feat: add chat

2026-08-29 03:49:30 +05:30
parent 3b10e726b7
commit d50031cdb3
21 changed files with 6960 additions and 11 deletions
@@ -55,6 +55,22 @@ func NotificationsRule() ChannelRule {
 	}
 }

+// ConversationRule allows a caller to subscribe to a thread's channel only
+// while they are a participant. isParticipant is injected rather than taking a
+// repository dependency here, so the authorization check stays the service's
+// single source of truth.
+func ConversationRule(isParticipant func(ctx context.Context, userID, conversationID string) (bool, error)) ChannelRule {
+	return ChannelRule{
+		Prefix: "private-conversation.",
+		Authorize: func(ctx context.Context, userID, suffix string) (bool, error) {
+			if suffix == "" {
+				return false, nil
+			}
+			return isParticipant(ctx, userID, suffix)
+		},
+	}
+}
+
 type broadcastingAuthResp struct {
 	Auth        string `json:"auth"`
 	ChannelData string `json:"channel_data,omitempty"`
@@ -3,6 +3,7 @@ package handler
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -77,6 +78,44 @@ func TestBroadcastingAuth_Authorization(t *testing.T) {

 // A prefix match must not be mistaken for authorization: "…user-a-evil" starts
 // with the victim's id but is a different channel.
+// ConversationRule delegates to the chat service's membership check, so the
+// realtime channel and the REST endpoints can never disagree about who is in a
+// thread.
+func TestConversationRule(t *testing.T) {
+	const member, outsider = "member-1", "outsider-1"
+	rule := ConversationRule(func(_ context.Context, userID, conversationID string) (bool, error) {
+		if conversationID == "boom" {
+			return false, errors.New("database down")
+		}
+		return userID == member && conversationID == "conv-1", nil
+	})
+
+	if rule.Prefix != "private-conversation." {
+		t.Errorf("prefix = %q", rule.Prefix)
+	}
+	tests := []struct {
+		name    string
+		user    string
+		suffix  string
+		wantOK  bool
+		wantErr bool
+	}{
+		{"participant", member, "conv-1", true, false},
+		{"outsider", outsider, "conv-1", false, false},
+		{"participant of another thread", member, "conv-2", false, false},
+		{"empty conversation id", member, "", false, false},
+		{"lookup failure is not a denial", member, "boom", false, true},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			ok, err := rule.Authorize(context.Background(), tc.user, tc.suffix)
+			if ok != tc.wantOK || (err != nil) != tc.wantErr {
+				t.Errorf("= (%v, %v), want (%v, err=%v)", ok, err, tc.wantOK, tc.wantErr)
+			}
+		})
+	}
+}
+
 func TestBroadcastingAuth_SuffixIsComparedExactly(t *testing.T) {
 	rec := serve(t, testAuthHandler(t), testUser, "1234.5678", "private-notifications."+testUser+"-evil")
 	if rec.Code != http.StatusForbidden {
@@ -0,0 +1,626 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/prabhupadasays/spsays-bff/internal/middleware"
+	"github.com/prabhupadasays/spsays-bff/internal/repository"
+	"github.com/prabhupadasays/spsays-bff/internal/service"
+	"github.com/prabhupadasays/spsays-bff/pkg/response"
+)
+
+// ChatHandler exposes the chat inbox, threads and messages.
+//
+// Every route is session-authenticated and every read re-checks membership in
+// the service, so a conversation id is not a capability: knowing one gets you
+// nothing if you were never in the thread (or have left it).
+type ChatHandler struct {
+	svc *service.ChatService
+}
+
+func NewChatHandler(svc *service.ChatService) *ChatHandler { return &ChatHandler{svc: svc} }
+
+// writeChatError maps service errors onto status codes. Not-a-participant is a
+// 404, not a 403: confirming a thread exists to someone outside it leaks that
+// two people are talking.
