diff --git a/go/cmd/bd2server/main.go b/go/cmd/bd2server/main.go
index 71f9642..1cb7d74 100644
--- a/go/cmd/bd2server/main.go
+++ b/go/cmd/bd2server/main.go
@@ -670,6 +670,20 @@ func serve(args []string) (serveErr error) {
 		return fmt.Errorf("read initial hunting AP: %w", err)
 	}
 	gameplayStore := stateio.EntrySnapshotStore{Entries: stateRepository, Domain: "missions", Bucket: "gameplay"}
+	contentOpeningDesign, err := gamedata.LoadContentOpeningDesign(gameData, *gameDataVersion)
+	if err != nil {
+		return fmt.Errorf("load content opening GameData: %w", err)
+	}
+	contentOpenService, err := player.NewContentOpenService(contentOpeningDesign, ownedItems, gameplayStore, func() (uint64, error) {
+		experience, err := missionService.AchievementExperience()
+		if err != nil {
+			return 0, err
+		}
+		return levelDesign.Level(experience), nil
+	})
+	if err != nil {
+		return fmt.Errorf("load content opening state: %w", err)
+	}
 	huntingService, err := hunting.Open(gameplayStore, gameData, *gameDataVersion, ownedItems, wallet,
 		worldService.CurrentPackID, freeHuntingAP, bonusHuntingAP)
 	if err != nil {
@@ -1115,6 +1129,7 @@ func serve(args []string) (serveErr error) {
 		costumePotentialService,
 		costumeBurstService,
 		friendshipService,
+		contentOpenService,
 		masterTitleService,
 		recruitService,
 		foodService,
diff --git a/go/internal/server/gamedata/content_open.go b/go/internal/server/gamedata/content_open.go
new file mode 100644
index 0000000..75c43d7
--- /dev/null
+++ b/go/internal/server/gamedata/content_open.go
@@ -0,0 +1,106 @@
+package gamedata
+
+import (
+	"database/sql"
+	"fmt"
+)
+
+// ContentOpeningDesign describes the rapport prologue's prerequisite and
+// completion marker. The client maps ContentOpenRequest type 1 to group 23,
+// detail 2; ticket identities and level requirements remain version data.
+type ContentOpeningDesign struct {
+	Prerequisite, Completion ContentOpenRule
+}
+
+func LoadContentOpeningDesign(root, version string) (*ContentOpeningDesign, error) {
+	db, done, err := openStatDatabase(root, version)
+	if err != nil {
+		return nil, err
+	}
+	defer done()
+	return loadContentOpeningDesign(db)
+}
+
+func loadContentOpeningDesign(db *sql.DB) (*ContentOpeningDesign, error) {
+	if db == nil {
+		return nil, fmt.Errorf("gamedata: nil content opening database")
+	}
+	tickets := map[uint64]uint64{}
+	rows, err := db.Query("SELECT id,ProtoBuf FROM ContentTicketTable ORDER BY id")
+	if err != nil {
+		return nil, err
+	}
+	for rows.Next() {
+		var id uint64
+		var raw []byte
+		if err = rows.Scan(&id, &raw); err != nil {
+			break
+		}
+		var protoID, typ uint64
+		protoID, err = friendshipScalar(raw, 4)
+		if err == nil {
+			typ, err = friendshipScalar(raw, 8)
+		}
+		if err != nil || id == 0 || protoID != id || typ < 1 || typ > 6 {
+			err = fmt.Errorf("gamedata: invalid content ticket %d", id)
+			break
+		}
+		if _, exists := tickets[id]; exists {
+			err = fmt.Errorf("gamedata: duplicate content ticket %d", id)
+			break
+		}
+		tickets[id] = typ
+	}
+	if err == nil {
+		err = rows.Err()
+	}
+	rows.Close()
+	if err != nil {
+		return nil, err
+	}
+	rows, err = db.Query("SELECT groupId,id,ticketId,ProtoBuf FROM ContentOpenTable ORDER BY groupId,id")
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	d := &ContentOpeningDesign{}
+	seen := map[[2]uint64]bool{}
+	for rows.Next() {
+		var group, id, ticket uint64
+		var raw []byte
+		if err := rows.Scan(&group, &id, &ticket, &raw); err != nil {
+			return nil, err
+		}
