{}]struct{}{}
+	}
+	h.subscribers[key][events] = struct{}{}
+	h.mu.Unlock()
+
+	return events, func() {
+		h.mu.Lock()
+		defer h.mu.Unlock()
+
+		delete(h.subscribers[key], events)
+		if len(h.subscribers[key]) == 0 {
+			delete(h.subscribers, key)
+		}
+		close(events)
+	}
+}
+
+func (h *ChatEventHub) Publish(itemID string, channel string) {
+	key := chatEventKey(itemID, channel)
+
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	for events := range h.subscribers[key] {
+		select {
+		case events <- struct{}{}:
+		default:
+		}
+	}
+}
+
+func chatEventKey(itemID string, channel string) string {
+	return itemID + ":" + channel
+}
--- a/backend/internal/calendar/routes.go
+++ b/backend/internal/calendar/routes.go
@@ -22,6 +22,7 @@ type Routes struct {
 	store              Store
 	provider           Provider
 	commemorative      CommemorativeProvider
+	chatEvents         *ChatEventHub
 	uploadMaxSizeBytes int64
 	uploadAllowedMIMEs map[string]bool
 	storageDriver      string
@@ -54,6 +55,7 @@ func NewRoutes(store Store, provider Provider, commemorative CommemorativeProvid
 		store:              store,
 		provider:           provider,
 		commemorative:      commemorative,
+		chatEvents:         NewChatEventHub(),
 		uploadMaxSizeBytes: int64(options.UploadMaxSizeMB) * 1024 * 1024,
 		uploadAllowedMIMEs: allowedMIMEs,
 		storageDriver:      options.StorageDriver,
@@ -80,7 +82,15 @@ func (r Routes) Register(router *gin.RouterGroup, requireAuth gin.HandlerFunc) {
 	router.DELETE("/items/:itemId", r.cancelCalendarItem)
 	router.GET("/items/:itemId/attachments", r.listAttachments)
 	router.POST("/items/:itemId/attachments", r.uploadAttachment)
+	router.GET("/items/:itemId/chat", r.listChatMessages)
+	router.GET("/items/:itemId/chat/stream", r.streamChatMessages)
+	router.POST("/items/:itemId/chat", r.createChatMessage)
+	router.PATCH("/chat/messages/:messageId", r.updateChatMessage)
+	router.DELETE("/chat/messages/:messageId", r.deleteChatMessage)
+	router.POST("/chat/messages/:messageId/attachments", r.uploadChatAttachment)
+	router.GET("/chat/attachments/:attachmentId/download", r.downloadChatAttachment)
 	router.GET("/attachments/:attachmentId/download", r.downloadAttachment)
+	router.DELETE("/attachments/:attachmentId", r.deleteAttachment)
 }

 func (r Routes) holidays(c *gin.Context) {
@@ -604,6 +614,376 @@ func (r Routes) listAttachments(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"attachments": attachments})
 }