+func writeChatError(w http.ResponseWriter, err error) {
+	switch {
+	case errors.Is(err, repository.ErrNotParticipant), errors.Is(err, repository.ErrConversationGone):
+		response.Error(w, http.StatusNotFound, "conversation not found")
+	case errors.Is(err, service.ErrAvatarUnset):
+		response.Error(w, http.StatusNotFound, err.Error())
+	case errors.Is(err, service.ErrChatBadAvatarKey):
+		response.Error(w, http.StatusBadRequest, err.Error())
+	case errors.Is(err, repository.ErrMessageNotHere):
+		response.Error(w, http.StatusNotFound, "message not found")
+	case errors.Is(err, repository.ErrAttachmentGone):
+		response.Error(w, http.StatusNotFound, "attachment not found")
+	case errors.Is(err, service.ErrChatMediaOff):
+		response.Error(w, http.StatusServiceUnavailable, err.Error())
+	case errors.Is(err, service.ErrChatBadMedia):
+		response.Error(w, http.StatusBadRequest, err.Error())
+	case errors.Is(err, service.ErrChatNotAdmin), errors.Is(err, service.ErrChatOwnerImmutable),
+		errors.Is(err, service.ErrChatAdminsOnly):
+		response.Error(w, http.StatusForbidden, err.Error())
+	case errors.Is(err, service.ErrChatNotGroup), errors.Is(err, service.ErrChatBadRole),
+		errors.Is(err, service.ErrChatBadPolicy):
+		response.Error(w, http.StatusBadRequest, err.Error())
+	case errors.Is(err, service.ErrChatNotSender):
+		response.Error(w, http.StatusForbidden, err.Error())
+	case errors.Is(err, service.ErrMessageDeleted), errors.Is(err, service.ErrChatBadReport):
+		response.Error(w, http.StatusBadRequest, err.Error())
+	case errors.Is(err, service.ErrChatNotAccepting):
+		response.Error(w, http.StatusForbidden, err.Error())
+	case errors.Is(err, service.ErrChatBadWhoCanMessage), errors.Is(err, service.ErrChatBadAccountAge),
+		errors.Is(err, service.ErrChatGenderUnset):
+		response.Error(w, http.StatusBadRequest, err.Error())
+	case errors.Is(err, service.ErrChatBlocked):
+		response.Error(w, http.StatusForbidden, err.Error())
+	case errors.Is(err, service.ErrChatReadOnly):
+		response.Error(w, http.StatusConflict, "Kautilya is not available yet")
+	case errors.Is(err, service.ErrChatEmptyBody), errors.Is(err, service.ErrChatBodyTooLong),
+		errors.Is(err, service.ErrChatBadMuteDuration),
+		errors.Is(err, repository.ErrReplyTargetNotHere):
+		response.Error(w, http.StatusBadRequest, err.Error())
+	default:
+		response.Error(w, http.StatusInternalServerError, "chat request failed")
+	}
+}
+
+// Inbox — GET /chat/conversations?tab=chats|kautilya
+func (h *ChatHandler) Inbox(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.UserID(r.Context())
+	tab := r.URL.Query().Get("tab")
+	items, err := h.svc.Inbox(r.Context(), userID, tab, atoiOr(r.URL.Query().Get("limit"), 0))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, items)
+}
+
+type openDMReq struct {
+	// Handle, not id: profiles are addressed by handle everywhere else, and
+	// the public profile payload carries no user id.
+	Handle string `json:"handle"`
+}
+
+// OpenDM — POST /chat/conversations/dm. Idempotent: returns the existing
+// thread when there is one, so the client can call it every time it opens a
+// profile without checking first.
