diff --git a/cmd/storage-migrate/main.go b/cmd/storage-migrate/main.go
index bdb1561..7ee9cb2 100644
--- a/cmd/storage-migrate/main.go
+++ b/cmd/storage-migrate/main.go
@@ -284,7 +284,7 @@ var copyOrder = []string{
 	"projects", "users", "profiles", "settings", "plugins",
 	"conversations", "runs", "messages", "events", "artifacts",
 	"hitl_cards", "plans", "todos", "knowledge", "knowledge_vectors",
-	"activity_cards", "command_audit", "prompt_modules",
+	"activity_cards", "project_event_shares", "command_audit", "prompt_modules",
 	"sessions", "api_keys",
 	"plugin_grants", "plugin_schema", "plugin_kv", "background_tasks",
 	"memory_entries", "audit_events", "pending_confirms", "llm_usage_daily",
@@ -784,7 +784,7 @@ func advanceSequences(db *sql.DB, table string) error {
 // checkOwners：业务行引用的 owner 必须存在于 users（单租户默认 ”/'local'
 // 除外）。未知 owner 阻塞迁移（U4/R7：不静默带过未知归属）。
 func checkOwners(db *sql.DB, src *sql.DB) error {
-	ownerTables := []string{"projects", "conversations", "runs", "artifacts", "knowledge", "hitl_cards", "profiles", "activity_cards", "command_audit"}
+	ownerTables := []string{"projects", "conversations", "runs", "artifacts", "knowledge", "hitl_cards", "profiles", "activity_cards", "project_event_shares", "command_audit"}
 	for _, t := range ownerTables {
 		if !sqliteHasTable(src, t) {
 			continue
diff --git a/internal/app/app.go b/internal/app/app.go
index 67587f3..33749b7 100644
--- a/internal/app/app.go
+++ b/internal/app/app.go
@@ -528,6 +528,7 @@ func Run(opt Options) error {
 
 	// 收件箱任务卡：事件走会话事件管道（持久化/seq/重放）；关闭即 T0 基线。
 	cardSvc := cardsvc.New(st, mgr.EmitCardEvent)
+	cardSvc.SetProjectSharedEmitter(mgr.EmitProjectSharedCardEvent)
 	surfaceSvc := surfacesvc.New(st, mgr.EmitCardEvent)
 	go func() { // 启动恢复：重发「快照已落盘、事件未发出」的待恢复投影（KTD）。
 		if n, err := surfaceSvc.RecoverPendingEvents(context.Background()); err == nil && n > 0 {
diff --git a/internal/cardsvc/cardsvc.go b/internal/cardsvc/cardsvc.go
index a17b6dc..6b4d0ab 100644
--- a/internal/cardsvc/cardsvc.go
+++ b/internal/cardsvc/cardsvc.go
@@ -27,8 +27,9 @@ var (
 const cardAppendWindow = 250 * time.Millisecond
 
 type Service struct {
-	st   *store.Store
-	emit Emitter
+	st                *store.Store
+	emit              Emitter
+	projectSharedEmit ProjectSharedEmitter
 	// MirrorConvCards EXT-12：会话卡是否镜像进项目公共流（缺省 true=现状全量
 	// 镜像；false 时会话卡只进本人会话流，项目级卡不受影响）。
 	MirrorConvCards bool
@@ -41,6 +42,42 @@ func New(st *store.Store, emit Emitter) *Service {
 	return &Service{st: st, emit: emit, now: time.Now, lastEmit: map[string]time.Time{}, MirrorConvCards: true}
 }
 
+// ProjectSharedEmitter is an internal trusted publication adapter. It is never
+// bound to model arguments or exposed as a mandatory extension capability.
+type ProjectSharedEmitter func(owner, producer, channel, runID string, typ core.StreamEventType, payload any) error
+
+func (s *Service) SetProjectSharedEmitter(emit ProjectSharedEmitter) { s.projectSharedEmit = emit }
+
+// PublishProjectCard explicitly publishes a project-level structural snapshot.
+// Ordinary Create/Update remain private unless this entry issues a new proof.
