diff --git a/db/migrations/00003_member_sessions.sql b/db/migrations/00003_member_sessions.sql
new file mode 100644
index 0000000..dc4bb68
--- /dev/null
+++ b/db/migrations/00003_member_sessions.sql
@@ -0,0 +1,16 @@
+-- +goose Up
+-- 一个会话对应一个成员 token，同一个成员可以在多台设备上各有一个会话。
+CREATE TABLE member_sessions (
+    token_hash bytea PRIMARY KEY,
+    member_id uuid NOT NULL REFERENCES members ON DELETE CASCADE,
+    created_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX ON member_sessions (member_id);
+
+-- bot 成员只通过 API Key 使用 HTTP 接口，不需要会话。
+INSERT INTO member_sessions (token_hash, member_id, created_at)
+SELECT m.token_hash, m.id, m.created_at FROM members m
+WHERE NOT EXISTS (SELECT FROM rooms r WHERE r.bot_member_id = m.id);
+
+ALTER TABLE members DROP COLUMN token_hash;
diff --git a/db/queries/members.sql b/db/queries/members.sql
index 64afd3a..a6443f7 100644
--- a/db/queries/members.sql
+++ b/db/queries/members.sql
@@ -1,9 +1,12 @@
 -- name: CreateMember :one
-INSERT INTO members (token_hash, name) VALUES (@token_hash, @name)
+INSERT INTO members (name) VALUES (@name)
 RETURNING *;
 
+-- name: CreateSession :exec
+INSERT INTO member_sessions (token_hash, member_id) VALUES (@token_hash, @member_id);
+
 -- name: MemberByToken :one
-SELECT * FROM members WHERE token_hash = @token_hash;
+SELECT * FROM members WHERE id = (SELECT member_id FROM member_sessions WHERE token_hash = @token_hash);
 
 -- name: UpdateMember :one
 -- 只覆盖传入的列，分别修改昵称和头像的两个并发请求因此不会互相还原；头像哈希传入空串表示清除。
diff --git a/internal/adapter/out/postgres/apikeys.go b/internal/adapter/out/postgres/apikeys.go
index ebb9ff1..21bd798 100644
--- a/internal/adapter/out/postgres/apikeys.go
+++ b/internal/adapter/out/postgres/apikeys.go
@@ -41,7 +41,7 @@ func (s *Store) ResetRoomAPIKey(ctx context.Context, roomID string, k port.NewAP
 				return err
 			}
 		} else {
-			m, err := q.CreateMember(ctx, query.CreateMemberParams{TokenHash: k.BotTokenHash, Name: botName})
+			m, err := q.CreateMember(ctx, botName)
 			if err != nil {
 				return err
 			}
diff --git a/internal/adapter/out/postgres/apikeys_test.go b/internal/adapter/out/postgres/apikeys_test.go
index 98c3c28..e593704 100644
--- a/internal/adapter/out/postgres/apikeys_test.go
+++ b/internal/adapter/out/postgres/apikeys_test.go
@@ -12,7 +12,7 @@ import (
 )
 
 func newAPIKey(key string) port.NewAPIKey {
-	return port.NewAPIKey{TokenHash: tokenHash(key), BotTokenHash: tokenHash("bot " + key)}
+	return port.NewAPIKey{TokenHash: tokenHash(key)}
 }
 