+func (h *ChatHandler) OpenDM(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.UserID(r.Context())
+	var req openDMReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil || req.Handle == "" {
+		response.Error(w, http.StatusBadRequest, "handle is required")
+		return
+	}
+	conv, err := h.svc.OpenDMByHandle(r.Context(), userID, req.Handle)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, conv)
+}
+
+type createGroupReq struct {
+	Title         string   `json:"title"`
+	MemberHandles []string `json:"member_handles"`
+}
+
+// CreateGroup — POST /chat/conversations/group
+func (h *ChatHandler) CreateGroup(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.UserID(r.Context())
+	var req createGroupReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	conv, err := h.svc.CreateGroup(r.Context(), userID, req.Title, req.MemberHandles)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusCreated, conv)
+}
+
+// OpenAIThread — POST /chat/conversations/kautilya
+func (h *ChatHandler) OpenAIThread(w http.ResponseWriter, r *http.Request) {
+	conv, err := h.svc.OpenAIThread(r.Context(), middleware.UserID(r.Context()))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, conv)
+}
+
+// Detail — GET /chat/conversations/{id}
+func (h *ChatHandler) Detail(w http.ResponseWriter, r *http.Request) {
+	detail, err := h.svc.Detail(r.Context(), middleware.UserID(r.Context()), chi.URLParam(r, "id"))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, detail)
+}
+
+// Messages — GET /chat/conversations/{id}/messages?before_seq=&limit=
+//
+// before_seq is an exclusive upper bound rather than an offset, so paging stays
+// stable while new messages keep arriving at the top.
+func (h *ChatHandler) Messages(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.UserID(r.Context())
+	convID := chi.URLParam(r, "id")
+	msgs, err := h.svc.Messages(r.Context(), userID, convID,
+		int64(atoiOr(r.URL.Query().Get("before_seq"), 0)),
+		atoiOr(r.URL.Query().Get("limit"), 0))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, msgs)
+}
+
+type mediaReq struct {
+	Key        string  `json:"key"`
+	Mime       string  `json:"mime"`
+	SizeBytes  *int64  `json:"size_bytes"`
+	Width      *int    `json:"width"`
+	Height     *int    `json:"height"`
+	DurationMs *int    `json:"duration_ms"`
+	Blurhash   *string `json:"blurhash"`
+	FileName   *string `json:"file_name"`
+}
+
+type sendReq struct {
+	Body        string  `json:"body"`
+	ClientMsgID *string `json:"client_msg_id"`
+	// preview_url is the link the sender chose to keep a card for; omitted
+	// when they dismissed it. Only the URL — never the card's contents.
+	PreviewURL  *string    `json:"preview_url"`
+	Attachments []mediaReq `json:"attachments"`
+	ReplyToID   *string    `json:"reply_to_id"`
+	// forward_from_id is deliberately NOT accepted yet: forwarding lands with
+	// its own "can the caller see the source?" check in a later phase, and
+	// accepting an unvalidated message reference in the meantime would let a
+	// client point at any message in the system.
+}
+
+// Send — POST /chat/conversations/{id}/messages
+func (h *ChatHandler) Send(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.UserID(r.Context())
+	convID := chi.URLParam(r, "id")
+	var req sendReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	media := make([]service.MediaAttachment, 0, len(req.Attachments))
+	for _, a := range req.Attachments {
+		media = append(media, service.MediaAttachment{
+			Key: a.Key, Mime: a.Mime, SizeBytes: a.SizeBytes, Width: a.Width,
+			Height: a.Height, DurationMs: a.DurationMs, Blurhash: a.Blurhash,
+			FileName: a.FileName,
+		})
+	}
+	msg, err := h.svc.Send(r.Context(), userID, convID, service.SendRequest{
+		Body:        req.Body,
+		ClientMsgID: req.ClientMsgID,
+		ReplyToID:   req.ReplyToID,
+		PreviewURL:  req.PreviewURL,
+		Attachments: media,
+	})
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusCreated, msg)
+}
+
+// Settings — GET /chat/settings
+func (h *ChatHandler) Settings(w http.ResponseWriter, r *http.Request) {
+	settings, err := h.svc.Settings(r.Context(), middleware.UserID(r.Context()))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, settings)
+}
+
+type chatSettingsReq struct {
+	ReadReceipts        *bool   `json:"read_receipts"`
+	WhoCanMessage       *string `json:"who_can_message"`
+	MinAccountAgeMonths *int    `json:"min_account_age_months"`
+	TrainKautilya       *bool   `json:"train_kautilya"`
+}
+
+// UpdateSettings — PATCH /chat/settings
+//
+// Fields are optional: anything omitted keeps its current value, so a toggle
+// doesn't have to send the whole object back.