+func (s *Service) PublishProjectCard(owner, producer string, card core.ActivityCard, ref string) (core.ActivityCard, error) {
+	if s.projectSharedEmit == nil || owner == "" || producer == "" || card.ProjectID == "" || card.ConversationID != "" {
+		return card, errors.New("card: trusted project publisher required")
+	}
+	if card.ID != "" {
+		current, err := s.st.GetCard(owner, card.ID)
+		if err != nil {
+			return card, err
+		}
+		if current.ProjectID != card.ProjectID || current.ConversationID != "" {
+			return card, store.ErrNotFound
+		}
+	} else {
+		card.ID = store.NewID("card")
+	}
+	now := s.now().UTC()
+	card.CreatedAt = now
+	card.UpdatedAt = now
+	if card.Status == "" {
+		card.Status = core.CardActive
+	}
+	if err := s.st.SaveCard(owner, &card, ref); err != nil {
+		return card, err
+	}
+	err := s.projectSharedEmit(owner, producer, string(core.ProjectChannelKey(card.ProjectID)), card.SourceRunID, core.EvCardCreated, core.CardPayload{Card: card})
+	return card, err
+}
+
 // emitCard 按卡归属发布卡片事件（D50）：
 //   - 会话卡 → 会话流；同时镜像项目流（伪会话键 "project:<projectId>"）——
 //     项目收件箱聚合视图（项目级卡 ∪ 各会话未决卡）的实时性依赖它；卡片事件
diff --git a/internal/runmgr/events.go b/internal/runmgr/events.go
index 9e41162..971e0c2 100644
--- a/internal/runmgr/events.go
+++ b/internal/runmgr/events.go
@@ -116,6 +116,34 @@ func (eb *eventBuffer) emit(conversationID, runID string, typ core.StreamEventTy
 	return 0, nil
 }
 
+// emitProjectShared persists an explicit internal publication and its proof
+// before fan-out. A client-visible payload cannot opt itself into this path.
+func (eb *eventBuffer) emitProjectShared(owner, producer, channel, runID string, typ core.StreamEventType, payload any) error {
+	project, ok := core.ProjectFromChannel(channel)
+	if !ok {
+		return store.ErrNotFound
+	}
+	encoded, err := json.Marshal(payload)
+	if err != nil {
+		return err
+	}
+	event := core.StreamEvent{ConversationID: channel, ProjectID: project, RunID: runID, Type: typ, Payload: encoded, TS: time.Now().UTC().Format(time.RFC3339Nano), V: core.ProtocolVersion}
+	eb.flushConversation(channel)
+	eb.flushing.Lock()
+	defer eb.flushing.Unlock()
+	events := []core.StreamEvent{event}
+	if _, err := eb.store.AppendProjectSharedEvents(owner, producer, channel, events); err != nil {
+		return err
+	}
+	for _, event := range events {
+		eb.bus.Publish(event)
+	}
+	if eb.onPersisted != nil {
+		eb.onPersisted(channel, events)
+	}
+	return nil
+}
+
 // append 落盘并按 seq 顺序发布。
 func (eb *eventBuffer) append(conversationID string, evs []core.StreamEvent) error {
 	eb.flushing.Lock()
diff --git a/internal/runmgr/runmgr.go b/internal/runmgr/runmgr.go
index e5fe6a3..b3f3d99 100644
--- a/internal/runmgr/runmgr.go
+++ b/internal/runmgr/runmgr.go
@@ -179,6 +179,12 @@ type IntentGate interface {
 	Match(ctx context.Context, input string) (branch, topID string)
 }
 
+// EmitProjectSharedCardEvent is an internal producer-authorized structural
+// publication entry, separate from the ordinary private card event emitter.
+func (m *Manager) EmitProjectSharedCardEvent(owner, producer, channel, runID string, typ core.StreamEventType, payload any) error {
+	return m.events.emitProjectShared(owner, producer, channel, runID, typ, payload)
+}
+
 // SetGate 注入意图闸门（装配期一次；插件意图 overlay 经 pluginhost 回调重建）。
 func (m *Manager) SetGate(g IntentGate) { m.gate = g }
 
diff --git a/internal/server/project_events.go b/internal/server/project_events.go
new file mode 100644
index 0000000..7058cec
--- /dev/null
+++ b/internal/server/project_events.go
@@ -0,0 +1,30 @@
+package server
+
+import (
+	core "agent-system-core"
+)
+
+// projectStreamMembership consults the registered resource authorizer using the
+// physical project's trusted owner, never the event publisher or payload claims.