+		values := make([]uint64, 6)
+		for i := range values {
+			values[i], err = friendshipScalar(raw, i+1)
+			if err != nil {
+				return nil, fmt.Errorf("gamedata: content opening %d/%d: %w", group, id, err)
+			}
+		}
+		key := [2]uint64{group, id}
+		if group == 0 || id == 0 || values[0] != group || values[1] != id || ticket == 0 || values[5] != ticket || tickets[ticket] == 0 || seen[key] {
+			return nil, fmt.Errorf("gamedata: invalid content opening %d/%d identity or ticket", group, id)
+		}
+		seen[key] = true
+		if group != 23 || (id != 1 && id != 2) {
+			continue
+		}
+		if tickets[ticket] != 1 {
+			return nil, fmt.Errorf("gamedata: rapport opening %d requires permanent content ticket", id)
+		}
+		rule := ContentOpenRule{TutorialID: values[3], SquadLevel: values[4], TicketID: ticket}
+		if id == 1 {
+			d.Prerequisite = rule
+		} else {
+			d.Completion = rule
+		}
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if !seen[[2]uint64{23, 1}] || !seen[[2]uint64{23, 2}] || d.Prerequisite.TicketID == d.Completion.TicketID {
+		return nil, fmt.Errorf("gamedata: missing or indistinguishable rapport opening rules")
+	}
+	return d, nil
+}
diff --git a/go/internal/server/gamedata/content_open_test.go b/go/internal/server/gamedata/content_open_test.go
new file mode 100644
index 0000000..f580495
--- /dev/null
+++ b/go/internal/server/gamedata/content_open_test.go
@@ -0,0 +1,66 @@
+package gamedata
+
+import (
+	"database/sql"
+	"testing"
+)
+
+func contentOpeningTestDB(t *testing.T) *sql.DB {
+	t.Helper()
+	db, err := sql.Open("sqlite", ":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	db.SetMaxOpenConns(1)
+	t.Cleanup(func() { db.Close() })
+	for _, q := range []string{"CREATE TABLE ContentOpenTable(groupId INTEGER,id INTEGER,ticketId INTEGER,ProtoBuf BLOB)", "CREATE TABLE ContentTicketTable(id INTEGER,ProtoBuf BLOB)"} {
+		if _, err := db.Exec(q); err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, id := range []uint64{901, 902} {
+		if _, err := db.Exec("INSERT INTO ContentTicketTable VALUES(?,?)", id, friendshipTestProto(map[int][]uint64{4: {id}, 8: {1}})); err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, id := range []uint64{1, 2} {
+		if _, err := db.Exec("INSERT INTO ContentOpenTable VALUES(23,?,?,?)", id, 900+id, friendshipTestProto(map[int][]uint64{1: {23}, 2: {id}, 4: {100 + id}, 5: {10 + id}, 6: {900 + id}})); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return db
+}
+
+func TestContentOpeningUsesVersionTicketsAndRequirements(t *testing.T) {
+	d, err := loadContentOpeningDesign(contentOpeningTestDB(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if d.Prerequisite != (ContentOpenRule{TicketID: 901, SquadLevel: 11, TutorialID: 101}) || d.Completion != (ContentOpenRule{TicketID: 902, SquadLevel: 12, TutorialID: 102}) {
+		t.Fatalf("design=%+v", d)
+	}
+}
+
+func TestContentOpeningRejectsIncompleteAndInvalidCatalog(t *testing.T) {
+	for _, tc := range []struct {
+		name, query string
+		args        []any
+	}{
+		{"missing completion", "DELETE FROM ContentOpenTable WHERE id=2", nil},
+		{"missing ticket", "DELETE FROM ContentTicketTable WHERE id=902", nil},
+		{"temporary ticket", "UPDATE ContentTicketTable SET ProtoBuf=? WHERE id=902", []any{friendshipTestProto(map[int][]uint64{4: {902}, 8: {2}})}},
+		{"wrong ticket identity", "UPDATE ContentTicketTable SET ProtoBuf=? WHERE id=901", []any{friendshipTestProto(map[int][]uint64{4: {999}, 8: {1}})}},
+		{"wrong opening identity", "UPDATE ContentOpenTable SET ProtoBuf=? WHERE id=2", []any{friendshipTestProto(map[int][]uint64{1: {23}, 2: {1}, 6: {902}})}},