 func resetAPIKey(t *testing.T, store *Store, roomID, key string) {
@@ -150,3 +150,16 @@ func TestConcurrentFirstResetsCreateOneBot(t *testing.T) {
 		t.Errorf("有 %d 把 Key、%d 个 bot 成员，期望各一个", n, bots)
 	}
 }
+
+func TestRoomBotHasNoSession(t *testing.T) {
+	store, pool := newStore(t)
+	id := createRoom(t, store, port.NewRoom{Kind: room.Persistent, Name: "大厅"})
+	resetAPIKey(t, store, id, "key-1")
+	var sessions int
+	if err := pool.QueryRow(t.Context(), "SELECT count(*) FROM member_sessions s JOIN rooms r ON r.bot_member_id = s.member_id WHERE r.id = $1", id).Scan(&sessions); err != nil {
+		t.Fatal(err)
+	}
+	if sessions != 0 {
+		t.Errorf("bot 成员有 %d 个会话，期望没有：bot 只通过 API Key 使用 HTTP 接口", sessions)
+	}
+}
diff --git a/internal/adapter/out/postgres/internal/query/members.sql.go b/internal/adapter/out/postgres/internal/query/members.sql.go
index 0ced928..5b89cc3 100644
--- a/internal/adapter/out/postgres/internal/query/members.sql.go
+++ b/internal/adapter/out/postgres/internal/query/members.sql.go
@@ -10,21 +10,15 @@ import (
 )
 
 const createMember = `-- name: CreateMember :one
-INSERT INTO members (token_hash, name) VALUES ($1, $2)
-RETURNING id, token_hash, name, avatar_hash, created_at
+INSERT INTO members (name) VALUES ($1)
+RETURNING id, name, avatar_hash, created_at
 `
 
-type CreateMemberParams struct {
-	TokenHash []byte
-	Name      string
-}
-
-func (q *Queries) CreateMember(ctx context.Context, arg CreateMemberParams) (Member, error) {
-	row := q.db.QueryRow(ctx, createMember, arg.TokenHash, arg.Name)
+func (q *Queries) CreateMember(ctx context.Context, name string) (Member, error) {
+	row := q.db.QueryRow(ctx, createMember, name)
 	var i Member
 	err := row.Scan(
 		&i.ID,
-		&i.TokenHash,
 		&i.Name,
 		&i.AvatarHash,
 		&i.CreatedAt,
@@ -32,8 +26,22 @@ func (q *Queries) CreateMember(ctx context.Context, arg CreateMemberParams) (Mem
 	return i, err
 }
 
+const createSession = `-- name: CreateSession :exec
+INSERT INTO member_sessions (token_hash, member_id) VALUES ($1, $2)
+`
+
+type CreateSessionParams struct {
+	TokenHash []byte
+	MemberID  string
+}
+
+func (q *Queries) CreateSession(ctx context.Context, arg CreateSessionParams) error {
+	_, err := q.db.Exec(ctx, createSession, arg.TokenHash, arg.MemberID)
+	return err
+}
+
 const memberByToken = `-- name: MemberByToken :one
-SELECT id, token_hash, name, avatar_hash, created_at FROM members WHERE token_hash = $1
+SELECT id, name, avatar_hash, created_at FROM members WHERE id = (SELECT member_id FROM member_sessions WHERE token_hash = $1)
 `
 
 func (q *Queries) MemberByToken(ctx context.Context, tokenHash []byte) (Member, error) {
@@ -41,7 +49,6 @@ func (q *Queries) MemberByToken(ctx context.Context, tokenHash []byte) (Member,
 	var i Member
 	err := row.Scan(
 		&i.ID,
-		&i.TokenHash,
 		&i.Name,
 		&i.AvatarHash,
 		&i.CreatedAt,
@@ -54,7 +61,7 @@ UPDATE members
 SET name = coalesce($1, name),
     avatar_hash = CASE WHEN $2::text IS NULL THEN avatar_hash ELSE NULLIF($2::text, '') END
 WHERE id = $3
-RETURNING id, token_hash, name, avatar_hash, created_at
+RETURNING id, name, avatar_hash, created_at
 `
 
 type UpdateMemberParams struct {
@@ -69,7 +76,6 @@ func (q *Queries) UpdateMember(ctx context.Context, arg UpdateMemberParams) (Mem
 	var i Member
 	err := row.Scan(
 		&i.ID,
-		&i.TokenHash,
 		&i.Name,
 		&i.AvatarHash,
 		&i.CreatedAt,
diff --git a/internal/adapter/out/postgres/internal/query/models.go b/internal/adapter/out/postgres/internal/query/models.go
index 2cb8ec7..6756aa0 100644
--- a/internal/adapter/out/postgres/internal/query/models.go
+++ b/internal/adapter/out/postgres/internal/query/models.go
@@ -10,7 +10,6 @@ import (
 
