diff --git a/internal/project/project_service.go b/internal/project/project_service.go
new file mode 100644
index 0000000..b85487a
--- /dev/null
+++ b/internal/project/project_service.go
@@ -0,0 +1,202 @@
+// Package project 内的 project_service.go 实装 ProjectService 接口。
+//
+// 鉴权矩阵（PM spec §1.3）：
+//
+//	read   private:  owner + admin
+//	read   internal: 任意已登录
+//	write  *:        owner + admin
+//
+// 已归档项目下的所有写操作（包含 Requirement / Issue 的写）一律返回
+// CodeProjectArchived；这是 spec 强约定，不区分 owner / admin。
+package project
+
+import (
+	"context"
+
+	"github.com/google/uuid"
+
+	"github.com/yan1h/agent-coding-workflow/internal/audit"
+	"github.com/yan1h/agent-coding-workflow/internal/infra/errs"
+)
+
+type projectService struct {
+	repo  Repository
+	audit audit.Recorder
+}
+
+// NewProjectService 用 Repository 与可选 audit recorder 构造 ProjectService。
+// recorder == nil 时跳过审计写入（便于单测）。
+func NewProjectService(repo Repository, rec audit.Recorder) ProjectService {
+	return &projectService{repo: repo, audit: rec}
+}
+
+// assertReadable 是 read 类操作的鉴权门面：private 仅 owner+admin，internal
+// 任意登录用户。失败统一返回 CodeNotFound（避免存在性探测）。
+func assertReadable(p *Project, c Caller) error {
+	if p.Visibility == VisibilityInternal {
+		return nil
+	}
+	if c.IsAdmin || p.OwnerID == c.UserID {
+		return nil
+	}
+	return errs.New(errs.CodeNotFound, "project 不存在")
+}
+
+// assertWritable 是 write 类操作的鉴权门面：仅 owner+admin。已归档项目额外
+// 拒绝；调用方应在执行写入前调用此函数。
+func assertWritable(p *Project, c Caller) error {
+	if !(c.IsAdmin || p.OwnerID == c.UserID) {
+		// stranger 对 private 看不见；对 internal 也不能写。统一 not_found 防探测。
+		if p.Visibility == VisibilityPrivate {
+			return errs.New(errs.CodeNotFound, "project 不存在")
+		}
+		return errs.New(errs.CodeForbidden, "无权修改该项目")
+	}
+	if p.ArchivedAt != nil {
+		return errs.New(errs.CodeProjectArchived, "项目已归档，禁止写操作")
+	}
+	return nil
+}
+
+func (s *projectService) Create(ctx context.Context, c Caller, in CreateProjectInput) (*Project, error) {
+	if in.Slug == "" || in.Name == "" {
+		return nil, errs.New(errs.CodeInvalidInput, "slug / name 必填")
+	}
+	if in.Visibility == "" {
+		in.Visibility = VisibilityPrivate
+	}
+	if !in.Visibility.IsValid() {
+		return nil, errs.New(errs.CodeInvalidInput, "visibility 非法")
+	}
+	p := &Project{
+		ID: uuid.New(), Slug: in.Slug, Name: in.Name, Description: in.Description,
+		Visibility: in.Visibility, OwnerID: c.UserID,
+	}
+	out, err := s.repo.CreateProject(ctx, p)
+	if err != nil {
+		return nil, err
+	}
+	s.recordAudit(ctx, c, "project.create", out.ID.String(), map[string]any{
+		"slug": out.Slug, "name": out.Name, "visibility": string(out.Visibility),
+	})
+	return out, nil
+}
+
+func (s *projectService) Get(ctx context.Context, c Caller, slug string) (*Project, error) {
+	p, err := s.repo.GetProjectBySlug(ctx, slug)
+	if err != nil {
+		return nil, err
+	}
+	if err := assertReadable(p, c); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+func (s *projectService) List(ctx context.Context, c Caller, includeArchived bool) ([]*Project, error) {
+	all, err := s.repo.ListProjects(ctx, includeArchived)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]*Project, 0, len(all))
+	for _, p := range all {
+		if assertReadable(p, c) == nil {