+func (s *Server) projectStreamMembership(actor, project string) bool {
+	p, err := s.st.ProjectMetadata(project)
+	if err != nil {
+		return false
+	}
+	return s.authorizeSharedResource(actor, "stream", "project", project, p.Owner, project)
+}
+
+func (s *Server) projectEventVisible(actor string, event core.StreamEvent) bool {
+	if s.projectLifecycle == nil {
+		return true
+	}
+	access, err := s.st.ResolveProjectEventAccess(event)
+	if err != nil || access.Owner == "" {
+		return false
+	}
+	if access.Owner == actor {
+		return true
+	}
+	project, ok := core.ProjectFromChannel(event.ConversationID)
+	return ok && access.Shared && s.projectStreamMembership(actor, project)
+}
diff --git a/internal/server/project_events_test.go b/internal/server/project_events_test.go
new file mode 100644
index 0000000..0360ded
--- /dev/null
+++ b/internal/server/project_events_test.go
@@ -0,0 +1,163 @@
+package server
+
+import (
+	"agent-system-backend/internal/cardsvc"
+	"agent-system-backend/pkg/extension"
+	core "agent-system-core"
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func projectStreamReplay(t *testing.T, s *Server, key, project string) *httptest.ResponseRecorder {
+	t.Helper()
+	r := httptest.NewRequest("GET", "/api/events?scope=project&projectId="+project+"&since=0", nil)
+	r.Header.Set("Authorization", "Bearer "+key)
+	ctx, cancel := context.WithTimeout(r.Context(), 200*time.Millisecond)
+	defer cancel()
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, r.WithContext(ctx))
+	return w
+}
+func projectEventFixture(t *testing.T) (*Server, string, string, string, *atomic.Bool) {
+	t.Helper()
+	s, st := newAuthTestServer(t)
+	alice, _ := st.CreateAPIKey("alice", "test")
+	bob, _ := st.CreateAPIKey("bob", "test")
+	p, _ := st.CreateProject("alice", "Project")
+	s.Cards = cardsvc.New(st, s.mgr.EmitCardEvent)
+	s.Cards.SetProjectSharedEmitter(s.mgr.EmitProjectSharedCardEvent)
+	member := &atomic.Bool{}
+	member.Store(true)
+	s.SetResourceAuthorizerV2(func(q extension.ResourceAuthzQuery) (bool, error) {
+		return q.ResourceType == "project" && q.ProjectID == p.ID && (q.Actor == "alice" || (q.Actor == "bob" && member.Load())), nil
+	})
+	return s, alice, bob, p.ID, member
+}
+func TestProjectEventsLegacyReplayIsPrivate(t *testing.T) {
+	s, alice, bob, p, _ := projectEventFixture(t)
+	s.DisableUploadIndexing = true
+	if w := lifecycleUpload(t, s, alice, p, "legacy-owner-private.txt", "PRIVATE"); w.Code != 200 {
+		t.Fatal(w.Code)
+	}
+	s.SetProjectLifecycle(extension.ProjectLifecycle{Work: func(context.Context, string, core.ID) (bool, error) { return true, nil }}, nil)
+	member := projectStreamReplay(t, s, bob, p)
+	if member.Code != 200 || bytes.Contains(member.Body.Bytes(), []byte("legacy-owner-private.txt")) || bytes.Contains(member.Body.Bytes(), []byte("builtin:txt")) {
+		t.Fatal("legacy private upload leaked to member")
+	}
+	owner := projectStreamReplay(t, s, alice, p)
+	if owner.Code != 200 || !bytes.Contains(owner.Body.Bytes(), []byte("legacy-owner-private.txt")) {
+		t.Fatal("owner lost private history")
+	}
+}
+func TestProjectEventsSharedProofAndPrivatePagination(t *testing.T) {
+	s, _, bob, p, _ := projectEventFixture(t)
+	s.SetProjectLifecycle(extension.ProjectLifecycle{}, nil)
+	card, err := s.Cards.Create("alice", core.ActivityCard{ProjectID: p, Title: "PRIVATE HISTORY"}, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	payload, _ := json.Marshal(map[string]any{"card": card, "owner": "bob", "shared": true, "producer": "plugin:rdm:structure"})
+	private := make([]core.StreamEvent, 1001)
+	for i := range private {
+		private[i] = core.StreamEvent{Type: core.EvCardUpdated, Payload: payload, TS: time.Now().UTC().Format(time.RFC3339Nano), V: 1}
+	}
+	if _, err := s.st.AppendEvents(core.ProjectChannelKey(p), private); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.Cards.PublishProjectCard("alice", "plugin:rdm:structure", core.ActivityCard{ProjectID: p, Title: "EXPLICIT SHARED"}, ""); err != nil {
+		t.Fatal(err)
+	}
+	w := projectStreamReplay(t, s, bob, p)
+	if w.Code != 200 || bytes.Contains(w.Body.Bytes(), []byte("PRIVATE HISTORY")) || !bytes.Contains(w.Body.Bytes(), []byte("EXPLICIT SHARED")) {
+		t.Fatal("private pagination/spoof proof failed")
+	}
+}
+func TestProjectEventsLivePrivacyAndRevocation(t *testing.T) {
+	s, _, bob, p, member := projectEventFixture(t)
+	s.SetProjectLifecycle(extension.ProjectLifecycle{}, nil)
+	httpServer := httptest.NewServer(s.Handler())
+	defer httpServer.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	req, _ := http.NewRequestWithContext(ctx, "GET", httpServer.URL+"/api/events?scope=project&projectId="+p, nil)
+	req.Header.Set("Authorization", "Bearer "+bob)
+	response, err := httpServer.Client().Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer response.Body.Close()