 type Member struct {
 	ID         string
-	TokenHash  []byte
 	Name       string
 	AvatarHash *string
 	CreatedAt  time.Time
diff --git a/internal/adapter/out/postgres/members.go b/internal/adapter/out/postgres/members.go
index a90ce23..7319456 100644
--- a/internal/adapter/out/postgres/members.go
+++ b/internal/adapter/out/postgres/members.go
@@ -15,11 +15,20 @@ import (
 var _ port.Members = (*Store)(nil)
 
 func (s *Store) CreateMember(ctx context.Context, tokenHash []byte, name string) (member.Member, error) {
-	row, err := s.q.CreateMember(ctx, query.CreateMemberParams{TokenHash: tokenHash, Name: name})
+	var m member.Member
+	err := pgx.BeginFunc(ctx, s.pool, func(tx pgx.Tx) error {
+		q := s.q.WithTx(tx)
+		row, err := q.CreateMember(ctx, name)
+		if err != nil {
+			return err
+		}
+		m = memberOf(row)
+		return q.CreateSession(ctx, query.CreateSessionParams{TokenHash: tokenHash, MemberID: row.ID})
+	})
 	if err != nil {
 		return member.Member{}, fmt.Errorf("创建成员：%w", err)
 	}
-	return memberOf(row), nil
+	return m, nil
 }
 
 func (s *Store) MemberByToken(ctx context.Context, tokenHash []byte) (member.Member, error) {
diff --git a/internal/adapter/out/postgres/migrate_test.go b/internal/adapter/out/postgres/migrate_test.go
index 21bff2a..5f0c829 100644
--- a/internal/adapter/out/postgres/migrate_test.go
+++ b/internal/adapter/out/postgres/migrate_test.go
@@ -11,6 +11,11 @@ import (
 	"time"
 
 	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/jackc/pgx/v5/stdlib"
+	"github.com/pressly/goose/v3"
+
+	"github.com/dihemoe/alisten/db/migrations"
+	"github.com/dihemoe/alisten/internal/app/port"
 )
 