+		{"invalid unrelated row", "INSERT INTO ContentOpenTable VALUES(1,1,999,?)", []any{friendshipTestProto(map[int][]uint64{1: {1}, 2: {1}, 6: {999}})}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			db := contentOpeningTestDB(t)
+			if _, err := db.Exec(tc.query, tc.args...); err != nil {
+				t.Fatal(err)
+			}
+			if _, err := loadContentOpeningDesign(db); err == nil {
+				t.Fatal("invalid catalog accepted")
+			}
+		})
+	}
+}
diff --git a/go/internal/server/player/content_open.go b/go/internal/server/player/content_open.go
new file mode 100644
index 0000000..29e74fc
--- /dev/null
+++ b/go/internal/server/player/content_open.go
@@ -0,0 +1,230 @@
+package player
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"sync"
+
+	"bd2server/internal/server/gamedata"
+	"bd2server/internal/server/stateio"
+	"bd2server/internal/server/wire"
+)
+
+const contentOpenPacketCode = 622
+
+type contentOpenReceipt struct {
+	Digest string `json:"digest"`
+	Body   []byte `json:"body"`
+}
+
+type contentOpenState struct {
+	Receipts map[string]contentOpenReceipt `json:"receipts"`
+}
+
+// ContentOpenService grants the completion ticket for the client's sole
+// implemented ContentOpen type (1). The prerequisite ticket is never spent.
+// Handle must run in the account request transaction: inventory and receipt
+// writes commit together, and account recovery reconstructs Inventory after
+// a dirty rollback. Receipts are reloaded for every request.
+type ContentOpenService struct {
+	mu         sync.Mutex
+	design     *gamedata.ContentOpeningDesign
+	inventory  *Inventory
+	store      stateio.Store
+	squadLevel func() (uint64, error)
+	session    string
+}
+
+func NewContentOpenService(design *gamedata.ContentOpeningDesign, inventory *Inventory, store stateio.Store, squadLevel func() (uint64, error)) (*ContentOpenService, error) {
+	if design == nil || inventory == nil || store == nil || squadLevel == nil || design.Prerequisite.TicketID == 0 || design.Completion.TicketID == 0 || design.Completion.TicketID == design.Prerequisite.TicketID {
+		return nil, errors.New("player: incomplete ContentOpen service")
+	}
+	s := &ContentOpenService{design: design, inventory: inventory, store: store, squadLevel: squadLevel}
+	if _, err := s.loadState(); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func (s *ContentOpenService) BeginSession(id string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.session = id
+}
+
+func (s *ContentOpenService) Handle(path string, request []byte) (int, []byte, bool, error) {
+	if path != "/ContentOpen" {
+		return 0, nil, false, nil
+	}
+	var seq, kind uint64
+	var haveSeq, haveKind bool
+	err := wire.Walk(request, func(field wire.Field) error {
+		switch field.Number {
+		case 1, 2:
+			if field.Type != 0 {
+				return errors.New("player: ContentOpen field must be varint")
+			}
+			value, _ := binary.Uvarint(field.Value)
+			if field.Number == 1 {
+				if haveSeq {
+					return errors.New("player: duplicate ContentOpen sequence")
+				}
+				seq, haveSeq = value, true
+			} else {
+				if haveKind {
+					return errors.New("player: duplicate ContentOpen type")
+				}
+				kind, haveKind = value, true
+			}
+		}
+		return nil
+	})
+	if err != nil || !haveSeq || seq == 0 || seq > math.MaxInt32 || !haveKind || kind != 1 {
+		if err == nil {
+			err = errors.New("player: invalid ContentOpen sequence or unsupported type")
+		}
+		return 0, nil, true, err