+func (r Routes) listChatMessages(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	channel := strings.TrimSpace(c.Query("channel"))
+	if channel == "" {
+		channel = ChatChannelExternal
+	}
+	if !isValidChatChannel(channel) {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Canal de chat invalido."})
+		return
+	}
+	if channel == ChatChannelInternal && claims.Role == users.RoleClientViewer {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return
+	}
+
+	viewerUserID := ""
+	if claims.Role == users.RoleClientViewer {
+		viewerUserID = claims.UserID
+	}
+
+	item, err := r.store.FindCalendarItem(c.Request.Context(), c.Param("itemId"), viewerUserID)
+	if errors.Is(err, ErrCalendarItemNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Postagem nao encontrada."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar a postagem."})
+		return
+	}
+
+	messages, err := r.store.ListChatMessages(c.Request.Context(), item.ID, channel)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar mensagens."})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"messages": messages})
+}
+
+func (r Routes) streamChatMessages(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	channel := strings.TrimSpace(c.Query("channel"))
+	if channel == "" {
+		channel = ChatChannelExternal
+	}
+	if !isValidChatChannel(channel) {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Canal de chat invalido."})
+		return
+	}
+	if channel == ChatChannelInternal && claims.Role == users.RoleClientViewer {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return
+	}
+
+	viewerUserID := ""
+	if claims.Role == users.RoleClientViewer {
+		viewerUserID = claims.UserID
+	}
+
+	item, err := r.store.FindCalendarItem(c.Request.Context(), c.Param("itemId"), viewerUserID)
+	if errors.Is(err, ErrCalendarItemNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Postagem nao encontrada."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar a postagem."})
+		return
+	}
+
+	events, unsubscribe := r.chatEvents.Subscribe(item.ID, channel)
+	defer unsubscribe()
+
+	c.Header("Content-Type", "text/event-stream")
+	c.Header("Cache-Control", "no-cache")
+	c.Header("Connection", "keep-alive")
+	c.Header("X-Accel-Buffering", "no")
+
+	flusher, ok := c.Writer.(http.Flusher)
+	if !ok {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Streaming nao suportado."})
+		return
+	}
+
+	_, _ = c.Writer.Write([]byte("event: ready\ndata: ok\n\n"))
+	flusher.Flush()
+
+	heartbeat := time.NewTicker(25 * time.Second)
+	defer heartbeat.Stop()
+
+	for {
+		select {
+		case <-c.Request.Context().Done():
+			return
+		case <-events:
+			_, _ = c.Writer.Write([]byte("event: chat\ndata: refresh\n\n"))
+			flusher.Flush()
+		case <-heartbeat.C:
+			_, _ = c.Writer.Write([]byte("event: ping\ndata: keepalive\n\n"))
+			flusher.Flush()
+		}
+	}
+}
+
+type createChatMessageRequest struct {
+	Channel string `json:"channel"`
+	Body    string `json:"body" binding:"max=4000"`
+}
+
+func (r Routes) createChatMessage(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	var input createChatMessageRequest
+	if err := c.ShouldBindJSON(&input); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Informe uma mensagem valida."})
+		return
+	}
+
+	channel := strings.TrimSpace(input.Channel)
+	if channel == "" {
+		channel = ChatChannelExternal
+	}
+	if !isValidChatChannel(channel) {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Canal de chat invalido."})
+		return
+	}
+	if channel == ChatChannelInternal && claims.Role == users.RoleClientViewer {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return
+	}
+
+	body := strings.TrimSpace(input.Body)
+	if body == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Informe uma mensagem valida."})
+		return
+	}
+
+	viewerUserID := ""
+	if claims.Role == users.RoleClientViewer {
+		viewerUserID = claims.UserID
+	}
+
+	item, err := r.store.FindCalendarItem(c.Request.Context(), c.Param("itemId"), viewerUserID)
+	if errors.Is(err, ErrCalendarItemNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Postagem nao encontrada."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar a postagem."})
+		return
+	}
+
+	message, err := r.store.CreateChatMessage(c.Request.Context(), CreateChatMessageInput{
+		CalendarItemID: item.ID,
+		Channel:        channel,
+		Body:           body,
+		CreatedBy:      claims.UserID,
+	})
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel enviar a mensagem."})
+		return
+	}
+
+	_ = r.store.RecordAudit(c.Request.Context(), claims.UserID, "chat_message.created", "calendar_item", item.ID, map[string]any{
+		"channel": channel,
+	})
+
+	r.chatEvents.Publish(item.ID, channel)
+
+	c.JSON(http.StatusCreated, gin.H{"message": message})
+}
+
+type updateChatMessageRequest struct {
+	Body string `json:"body" binding:"required,min=1,max=4000"`
+}
+
+func (r Routes) updateChatMessage(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	var input updateChatMessageRequest
+	if err := c.ShouldBindJSON(&input); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Informe uma mensagem valida."})
+		return
+	}
+
+	message, err := r.authorizedChatMessage(c, claims, c.Param("messageId"), true)
+	if err != nil {
+		return
+	}
+	if message.DeletedAt != nil {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Mensagem nao encontrada."})
+		return
+	}
+	if len(message.Attachments) > 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Mensagens com anexos nao podem ser editadas."})
+		return
+	}
+
+	updated, err := r.store.UpdateChatMessage(c.Request.Context(), message.ID, strings.TrimSpace(input.Body))
+	if errors.Is(err, ErrChatMessageNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Mensagem nao encontrada."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel editar a mensagem."})
+		return
+	}
+
+	r.chatEvents.Publish(updated.CalendarItemID, updated.Channel)
+
+	c.JSON(http.StatusOK, gin.H{"message": updated})
+}
+
+func (r Routes) deleteChatMessage(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	message, err := r.authorizedChatMessage(c, claims, c.Param("messageId"), true)
+	if err != nil {
+		return
+	}
+	if message.DeletedAt != nil {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Mensagem nao encontrada."})
+		return
+	}
+
+	deleted, err := r.store.DeleteChatMessage(c.Request.Context(), message.ID)
+	if errors.Is(err, ErrChatMessageNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Mensagem nao encontrada."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel excluir a mensagem."})
+		return
+	}
+
+	r.chatEvents.Publish(deleted.CalendarItemID, deleted.Channel)
+
+	c.JSON(http.StatusOK, gin.H{"message": deleted})
+}
+
+func (r Routes) uploadChatAttachment(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	message, err := r.authorizedChatMessage(c, claims, c.Param("messageId"), false)
+	if err != nil {
+		return
+	}
+	if message.DeletedAt != nil {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Mensagem nao encontrada."})
+		return
+	}
+	if message.CreatedBy == nil || *message.CreatedBy != claims.UserID {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return
+	}
+
+	upload, err := r.saveUploadedFile(c, filepath.Join("chat", message.ID))
+	if err != nil {
+		return
+	}
+
+	attachment, err := r.store.CreateChatAttachment(c.Request.Context(), CreateChatAttachmentInput{
+		ChatMessageID:    message.ID,
+		OriginalFilename: upload.originalFilename,
+		StoredFilename:   upload.storedFilename,
+		MimeType:         upload.mimeType,
+		SizeBytes:        upload.sizeBytes,
+		StorageDriver:    r.storageDriver,
+		StoragePath:      upload.storagePath,
+		CreatedBy:        claims.UserID,
+	})
+	if err != nil {
+		_ = os.Remove(upload.storagePath)
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel registrar o anexo."})
+		return
+	}
+
+	r.chatEvents.Publish(message.CalendarItemID, message.Channel)
+
+	c.JSON(http.StatusCreated, gin.H{"attachment": attachment})
+}
+
+func (r Routes) downloadChatAttachment(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok {
+		c.JSON(http.StatusUnauthorized, gin.H{"message": "Autenticacao obrigatoria."})
+		return
+	}
+
+	viewerUserID := ""
+	if claims.Role == users.RoleClientViewer {
+		viewerUserID = claims.UserID
+	}
+
+	attachment, err := r.store.FindChatAttachment(c.Request.Context(), c.Param("attachmentId"), viewerUserID)
+	if errors.Is(err, ErrAttachmentNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Anexo nao encontrado."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar o anexo."})
+		return
+	}
+
+	c.Header("Content-Type", attachment.MimeType)
+	c.Header("Content-Disposition", `attachment; filename="`+strings.ReplaceAll(attachment.OriginalFilename, `"`, "")+`"`)
+	c.File(attachment.StoragePath)
+}
+
+func (r Routes) authorizedChatMessage(c *gin.Context, claims auth.Claims, messageID string, requireOwner bool) (ChatMessage, error) {
+	message, err := r.store.FindChatMessage(c.Request.Context(), messageID)
+	if errors.Is(err, ErrChatMessageNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Mensagem nao encontrada."})
+		return ChatMessage{}, err
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar a mensagem."})
+		return ChatMessage{}, err
+	}
+	if message.Channel == ChatChannelInternal && claims.Role == users.RoleClientViewer {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return ChatMessage{}, errors.New("forbidden")
+	}
+
+	viewerUserID := ""
+	if claims.Role == users.RoleClientViewer {
+		viewerUserID = claims.UserID
+	}
+	if _, err := r.store.FindCalendarItem(c.Request.Context(), message.CalendarItemID, viewerUserID); err != nil {
+		if errors.Is(err, ErrCalendarItemNotFound) {
+			c.JSON(http.StatusNotFound, gin.H{"message": "Postagem nao encontrada."})
+		} else {
+			c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel carregar a postagem."})
+		}
+		return ChatMessage{}, err
+	}
+
+	if requireOwner && claims.Role != users.RoleSuperAdmin && (message.CreatedBy == nil || *message.CreatedBy != claims.UserID) {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return ChatMessage{}, errors.New("forbidden")
+	}
+
+	return message, nil
+}
+
 func (r Routes) uploadAttachment(c *gin.Context) {
 	claims, ok := auth.ClaimsFromContext(c)
 	if !ok || (claims.Role != users.RoleSuperAdmin && claims.Role != users.RoleAgencyUser) {
@@ -611,75 +991,23 @@ func (r Routes) uploadAttachment(c *gin.Context) {
 		return
 	}

-	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, r.uploadMaxSizeBytes)
-	file, header, err := c.Request.FormFile("file")
+	upload, err := r.saveUploadedFile(c, c.Param("itemId"))
 	if err != nil {
-		c.JSON(http.StatusBadRequest, gin.H{"message": "Envie um arquivo valido."})
-		return
-	}
-	defer file.Close()
-
-	if header.Size > r.uploadMaxSizeBytes {
-		c.JSON(http.StatusBadRequest, gin.H{"message": "Arquivo acima do limite permitido."})
-		return
-	}
-
-	head := make([]byte, 512)
-	n, err := file.Read(head)
-	if err != nil && err != io.EOF {
-		c.JSON(http.StatusBadRequest, gin.H{"message": "Nao foi possivel ler o arquivo."})
-		return
-	}
-	if _, err := file.Seek(0, io.SeekStart); err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel processar o arquivo."})
-		return
-	}
-
-	mimeType := http.DetectContentType(head[:n])
-	if len(r.uploadAllowedMIMEs) > 0 && !r.uploadAllowedMIMEs[mimeType] {
-		c.JSON(http.StatusBadRequest, gin.H{"message": "Tipo de arquivo nao permitido."})
-		return
-	}
-
-	storedFilename, err := randomStoredFilename(header.Filename)
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel preparar o arquivo."})
-		return
-	}
-
-	itemDir := filepath.Join(r.storageLocalPath, c.Param("itemId"))
-	if err := os.MkdirAll(itemDir, 0o750); err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel preparar o armazenamento."})
-		return
-	}
-
-	storagePath := filepath.Join(itemDir, storedFilename)
-	destination, err := os.OpenFile(storagePath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o640)
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel salvar o arquivo."})
-		return
-	}
-	defer destination.Close()
-
-	sizeBytes, err := io.Copy(destination, file)
-	if err != nil {
-		_ = os.Remove(storagePath)
-		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel salvar o arquivo."})
 		return
 	}

 	attachment, err := r.store.CreateAttachment(c.Request.Context(), CreateAttachmentInput{
 		CalendarItemID:   c.Param("itemId"),
-		OriginalFilename: filepath.Base(header.Filename),
-		StoredFilename:   storedFilename,
-		MimeType:         mimeType,
-		SizeBytes:        sizeBytes,
+		OriginalFilename: upload.originalFilename,
+		StoredFilename:   upload.storedFilename,
+		MimeType:         upload.mimeType,
+		SizeBytes:        upload.sizeBytes,
 		StorageDriver:    r.storageDriver,
-		StoragePath:      storagePath,
+		StoragePath:      upload.storagePath,
 		CreatedBy:        claims.UserID,
 	})
 	if err != nil {
-		_ = os.Remove(storagePath)
+		_ = os.Remove(upload.storagePath)
 		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel registrar o anexo."})
 		return
 	}
@@ -694,6 +1022,96 @@ func (r Routes) uploadAttachment(c *gin.Context) {
 	c.JSON(http.StatusCreated, gin.H{"attachment": attachment})
 }

