diff --git a/internal/acp/repository_test.go b/internal/acp/repository_test.go
new file mode 100644
index 0000000..fcaf2d4
--- /dev/null
+++ b/internal/acp/repository_test.go
@@ -0,0 +1,261 @@
+//go:build integration
+
+package acp_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	tcpg "github.com/testcontainers/testcontainers-go/modules/postgres"
+
+	"github.com/yan1h/agent-coding-workflow/internal/acp"
+	"github.com/yan1h/agent-coding-workflow/internal/infra/db"
+	"github.com/yan1h/agent-coding-workflow/internal/infra/errs"
+)
+
+func setupRepo(t *testing.T) (acp.Repository, *pgxpool.Pool) {
+	t.Helper()
+	ctx := context.Background()
+	container, err := tcpg.Run(ctx, "postgres:16-alpine",
+		tcpg.WithDatabase("acw"),
+		tcpg.WithUsername("acw"),
+		tcpg.WithPassword("acw"),
+	)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = container.Terminate(ctx) })
+
+	dsn, err := container.ConnectionString(ctx, "sslmode=disable")
+	require.NoError(t, err)
+	require.NoError(t, db.Migrate(ctx, dsn, "file://../../migrations"))
+
+	pool, err := db.NewPool(ctx, dsn)
+	require.NoError(t, err)
+	t.Cleanup(pool.Close)
+
+	return acp.NewPostgresRepository(pool), pool
+}
+
+func TestPgRepo_AgentKind_CRUD(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	repo, pool := setupRepo(t)
+
+	uid := mustInsertUser(t, ctx, pool, "admin@local", true)
+
+	// Create
+	k, err := repo.CreateAgentKind(ctx, &acp.AgentKind{
+		ID: uuid.New(), Name: "claude_code", DisplayName: "Claude Code",
+		BinaryPath: "claude-code", Args: []string{"--acp"},
+		EncryptedEnv: []byte("ciphertext"), Enabled: true, CreatedBy: uid,
+	})
+	require.NoError(t, err)
+	assert.Equal(t, "claude_code", k.Name)
+
+	// Get by ID
+	got, err := repo.GetAgentKindByID(ctx, k.ID)
+	require.NoError(t, err)
+	assert.Equal(t, k.Name, got.Name)
+
+	// Get by Name
+	got2, err := repo.GetAgentKindByName(ctx, "claude_code")
+	require.NoError(t, err)
+	assert.Equal(t, k.ID, got2.ID)
+
+	// List enabled
+	enabled, err := repo.ListEnabledAgentKinds(ctx)
+	require.NoError(t, err)
+	require.Len(t, enabled, 1)
+
+	// Update（enabled=false）
+	k.DisplayName = "Claude Code v2"
+	k.Enabled = false
+	updated, err := repo.UpdateAgentKind(ctx, k)
+	require.NoError(t, err)
+	assert.Equal(t, "Claude Code v2", updated.DisplayName)
+	assert.False(t, updated.Enabled)
+
+	enabled, _ = repo.ListEnabledAgentKinds(ctx)
+	assert.Empty(t, enabled)
+
+	// Delete
+	require.NoError(t, repo.DeleteAgentKind(ctx, k.ID))
+	_, err = repo.GetAgentKindByID(ctx, k.ID)
+	ae, ok := errs.As(err)
+	require.True(t, ok)
+	assert.Equal(t, errs.CodeAcpAgentKindNotFound, ae.Code)
+}
+
+func TestPgRepo_AgentKind_DeleteInUse(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	repo, pool := setupRepo(t)
+
+	uid := mustInsertUser(t, ctx, pool, "admin2@local", true)