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.session == "" {
+		return 0, nil, true, errors.New("player: ContentOpen requires authenticated session")
+	}
+	sessionHash := sha256.Sum256([]byte(s.session))
+	key := hex.EncodeToString(sessionHash[:]) + ":" + strconv.FormatUint(seq, 10)
+	requestHash := sha256.Sum256(request)
+	digest := hex.EncodeToString(requestHash[:])
+	state, err := s.loadState()
+	if err != nil {
+		return 0, nil, true, err
+	}
+	if receipt, ok := state.Receipts[key]; ok {
+		if receipt.Digest != digest {
+			return 0, nil, true, errors.New("player: ContentOpen sequence reused with different request")
+		}
+		return contentOpenPacketCode, append([]byte(nil), receipt.Body...), true, nil
+	}
+	var prerequisite, complete bool
+	var bundle []byte
+	for _, item := range s.inventory.All() {
+		if item.Type != 19 || item.Count == 0 {
+			continue
+		}
+		prerequisite = prerequisite || item.ID == s.design.Prerequisite.TicketID
+		if item.ID == s.design.Completion.TicketID && !complete {
+			if item.Count != 1 || item.InvenIndex == 0 || item.InvenIndex > math.MaxInt64 {
+				return 0, nil, true, errors.New("player: invalid owned ContentOpen completion ticket")
+			}
+			complete = true
+			bundle = wire.AppendBytes(bundle, 1, ItemWire(item))
+		}
+	}
+	if !complete {
+		if !prerequisite {
+			return 0, nil, true, errors.New("player: ContentOpen prerequisite ticket is not owned")
+		}
+		level, err := s.squadLevel()
+		if err != nil {
+			return 0, nil, true, fmt.Errorf("player: ContentOpen squad level: %w", err)
+		}
+		if level < max(s.design.Prerequisite.SquadLevel, s.design.Completion.SquadLevel) {
+			return 0, nil, true, errors.New("player: ContentOpen squad level is too low")
+		}
+		items, err := s.inventory.GrantOnce("content-open:"+strconv.FormatUint(s.design.Completion.TicketID, 10), []gamedata.BattleReward{{Type: 19, ID: s.design.Completion.TicketID, Count: 1}})
+		if err != nil {
+			return 0, nil, true, fmt.Errorf("player: grant ContentOpen ticket: %w", err)
+		}
+		if len(items) != 1 {
+			return 0, nil, true, errors.New("player: ContentOpen grant marker has no completion ticket")
+		}
+		for _, item := range items {
+			bundle = wire.AppendBytes(bundle, 1, ItemWire(item))
+		}
+	}
+	body := wire.AppendBytes(nil, 1, bundle)
+	state.Receipts[key] = contentOpenReceipt{Digest: digest, Body: body}
+	data, err := json.Marshal(state)
+	if err != nil {
+		return 0, nil, true, err
+	}
+	if err := s.store.Save("content_open", data); err != nil {
+		return 0, nil, true, fmt.Errorf("player: persist ContentOpen receipt: %w", err)
+	}
+	return contentOpenPacketCode, append([]byte(nil), body...), true, nil
+}
+
+func (s *ContentOpenService) loadState() (contentOpenState, error) {
+	state := contentOpenState{Receipts: make(map[string]contentOpenReceipt)}
+	data, err := s.store.Load("content_open")
+	if err != nil || data == nil {
+		return state, err
+	}
+	if err := stateio.RequireExactJSONObject(data, "receipts"); err != nil {
+		return state, fmt.Errorf("player: invalid ContentOpen state: %w", err)
+	}
+	if err := json.Unmarshal(data, &state); err != nil || state.Receipts == nil {
+		return state, errors.New("player: invalid ContentOpen receipts")
+	}
+	validHash := func(value string) bool {
+		decoded, err := hex.DecodeString(value)
+		return err == nil && len(decoded) == sha256.Size && hex.EncodeToString(decoded) == value
+	}
+	for key, receipt := range state.Receipts {
+		hash, sequence, found := strings.Cut(key, ":")
+		seq, err := strconv.ParseUint(sequence, 10, 32)