+type savedUpload struct {
+	originalFilename string
+	storedFilename   string
+	mimeType         string
+	sizeBytes        int64
+	storagePath      string
+}
+
+func (r Routes) saveUploadedFile(c *gin.Context, relativeDir string) (savedUpload, error) {
+	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, r.uploadMaxSizeBytes)
+	file, header, err := c.Request.FormFile("file")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Envie um arquivo valido."})
+		return savedUpload{}, err
+	}
+	defer file.Close()
+
+	if header.Size > r.uploadMaxSizeBytes {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Arquivo acima do limite permitido."})
+		return savedUpload{}, errors.New("file too large")
+	}
+
+	head := make([]byte, 512)
+	n, err := file.Read(head)
+	if err != nil && err != io.EOF {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Nao foi possivel ler o arquivo."})
+		return savedUpload{}, err
+	}
+	if _, err := file.Seek(0, io.SeekStart); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel processar o arquivo."})
+		return savedUpload{}, err
+	}
+
+	mimeType := normalizeUploadMimeType(http.DetectContentType(head[:n]), header.Filename)
+	if len(r.uploadAllowedMIMEs) > 0 && !r.uploadAllowedMIMEs[mimeType] {
+		c.JSON(http.StatusBadRequest, gin.H{"message": "Tipo de arquivo nao permitido."})
+		return savedUpload{}, errors.New("invalid mime")
+	}
+
+	storedFilename, err := randomStoredFilename(header.Filename)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel preparar o arquivo."})
+		return savedUpload{}, err
+	}
+
+	storageDir := filepath.Join(r.storageLocalPath, filepath.Clean(relativeDir))
+	if err := os.MkdirAll(storageDir, 0o750); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel preparar o armazenamento."})
+		return savedUpload{}, err
+	}
+
+	storagePath := filepath.Join(storageDir, storedFilename)
+	destination, err := os.OpenFile(storagePath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o640)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel salvar o arquivo."})
+		return savedUpload{}, err
+	}
+	defer destination.Close()
+
+	sizeBytes, err := io.Copy(destination, file)
+	if err != nil {
+		_ = os.Remove(storagePath)
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel salvar o arquivo."})
+		return savedUpload{}, err
+	}
+
+	return savedUpload{
+		originalFilename: filepath.Base(header.Filename),
+		storedFilename:   storedFilename,
+		mimeType:         mimeType,
+		sizeBytes:        sizeBytes,
+		storagePath:      storagePath,
+	}, nil
+}
+
+func normalizeUploadMimeType(detected string, filename string) string {
+	switch strings.ToLower(filepath.Ext(filename)) {
+	case ".docx":
+		if detected == "application/zip" || detected == "application/octet-stream" {
+			return "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
+		}
+	case ".doc":
+		if detected == "application/octet-stream" {
+			return "application/msword"
+		}
+	}
+
+	return detected
+}
+
 func (r Routes) downloadAttachment(c *gin.Context) {
 	claims, ok := auth.ClaimsFromContext(c)
 	if !ok {
@@ -721,6 +1139,37 @@ func (r Routes) downloadAttachment(c *gin.Context) {
 	c.File(attachment.StoragePath)
 }

+func (r Routes) deleteAttachment(c *gin.Context) {
+	claims, ok := auth.ClaimsFromContext(c)
+	if !ok || (claims.Role != users.RoleSuperAdmin && claims.Role != users.RoleAgencyUser) {
+		c.JSON(http.StatusForbidden, gin.H{"message": "Permissao insuficiente."})
+		return
+	}
+
+	attachment, err := r.store.DeleteAttachment(c.Request.Context(), c.Param("attachmentId"))
+	if errors.Is(err, ErrAttachmentNotFound) {
+		c.JSON(http.StatusNotFound, gin.H{"message": "Anexo nao encontrado."})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"message": "Nao foi possivel excluir o anexo."})
+		return
+	}
+
+	if attachment.StorageDriver == "local" {
+		_ = os.Remove(attachment.StoragePath)
+	}
+
+	_ = r.store.RecordAudit(c.Request.Context(), claims.UserID, "attachment.deleted", "calendar_item_attachment", attachment.ID, map[string]any{
+		"calendar_item_id": attachment.CalendarItemID,
+		"filename":         attachment.OriginalFilename,
+		"mime_type":        attachment.MimeType,
+		"size_bytes":       attachment.SizeBytes,
+	})
+
+	c.JSON(http.StatusOK, gin.H{"attachment": attachment})
+}
+
 func randomStoredFilename(original string) (string, error) {
 	bytes := make([]byte, 16)
 	if _, err := rand.Read(bytes); err != nil {
@@ -738,3 +1187,12 @@ func isValidCalendarItemStatus(status string) bool {
 		return false
 	}
 }
+
+func isValidChatChannel(channel string) bool {
+	switch channel {
+	case ChatChannelExternal, ChatChannelInternal:
+		return true
+	default:
+		return false
+	}
+}
--- a/backend/internal/config/config.go
+++ b/backend/internal/config/config.go
@@ -48,7 +48,7 @@ func Load() Config {
 		SuperAdminEmail:    env("SUPER_ADMIN_EMAIL", ""),
 		SuperAdminPassword: env("SUPER_ADMIN_PASSWORD", ""),
 		JWTSecret:          env("JWT_SECRET", ""),
-		AccessTokenTTL:     minutes("JWT_ACCESS_TOKEN_TTL_MINUTES", 15),
+		AccessTokenTTL:     minutes("JWT_ACCESS_TOKEN_TTL_MINUTES", 480),
 		RefreshTokenTTL:    hours("JWT_REFRESH_TOKEN_TTL_DAYS", 7*24),
 		CORSAllowedOrigins: list("CORS_ALLOWED_ORIGINS", "http://localhost:5173"),
 		CalendarProvider:   env("CALENDAR_PROVIDER", "brasilapi"),
@@ -56,14 +56,14 @@ func Load() Config {
 		CalendarAPIKey:     env("CALENDAR_API_KEY", ""),
 		CalendarCacheTTL:   hours("CALENDAR_CACHE_TTL_HOURS", 24),
 		UploadMaxSizeMB:    integer("UPLOAD_MAX_SIZE_MB", 10),
-		UploadAllowedMIMEs: list("UPLOAD_ALLOWED_MIME_TYPES", "image/jpeg,image/png,image/webp,application/pdf"),
+		UploadAllowedMIMEs: list("UPLOAD_ALLOWED_MIME_TYPES", "image/jpeg,image/png,image/webp,application/pdf,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
 		StorageDriver:      env("STORAGE_DRIVER", "local"),
 		StorageLocalPath:   env("STORAGE_LOCAL_PATH", "/var/lib/mira/uploads"),
 		SMTPHost:           env("SMTP_HOST", ""),
 		SMTPPort:           env("SMTP_PORT", "587"),
 		SMTPUser:           env("SMTP_USER", ""),
-		SMTPPassword:       env("SMTP_PASSWORD", ""),
-		SMTPFromEmail:      env("SMTP_FROM_EMAIL", ""),
+		SMTPPassword:       envAlias("SMTP_PASS", "SMTP_PASSWORD", ""),
+		SMTPFromEmail:      envAlias("MAIL_FROM", "SMTP_FROM_EMAIL", ""),
 		SMTPFromName:       env("SMTP_FROM_NAME", "Mira"),
 	}
 }
@@ -76,6 +76,14 @@ func env(key, fallback string) string {
 	return value
 }