+			out = append(out, p)
+		}
+	}
+	return out, nil
+}
+
+func (s *projectService) Update(ctx context.Context, c Caller, slug string, in UpdateProjectInput) (*Project, error) {
+	p, err := s.repo.GetProjectBySlug(ctx, slug)
+	if err != nil {
+		return nil, err
+	}
+	if err := assertWritable(p, c); err != nil {
+		return nil, err
+	}
+	changed := map[string]any{}
+	if in.Name != nil {
+		p.Name = *in.Name
+		changed["name"] = *in.Name
+	}
+	if in.Description != nil {
+		p.Description = *in.Description
+		changed["description"] = "<changed>"
+	}
+	if in.Visibility != nil {
+		if !in.Visibility.IsValid() {
+			return nil, errs.New(errs.CodeInvalidInput, "visibility 非法")
+		}
+		p.Visibility = *in.Visibility
+		changed["visibility"] = string(*in.Visibility)
+	}
+	if len(changed) == 0 {
+		return p, nil
+	}
+	out, err := s.repo.UpdateProject(ctx, p)
+	if err != nil {
+		return nil, err
+	}
+	s.recordAudit(ctx, c, "project.update", out.ID.String(), map[string]any{"changed_fields": changed})
+	return out, nil
+}
+
+func (s *projectService) Archive(ctx context.Context, c Caller, slug string) error {
+	p, err := s.repo.GetProjectBySlug(ctx, slug)
+	if err != nil {
+		return err
+	}
+	// 归档/取消归档仍要 owner+admin 校验，但已归档不再额外阻塞 archive。
+	if !(c.IsAdmin || p.OwnerID == c.UserID) {
+		if p.Visibility == VisibilityPrivate {
+			return errs.New(errs.CodeNotFound, "project 不存在")
+		}
+		return errs.New(errs.CodeForbidden, "无权操作该项目")
+	}
+	if p.ArchivedAt != nil {
+		return nil // 幂等
+	}
+	if err := s.repo.ArchiveProject(ctx, p.ID); err != nil {
+		return err
+	}
+	s.recordAudit(ctx, c, "project.archive", p.ID.String(), nil)
+	return nil
+}
+
+func (s *projectService) Unarchive(ctx context.Context, c Caller, slug string) error {
+	p, err := s.repo.GetProjectBySlug(ctx, slug)
+	if err != nil {
+		return err
+	}
+	if !(c.IsAdmin || p.OwnerID == c.UserID) {
+		if p.Visibility == VisibilityPrivate {
+			return errs.New(errs.CodeNotFound, "project 不存在")
+		}
+		return errs.New(errs.CodeForbidden, "无权操作该项目")
+	}
+	if p.ArchivedAt == nil {
+		return nil
+	}
+	if err := s.repo.UnarchiveProject(ctx, p.ID); err != nil {
+		return err
+	}
+	s.recordAudit(ctx, c, "project.unarchive", p.ID.String(), nil)
+	return nil
+}
+
+// recordAudit 是 best-effort 写入：失败仅吞错（不影响业务）。ctx 用
+// context.WithoutCancel 派生，使 HTTP 响应已返回但审计仍能落库。
+func (s *projectService) recordAudit(ctx context.Context, c Caller, action, targetID string, meta map[string]any) {
+	if s.audit == nil {
+		return
+	}
+	uid := c.UserID
+	_ = s.audit.Record(context.WithoutCancel(ctx), audit.Entry{
+		UserID:     &uid,
+		Action:     action,
+		TargetType: "project",
+		TargetID:   targetID,
+		Metadata:   meta,
+	})
+}
diff --git a/internal/project/project_service_test.go b/internal/project/project_service_test.go
new file mode 100644
index 0000000..af6984d
--- /dev/null
+++ b/internal/project/project_service_test.go
@@ -0,0 +1,473 @@
+package project
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+
+	"github.com/yan1h/agent-coding-workflow/internal/audit"
+	"github.com/yan1h/agent-coding-workflow/internal/infra/errs"
+)
+
+// fakeRepo 是内存版 Repository，仅用于 service 单测；按 ID/slug 查找用 map，
+// number 自增手动维护。并发安全（一把大锁就够）。