+		if !found || !validHash(hash) || err != nil || seq == 0 || seq > math.MaxInt32 || strconv.FormatUint(seq, 10) != sequence || !validHash(receipt.Digest) {
+			return state, errors.New("player: invalid ContentOpen receipt identity")
+		}
+		if err := validateContentOpenBody(receipt.Body, s.design.Completion.TicketID); err != nil {
+			return state, err
+		}
+	}
+	return state, nil
+}
+
+func validateContentOpenBody(body []byte, ticketID uint64) error {
+	unwrap := func(data []byte) ([]byte, error) {
+		var value []byte
+		var found bool
+		err := wire.Walk(data, func(field wire.Field) error {
+			if field.Number != 1 || field.Type != 2 || found {
+				return errors.New("player: invalid ContentOpen receipt bundle")
+			}
+			value, found = field.Value, true
+			return nil
+		})
+		if err != nil {
+			return nil, err
+		}
+		if !found {
+			return nil, errors.New("player: missing ContentOpen receipt bundle")
+		}
+		return value, nil
+	}
+	bundle, err := unwrap(body)
+	if err != nil {
+		return err
+	}
+	item, err := unwrap(bundle)
+	if err != nil {
+		return err
+	}
+	for field, want := range map[int]uint64{2: ticketID, 3: 19, 4: 1} {
+		value, present, err := wire.Varint(item, field)
+		if err != nil || !present || value != want {
+			return errors.New("player: invalid ContentOpen receipt ticket")
+		}
+	}
+	index, present, err := wire.Varint(item, 1)
+	if err != nil || !present || index == 0 || index > math.MaxInt64 {
+		return errors.New("player: invalid ContentOpen receipt ticket index")
+	}
+	return nil
+}
diff --git a/go/internal/server/player/content_open_test.go b/go/internal/server/player/content_open_test.go
new file mode 100644
index 0000000..e22ad07
--- /dev/null
+++ b/go/internal/server/player/content_open_test.go
@@ -0,0 +1,257 @@
+package player
+
+import (
+	"bytes"
+	"errors"
+	"path/filepath"
+	"testing"
+
+	"bd2server/internal/server/accountstate"
+	"bd2server/internal/server/gamedata"
+	"bd2server/internal/server/stateio"
+	"bd2server/internal/server/versionconfig"
+	"bd2server/internal/server/wire"
+)
+
+func contentOpenHarness(t *testing.T, store stateio.Store, prerequisite bool, level uint64) (*ContentOpenService, *Inventory) {
+	t.Helper()
+	starter := &Starter{Version: versionconfig.State()}
+	if prerequisite {
+		starter.Items = []Item{{InvenIndex: 100, Type: 19, ID: 41, Count: 1}}
+	}
+	inventory, err := OpenInventory(store, starter)
+	if err != nil {
+		t.Fatal(err)
+	}
+	design := &gamedata.ContentOpeningDesign{Prerequisite: gamedata.ContentOpenRule{TicketID: 41, SquadLevel: 3}, Completion: gamedata.ContentOpenRule{TicketID: 42, SquadLevel: 2}}
+	service, err := NewContentOpenService(design, inventory, store, func() (uint64, error) { return level, nil })
+	if err != nil {
+		t.Fatal(err)
+	}
+	service.BeginSession("authenticated-session")
+	return service, inventory
+}
+
+func contentOpenRequest(seq, kind uint64) []byte {
+	return wire.AppendVarint(wire.AppendVarint(nil, 1, seq), 2, kind)
+}
+
+func contentOpenTicketCount(inventory *Inventory, id uint64) uint64 {
+	var count uint64
+	for _, item := range inventory.All() {
+		if item.Type == 19 && item.ID == id {
+			count += item.Count
+		}
+	}
+	return count
+}
+
+func assertContentOpenResponse(t *testing.T, body []byte) {
+	t.Helper()
+	bundle, present, err := wire.Bytes(body, 1)
+	if err != nil || !present {
+		t.Fatalf("missing RewardDBInfoBundle: %x %v", body, err)
+	}
+	item, present, err := wire.Bytes(bundle, 1)
+	if err != nil || !present {
+		t.Fatalf("missing completion ItemDBInfo: %x %v", bundle, err)