+func envAlias(primary string, secondary string, fallback string) string {
+	value := strings.TrimSpace(os.Getenv(primary))
+	if value != "" {
+		return value
+	}
+	return env(secondary, fallback)
+}
+
 func list(key, fallback string) []string {
 	raw := env(key, fallback)
 	parts := strings.Split(raw, ",")
--- a/backend/internal/httpserver/server.go
+++ b/backend/internal/httpserver/server.go
@@ -9,6 +9,7 @@ import (
 	"mira/backend/internal/clients"
 	"mira/backend/internal/config"
 	"mira/backend/internal/database"
+	"mira/backend/internal/mail"
 	"mira/backend/internal/security"
 	"mira/backend/internal/users"

@@ -39,8 +40,17 @@ func New(cfg config.Config, logger *slog.Logger, db *database.DB, userStore user

 	tokenService := auth.NewTokenService(cfg.JWTSecret, cfg.AccessTokenTTL)
 	requireAuth := auth.RequireAuth(tokenService)
-	authRoutes := auth.NewRoutes(userStore, tokenService)
-	userRoutes := users.NewRoutes(userStore, cfg.AppPublicURL)
+	sessionStore := auth.NewSessionStore(db.Pool)
+	authRoutes := auth.NewRoutes(userStore, sessionStore, tokenService, cfg.RefreshTokenTTL, cfg.AppEnv == "production")
+	mailSender := mail.NewSender(mail.SMTPConfig{
+		Host:     cfg.SMTPHost,
+		Port:     cfg.SMTPPort,
+		User:     cfg.SMTPUser,
+		Password: cfg.SMTPPassword,
+		From:     cfg.SMTPFromEmail,
+		FromName: cfg.SMTPFromName,
+	})
+	userRoutes := users.NewRoutes(userStore, cfg.AppPublicURL, mailSender)
 	clientRoutes := clients.NewRoutes(clientStore)
 	calendarRoutes := calendar.NewRoutes(calendarStore, calendar.NewBrasilAPIProvider(cfg.CalendarAPIBaseURL), calendar.NewFeriadosBrasilProvider(), calendar.RouteOptions{
 		UploadMaxSizeMB:    cfg.UploadMaxSizeMB,
--- a/backend/internal/mail/smtp.go
+++ b/backend/internal/mail/smtp.go
@@ -0,0 +1,150 @@
+package mail
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net"
+	"net/mail"
+	"net/smtp"
+	"strings"
+)
+
+type SMTPConfig struct {
+	Host     string
+	Port     string
+	User     string
+	Password string
+	From     string
+	FromName string
+}
+
+type Sender struct {
+	cfg SMTPConfig
+}
+
+func NewSender(cfg SMTPConfig) Sender {
+	if strings.TrimSpace(cfg.Port) == "" {
+		cfg.Port = "587"
+	}
+	return Sender{cfg: cfg}
+}
+
+func (s Sender) IsConfigured() bool {
+	return strings.TrimSpace(s.cfg.Host) != "" &&
+		strings.TrimSpace(s.cfg.Port) != "" &&
+		strings.TrimSpace(s.cfg.From) != ""
+}
+
+func (s Sender) SendInvitation(to string, invitationURL string) error {
+	subject := "Convite para acessar o Mira"
+	textBody := "Voce foi convidado para acessar o Mira.\n\nCrie sua senha pelo link abaixo:\n" + invitationURL + "\n\nEste convite expira em 7 dias."
+	htmlBody := `<p>Voce foi convidado para acessar o Mira.</p><p><a href="` + invitationURL + `">Criar minha senha</a></p><p>Este convite expira em 7 dias.</p>`
+
+	return s.send(to, subject, textBody, htmlBody)
+}
+
+func (s Sender) send(to string, subject string, textBody string, htmlBody string) error {
+	if !s.IsConfigured() {
+		return nil
+	}
+
+	from := mail.Address{Name: strings.TrimSpace(s.cfg.FromName), Address: strings.TrimSpace(s.cfg.From)}
+	recipient := mail.Address{Address: strings.TrimSpace(to)}
+	boundary := "mira-mail-boundary"
+	message := strings.Join([]string{
+		"From: " + from.String(),
+		"To: " + recipient.String(),
+		"Subject: " + subject,
+		"MIME-Version: 1.0",
+		"Content-Type: multipart/alternative; boundary=\"" + boundary + "\"",
+		"",
+		"--" + boundary,
+		"Content-Type: text/plain; charset=UTF-8",
+		"",
+		textBody,
+		"--" + boundary,
+		"Content-Type: text/html; charset=UTF-8",
+		"",
+		htmlBody,
+		"--" + boundary + "--",
+		"",
+	}, "\r\n")
+
+	host := strings.TrimSpace(s.cfg.Host)
+	port := strings.TrimSpace(s.cfg.Port)
+	addr := net.JoinHostPort(host, port)
+	var auth smtp.Auth
+	if strings.TrimSpace(s.cfg.User) != "" || strings.TrimSpace(s.cfg.Password) != "" {
+		auth = smtp.PlainAuth("", strings.TrimSpace(s.cfg.User), strings.TrimSpace(s.cfg.Password), host)
+	}
+
+	if port == "465" {
+		if err := sendMailTLS(addr, host, auth, from.Address, []string{recipient.Address}, []byte(message)); err != nil {
+			return fmt.Errorf("send smtp email: %w", err)
+		}
+		return nil
+	}
+
+	if err := sendMailStartTLS(addr, host, auth, from.Address, []string{recipient.Address}, []byte(message)); err != nil {
+		return fmt.Errorf("send smtp email: %w", err)
+	}
+	return nil
+}
+
+func sendMailStartTLS(addr string, host string, auth smtp.Auth, from string, to []string, message []byte) error {
+	client, err := smtp.Dial(addr)
+	if err != nil {
+		return err
+	}
+	defer client.Quit()
+
+	if ok, _ := client.Extension("STARTTLS"); ok {
+		if err := client.StartTLS(&tls.Config{ServerName: host, MinVersion: tls.VersionTLS12}); err != nil {
+			return err
+		}
+	}
+
+	return sendMailWithClient(client, auth, from, to, message)
+}
+
+func sendMailTLS(addr string, host string, auth smtp.Auth, from string, to []string, message []byte) error {
+	conn, err := tls.Dial("tcp", addr, &tls.Config{ServerName: host, MinVersion: tls.VersionTLS12})
+	if err != nil {
+		return err
+	}
+
+	client, err := smtp.NewClient(conn, host)
+	if err != nil {
+		_ = conn.Close()
+		return err
+	}
+	defer client.Quit()
+
+	return sendMailWithClient(client, auth, from, to, message)
+}
+
+func sendMailWithClient(client *smtp.Client, auth smtp.Auth, from string, to []string, message []byte) error {
+	if auth != nil {
+		if err := client.Auth(auth); err != nil {
+			return err
+		}
+	}
+	if err := client.Mail(from); err != nil {
+		return err
+	}
+	for _, recipient := range to {
+		if err := client.Rcpt(recipient); err != nil {
+			return err
+		}
+	}
+
+	writer, err := client.Data()
+	if err != nil {
+		return err
+	}
+	if _, err := writer.Write(message); err != nil {
+		_ = writer.Close()
+		return err
+	}
+	return writer.Close()
+}
--- a/backend/internal/security/headers.go
+++ b/backend/internal/security/headers.go
@@ -9,7 +9,7 @@ import (