+func (h *ChatHandler) UpdateSettings(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.UserID(r.Context())
+	current, err := h.svc.Settings(r.Context(), userID)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+
+	var req chatSettingsReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if req.ReadReceipts != nil {
+		current.ReadReceipts = *req.ReadReceipts
+	}
+	if req.WhoCanMessage != nil {
+		current.WhoCanMessage = *req.WhoCanMessage
+	}
+	if req.MinAccountAgeMonths != nil {
+		current.MinAccountAgeMonths = *req.MinAccountAgeMonths
+	}
+	if req.TrainKautilya != nil {
+		current.TrainKautilya = *req.TrainKautilya
+	}
+
+	saved, err := h.svc.SaveSettings(r.Context(), userID, current)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, saved)
+}
+
+type linkPreviewReq struct {
+	URL string `json:"url"`
+}
+
+// LinkPreview — POST /chat/link-preview
+//
+// The composer calls this as a link is typed so the sender can see the card
+// and dismiss it before sending. Only the URL travels in either direction's
+// trust boundary: the BFF fetches the metadata itself.
+func (h *ChatHandler) LinkPreview(w http.ResponseWriter, r *http.Request) {
+	var req linkPreviewReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil || strings.TrimSpace(req.URL) == "" {
+		response.Error(w, http.StatusBadRequest, "url is required")
+		return
+	}
+	preview, err := h.svc.LinkPreview(r.Context(), req.URL)
+	if err != nil {
+		// No card is a normal outcome, not a server fault.
+		response.Error(w, http.StatusUnprocessableEntity, "no preview available")
+		return
+	}
+	response.JSON(w, http.StatusOK, preview)
+}
+
+type chatPresignReq struct {
+	ContentType string `json:"content_type"`
+}
+
+// PresignAttachment — POST /chat/conversations/{id}/attachments/presign
+func (h *ChatHandler) PresignAttachment(w http.ResponseWriter, r *http.Request) {
+	var req chatPresignReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	upload, key, err := h.svc.PresignAttachment(r.Context(),
+		middleware.UserID(r.Context()), chi.URLParam(r, "id"), strings.TrimSpace(req.ContentType))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	// The key comes back so the client can name it when it sends the message;
+	// there is no public URL, by design.
+	response.JSON(w, http.StatusOK, map[string]string{"upload_url": upload, "key": key})
+}
+
+// Attachment — GET /chat/attachments/{attachmentID}
+//
+// A stable URL that redirects to a short-lived signed one. Membership is
+// re-checked on every fetch, so access revoked after a link was shared stops
+// working — which a signed URL baked into the message payload could not do.
+func (h *ChatHandler) Attachment(w http.ResponseWriter, r *http.Request) {
+	url, err := h.svc.AttachmentURL(r.Context(),
+		middleware.UserID(r.Context()), chi.URLParam(r, "attachmentID"))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	// Private and short-lived: never let a shared cache hold onto it.
+	w.Header().Set("Cache-Control", "private, no-store")
+	http.Redirect(w, r, url, http.StatusFound)
+}
+
+// PresignGroupAvatar — POST /chat/conversations/{id}/avatar/presign
+func (h *ChatHandler) PresignGroupAvatar(w http.ResponseWriter, r *http.Request) {
+	var req chatPresignReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	upload, key, err := h.svc.PresignGroupAvatar(r.Context(),
+		middleware.UserID(r.Context()), chi.URLParam(r, "id"), strings.TrimSpace(req.ContentType))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, map[string]string{"upload_url": upload, "key": key})
+}
+
+// GroupAvatar — GET /chat/conversations/{id}/avatar
+//
+// Stable URL that redirects to a short-lived signed one, re-checking
+// membership each time, exactly as message attachments do.