+	}
+	for field, want := range map[int]uint64{2: 42, 3: 19, 4: 1} {
+		got, present, err := wire.Varint(item, field)
+		if err != nil || !present || got != want {
+			t.Fatalf("ItemDBInfo field %d=%d, want %d", field, got, want)
+		}
+	}
+}
+
+func TestContentOpenTicketOnceAcrossSequencesAndSessions(t *testing.T) {
+	store := stateio.NewMemory()
+	service, inventory := contentOpenHarness(t, store, true, 3)
+	request := contentOpenRequest(1, 1)
+	code, body, handled, err := service.Handle("/ContentOpen", request)
+	if err != nil || !handled || code != 622 {
+		t.Fatalf("open: %d %v %v", code, handled, err)
+	}
+	assertContentOpenResponse(t, body)
+	for _, tc := range []struct {
+		session string
+		seq     uint64
+	}{{"authenticated-session", 1}, {"authenticated-session", 2}, {"another-session", 1}} {
+		service.BeginSession(tc.session)
+		_, next, _, err := service.Handle("/ContentOpen", contentOpenRequest(tc.seq, 1))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !bytes.Equal(next, body) {
+			t.Fatal("ticket repair/retry returned a different item")
+		}
+	}
+	if contentOpenTicketCount(inventory, 41) != 1 || contentOpenTicketCount(inventory, 42) != 1 {
+		t.Fatal("prerequisite consumed or completion duplicated")
+	}
+	data, err := store.Load("content_open")
+	if err != nil || bytes.Contains(data, []byte("authenticated-session")) || bytes.Contains(data, []byte("another-session")) {
+		t.Fatal("receipt contains session credentials")
+	}
+	service.BeginSession("authenticated-session")
+	changed := wire.AppendVarint(append([]byte(nil), request...), 3, 7)
+	if _, _, _, err := service.Handle("/ContentOpen", changed); err == nil {
+		t.Fatal("same sequence accepted different request")
+	}
+}
+
+func TestContentOpenRequiresSessionAndRepairsOwnedTicket(t *testing.T) {
+	store := stateio.NewMemory()
+	service, inventory := contentOpenHarness(t, store, false, 0)
+	service.BeginSession("")
+	if _, _, _, err := service.Handle("/ContentOpen", contentOpenRequest(1, 1)); err == nil {
+		t.Fatal("missing authenticated session accepted")
+	}
+	if _, err := inventory.GrantOnce("existing-completion", []gamedata.BattleReward{{ID: 42, Type: 19, Count: 1}}); err != nil {
+		t.Fatal(err)
+	}
+	service.BeginSession("repair-session")
+	_, body, _, err := service.Handle("/ContentOpen", contentOpenRequest(1, 1))
+	if err != nil {
+		t.Fatal(err)
+	}
+	assertContentOpenResponse(t, body)
+	if contentOpenTicketCount(inventory, 42) != 1 {
+		t.Fatal("repair duplicated owned completion")
+	}
+}
+
+func TestContentOpenRejectsCorruptReceiptAtOpenAndAfterConstruction(t *testing.T) {
+	store := stateio.NewMemory()
+	service, inventory := contentOpenHarness(t, store, true, 3)
+	if err := store.Save("content_open", []byte(`{"receipts":{"credentials:1":{"digest":"bad","body":"CgA="}}}`)); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, _, err := service.Handle("/ContentOpen", contentOpenRequest(1, 1)); err == nil {
+		t.Fatal("corrupt reloaded receipt accepted")
+	}
+	if contentOpenTicketCount(inventory, 42) != 0 {
+		t.Fatal("corrupt receipts granted completion")
+	}
+	if _, err := NewContentOpenService(service.design, inventory, store, service.squadLevel); err == nil {
+		t.Fatal("corrupt receipt accepted during open")
+	}
+}
+
+func TestContentOpenRejectsUnqualifiedAndMalformedRequests(t *testing.T) {
+	for _, tc := range []struct {
+		name         string
+		prerequisite bool
+		level        uint64
+		request      []byte
+	}{
+		{"missing-prerequisite", false, 3, contentOpenRequest(1, 1)},