+type fakeRepo struct {
+	mu           sync.Mutex
+	projects     map[uuid.UUID]*Project
+	requirements map[uuid.UUID]*Requirement
+	issues       map[uuid.UUID]*Issue
+}
+
+func newFakeRepo() *fakeRepo {
+	return &fakeRepo{
+		projects:     map[uuid.UUID]*Project{},
+		requirements: map[uuid.UUID]*Requirement{},
+		issues:       map[uuid.UUID]*Issue{},
+	}
+}
+
+func (r *fakeRepo) cloneProject(p *Project) *Project { v := *p; return &v }
+func (r *fakeRepo) cloneReq(p *Requirement) *Requirement { v := *p; return &v }
+func (r *fakeRepo) cloneIssue(p *Issue) *Issue { v := *p; return &v }
+
+func (r *fakeRepo) CreateProject(_ context.Context, p *Project) (*Project, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for _, x := range r.projects {
+		if x.Slug == p.Slug {
+			return nil, errs.New(errs.CodeProjectSlugTaken, "slug 已被使用")
+		}
+	}
+	now := time.Now()
+	p.CreatedAt, p.UpdatedAt = now, now
+	r.projects[p.ID] = r.cloneProject(p)
+	return r.cloneProject(p), nil
+}
+
+func (r *fakeRepo) GetProjectBySlug(_ context.Context, slug string) (*Project, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for _, p := range r.projects {
+		if p.Slug == slug {
+			return r.cloneProject(p), nil
+		}
+	}
+	return nil, errs.New(errs.CodeNotFound, "project 不存在")
+}
+
+func (r *fakeRepo) GetProjectByID(_ context.Context, id uuid.UUID) (*Project, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	p, ok := r.projects[id]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "project 不存在")
+	}
+	return r.cloneProject(p), nil
+}
+
+func (r *fakeRepo) ListProjects(_ context.Context, includeArchived bool) ([]*Project, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	out := make([]*Project, 0, len(r.projects))
+	for _, p := range r.projects {
+		if !includeArchived && p.ArchivedAt != nil {
+			continue
+		}
+		out = append(out, r.cloneProject(p))
+	}
+	return out, nil
+}
+
+func (r *fakeRepo) UpdateProject(_ context.Context, p *Project) (*Project, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.projects[p.ID]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "project 不存在")
+	}
+	cur.Name, cur.Description, cur.Visibility = p.Name, p.Description, p.Visibility
+	cur.UpdatedAt = time.Now()
+	return r.cloneProject(cur), nil
+}
+
+func (r *fakeRepo) ArchiveProject(_ context.Context, id uuid.UUID) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	p, ok := r.projects[id]
+	if !ok {
+		return nil
+	}
+	now := time.Now()
+	p.ArchivedAt, p.UpdatedAt = &now, now
+	return nil
+}
+
+func (r *fakeRepo) UnarchiveProject(_ context.Context, id uuid.UUID) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	p, ok := r.projects[id]
+	if !ok {
+		return nil
+	}
+	p.ArchivedAt, p.UpdatedAt = nil, time.Now()
+	return nil
+}
+
+// ===== Requirement =====
+
+func (r *fakeRepo) nextRequirementNumber(projectID uuid.UUID) int {
+	max := 0
+	for _, x := range r.requirements {
+		if x.ProjectID == projectID && x.Number > max {
+			max = x.Number
+		}
+	}
+	return max + 1
+}
+
+func (r *fakeRepo) CreateRequirement(_ context.Context, in *Requirement) (*Requirement, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	in.Number = r.nextRequirementNumber(in.ProjectID)
+	now := time.Now()