+	if _, err := s.Cards.Create("alice", core.ActivityCard{ProjectID: p, Title: "LIVE PRIVATE"}, ""); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.Cards.PublishProjectCard("alice", "plugin:rdm:structure", core.ActivityCard{ProjectID: p, Title: "LIVE SHARED"}, ""); err != nil {
+		t.Fatal(err)
+	}
+	reader := bufio.NewReader(response.Body)
+	var before bytes.Buffer
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			t.Fatalf("live shared event did not arrive: %v", err)
+		}
+		before.WriteString(line)
+		if bytes.Contains([]byte(line), []byte("LIVE SHARED")) {
+			break
+		}
+	}
+	if bytes.Contains(before.Bytes(), []byte("LIVE PRIVATE")) {
+		t.Fatal("live private frame leaked before revocation")
+	}
+	member.Store(false)
+	if _, err := s.Cards.PublishProjectCard("alice", "plugin:rdm:structure", core.ActivityCard{ProjectID: p, Title: "AFTER REMOVAL"}, ""); err != nil {
+		t.Fatal(err)
+	}
+	body, err := io.ReadAll(reader)
+	if err != nil {
+		t.Fatalf("revoked stream did not stop: %v", err)
+	}
+	if bytes.Contains(body, []byte("LIVE PRIVATE")) || bytes.Contains(body, []byte("AFTER REMOVAL")) {
+		t.Fatal("live private/revoked event leaked")
+	}
+}
+func TestUnregisteredProjectEventsRetainLegacyReads(t *testing.T) {
+	s, _, bob, p, _ := projectEventFixture(t)
+	if _, err := s.Cards.Create("alice", core.ActivityCard{ProjectID: p, Title: "LEGACY BASE"}, ""); err != nil {
+		t.Fatal(err)
+	}
+	w := projectStreamReplay(t, s, bob, p)
+	if w.Code != 200 || !bytes.Contains(w.Body.Bytes(), []byte("LEGACY BASE")) {
+		t.Fatal("unregistered project stream changed")
+	}
+}
+
+func TestProjectEventsIdleStreamStopsAfterMembershipRemoval(t *testing.T) {
+	previous := sseAuthRecheck
+	sseAuthRecheck = 20 * time.Millisecond
+	defer func() { sseAuthRecheck = previous }()
+	s, _, bob, p, member := projectEventFixture(t)
+	s.SetProjectLifecycle(extension.ProjectLifecycle{}, nil)
+	httpServer := httptest.NewServer(s.Handler())
+	defer httpServer.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	request, _ := http.NewRequestWithContext(ctx, "GET", httpServer.URL+"/api/events?scope=project&projectId="+p, nil)
+	request.Header.Set("Authorization", "Bearer "+bob)
+	response, err := httpServer.Client().Do(request)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer response.Body.Close()
+	member.Store(false)
+	body, err := io.ReadAll(response.Body)
+	if err != nil || !bytes.Contains(body, []byte("project-access-revoked")) {
+		t.Fatal("idle project stream kept revoked member connected")
+	}
+}
diff --git a/internal/server/project_lifecycle_test.go b/internal/server/project_lifecycle_test.go
index 47ea686..a58553e 100644
--- a/internal/server/project_lifecycle_test.go
+++ b/internal/server/project_lifecycle_test.go
@@ -409,8 +409,9 @@ func TestProjectLifecycleUploadSuppressesPrivateProjectCards(t *testing.T) {
 		return q.ResourceType == "project" && q.ProjectID == p.ID && (q.Actor == "alice" || q.Actor == "bob"), nil
 	})
 	s.Cards = cardsvc.New(st, s.mgr.EmitCardEvent)
+	s.Cards.SetProjectSharedEmitter(s.mgr.EmitProjectSharedCardEvent)
 	s.DisableUploadIndexing = true
-	if _, err := s.Cards.Create("alice", core.ActivityCard{ProjectID: p.ID, Title: "Shared structure", Kind: core.CardKindProgress}, ""); err != nil {
+	if _, err := s.Cards.PublishProjectCard("alice", "plugin:rdm:structure", core.ActivityCard{ProjectID: p.ID, Title: "Shared structure", Kind: core.CardKindProgress}, ""); err != nil {
 		t.Fatal(err)
 	}
 	// The owner path already admitted upload before the member authorization fix.
diff --git a/internal/server/server.go b/internal/server/server.go
index 426070e..d90b3c3 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -431,6 +431,7 @@ var sseAuthRecheck = 15 * time.Second
 func (s *Server) events(w http.ResponseWriter, r *http.Request) {
 	conversationID := r.URL.Query().Get("conversationId")
 	isProject := false
+	streamProject := ""
 	// 项目流（D50）：scope=project&projectId=<id> 订阅项目频道——伪会话键
 	// "project:<id>" 复用会话流的持久化/seq/重放机制；租户边界按项目校验。
 	if r.URL.Query().Get("scope") == "project" {
@@ -448,6 +449,7 @@ func (s *Server) events(w http.ResponseWriter, r *http.Request) {
 		}
 		conversationID = string(core.ProjectChannelKey(core.ID(pid)))
 		isProject = true
+		streamProject = pid
 	} else if conversationID == "" {
 		http.Error(w, "conversationId required", http.StatusBadRequest)
 		return
@@ -509,28 +511,38 @@ func (s *Server) events(w http.ResponseWriter, r *http.Request) {
 	live, stop := s.Subscribe(conversationID)
 	defer stop()
 
+	lastVisible := since
 	send := func(e core.StreamEvent) bool {
+		if e.Seq <= lastVisible {
+			return true
+		}
+		if isProject && !s.projectEventVisible(wantOwner, e) {
+			return r.Context().Err() == nil
+		}
 		buf, _ := json.Marshal(e)
 		fmt.Fprintf(w, "id: %d\nevent: %s\ndata: %s\n\n", e.Seq, e.Type, buf)
 		flusher.Flush()
+		lastVisible = e.Seq
 		return r.Context().Err() == nil
 	}
 
-	lastSent := since
+	// Seen progresses even when a private frame is filtered. Visible only tracks
+	// frames delivered to this actor, preserving authoritative seq and resumption.