+	pid, wsid := mustInsertProjectWorkspace(t, ctx, pool, uid)
+
+	k, err := repo.CreateAgentKind(ctx, &acp.AgentKind{
+		ID: uuid.New(), Name: "kind-in-use", DisplayName: "x",
+		BinaryPath: "x", Enabled: true, CreatedBy: uid,
+	})
+	require.NoError(t, err)
+
+	_, err = repo.InsertSession(ctx, &acp.Session{
+		ID: uuid.New(), WorkspaceID: wsid, ProjectID: pid,
+		AgentKindID: k.ID, UserID: uid,
+		Branch: "main", CwdPath: "/tmp", IsMainWorktree: true, Status: acp.SessionRunning,
+	})
+	require.NoError(t, err)
+
+	err = repo.DeleteAgentKind(ctx, k.ID)
+	ae, ok := errs.As(err)
+	require.True(t, ok)
+	assert.Equal(t, errs.CodeAcpAgentKindInUse, ae.Code)
+}
+
+func TestPgRepo_Session_Lifecycle(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	repo, pool := setupRepo(t)
+
+	uid := mustInsertUser(t, ctx, pool, "u3@local", false)
+	pid, wsid := mustInsertProjectWorkspace(t, ctx, pool, uid)
+	k, _ := repo.CreateAgentKind(ctx, &acp.AgentKind{
+		ID: uuid.New(), Name: "kind3", DisplayName: "x",
+		BinaryPath: "x", Enabled: true, CreatedBy: uid,
+	})
+
+	sess, err := repo.InsertSession(ctx, &acp.Session{
+		ID: uuid.New(), WorkspaceID: wsid, ProjectID: pid,
+		AgentKindID: k.ID, UserID: uid,
+		Branch: "feat-x", CwdPath: "/tmp", IsMainWorktree: false, Status: acp.SessionStarting,
+	})
+	require.NoError(t, err)
+
+	// Count active
+	n, _ := repo.CountActiveSessions(ctx)
+	assert.Equal(t, int64(1), n)
+	n2, _ := repo.CountActiveSessionsByUser(ctx, uid)
+	assert.Equal(t, int64(1), n2)
+
+	// Update running
+	require.NoError(t, repo.UpdateSessionRunning(ctx, sess.ID, "agent-sid-abc", 12345))
+	got, _ := repo.GetSessionByID(ctx, sess.ID)
+	assert.Equal(t, acp.SessionRunning, got.Status)
+	require.NotNil(t, got.AgentSessionID)
+	assert.Equal(t, "agent-sid-abc", *got.AgentSessionID)
+	require.NotNil(t, got.PID)
+	assert.Equal(t, int32(12345), *got.PID)
+
+	// Update finished
+	ec := int32(0)
+	require.NoError(t, repo.UpdateSessionFinished(ctx, sess.ID, acp.SessionExited, &ec, nil))
+	got, _ = repo.GetSessionByID(ctx, sess.ID)
+	assert.Equal(t, acp.SessionExited, got.Status)
+	assert.False(t, got.Status.IsActive())
+
+	// Reset stuck（应无影响：本 session 已 exited）
+	rows, _ := repo.ResetStuckSessionsOnRestart(ctx)
+	assert.Empty(t, rows)
+}
+
+func TestPgRepo_Session_ResetStuck(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	repo, pool := setupRepo(t)
+
+	uid := mustInsertUser(t, ctx, pool, "u4@local", false)
+	pid, wsid := mustInsertProjectWorkspace(t, ctx, pool, uid)
+	k, _ := repo.CreateAgentKind(ctx, &acp.AgentKind{
+		ID: uuid.New(), Name: "kind4", DisplayName: "x",
+		BinaryPath: "x", Enabled: true, CreatedBy: uid,
+	})
+
+	for i := 0; i < 2; i++ {
+		_, _ = repo.InsertSession(ctx, &acp.Session{
+			ID: uuid.New(), WorkspaceID: wsid, ProjectID: pid,