+	in.CreatedAt, in.UpdatedAt = now, now
+	if in.Phase == "" {
+		in.Phase = PhasePlanning
+	}
+	if in.Status == "" {
+		in.Status = StatusOpen
+	}
+	r.requirements[in.ID] = r.cloneReq(in)
+	return r.cloneReq(in), nil
+}
+
+func (r *fakeRepo) GetRequirementByNumber(_ context.Context, projectID uuid.UUID, number int) (*Requirement, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for _, x := range r.requirements {
+		if x.ProjectID == projectID && x.Number == number {
+			return r.cloneReq(x), nil
+		}
+	}
+	return nil, errs.New(errs.CodeNotFound, "requirement 不存在")
+}
+
+func (r *fakeRepo) GetRequirementByID(_ context.Context, id uuid.UUID) (*Requirement, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	x, ok := r.requirements[id]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "requirement 不存在")
+	}
+	return r.cloneReq(x), nil
+}
+
+func (r *fakeRepo) ListRequirements(_ context.Context, projectID uuid.UUID, phase Phase, status Status) ([]*Requirement, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	out := make([]*Requirement, 0)
+	for _, x := range r.requirements {
+		if x.ProjectID != projectID {
+			continue
+		}
+		if phase != "" && x.Phase != phase {
+			continue
+		}
+		if status != "" && x.Status != status {
+			continue
+		}
+		out = append(out, r.cloneReq(x))
+	}
+	return out, nil
+}
+
+func (r *fakeRepo) UpdateRequirement(_ context.Context, in *Requirement) (*Requirement, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.requirements[in.ID]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "requirement 不存在")
+	}
+	cur.Title, cur.Description, cur.OwnerID = in.Title, in.Description, in.OwnerID
+	cur.UpdatedAt = time.Now()
+	return r.cloneReq(cur), nil
+}
+
+func (r *fakeRepo) UpdateRequirementPhase(_ context.Context, id uuid.UUID, to Phase) (*Requirement, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.requirements[id]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "requirement 不存在")
+	}
+	cur.Phase = to
+	cur.UpdatedAt = time.Now()
+	return r.cloneReq(cur), nil
+}
+
+func (r *fakeRepo) CloseRequirement(_ context.Context, id uuid.UUID) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.requirements[id]
+	if !ok || cur.Status != StatusOpen {
+		return nil
+	}
+	now := time.Now()
+	cur.Status, cur.ClosedAt, cur.UpdatedAt = StatusClosed, &now, now
+	return nil
+}
+
+func (r *fakeRepo) ReopenRequirement(_ context.Context, id uuid.UUID) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.requirements[id]
+	if !ok || cur.Status != StatusClosed {
+		return nil
+	}
+	cur.Status, cur.ClosedAt, cur.UpdatedAt = StatusOpen, nil, time.Now()
+	return nil
+}
+
+// ===== Issue =====
+
+func (r *fakeRepo) nextIssueNumber(projectID uuid.UUID) int {
+	max := 0
+	for _, x := range r.issues {
+		if x.ProjectID == projectID && x.Number > max {
+			max = x.Number
+		}
+	}
+	return max + 1
+}
+
+func (r *fakeRepo) CreateIssue(_ context.Context, in *Issue) (*Issue, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	in.Number = r.nextIssueNumber(in.ProjectID)
+	now := time.Now()
+	in.CreatedAt, in.UpdatedAt = now, now
+	if in.Status == "" {
+		in.Status = StatusOpen
+	}
+	r.issues[in.ID] = r.cloneIssue(in)
+	return r.cloneIssue(in), nil