 func migrate(ctx context.Context, pool *pgxpool.Pool, logger *slog.Logger) error {
@@ -128,3 +133,49 @@ func TestMigrationLogsKeepFixedFields(t *testing.T) {
 		}
 	}
 }
+
+func TestMemberSessionsMigrationKeepsMemberTokens(t *testing.T) {
+	ctx := t.Context()
+	name := fmt.Sprintf("test_%d", databases.Add(1))
+	if _, err := admin.Exec(ctx, "CREATE DATABASE "+name); err != nil {
+		t.Fatal(err)
+	}
+	cfg := server.Copy()
+	cfg.ConnConfig.Database = name
+	pool := connect(t, cfg)
+	db := stdlib.OpenDBFromPool(pool)
+	t.Cleanup(func() { _ = db.Close() })
+	provider, err := goose.NewProvider(goose.DialectPostgres, db, migrations.FS)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := provider.UpTo(ctx, 2); err != nil {
+		t.Fatal(err)
+	}
+	created := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	var guest, bot string
+	if err := pool.QueryRow(ctx, "INSERT INTO members (token_hash, name, created_at) VALUES ($1, '游客-1a2b', $2) RETURNING id", tokenHash("guest"), created).Scan(&guest); err != nil {
+		t.Fatal(err)
+	}
+	if err := pool.QueryRow(ctx, "INSERT INTO members (token_hash, name) VALUES ($1, 'bot') RETURNING id", tokenHash("bot")).Scan(&bot); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := pool.Exec(ctx, "INSERT INTO rooms (kind, name, description, bot_member_id) VALUES ('persistent', '大厅', '', $1)", bot); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := provider.Up(ctx); err != nil {
+		t.Fatal(err)
+	}
+
+	store := New(pool)
+	if m, err := store.MemberByToken(ctx, tokenHash("guest")); err != nil || m.ID != guest {
+		t.Errorf("迁移之后按原来的 token 找到 %#v, %v，期望成员 %s", m, err, guest)
+	}
+	var sessionCreated time.Time
+	if err := pool.QueryRow(ctx, "SELECT created_at FROM member_sessions WHERE member_id = $1", guest).Scan(&sessionCreated); err != nil || !sessionCreated.Equal(created) {
+		t.Errorf("会话的创建时间 = %v, %v，期望沿用成员的创建时间 %v", sessionCreated, err, created)
+	}
+	if _, err := store.MemberByToken(ctx, tokenHash("bot")); !errors.Is(err, port.ErrMemberNotFound) {
+		t.Errorf("bot 成员原来的 token 在迁移之后 = %v，期望不再有效", err)
+	}
+}
diff --git a/internal/adapter/out/postgres/rooms_test.go b/internal/adapter/out/postgres/rooms_test.go
index 7314ec8..1f328b1 100644
--- a/internal/adapter/out/postgres/rooms_test.go
+++ b/internal/adapter/out/postgres/rooms_test.go
@@ -25,7 +25,7 @@ func addTicket(t *testing.T, pool *pgxpool.Pool, roomID string) {
 	t.Helper()
 	_, err := pool.Exec(t.Context(), `
 		WITH m AS (
-			INSERT INTO members (token_hash, name) VALUES (sha256(gen_random_uuid()::text::bytea), '甲')
+			INSERT INTO members (name) VALUES ('甲')
 			RETURNING id
 		)
 		INSERT INTO room_tickets (token_hash, room_id, member_id) SELECT sha256(gen_random_uuid()::text::bytea), $1, id FROM m`,
diff --git a/internal/app/identity/identity.go b/internal/app/identity/identity.go
index a160861..f3068de 100644
--- a/internal/app/identity/identity.go
+++ b/internal/app/identity/identity.go
@@ -131,9 +131,7 @@ func (s *Service) EnterRoom(ctx context.Context, roomID, ticket string) (*realti
 	return s.gateway.Join(logctx.WithMember(logctx.WithRoom(ctx, r.Info.ID), holder.Member.ID), r.Info.ID, holder.Member)
 }
 
-// 每次都准备好 bot 成员的 token：房间还没有 bot 成员时由存储用它创建，这个随机值不交给任何人。
 func NewAPIKey() (string, port.NewAPIKey) {
 	key, hash := newSecret()
-	_, botHash := newSecret()
-	return key, port.NewAPIKey{TokenHash: hash, BotTokenHash: botHash}
+	return key, port.NewAPIKey{TokenHash: hash}
 }
diff --git a/internal/app/port/apikey.go b/internal/app/port/apikey.go
index 0d4535c..da8f825 100644
--- a/internal/app/port/apikey.go
+++ b/internal/app/port/apikey.go
@@ -8,8 +8,6 @@ import (
 // 常驻房间的 API Key 是房间 bot 成员的票据。
 type NewAPIKey struct {
 	TokenHash []byte
-	// 房间还没有 bot 成员时用它创建：对应的随机值不交给任何人，bot 因此没有可用的成员 token。
-	BotTokenHash []byte
 }
 
 type APIKeyStatus struct {
diff --git a/internal/app/port/member.go b/internal/app/port/member.go
index 18bba50..00c3a9d 100644
--- a/internal/app/port/member.go
+++ b/internal/app/port/member.go
@@ -9,7 +9,7 @@ import (
 
 var ErrMemberNotFound = errors.New("成员不存在")
 