 func Headers() gin.HandlerFunc {
 	return func(c *gin.Context) {
-		c.Header("Content-Security-Policy", "default-src 'self'; frame-ancestors 'none'")
+		c.Header("Content-Security-Policy", "default-src 'self'; base-uri 'self'; frame-ancestors 'none'; form-action 'self'")
 		c.Header("X-Content-Type-Options", "nosniff")
 		c.Header("X-Frame-Options", "DENY")
 		c.Header("Referrer-Policy", "strict-origin-when-cross-origin")
--- a/backend/internal/users/invitations.go
+++ b/backend/internal/users/invitations.go
@@ -25,6 +25,8 @@ type Invitation struct {
 	CreatedBy     *string    `json:"created_by"`
 	CreatedAt     time.Time  `json:"created_at"`
 	InvitationURL string     `json:"invitation_url,omitempty"`
+	EmailSent     bool       `json:"email_sent"`
+	EmailError    string     `json:"email_error,omitempty"`
 }

 type CreateInvitationInput struct {
--- a/backend/internal/users/routes.go
+++ b/backend/internal/users/routes.go
@@ -5,18 +5,22 @@ import (
 	"strings"
 	"time"

+	"mira/backend/internal/mail"
+
 	"github.com/gin-gonic/gin"
 )

 type Routes struct {
 	store        Store
 	appPublicURL string
+	mailSender   mail.Sender
 }

-func NewRoutes(store Store, appPublicURL string) Routes {
+func NewRoutes(store Store, appPublicURL string, mailSender mail.Sender) Routes {
 	return Routes{
 		store:        store,
 		appPublicURL: strings.TrimRight(appPublicURL, "/"),
+		mailSender:   mailSender,
 	}
 }

@@ -106,6 +110,14 @@ func (r Routes) createInvitation(c *gin.Context) {
 	}

 	invitation.InvitationURL = r.invitationURL(token)
+	invitation.EmailSent = false
+	if r.mailSender.IsConfigured() {
+		if err := r.mailSender.SendInvitation(invitation.Email, invitation.InvitationURL); err != nil {
+			invitation.EmailError = "Convite criado, mas nao foi possivel enviar o e-mail."
+		} else {
+			invitation.EmailSent = true
+		}
+	}

 	c.JSON(http.StatusCreated, gin.H{"invitation": invitation})
 }
--- a/backend/migrations/005_refresh_tokens.sql
+++ b/backend/migrations/005_refresh_tokens.sql
@@ -0,0 +1,11 @@
+CREATE TABLE IF NOT EXISTS refresh_tokens (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  token_hash TEXT NOT NULL UNIQUE,
+  expires_at TIMESTAMPTZ NOT NULL,
+  revoked_at TIMESTAMPTZ,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_refresh_tokens_user_id ON refresh_tokens (user_id);
+CREATE INDEX IF NOT EXISTS idx_refresh_tokens_token_hash ON refresh_tokens (token_hash);
--- a/backend/migrations/006_calendar_item_chat_messages.sql
+++ b/backend/migrations/006_calendar_item_chat_messages.sql
@@ -0,0 +1,11 @@
+CREATE TABLE IF NOT EXISTS calendar_item_chat_messages (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  calendar_item_id UUID NOT NULL REFERENCES calendar_items(id) ON DELETE CASCADE,
+  channel TEXT NOT NULL CHECK (channel IN ('external', 'internal')),
+  body TEXT NOT NULL,
+  created_by UUID REFERENCES users(id) ON DELETE SET NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_calendar_item_chat_messages_item_channel
+  ON calendar_item_chat_messages (calendar_item_id, channel, created_at);
--- a/backend/migrations/007_chat_message_features.sql
+++ b/backend/migrations/007_chat_message_features.sql
@@ -0,0 +1,19 @@
+ALTER TABLE calendar_item_chat_messages
+ADD COLUMN IF NOT EXISTS edited_at TIMESTAMPTZ,
+ADD COLUMN IF NOT EXISTS deleted_at TIMESTAMPTZ;
+
+CREATE TABLE IF NOT EXISTS calendar_item_chat_attachments (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  chat_message_id UUID NOT NULL REFERENCES calendar_item_chat_messages(id) ON DELETE CASCADE,
+  original_filename TEXT NOT NULL,
+  stored_filename TEXT NOT NULL,
+  mime_type TEXT NOT NULL,
+  size_bytes BIGINT NOT NULL CHECK (size_bytes >= 0),
+  storage_driver TEXT NOT NULL,
+  storage_path TEXT NOT NULL,
+  created_by UUID REFERENCES users(id) ON DELETE SET NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_calendar_item_chat_attachments_message
+  ON calendar_item_chat_attachments (chat_message_id, created_at);
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -41,8 +41,8 @@ services:
      SMTP_HOST: ${SMTP_HOST}
      SMTP_PORT: ${SMTP_PORT}
      SMTP_USER: ${SMTP_USER}
-      SMTP_PASSWORD: ${SMTP_PASSWORD}
-      SMTP_FROM_EMAIL: ${SMTP_FROM_EMAIL}
+      SMTP_PASS: ${SMTP_PASS}
+      MAIL_FROM: ${MAIL_FROM}
      SMTP_FROM_NAME: ${SMTP_FROM_NAME}
      UPLOAD_MAX_SIZE_MB: ${UPLOAD_MAX_SIZE_MB}
      UPLOAD_ALLOWED_MIME_TYPES: ${UPLOAD_ALLOWED_MIME_TYPES}
--- a/frontend/nginx.conf
+++ b/frontend/nginx.conf
@@ -9,6 +9,7 @@ server {
  add_header X-Frame-Options "DENY" always;
  add_header Referrer-Policy "strict-origin-when-cross-origin" always;
  add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;
+  add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; font-src 'self'; img-src 'self' blob: data:; connect-src 'self' http://localhost:8081 http://127.0.0.1:8081; base-uri 'self'; form-action 'self'; frame-ancestors 'none'" always;

  location / {
    try_files $uri $uri/ /index.html;
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -10,21 +10,63 @@ import { ClientDashboardView } from "./views/ClientDashboardView";
 import { PostDetailView } from "./views/PostDetailView";
 import { Topbar } from "./components/layout/Topbar";
 import { Sidebar } from "./components/layout/Sidebar";
-import { clearStoredToken, getStoredToken, loadCurrentUser, type AuthUser } from "@/lib/auth";
+import { clearStoredToken, getStoredToken, loadCurrentUser, logout, refreshSession, type AuthUser } from "@/lib/auth";
 import { listClients, type Client } from "@/lib/clients";