+}
+
+func (r *fakeRepo) GetIssueByNumber(_ context.Context, projectID uuid.UUID, number int) (*Issue, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for _, x := range r.issues {
+		if x.ProjectID == projectID && x.Number == number {
+			return r.cloneIssue(x), nil
+		}
+	}
+	return nil, errs.New(errs.CodeNotFound, "issue 不存在")
+}
+
+func (r *fakeRepo) ListIssues(_ context.Context, projectID uuid.UUID, filter IssueFilter, requirementID *uuid.UUID) ([]*Issue, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	out := make([]*Issue, 0)
+	for _, x := range r.issues {
+		if x.ProjectID != projectID {
+			continue
+		}
+		if filter.Status != "" && x.Status != filter.Status {
+			continue
+		}
+		if filter.Requirement != nil {
+			switch {
+			case *filter.Requirement == 0:
+				if x.RequirementID != nil {
+					continue
+				}
+			default:
+				if x.RequirementID == nil || *x.RequirementID != *requirementID {
+					continue
+				}
+			}
+		}
+		if filter.AssigneeID != nil {
+			if x.AssigneeID == nil || *x.AssigneeID != *filter.AssigneeID {
+				continue
+			}
+		}
+		out = append(out, r.cloneIssue(x))
+	}
+	return out, nil
+}
+
+func (r *fakeRepo) ListIssuesByRequirement(_ context.Context, requirementID uuid.UUID) ([]*Issue, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	out := make([]*Issue, 0)
+	for _, x := range r.issues {
+		if x.RequirementID != nil && *x.RequirementID == requirementID {
+			out = append(out, r.cloneIssue(x))
+		}
+	}
+	return out, nil
+}
+
+func (r *fakeRepo) UpdateIssueCore(_ context.Context, id uuid.UUID, title, description string, requirementID *uuid.UUID) (*Issue, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.issues[id]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "issue 不存在")
+	}
+	cur.Title, cur.Description, cur.RequirementID = title, description, requirementID
+	cur.UpdatedAt = time.Now()
+	return r.cloneIssue(cur), nil
+}
+
+func (r *fakeRepo) UpdateIssueAssignee(_ context.Context, id uuid.UUID, assignee *uuid.UUID) (*Issue, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.issues[id]
+	if !ok {
+		return nil, errs.New(errs.CodeNotFound, "issue 不存在")
+	}
+	cur.AssigneeID = assignee
+	cur.UpdatedAt = time.Now()
+	return r.cloneIssue(cur), nil
+}
+
+func (r *fakeRepo) CloseIssue(_ context.Context, id uuid.UUID) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.issues[id]
+	if !ok || cur.Status != StatusOpen {
+		return nil
+	}
+	now := time.Now()
+	cur.Status, cur.ClosedAt, cur.UpdatedAt = StatusClosed, &now, now
+	return nil
+}
+
+func (r *fakeRepo) ReopenIssue(_ context.Context, id uuid.UUID) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cur, ok := r.issues[id]
+	if !ok || cur.Status != StatusClosed {
+		return nil
+	}
+	cur.Status, cur.ClosedAt, cur.UpdatedAt = StatusOpen, nil, time.Now()
+	return nil
+}
+
+// spyAudit 收集所有写入的 audit entry，方便断言。
+type spyAudit struct {
+	mu      sync.Mutex
+	entries []audit.Entry
+}
+
+func (s *spyAudit) Record(_ context.Context, e audit.Entry) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.entries = append(s.entries, e)
+	return nil
+}
+
+func (s *spyAudit) actions() []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	out := make([]string, 0, len(s.entries))