-// 成员 token 只以 SHA-256 哈希的形式出现在端口中。
+// 成员 token 只以 SHA-256 哈希的形式出现在端口中。一个成员 token 是成员的一个会话，同一个成员可以有多个会话。
 type Members interface {
 	CreateMember(ctx context.Context, tokenHash []byte, name string) (member.Member, error)
 	MemberByToken(ctx context.Context, tokenHash []byte) (member.Member, error)
diff --git a/internal/app/port/porttest/store.go b/internal/app/port/porttest/store.go
index 7ab212e..1279249 100644
--- a/internal/app/port/porttest/store.go
+++ b/internal/app/port/porttest/store.go
@@ -23,9 +23,11 @@ type Store struct {
 	mu      sync.Mutex
 	ids     int
 	members []storedMember
-	rooms   []port.RoomRecord
-	states  map[string]*roomState
-	tickets map[string]storedTicket
+	// 会话的 token 哈希到成员 ID。
+	sessions map[string]string
+	rooms    []port.RoomRecord
+	states   map[string]*roomState
+	tickets  map[string]storedTicket
 	// 房间 ID 到 bot 成员 ID。
 	bots      map[string]string
 	cookies   map[string]string
@@ -33,8 +35,7 @@ type Store struct {
 }
 
 type storedMember struct {
-	tokenHash string
-	member    member.Member
+	member member.Member
 }
 
 type storedTicket struct {
@@ -54,10 +55,11 @@ var (
 
 func New() *Store {
 	return &Store{
-		states:  map[string]*roomState{},
-		tickets: map[string]storedTicket{},
-		bots:    map[string]string{},
-		cookies: map[string]string{},
+		states:   map[string]*roomState{},
+		sessions: map[string]string{},
+		tickets:  map[string]storedTicket{},
+		bots:     map[string]string{},
+		cookies:  map[string]string{},
 	}
 }
 
@@ -84,27 +86,34 @@ func (s *Store) CreateMember(_ context.Context, tokenHash []byte, name string) (
 	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	for _, m := range s.members {
-		if m.tokenHash == string(tokenHash) {
-			return member.Member{}, errors.New("token 哈希重复")
-		}
+	if _, ok := s.sessions[string(tokenHash)]; ok {
+		return member.Member{}, errors.New("token 哈希重复")
 	}
 	m := member.Member{ID: s.newID(), Name: name}
-	s.members = append(s.members, storedMember{tokenHash: string(tokenHash), member: m})
+	s.members = append(s.members, storedMember{member: m})
+	s.sessions[string(tokenHash)] = m.ID
 	return m, nil
 }
 
 func (s *Store) MemberByToken(_ context.Context, tokenHash []byte) (member.Member, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	for _, m := range s.members {
-		if m.tokenHash == string(tokenHash) {
-			return m.member, nil
-		}
+	if m := s.member(s.sessions[string(tokenHash)]); m != nil {
+		return m.member, nil
 	}
 	return member.Member{}, port.ErrMemberNotFound
 }
 
+// 调用方持有 s.mu。
+func (s *Store) member(id string) *storedMember {
+	for i := range s.members {
+		if s.members[i].member.ID == id {
+			return &s.members[i]
+		}
+	}
+	return nil
+}
+
 func (s *Store) UpdateMember(_ context.Context, id string, name, avatarHash *string) (member.Member, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -194,7 +203,7 @@ func (s *Store) ResetRoomAPIKey(_ context.Context, roomID string, k port.NewAPIK
 		maps.DeleteFunc(s.tickets, func(_ string, t storedTicket) bool { return t.roomID == r.Info.ID && t.memberID == bot })
 	} else {
 		bot = s.newID()
-		s.members = append(s.members, storedMember{tokenHash: string(k.BotTokenHash), member: member.Member{ID: bot, Name: "bot"}})
+		s.members = append(s.members, storedMember{member: member.Member{ID: bot, Name: "bot"}})
 		s.bots[r.Info.ID] = bot
 	}
 	s.tickets[string(k.TokenHash)] = storedTicket{roomID: r.Info.ID, memberID: bot, createdAt: time.Now()}