+	lastSeen := since
 	for {
-		replay, err := s.st.EventsAfter(conversationID, lastSent, 1000)
+		replay, err := s.st.EventsAfter(conversationID, lastSeen, 1000)
 		if err != nil || len(replay) == 0 {
 			break
 		}
 		for _, e := range replay {
-			if e.Seq <= lastSent {
+			if e.Seq <= lastSeen {
 				continue
 			}
 			if !send(e) {
 				stop()
 				return
 			}
-			lastSent = e.Seq
+			lastSeen = e.Seq
 		}
 		if len(replay) < 1000 {
 			break
@@ -548,6 +560,11 @@ func (s *Server) events(w http.ResponseWriter, r *http.Request) {
 			stop()
 			return
 		case <-recheck.C:
+			if isProject && s.projectLifecycle != nil && !s.projectStreamMembership(wantOwner, streamProject) {
+				fmt.Fprint(w, ": project-access-revoked\n\n")
+				flusher.Flush()
+				return
+			}
 			if !stillAuthed() {
 				fmt.Fprint(w, ": session-expired\n\n")
 				flusher.Flush()
@@ -562,14 +579,19 @@ func (s *Server) events(w http.ResponseWriter, r *http.Request) {
 				stop()
 				return
 			}
-			if e.ConversationID != conversationID || e.Seq <= lastSent {
+			if e.ConversationID != conversationID || e.Seq <= lastSeen {
 				continue
 			}
+			if isProject && s.projectLifecycle != nil && !s.projectStreamMembership(wantOwner, streamProject) {
+				fmt.Fprint(w, ": project-access-revoked\n\n")
+				flusher.Flush()
+				return
+			}
 			if !send(e) {
 				stop()
 				return
 			}
-			lastSent = e.Seq
+			lastSeen = e.Seq
 		}
 	}
 }
diff --git a/internal/store/messages.go b/internal/store/messages.go
index 36c2042..58724f2 100644
--- a/internal/store/messages.go
+++ b/internal/store/messages.go
@@ -266,6 +266,10 @@ func (s *Store) ChildRuns(runID string) ([]core.Run, error) {
 // 成功后回填 evs[i].Seq。事务内锁定会话序列：PG 用事务级咨询锁（跨实例安全），
 // SQLite 单写连接天然串行。空批次为空操作。
 func (s *Store) AppendEvents(conversationID string, evs []core.StreamEvent) (int64, error) {
+	return s.appendEvents(conversationID, evs, "", "")
+}
+
+func (s *Store) appendEvents(conversationID string, evs []core.StreamEvent, owner, producer string) (int64, error) {
 	if len(evs) == 0 {
 		return 0, nil
 	}
@@ -298,6 +302,13 @@ func (s *Store) AppendEvents(conversationID string, evs []core.StreamEvent) (int
 	if _, err := tx.Exec(s.q(sb.String()), args...); err != nil {
 		return 0, err
 	}
+	if producer != "" {
+		for i, e := range evs {
+			if err := s.saveProjectEventProof(tx, conversationID, base.Int64+int64(i)+1, e, owner, producer); err != nil {
+				return 0, err
+			}
+		}
+	}
 	// KTD6：事件提交与 NOTIFY 同事务（outbox 语义的前半——通知不早于事件
 	// 可见；后半的命令 outbox 走 EnqueueCommandInTx 由批准路径使用）。
 	if s.dialect.name() == "postgres" {
diff --git a/internal/store/migrate.go b/internal/store/migrate.go
index 4428563..c31e0e8 100644
--- a/internal/store/migrate.go
+++ b/internal/store/migrate.go
@@ -841,6 +841,13 @@ func init() {
 				`DROP INDEX IF EXISTS idx_redeem_attempts_ip_at`,
 				`DROP TABLE IF EXISTS redeem_attempts`,
 			}}},
+		migration{version: 30, name: "project_event_publication_proofs",
+			up: map[string][]string{
+				"sqlite":   {`CREATE TABLE project_event_shares(channel TEXT NOT NULL,seq INTEGER NOT NULL,event_type TEXT NOT NULL,payload_sha256 TEXT NOT NULL,owner TEXT NOT NULL,resource_type TEXT NOT NULL,resource_id TEXT NOT NULL,producer TEXT NOT NULL,created_at TEXT NOT NULL,PRIMARY KEY(channel,seq),FOREIGN KEY(channel,seq) REFERENCES events(conversation_id,seq) ON DELETE CASCADE)`},
+				"postgres": {`CREATE TABLE project_event_shares(channel TEXT NOT NULL,seq BIGINT NOT NULL,event_type TEXT NOT NULL,payload_sha256 TEXT NOT NULL,owner TEXT NOT NULL,resource_type TEXT NOT NULL,resource_id TEXT NOT NULL,producer TEXT NOT NULL,created_at TEXT NOT NULL,PRIMARY KEY(channel,seq),FOREIGN KEY(channel,seq) REFERENCES events(conversation_id,seq) ON DELETE CASCADE)`},
+			},