+func (h *ChatHandler) GroupAvatar(w http.ResponseWriter, r *http.Request) {
+	url, err := h.svc.GroupAvatarURL(r.Context(),
+		middleware.UserID(r.Context()), chi.URLParam(r, "id"))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	w.Header().Set("Cache-Control", "private, no-store")
+	http.Redirect(w, r, url, http.StatusFound)
+}
+
+// Gallery — GET /chat/conversations/{id}/gallery?tab=media|links&before=
+func (h *ChatHandler) Gallery(w http.ResponseWriter, r *http.Request) {
+	var before *time.Time
+	if raw := r.URL.Query().Get("before"); raw != "" {
+		if t, err := time.Parse(time.RFC3339Nano, raw); err == nil {
+			before = &t
+		}
+	}
+	items, err := h.svc.Gallery(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), r.URL.Query().Get("tab"), before,
+		atoiOr(r.URL.Query().Get("limit"), 0))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, items)
+}
+
+// Starred — GET /chat/conversations/{id}/starred
+func (h *ChatHandler) Starred(w http.ResponseWriter, r *http.Request) {
+	msgs, err := h.svc.Starred(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), atoiOr(r.URL.Query().Get("limit"), 0))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, msgs)
+}
+
+// Star / Unstar — POST|DELETE /chat/conversations/{id}/messages/{messageID}/star
+func (h *ChatHandler) Star(w http.ResponseWriter, r *http.Request) {
+	h.setStar(w, r, true)
+}
+
+func (h *ChatHandler) Unstar(w http.ResponseWriter, r *http.Request) {
+	h.setStar(w, r, false)
+}
+
+func (h *ChatHandler) setStar(w http.ResponseWriter, r *http.Request, starred bool) {
+	err := h.svc.SetStar(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), chi.URLParam(r, "messageID"), starred)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+// DeleteMessage — DELETE /chat/conversations/{id}/messages/{messageID}?scope=me|everyone
+func (h *ChatHandler) DeleteMessage(w http.ResponseWriter, r *http.Request) {
+	scope := r.URL.Query().Get("scope")
+	if scope == "" {
+		scope = service.DeleteForMe // the safer default
+	}
+	err := h.svc.DeleteMessage(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "messageID"), scope)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+type forwardReq struct {
+	MessageID string `json:"message_id"`
+}
+
+// Forward — POST /chat/conversations/{id}/forward
+//
+// The path names the DESTINATION; the body names the message being copied in.
+func (h *ChatHandler) Forward(w http.ResponseWriter, r *http.Request) {
+	var req forwardReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil || req.MessageID == "" {
+		response.Error(w, http.StatusBadRequest, "message_id is required")
+		return
+	}
+	msg, err := h.svc.ForwardMessage(r.Context(), middleware.UserID(r.Context()),
+		req.MessageID, chi.URLParam(r, "id"))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusCreated, msg)
+}
+
+type chatReportReq struct {
+	Category string `json:"category"`
+	Reason   string `json:"reason"`
+}
+
+// ReportMessage — POST /chat/conversations/{id}/messages/{messageID}/report
+func (h *ChatHandler) ReportMessage(w http.ResponseWriter, r *http.Request) {
+	var req chatReportReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	err := h.svc.ReportMessage(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "messageID"), req.Category, req.Reason)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+type membersReq struct {
+	// Handles, not ids: search results and follow lists identify people by
+	// handle, and it matches /u/{handle}/block elsewhere in the API.