+const APP_STATE_STORAGE_KEY = "mira_app_state";
+const validViews = new Set(["dashboard", "clients", "client-dashboard", "post-detail", "calendar", "users"]);
+
+type StoredAppState = {
+  currentView: string;
+  selectedClientId: string | null;
+  selectedPostId: string | null;
+};
+
+function readStoredAppState(): StoredAppState {
+  const fallback = {
+    currentView: "dashboard",
+    selectedClientId: null,
+    selectedPostId: null,
+  };
+
+  try {
+    const raw = localStorage.getItem(APP_STATE_STORAGE_KEY);
+    if (!raw) return fallback;
+
+    const parsed = JSON.parse(raw) as Partial<StoredAppState>;
+    const currentView = typeof parsed.currentView === "string" && validViews.has(parsed.currentView)
+      ? parsed.currentView
+      : fallback.currentView;
+    const selectedClientId = typeof parsed.selectedClientId === "string" ? parsed.selectedClientId : null;
+    const selectedPostId = typeof parsed.selectedPostId === "string" ? parsed.selectedPostId : null;
+
+    if (currentView === "client-dashboard" && !selectedClientId) return fallback;
+    if (currentView === "post-detail" && !selectedPostId) return fallback;
+
+    return {
+      currentView,
+      selectedClientId,
+      selectedPostId,
+    };
+  } catch {
+    return fallback;
+  }
+}
+
 export default function App() {
+  const storedAppState = readStoredAppState();
  const [user, setUser] = useState<AuthUser | null>(null);
  const [clients, setClients] = useState<Client[]>([]);
-  const [selectedClientId, setSelectedClientId] = useState<string | null>(null);
+  const [selectedClientId, setSelectedClientId] = useState<string | null>(storedAppState.selectedClientId);
  const [isCheckingSession, setIsCheckingSession] = useState(true);
  const [clientsError, setClientsError] = useState("");
-  const [currentView, setCurrentView] = useState("dashboard"); // 'dashboard' | 'calendar' | 'users'
-  const [selectedPostId, setSelectedPostId] = useState<string | null>(null);
+  const [currentView, setCurrentView] = useState(storedAppState.currentView);
+  const [selectedPostId, setSelectedPostId] = useState<string | null>(storedAppState.selectedPostId);
  const invitationToken =
    window.location.pathname === "/accept-invitation"
      ? new URLSearchParams(window.location.search).get("token")
      : null;
+  const isClientViewer = user?.role === "client_viewer";

  async function refreshClients(token = getStoredToken()) {
    if (!token) return;
@@ -45,7 +87,16 @@ export default function App() {
    const token = getStoredToken();

    if (!token) {
-      setIsCheckingSession(false);
+      refreshSession()
+        .then((response) => {
+          setUser(response.user);
+          return refreshClients(response.access_token);
+        })
+        .catch(() => {
+          clearStoredToken();
+          setUser(null);
+        })
+        .finally(() => setIsCheckingSession(false));
      return;
    }

@@ -55,14 +106,51 @@ export default function App() {
        return refreshClients(token);
      })
      .catch(() => {
-        clearStoredToken();
-        setUser(null);
+        return refreshSession()
+          .then((response) => {
+            setUser(response.user);
+            return refreshClients(response.access_token);
+          })
+          .catch(() => {
+            clearStoredToken();
+            setUser(null);
+          });
      })
      .finally(() => setIsCheckingSession(false));
  }, []);

+  useEffect(() => {
+    localStorage.setItem(
+      APP_STATE_STORAGE_KEY,
+      JSON.stringify({
+        currentView,
+        selectedClientId,
+        selectedPostId,
+      }),
+    );
+  }, [currentView, selectedClientId, selectedPostId]);
+
+  useEffect(() => {
+    if (currentView === "client-dashboard" && !selectedClientId) {
+      setCurrentView("clients");
+    }
+    if (currentView === "post-detail" && !selectedPostId) {
+      setCurrentView("calendar");
+    }
+  }, [currentView, selectedClientId, selectedPostId]);
+
+  useEffect(() => {
+    if (!isClientViewer) return;
+
+    setSelectedClientId((current) => current ?? clients[0]?.id ?? null);
+    if (currentView === "clients" || currentView === "users" || currentView === "client-dashboard") {
+      setCurrentView("dashboard");
+    }
+  }, [clients, currentView, isClientViewer]);
+
  function handleLogout() {
-    clearStoredToken();
+    void logout();
+    localStorage.removeItem(APP_STATE_STORAGE_KEY);
    setUser(null);
    setClients([]);
    setSelectedClientId(null);
@@ -75,9 +163,9 @@ export default function App() {
    void refreshClients();
  }

-  function handleInvitationAccepted(loadedUser: AuthUser) {
-    setUser(loadedUser);
-    void refreshClients();
+  function handleInvitationAccepted() {
+    clearStoredToken();
+    setUser(null);
  }

  function handleClientCreated(client: Client) {
@@ -166,9 +254,14 @@ export default function App() {
        <div className="flex-1 overflow-x-hidden">
          <main className="p-4 md:p-8 max-w-7xl mx-auto w-full">
            {currentView === "dashboard" && (
-              <DashboardView onViewChange={setCurrentView} onPostSelect={handlePostSelect} />
+              <DashboardView
+                selectedClientId={isClientViewer ? selectedClientId : null}
+                canCreatePost={!isClientViewer}
+                onViewChange={setCurrentView}
+                onPostSelect={handlePostSelect}
+              />
            )}
-            {currentView === "clients" && (
+            {!isClientViewer && currentView === "clients" && (
              <ClientsView
                clients={clients}
                onClientCreated={handleClientCreated}
@@ -177,7 +270,7 @@ export default function App() {
                onClientSelect={setSelectedClientId}
              />
            )}
-            {currentView === "client-dashboard" && selectedClientId && (
+            {!isClientViewer && currentView === "client-dashboard" && selectedClientId && (
              <ClientDashboardView
                client={clients.find((client) => client.id === selectedClientId) ?? null}
                selectedClientId={selectedClientId}
@@ -186,12 +279,12 @@ export default function App() {
              />
            )}
            {currentView === "post-detail" && selectedPostId && (
-              <PostDetailView itemId={selectedPostId} onBack={() => setCurrentView("calendar")} />
+              <PostDetailView itemId={selectedPostId} onBack={() => setCurrentView("calendar")} user={user} />
            )}
            {currentView === "calendar" && (
              <CalendarView clients={clients} selectedClientId={selectedClientId} user={user} onPostSelect={handlePostSelect} />
            )}
-            {currentView === "users" && <UsersView clients={clients} />}
+            {!isClientViewer && currentView === "users" && <UsersView clients={clients} />}
          </main>
        </div>
      </div>
--- a/frontend/src/components/layout/Sidebar.tsx
+++ b/frontend/src/components/layout/Sidebar.tsx
@@ -21,12 +21,18 @@ type NavProps = {

 export function Sidebar({ currentView, onViewChange, user, onLogout, clients, selectedClientId, onClientSelect, clientsError }: NavProps) {
  const [clientSearch, setClientSearch] = useState("");
-  const navItems = [
-    { id: "dashboard", label: "Dashboard Semanal", icon: LayoutDashboard },
-    { id: "clients", label: "Clientes", icon: Building2 },
-    { id: "calendar", label: "Calendário", icon: CalendarDays },
-    { id: "users", label: "Pessoas", icon: Users },
-  ];
+  const isClientViewer = user.role === "client_viewer";
+  const navItems = isClientViewer
+    ? [
+        { id: "dashboard", label: "Dashboard Semanal", icon: LayoutDashboard },
+        { id: "calendar", label: "Calendário", icon: CalendarDays },
+      ]
+    : [
+        { id: "dashboard", label: "Dashboard Semanal", icon: LayoutDashboard },
+        { id: "clients", label: "Clientes", icon: Building2 },
+        { id: "calendar", label: "Calendário", icon: CalendarDays },
+        { id: "users", label: "Pessoas", icon: Users },
+      ];

  const filteredClients = useMemo(() => {
    const term = clientSearch.trim().toLowerCase();
@@ -43,20 +49,24 @@ export function Sidebar({ currentView, onViewChange, user, onLogout, clients, se
        <span className="font-semibold text-lg tracking-tight">Mira</span>
      </div>