+	for _, e := range s.entries {
+		out = append(out, e.Action)
+	}
+	return out
+}
+
+// seedProject 写一条测试用 Project 并返回。caller 默认为 owner。
+func seedProject(t *testing.T, r *fakeRepo, ownerID uuid.UUID) *Project {
+	t.Helper()
+	p := &Project{
+		ID: uuid.New(), Slug: "demo", Name: "Demo",
+		Visibility: VisibilityPrivate, OwnerID: ownerID,
+	}
+	out, err := r.CreateProject(context.Background(), p)
+	require.NoError(t, err)
+	return out
+}
+
+func TestProjectService_Create_HappyPath(t *testing.T) {
+	repo := newFakeRepo()
+	spy := &spyAudit{}
+	svc := NewProjectService(repo, spy)
+	owner := uuid.New()
+	p, err := svc.Create(context.Background(), Caller{UserID: owner, IsAdmin: false}, CreateProjectInput{
+		Slug: "demo", Name: "Demo", Visibility: VisibilityPrivate,
+	})
+	require.NoError(t, err)
+	require.Equal(t, "demo", p.Slug)
+	require.Equal(t, owner, p.OwnerID)
+	require.Equal(t, []string{"project.create"}, spy.actions())
+}
+
+func TestProjectService_Create_SlugTaken(t *testing.T) {
+	repo := newFakeRepo()
+	owner := uuid.New()
+	seedProject(t, repo, owner)
+	svc := NewProjectService(repo, nil)
+	_, err := svc.Create(context.Background(), Caller{UserID: owner}, CreateProjectInput{
+		Slug: "demo", Name: "Other", Visibility: VisibilityPrivate,
+	})
+	ae, ok := errs.As(err)
+	require.True(t, ok)
+	require.Equal(t, errs.CodeProjectSlugTaken, ae.Code)
+}
+
+func TestProjectService_Get_PrivateRejectsStranger(t *testing.T) {
+	repo := newFakeRepo()
+	owner := uuid.New()
+	seedProject(t, repo, owner)
+	svc := NewProjectService(repo, nil)
+	_, err := svc.Get(context.Background(), Caller{UserID: uuid.New()}, "demo")
+	ae, ok := errs.As(err)
+	require.True(t, ok)
+	// stranger 看 private project：屏蔽存在性，按 not_found 处理。
+	require.Equal(t, errs.CodeNotFound, ae.Code)
+}
+
+func TestProjectService_Get_InternalAllowsLoggedIn(t *testing.T) {
+	repo := newFakeRepo()
+	owner := uuid.New()
+	p := seedProject(t, repo, owner)
+	p.Visibility = VisibilityInternal
+	_, err := repo.UpdateProject(context.Background(), p)
+	require.NoError(t, err)
+	svc := NewProjectService(repo, nil)
+	got, err := svc.Get(context.Background(), Caller{UserID: uuid.New()}, "demo")
+	require.NoError(t, err)
+	require.Equal(t, "demo", got.Slug)
+}
+
+func TestProjectService_Update_RequiresOwnerOrAdmin(t *testing.T) {
+	repo := newFakeRepo()
+	owner := uuid.New()
+	seedProject(t, repo, owner)
+	svc := NewProjectService(repo, nil)
+	name := "Renamed"
+	_, err := svc.Update(context.Background(), Caller{UserID: uuid.New()}, "demo", UpdateProjectInput{Name: &name})
+	ae, ok := errs.As(err)
+	require.True(t, ok)
+	require.Equal(t, errs.CodeNotFound, ae.Code, "stranger 看 private 直接 not_found")
+}
+
+func TestProjectService_Archive_BlocksWrites(t *testing.T) {
+	repo := newFakeRepo()
+	owner := uuid.New()
+	seedProject(t, repo, owner)
+	svc := NewProjectService(repo, nil)
+	require.NoError(t, svc.Archive(context.Background(), Caller{UserID: owner}, "demo"))
+	name := "X"
+	_, err := svc.Update(context.Background(), Caller{UserID: owner}, "demo", UpdateProjectInput{Name: &name})
+	ae, ok := errs.As(err)
+	require.True(t, ok)
+	require.Equal(t, errs.CodeProjectArchived, ae.Code)
+}