+	MemberHandles []string `json:"member_handles"`
+}
+
+// AddMembers — POST /chat/conversations/{id}/members
+func (h *ChatHandler) AddMembers(w http.ResponseWriter, r *http.Request) {
+	var req membersReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if err := h.svc.AddMembers(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), req.MemberHandles); err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+// RemoveMember — DELETE /chat/conversations/{id}/members/{handle}
+//
+// Passing your own handle is how you leave.
+func (h *ChatHandler) RemoveMember(w http.ResponseWriter, r *http.Request) {
+	if err := h.svc.RemoveMember(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), chi.URLParam(r, "handle")); err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+type roleReq struct {
+	Role string `json:"role"`
+}
+
+// SetMemberRole — PATCH /chat/conversations/{id}/members/{userID}
+func (h *ChatHandler) SetMemberRole(w http.ResponseWriter, r *http.Request) {
+	var req roleReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if err := h.svc.SetMemberRole(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), chi.URLParam(r, "handle"), req.Role); err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+type updateGroupReq struct {
+	Title      *string `json:"title"`
+	SendPolicy *string `json:"send_policy"`
+	// AvatarKey comes from PresignGroupAvatar; the service checks it belongs
+	// to this group before storing it.
+	AvatarKey *string `json:"avatar_key"`
+}
+
+// UpdateGroup — PATCH /chat/conversations/{id}
+func (h *ChatHandler) UpdateGroup(w http.ResponseWriter, r *http.Request) {
+	var req updateGroupReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if err := h.svc.UpdateGroup(r.Context(), middleware.UserID(r.Context()),
+		chi.URLParam(r, "id"), req.Title, req.SendPolicy, req.AvatarKey); err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+type receiptReq struct {
+	Seq int64 `json:"seq"`
+}
+
+// MarkRead — POST /chat/conversations/{id}/read
+func (h *ChatHandler) MarkRead(w http.ResponseWriter, r *http.Request) {
+	h.receipt(w, r, h.svc.MarkRead)
+}
+
+// MarkDelivered — POST /chat/conversations/{id}/delivered
+func (h *ChatHandler) MarkDelivered(w http.ResponseWriter, r *http.Request) {
+	h.receipt(w, r, h.svc.MarkDelivered)
+}
+
+func (h *ChatHandler) receipt(w http.ResponseWriter, r *http.Request, apply func(ctx context.Context, userID, convID string, seq int64) error) {
+	var req receiptReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	if err := apply(r.Context(), middleware.UserID(r.Context()), chi.URLParam(r, "id"), req.Seq); err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.NoContent(w)
+}
+
+type muteReq struct {
+	// Duration is one of 8h, 1w, always, off.
+	Duration string `json:"duration"`
+}
+
+// SetMute — POST /chat/conversations/{id}/mute
+//
+// Muting silences alerts for the caller only; the thread keeps receiving
+// messages and its unread count keeps climbing.
+func (h *ChatHandler) SetMute(w http.ResponseWriter, r *http.Request) {
+	var req muteReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		response.Error(w, http.StatusBadRequest, "invalid JSON body")
+		return
+	}
+	until, err := h.svc.SetMute(r.Context(), middleware.UserID(r.Context()), chi.URLParam(r, "id"), req.Duration)
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, map[string]any{"muted_until": until})
+}
+
+// Receipts — GET /chat/conversations/{id}/receipts
+func (h *ChatHandler) Receipts(w http.ResponseWriter, r *http.Request) {
+	rc, err := h.svc.Receipts(r.Context(), middleware.UserID(r.Context()), chi.URLParam(r, "id"))
+	if err != nil {
+		writeChatError(w, err)
+		return
+	}
+	response.JSON(w, http.StatusOK, rc)
+}
+
+func atoiOr(s string, fallback int) int {
+	if s == "" {
+		return fallback
+	}
+	n, err := strconv.Atoi(s)
+	if err != nil || n < 0 {
+		return fallback
+	}
+	return n
+}