-      <div className="p-4 border-b border-border/40">
-        <div className="relative">
-          <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
-          <Input 
-            placeholder="Buscar clientes..." 
-            className="pl-9 h-9 bg-muted/50 border-none shadow-none focus-visible:ring-1"
-            value={clientSearch}
-            onChange={(event) => setClientSearch(event.target.value)}
-          />
+      {!isClientViewer && (
+        <div className="p-4 border-b border-border/40">
+          <div className="relative">
+            <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
+            <Input
+              placeholder="Buscar clientes..."
+              className="pl-9 h-9 bg-muted/50 border-none shadow-none focus-visible:ring-1"
+              value={clientSearch}
+              onChange={(event) => setClientSearch(event.target.value)}
+            />
+          </div>
        </div>
-      </div>
+      )}

      <nav className="flex-1 p-4 space-y-1 overflow-y-auto">
-        <div className="text-xs font-semibold text-muted-foreground uppercase tracking-wider mb-2 ml-2">Agência</div>
+        <div className="text-xs font-semibold text-muted-foreground uppercase tracking-wider mb-2 ml-2">
+          {isClientViewer ? "Cliente" : "Agência"}
+        </div>
        {navItems.map((item) => {
          const Icon = item.icon;
          const isActive = currentView === item.id;
@@ -77,6 +87,7 @@ export function Sidebar({ currentView, onViewChange, user, onLogout, clients, se
          );
        })}

+        {!isClientViewer && (
        <div className="pt-5">
          <div className="text-xs font-semibold text-muted-foreground uppercase tracking-wider mb-2 ml-2">Dashboards</div>
          {clientsError && (
@@ -110,6 +121,7 @@ export function Sidebar({ currentView, onViewChange, user, onLogout, clients, se
            })}
          </div>
        </div>
+        )}
      </nav>

      <div className="p-4 border-t border-border/40 space-y-4">
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -15,6 +15,7 @@ export async function apiRequest<T>(path: string, options: RequestOptions = {}):
  const response = await fetch(`${API_BASE_URL}${path}`, {
    ...options,
    headers,
+    credentials: "include",
  });

  const data = await response.json().catch(() => ({}));
@@ -40,6 +41,7 @@ export async function apiFormRequest<T>(path: string, formData: FormData, token?
    method: "POST",
    headers,
    body: formData,
+    credentials: "include",
  });

  const data = await response.json().catch(() => ({}));
--- a/frontend/src/lib/auth.ts
+++ b/frontend/src/lib/auth.ts
@@ -16,20 +16,35 @@ type LoginResponse = {
  user: AuthUser;
 };

+type AcceptInvitationResponse = {
+  message: string;
+  user: AuthUser;
+};
+
 type MeResponse = {
  user: AuthUser;
 };

 export function getStoredToken() {
-  return localStorage.getItem(TOKEN_STORAGE_KEY);
+  return sessionStorage.getItem(TOKEN_STORAGE_KEY);
 }

 export function storeToken(token: string) {
-  localStorage.setItem(TOKEN_STORAGE_KEY, token);
+  localStorage.removeItem(TOKEN_STORAGE_KEY);
+  sessionStorage.setItem(TOKEN_STORAGE_KEY, token);
 }

 export function clearStoredToken() {
  localStorage.removeItem(TOKEN_STORAGE_KEY);
+  sessionStorage.removeItem(TOKEN_STORAGE_KEY);
+}
+
+export async function logout() {
+  await apiRequest<{ message: string }>("/auth/logout", {
+    method: "POST",
+  }).catch(() => undefined);
+  localStorage.removeItem(TOKEN_STORAGE_KEY);
+  sessionStorage.removeItem(TOKEN_STORAGE_KEY);
 }

 export async function login(email: string, password: string) {
@@ -43,11 +58,19 @@ export async function login(email: string, password: string) {
 }

 export async function acceptInvitation(token: string, name: string, password: string) {
-  const response = await apiRequest<LoginResponse>("/auth/invitations/accept", {
+  const response = await apiRequest<AcceptInvitationResponse>("/auth/invitations/accept", {
    method: "POST",
    body: JSON.stringify({ token, name, password }),
  });

+  return response;
+}
+
+export async function refreshSession() {
+  const response = await apiRequest<LoginResponse>("/auth/refresh", {
+    method: "POST",
+  });
+
  storeToken(response.access_token);
  return response;
 }
--- a/frontend/src/lib/calendar.ts
+++ b/frontend/src/lib/calendar.ts
@@ -1,4 +1,4 @@
-import { API_BASE_URL, apiFormRequest, apiRequest } from "@/lib/api";
+import { API_BASE_URL, ApiError, apiFormRequest, apiRequest } from "@/lib/api";

 export type Holiday = {
  id: string;
@@ -51,6 +51,34 @@ export type Attachment = {
  created_at: string;
 };

+export type ChatChannel = "external" | "internal";
+
+export type ChatMessage = {
+  id: string;
+  calendar_item_id: string;
+  channel: ChatChannel;
+  body: string;
+  created_by: string | null;
+  author_name: string;
+  author_role: string;
+  created_at: string;
+  edited_at: string | null;
+  deleted_at: string | null;
+  attachments: ChatAttachment[] | null;
+};
+
+export type ChatAttachment = {
+  id: string;
+  chat_message_id: string;
+  original_filename: string;
+  stored_filename: string;
+  mime_type: string;
+  size_bytes: number;
+  storage_driver: string;
+  created_by: string | null;
+  created_at: string;
+};
+
 export type CreateCustomDateInput = {
  client_id?: string;
  name: string;
@@ -120,6 +148,18 @@ type AttachmentResponse = {
  attachment: Attachment;
 };

+type ChatAttachmentResponse = {
+  attachment: ChatAttachment;
+};
+
+type ChatMessagesResponse = {
+  messages: ChatMessage[];
+};
+
+type ChatMessageResponse = {
+  message: ChatMessage;
+};
+
 export async function listHolidays(token: string, year: number) {
  const response = await apiRequest<HolidaysResponse>(`/calendar/holidays?year=${year}`, {
    method: "GET",
@@ -251,6 +291,99 @@ export async function uploadAttachment(token: string, itemId: string, file: File
  return response.attachment;
 }

+export async function deleteAttachment(token: string, attachmentId: string) {
+  const response = await apiRequest<AttachmentResponse>(`/calendar/attachments/${attachmentId}`, {
+    method: "DELETE",
+    token,
+  });
+
+  return response.attachment;
+}
+
+export async function listChatMessages(token: string, itemId: string, channel: ChatChannel) {
+  const params = new URLSearchParams({ channel });
+  const response = await apiRequest<ChatMessagesResponse>(`/calendar/items/${itemId}/chat?${params.toString()}`, {
+    method: "GET",
+    token,
+  });
+
+  return response.messages;
+}
+
+export async function createChatMessage(token: string, itemId: string, channel: ChatChannel, body: string) {
+  const response = await apiRequest<ChatMessageResponse>(`/calendar/items/${itemId}/chat`, {
+    method: "POST",
+    token,
+    body: JSON.stringify({ channel, body }),
+  });
+
+  return response.message;
+}
+
+export async function updateChatMessage(token: string, messageId: string, body: string) {
+  const response = await apiRequest<ChatMessageResponse>(`/calendar/chat/messages/${messageId}`, {
+    method: "PATCH",
+    token,
+    body: JSON.stringify({ body }),
+  });
+
+  return response.message;
+}
+
+export async function deleteChatMessage(token: string, messageId: string) {
+  const response = await apiRequest<ChatMessageResponse>(`/calendar/chat/messages/${messageId}`, {
+    method: "DELETE",
+    token,
+  });
+
+  return response.message;
+}
+
+export async function uploadChatAttachment(token: string, messageId: string, file: File) {
+  const formData = new FormData();
+  formData.set("file", file);
+
+  const response = await apiFormRequest<ChatAttachmentResponse>(`/calendar/chat/messages/${messageId}/attachments`, formData, token);
+  return response.attachment;
+}
+
+export async function downloadAttachmentBlob(token: string, attachmentId: string) {
+  return downloadProtectedBlob(token, attachmentDownloadURL(attachmentId));
+}
+
+export async function downloadChatAttachmentBlob(token: string, attachmentId: string) {
+  return downloadProtectedBlob(token, chatAttachmentDownloadURL(attachmentId));
+}
+
+async function downloadProtectedBlob(token: string, url: string) {
+  const response = await fetch(url, {
+    headers: {
+      Authorization: `Bearer ${token}`,
+    },
+    credentials: "include",
+  });
+
+  if (!response.ok) {
+    const data = await response.json().catch(() => ({}));
+    const message =
+      typeof data === "object" && data !== null && "message" in data
+        ? String(data.message)
+        : "Nao foi possivel baixar o anexo.";
+    throw new ApiError(message, response.status);
+  }
+
+  return response.blob();
+}
+
 export function attachmentDownloadURL(attachmentId: string) {
  return `${API_BASE_URL}/calendar/attachments/${attachmentId}/download`;
 }
+
+export function chatAttachmentDownloadURL(attachmentId: string) {
+  return `${API_BASE_URL}/calendar/chat/attachments/${attachmentId}/download`;
+}
+
+export function chatStreamURL(itemId: string, channel: ChatChannel) {
+  const params = new URLSearchParams({ channel });
+  return `${API_BASE_URL}/calendar/items/${itemId}/chat/stream?${params.toString()}`;
+}
--- a/frontend/src/lib/users.ts
+++ b/frontend/src/lib/users.ts
@@ -11,6 +11,8 @@ export type Invitation = {
  accepted_at: string | null;
  created_at: string;
  invitation_url?: string;
+  email_sent: boolean;
+  email_error?: string;
 };