+			down: map[string][]string{"sqlite": {`DROP TABLE IF EXISTS project_event_shares`}, "postgres": {`DROP TABLE IF EXISTS project_event_shares`}},
+		},
 	)
 }
 
diff --git a/internal/store/migrate_compat.go b/internal/store/migrate_compat.go
index ac0347d..86c692c 100644
--- a/internal/store/migrate_compat.go
+++ b/internal/store/migrate_compat.go
@@ -34,6 +34,7 @@ var migrationBreaksOldReaders = map[int]bool{
 	27: false,
 	28: false, // auth_version_account_events：仅加列与新表，旧读者不受影响
 	29: false, // redeem_attempts：新表，旧读者不受影响
+	30: false, // project_event_publication_proofs：新表，旧读者不受影响
 }
 
 // SchemaTarget 是本二进制会迁移到的 schema 版本。
diff --git a/internal/store/project_events.go b/internal/store/project_events.go
new file mode 100644
index 0000000..ea6e7c4
--- /dev/null
+++ b/internal/store/project_events.go
@@ -0,0 +1,147 @@
+package store
+
+import (
+	core "agent-system-core"
+	"crypto/sha256"
+	"database/sql"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// ProjectEventAccess is trusted read metadata; payload claims never establish it.
+type ProjectEventAccess struct {
+	Owner    string
+	Shared   bool
+	Producer string
+}
+type eventResource struct{ owner, project, conversation, kind, id string }
+type eventQuery interface{ QueryRow(string, ...any) *sql.Row }
+
+func cardEventID(e core.StreamEvent) (string, error) {
+	switch e.Type {
+	case core.EvCardCreated, core.EvCardUpdated, core.EvCardStatus, core.EvCardResolved:
+	default:
+		return "", nil
+	}
+	var payload struct {
+		Card struct {
+			ID string `json:"id"`
+		} `json:"card"`
+		CardID string `json:"cardId"`
+	}
+	if err := json.Unmarshal(e.Payload, &payload); err != nil {
+		return "", err
+	}
+	switch e.Type {
+	case core.EvCardCreated, core.EvCardUpdated:
+		return payload.Card.ID, nil
+	case core.EvCardStatus, core.EvCardResolved:
+		return payload.CardID, nil
+	}
+	return "", nil
+}
+func eventPayloadHash(payload []byte) string {
+	hash := sha256.Sum256(payload)
+	return hex.EncodeToString(hash[:])
+}
+
+func (s *Store) projectEventResource(q eventQuery, e core.StreamEvent) (eventResource, error) {
+	var resource eventResource
+	id, err := cardEventID(e)
+	if err != nil {
+		return resource, err
+	}
+	switch e.Type {
+	case core.EvCardCreated, core.EvCardUpdated, core.EvCardStatus, core.EvCardResolved:
+		if id == "" {
+			return resource, ErrNotFound
+		}
+	}
+	if id != "" {
+		resource.kind, resource.id = "card", id
+		err = q.QueryRow(s.q(`SELECT owner,project_id,conversation_id FROM activity_cards WHERE id=?`), id).Scan(&resource.owner, &resource.project, &resource.conversation)
+	} else if e.Type == core.EvArtifactCreated {
+		var payload struct {
+			Artifact struct {
+				ID string `json:"id"`
+			} `json:"artifact"`
+		}
+		if err := json.Unmarshal(e.Payload, &payload); err != nil {
+			return resource, err
+		}
+		if payload.Artifact.ID == "" {
+			return resource, ErrNotFound
+		}
+		resource.kind, resource.id = "artifact", payload.Artifact.ID
+		err = q.QueryRow(s.q(`SELECT owner,project_id FROM artifacts WHERE id=?`), resource.id).Scan(&resource.owner, &resource.project)
+	} else if e.RunID != "" {
+		resource.kind, resource.id = "run", e.RunID
+		err = q.QueryRow(s.q(`SELECT owner,project_id,conversation_id FROM runs WHERE id=?`), e.RunID).Scan(&resource.owner, &resource.project, &resource.conversation)
+	} else {
+		return resource, ErrNotFound
+	}
+	if errors.Is(err, sql.ErrNoRows) {
+		return resource, ErrNotFound
+	}
+	if err != nil {
+		return resource, err
+	}
+	project, ok := core.ProjectFromChannel(e.ConversationID)
+	if !ok || resource.owner == "" || resource.project != project || (e.ProjectID != "" && e.ProjectID != project) {
+		return resource, ErrNotFound
+	}
+	return resource, nil
+}
+
+// ResolveProjectEventAccess resolves immutable resource ownership and verifies an
+// exact internal publication record. Old events retain their private default.