+		{"level", true, 2, contentOpenRequest(1, 1)},
+		{"unknown", true, 3, contentOpenRequest(1, 2)},
+		{"zero-type", true, 3, contentOpenRequest(1, 0)},
+		{"group-is-not-type", true, 3, contentOpenRequest(1, 23)},
+		{"zero-sequence", true, 3, contentOpenRequest(0, 1)},
+		{"wrong-wire", true, 3, wire.AppendBytes(wire.AppendVarint(nil, 1, 1), 2, []byte{1})},
+		{"truncated-trailing-wire", true, 3, append(contentOpenRequest(1, 1), 0x1a, 0x02, 0x01)},
+		{"duplicate-type", true, 3, wire.AppendVarint(contentOpenRequest(1, 1), 2, 1)},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			store := stateio.NewMemory()
+			service, inventory := contentOpenHarness(t, store, tc.prerequisite, tc.level)
+			_, _, handled, err := service.Handle("/ContentOpen", tc.request)
+			if err == nil || !handled {
+				t.Fatal("invalid request accepted")
+			}
+			if contentOpenTicketCount(inventory, 42) != 0 {
+				t.Fatal("rejected request granted ticket")
+			}
+			state, err := store.Load("content_open")
+			if err != nil || state != nil {
+				t.Fatal("rejected request persisted receipt")
+			}
+		})
+	}
+}
+
+type contentOpenFailStore struct {
+	stateio.AtomicEntryStore
+	fail bool
+}
+
+func (s *contentOpenFailStore) Save(name string, payload []byte) error {
+	if name == "content_open" && s.fail {
+		return errors.New("injected receipt write failure")
+	}
+	return s.AtomicEntryStore.Save(name, payload)
+}
+
+func TestContentOpenSQLiteReceiptRestartAndRollback(t *testing.T) {
+	for _, fail := range []bool{false, true} {
+		t.Run(map[bool]string{false: "durable-exact-retry", true: "failed-receipt-rolls-back-ticket"}[fail], func(t *testing.T) {
+			path := filepath.Join(t.TempDir(), "state.db")
+			repo, err := accountstate.Open(path)
+			if err != nil {
+				t.Fatal(err)
+			}
+			store := &contentOpenFailStore{AtomicEntryStore: repo, fail: fail}
+			service, _ := contentOpenHarness(t, store, true, 3)
+			op, err := repo.BeginOperation()
+			if err != nil {
+				t.Fatal(err)
+			}
+			request := contentOpenRequest(1, 1)
+			_, body, _, err := service.Handle("/ContentOpen", request)
+			if fail {
+				if err == nil {
+					t.Fatal("receipt failure ignored")
+				}
+				if err := op.Rollback(); err == nil {
+					t.Fatal("dirty rollback did not request account recovery")
+				}
+			} else {
+				if err != nil {
+					t.Fatal(err)
+				}
+				if err := op.Commit(); err != nil {
+					t.Fatal(err)
+				}
+			}
+			if err := repo.Close(); err != nil {
+				t.Fatal(err)
+			}
+			repo, err = accountstate.Open(path)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer repo.Close()
+			service, inventory := contentOpenHarness(t, repo, true, 3)
+			if fail {
+				if contentOpenTicketCount(inventory, 42) != 0 {
+					t.Fatal("uncommitted completion survived restart")
+				}
+				data, err := repo.Load("content_open")
+				if err != nil || data != nil {
+					t.Fatal("failed receipt survived restart")
+				}
+			}
+			op, err = repo.BeginOperation()
+			if err != nil {
+				t.Fatal(err)
+			}
+			_, replay, _, err := service.Handle("/ContentOpen", request)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := op.Commit(); err != nil {
+				t.Fatal(err)
+			}
+			if !fail && !bytes.Equal(body, replay) {
+				t.Fatal("exact retry changed after restart")
+			}
+			assertContentOpenResponse(t, replay)
+			if contentOpenTicketCount(inventory, 42) != 1 || contentOpenTicketCount(inventory, 41) != 1 {
+				t.Fatal("ticket ownership not preserved exactly once")
+			}
+		})
+	}
+}