 type UsersResponse = {
--- a/frontend/src/views/AcceptInvitationView.tsx
+++ b/frontend/src/views/AcceptInvitationView.tsx
@@ -3,11 +3,11 @@ import { ArrowRight, CalendarDays } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
-import { acceptInvitation, type AuthUser } from "@/lib/auth";
+import { acceptInvitation } from "@/lib/auth";

 type AcceptInvitationViewProps = {
  token: string;
-  onAccepted: (user: AuthUser) => void;
+  onAccepted: () => void;
 };

 export function AcceptInvitationView({ token, onAccepted }: AcceptInvitationViewProps) {
@@ -22,9 +22,10 @@ export function AcceptInvitationView({ token, onAccepted }: AcceptInvitationView
    setIsSubmitting(true);
    setError("");
    try {
-      const response = await acceptInvitation(token, name, password);
-      onAccepted(response.user);
+      await acceptInvitation(token, name, password);
+      onAccepted();
      window.history.replaceState({}, "", "/");
+      window.location.assign("/");
    } catch (err) {
      setError(err instanceof Error ? err.message : "Não foi possível aceitar o convite.");
    } finally {
@@ -77,7 +78,7 @@ export function AcceptInvitationView({ token, onAccepted }: AcceptInvitationView
          )}

          <Button className="w-full" type="submit" disabled={isSubmitting}>
-            {isSubmitting ? "Ativando..." : "Entrar no Mira"}
+            {isSubmitting ? "Ativando..." : "Criar senha"}
            <ArrowRight className="ml-2 h-4 w-4" />
          </Button>
        </form>
--- a/frontend/src/views/CalendarView.tsx
+++ b/frontend/src/views/CalendarView.tsx
@@ -50,6 +50,7 @@ type CalendarEvent = {

 const monthFormatter = new Intl.DateTimeFormat("pt-BR", { month: "long", year: "numeric" });
 const dateFormatter = new Intl.DateTimeFormat("pt-BR", { day: "2-digit", month: "long", year: "numeric" });
+const attachmentAcceptTypes = "image/jpeg,image/png,image/webp,application/pdf,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document,.doc,.docx";
 const statusLabels: Record<CalendarItem["status"], string> = {
  rascunho: "Rascunho",
  planejado: "Planejado",
@@ -923,7 +924,7 @@ export function CalendarView({ clients, selectedClientId, user, onPostSelect }:
               <form className="space-y-4 border-t border-border/40 pt-4" onSubmit={handleUploadAttachment}>
                 <div className="grid gap-2">
                   <Label htmlFor="attachment">Anexos</Label>
-                   <Input id="attachment" name="attachment" type="file" accept="image/jpeg,image/png,image/webp,application/pdf" />
+                   <Input id="attachment" name="attachment" type="file" accept={attachmentAcceptTypes} />
                 </div>

                 {attachments.length > 0 && (
--- a/frontend/src/views/DashboardView.tsx
+++ b/frontend/src/views/DashboardView.tsx
@@ -20,6 +20,7 @@ type DashboardViewProps = {
  title?: string;
  description?: string;
  compact?: boolean;
+  canCreatePost?: boolean;
  onViewChange: (view: string) => void;
  onPostSelect: (postId: string) => void;
 };
@@ -41,6 +42,7 @@ export function DashboardView({
  title = "Dashboard Semanal",
  description,
  compact = false,
+  canCreatePost = true,
  onViewChange,
  onPostSelect,
 }: DashboardViewProps) {
@@ -119,10 +121,12 @@ export function DashboardView({
            <Filter className="mr-2 h-4 w-4" />
            Filtros
          </Button>
-          <Button size="sm" className="h-9" onClick={() => onViewChange("calendar")}>
-            <Plus className="mr-2 h-4 w-4" />
-            Novo Post
-          </Button>
+          {canCreatePost && (
+            <Button size="sm" className="h-9" onClick={() => onViewChange("calendar")}>
+              <Plus className="mr-2 h-4 w-4" />
+              Novo Post
+            </Button>
+          )}
        </div>
      </div>

--- a/frontend/src/views/PostDetailView.tsx
+++ b/frontend/src/views/PostDetailView.tsx
--- a/frontend/src/views/UsersView.tsx
+++ b/frontend/src/views/UsersView.tsx
@@ -26,6 +26,7 @@ export function UsersView({ clients }: UsersViewProps) {
  const [role, setRole] = useState<Invitation["role"]>("agency_user");
  const [clientId, setClientId] = useState("");
  const [createdURL, setCreatedURL] = useState("");
+  const [inviteStatus, setInviteStatus] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const [isSubmitting, setIsSubmitting] = useState(false);
  const [error, setError] = useState("");
@@ -59,6 +60,7 @@ export function UsersView({ clients }: UsersViewProps) {
    setIsSubmitting(true);
    setError("");
    setCreatedURL("");
+    setInviteStatus("");
    try {
      const invitation = await createInvitation(token, {
        email,
@@ -69,6 +71,11 @@ export function UsersView({ clients }: UsersViewProps) {
      setEmail("");
      setClientId("");
      setCreatedURL(invitation.invitation_url ?? "");
+      setInviteStatus(
+        invitation.email_sent
+          ? "Convite criado e e-mail enviado."
+          : invitation.email_error || "Convite criado. Configure o SMTP para enviar por e-mail ou copie o link abaixo.",
+      );
    } catch (err) {
      setError(err instanceof Error ? err.message : "Não foi possível criar o convite.");
    } finally {
@@ -144,6 +151,12 @@ export function UsersView({ clients }: UsersViewProps) {
            </Button>
          </form>

+          {inviteStatus && (
+            <div className="mt-4 rounded-lg border border-border bg-muted/30 px-3 py-2 text-sm text-muted-foreground">
+              {inviteStatus}
+            </div>
+          )}
+
          {createdURL && (
            <div className="mt-4 rounded-lg border border-border bg-muted/30 p-3">
              <div className="text-xs font-medium text-muted-foreground mb-2">Link do convite</div>