+func (s *Store) ResolveProjectEventAccess(e core.StreamEvent) (ProjectEventAccess, error) {
+	resource, err := s.projectEventResource(s.db, e)
+	if err != nil {
+		return ProjectEventAccess{}, err
+	}
+	access := ProjectEventAccess{Owner: resource.owner}
+	var owner, kind, id, producer, typ, hash string
+	err = s.db.QueryRow(s.q(`SELECT owner,resource_type,resource_id,producer,event_type,payload_sha256 FROM project_event_shares WHERE channel=? AND seq=?`), e.ConversationID, e.Seq).Scan(&owner, &kind, &id, &producer, &typ, &hash)
+	if errors.Is(err, sql.ErrNoRows) {
+		return access, nil
+	}
+	if err != nil {
+		return ProjectEventAccess{}, err
+	}
+	if owner != resource.owner || kind != resource.kind || id != resource.id || strings.TrimSpace(producer) == "" || typ != string(e.Type) || hash != eventPayloadHash(e.Payload) || resource.conversation != "" {
+		return ProjectEventAccess{}, ErrNotFound
+	}
+	access.Shared, access.Producer = true, producer
+	return access, nil
+}
+
+// AppendProjectSharedEvents is an internal publication boundary, not an API or
+// model tool. Events and their exact sharing proofs commit together. Caller
+// identity must own a project-level card; private conversation cards cannot be
+// published through this structural-card path.
+func (s *Store) AppendProjectSharedEvents(owner, producer, channel string, events []core.StreamEvent) (int64, error) {
+	if owner == "" || strings.TrimSpace(producer) == "" {
+		return 0, fmt.Errorf("store: shared event requires owner and producer")
+	}
+	if _, ok := core.ProjectFromChannel(channel); !ok {
+		return 0, ErrNotFound
+	}
+	return s.appendEvents(channel, events, owner, producer)
+}
+
+func (s *Store) saveProjectEventProof(tx *sql.Tx, channel string, seq int64, e core.StreamEvent, owner, producer string) error {
+	e.ConversationID = channel
+	resource, err := s.projectEventResource(tx, e)
+	if err != nil {
+		return err
+	}
+	if resource.kind != "card" || resource.owner != owner || resource.conversation != "" {
+		return ErrNotFound
+	}
+	_, err = tx.Exec(s.q(`INSERT INTO project_event_shares(channel,seq,event_type,payload_sha256,owner,resource_type,resource_id,producer,created_at) VALUES(?,?,?,?,?,?,?,?,?)`), channel, seq, string(e.Type), eventPayloadHash(e.Payload), resource.owner, resource.kind, resource.id, producer, nowISO())
+	return err
+}
diff --git a/internal/store/project_events_test.go b/internal/store/project_events_test.go
new file mode 100644
index 0000000..2c69aab
--- /dev/null
+++ b/internal/store/project_events_test.go
@@ -0,0 +1,140 @@
+package store
+
+import (
+	core "agent-system-core"
+	"encoding/json"
+	"testing"
+	"time"
+)
+
+func storedProjectCardEvent(t *testing.T, st *Store, owner, project, id string) core.StreamEvent {
+	t.Helper()
+	card := core.ActivityCard{ID: id, ProjectID: project, Title: "PRIVATE", CreatedAt: time.Now().UTC(), UpdatedAt: time.Now().UTC()}
+	if err := st.SaveCard(owner, &card, ""); err != nil {
+		t.Fatal(err)
+	}
+	payload, _ := json.Marshal(core.CardPayload{Card: card})
+	return core.StreamEvent{ConversationID: core.ProjectChannelKey(project), ProjectID: project, Type: core.EvCardCreated, Payload: payload, TS: time.Now().UTC().Format(time.RFC3339Nano), V: 1}
+}
+func TestProjectEventSharedProofBindsExactEvent(t *testing.T) {
+	st := openTestStore(t)
+	p, _ := st.CreateProject("alice", "Project")
+	e := storedProjectCardEvent(t, st, "alice", p.ID, "card-a")
+	private := []core.StreamEvent{e}
+	if _, err := st.AppendEvents(e.ConversationID, private); err != nil {
+		t.Fatal(err)
+	}
+	access, err := st.ResolveProjectEventAccess(private[0])
+	if err != nil || access.Owner != "alice" || access.Shared {
+		t.Fatalf("private access=%+v %v", access, err)
+	}
+	shared := []core.StreamEvent{e}
+	if _, err := st.AppendProjectSharedEvents("alice", "plugin:rdm:structure", e.ConversationID, shared); err != nil {
+		t.Fatal(err)
+	}
+	access, err = st.ResolveProjectEventAccess(shared[0])
+	if err != nil || !access.Shared || access.Owner != "alice" {
+		t.Fatalf("shared proof=%+v %v", access, err)
+	}
+	access, err = st.ResolveProjectEventAccess(private[0])
+	if err != nil || access.Shared {