+			AgentKindID: k.ID, UserID: uid,
+			Branch: "stuck", CwdPath: "/tmp", IsMainWorktree: false, Status: acp.SessionRunning,
+		})
+	}
+
+	rows, err := repo.ResetStuckSessionsOnRestart(ctx)
+	require.NoError(t, err)
+	assert.Len(t, rows, 2)
+	for _, s := range rows {
+		assert.Equal(t, acp.SessionCrashed, s.Status)
+	}
+	rows2, _ := repo.ResetStuckSessionsOnRestart(ctx)
+	assert.Empty(t, rows2)
+}
+
+func TestPgRepo_Event_OrderAndPurge(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	repo, pool := setupRepo(t)
+
+	uid := mustInsertUser(t, ctx, pool, "u5@local", false)
+	pid, wsid := mustInsertProjectWorkspace(t, ctx, pool, uid)
+	k, _ := repo.CreateAgentKind(ctx, &acp.AgentKind{
+		ID: uuid.New(), Name: "kind5", DisplayName: "x",
+		BinaryPath: "x", Enabled: true, CreatedBy: uid,
+	})
+	sess, _ := repo.InsertSession(ctx, &acp.Session{
+		ID: uuid.New(), WorkspaceID: wsid, ProjectID: pid,
+		AgentKindID: k.ID, UserID: uid,
+		Branch: "main", CwdPath: "/tmp", IsMainWorktree: true, Status: acp.SessionRunning,
+	})
+
+	for i := 0; i < 3; i++ {
+		method := "session/update"
+		_, err := repo.InsertEvent(ctx, &acp.Event{
+			SessionID: sess.ID, Direction: acp.DirectionOut, RPCKind: acp.RPCNotification,
+			Method: &method, Payload: []byte(`{"foo":"bar"}`), PayloadSize: 13, Truncated: false,
+		})
+		require.NoError(t, err)
+	}
+
+	// ListSince 0 → 全部 3 条
+	all, err := repo.ListEventsSince(ctx, sess.ID, 0, 100)
+	require.NoError(t, err)
+	require.Len(t, all, 3)
+	assert.True(t, all[0].ID < all[1].ID && all[1].ID < all[2].ID)
+
+	// Since 第 1 条 ID → 仅 2 条
+	rest, _ := repo.ListEventsSince(ctx, sess.ID, all[0].ID, 100)
+	assert.Len(t, rest, 2)
+
+	// Purge before now+1m → 全删
+	n, _ := repo.PurgeEventsBefore(ctx, time.Now().Add(time.Minute))
+	assert.Equal(t, int64(3), n)
+}
+
+// ===== test helpers =====
+
+func mustInsertUser(t *testing.T, ctx context.Context, pool *pgxpool.Pool, email string, admin bool) uuid.UUID {
+	t.Helper()
+	id := uuid.New()
+	_, err := pool.Exec(ctx, `INSERT INTO users (id, email, password_hash, display_name, is_admin)
+		VALUES ($1, $2, 'h', 'n', $3)`, id, email, admin)
+	require.NoError(t, err)
+	return id
+}
+
+func mustInsertProjectWorkspace(t *testing.T, ctx context.Context, pool *pgxpool.Pool, owner uuid.UUID) (uuid.UUID, uuid.UUID) {
+	t.Helper()
+	pid := uuid.New()
+	wsid := uuid.New()
+	slug := "p-" + pid.String()[:8]
+	wsslug := "ws-" + wsid.String()[:8]
+	_, err := pool.Exec(ctx, `INSERT INTO projects (id, slug, name, owner_id) VALUES ($1, $2, 'p', $3)`,
+		pid, slug, owner)
+	require.NoError(t, err)
+	_, err = pool.Exec(ctx, `INSERT INTO workspaces (id, project_id, slug, name, git_remote_url, main_path)
+		VALUES ($1, $2, $3, 'w', 'git@x:y.git', '/tmp')`, wsid, pid, wsslug)
+	require.NoError(t, err)
+	return pid, wsid
+}