+		t.Fatal("publication retroactively shared private history")
+	}
+	for _, mutate := range []func(*core.StreamEvent){func(e *core.StreamEvent) { e.Type = core.EvCardUpdated }, func(e *core.StreamEvent) { e.Payload = append(e.Payload, ' ') }, func(e *core.StreamEvent) { e.Seq += 100 }, func(e *core.StreamEvent) { e.ConversationID = "project:another" }, func(e *core.StreamEvent) { e.ProjectID = "another" }} {
+		changed := shared[0]
+		mutate(&changed)
+		access, err = st.ResolveProjectEventAccess(changed)
+		if err == nil && access.Shared {
+			t.Fatal("mutated event retained sharing")
+		}
+	}
+	bad := []core.StreamEvent{e}
+	before, _ := st.LastEventSeq(e.ConversationID)
+	if _, err := st.AppendProjectSharedEvents("bob", "plugin:rdm:structure", e.ConversationID, bad); err == nil {
+		t.Fatal("other owner issued publication")
+	}
+	after, _ := st.LastEventSeq(e.ConversationID)
+	if after != before {
+		t.Fatal("rejected publication appended event")
+	}
+}
+func TestProjectEventMigrationPreservesPrivateHistory(t *testing.T) {
+	st := openTestStore(t)
+	if err := st.MigrateDown(29); err != nil {
+		t.Fatal(err)
+	}
+	p, _ := st.CreateProject("alice", "Legacy")
+	e := storedProjectCardEvent(t, st, "alice", p.ID, "legacy-card")
+	events := []core.StreamEvent{e}
+	if _, err := st.AppendEvents(e.ConversationID, events); err != nil {
+		t.Fatal(err)
+	}
+	before, _ := st.EventsAfter(e.ConversationID, 0, 100)
+	if err := st.migrate(); err != nil {
+		t.Fatal(err)
+	}
+	after, _ := st.EventsAfter(e.ConversationID, 0, 100)
+	b, _ := json.Marshal(before)
+	a, _ := json.Marshal(after)
+	if string(a) != string(b) {
+		t.Fatal("upgrade changed private event history")
+	}
+	access, err := st.ResolveProjectEventAccess(after[0])
+	if err != nil || access.Owner != "alice" || access.Shared {
+		t.Fatalf("legacy privacy=%+v %v", access, err)
+	}
+}
+
+func TestProjectSharedEventBatchRollsBackProofAndEvents(t *testing.T) {
+	st := openTestStore(t)
+	p, _ := st.CreateProject("alice", "Project")
+	a := storedProjectCardEvent(t, st, "alice", p.ID, "card-a")
+	b := storedProjectCardEvent(t, st, "bob", p.ID, "card-b")
+	if _, err := st.AppendProjectSharedEvents("alice", "plugin:rdm:structure", a.ConversationID, []core.StreamEvent{a, b}); err == nil {
+		t.Fatal("mixed owner batch published")
+	}
+	var count int
+	for _, table := range []string{"events", "project_event_shares"} {
+		if err := st.db.QueryRow("SELECT COUNT(*) FROM " + table).Scan(&count); err != nil || count != 0 {
+			t.Fatalf("partial %s publication: count=%d error=%v", table, count, err)
+		}
+	}
+}
+
+func TestProjectEventInvalidProofAndMissingOwnerFailClosed(t *testing.T) {
+	st := openTestStore(t)
+	p, _ := st.CreateProject("alice", "Project")
+	e := storedProjectCardEvent(t, st, "alice", p.ID, "card-a")
+	shared := []core.StreamEvent{e}
+	if _, err := st.AppendProjectSharedEvents("alice", "plugin:rdm:structure", e.ConversationID, shared); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := st.db.Exec(`UPDATE project_event_shares SET producer=''`); err != nil {
+		t.Fatal(err)
+	}
+	if access, err := st.ResolveProjectEventAccess(shared[0]); err == nil || access.Shared {
+		t.Fatal("corrupted publication proof was accepted")
+	}
+	if _, err := st.db.Exec(`UPDATE activity_cards SET owner=''`); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := st.ResolveProjectEventAccess(shared[0]); err == nil {
+		t.Fatal("missing resource owner was accepted")
+	}
+}
+
+func TestProjectSharingRejectsPrivateConversationCards(t *testing.T) {
+	st := openTestStore(t)
+	p, _ := st.CreateProject("alice", "Project")
+	e := storedProjectCardEvent(t, st, "alice", p.ID, "card-a")
+	if _, err := st.db.Exec(`UPDATE activity_cards SET conversation_id='private-conversation'`); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := st.AppendProjectSharedEvents("alice", "plugin:rdm:structure", e.ConversationID, []core.StreamEvent{e}); err == nil {
+		t.Fatal("private conversation card publicly marked")
+	}
+	events, err := st.EventsAfter(e.ConversationID, 0, 100)
+	if err != nil || len(events) != 0 {
+		t.Fatal("rejected conversation publication appended events")
+	}
+}