feat: persist authenticated queue probe RTT

multiplayer-next.md

@@ -49,7 +49,10 @@ product policy are in [`docs/MATCHMAKING.md`](docs/MATCHMAKING.md).
   delegates the final proposal claim to the durable transaction boundary;
   queue tickets now also retain server-derived probe RTT metadata for
   authoritative matcher reads; ranked metadata/provider wiring and live
-  Redis repair remain.
+  Redis repair remain. The authenticated probe API now records validated
+  server-computed RTT values into the active player's durable queue ticket and
+  fails closed when that write is unavailable; Steam/coordinator evidence
+  acquisition and multi-region probe population remain.
 - [ ] **IN PROGRESS:** Run the Go control plane against PostgreSQL/Redis with
   independently runnable API, matcher, allocator and maintenance roles. The
   `cmd/control-plane` API role now opens PostgreSQL, applies migrations, wires

multiplayer-todo.md

@@ -1193,7 +1193,7 @@ the local/CI/community transport, not a silent production fallback.
 | # | Task | Acceptance |
 |---|---|---|
 | 8.14 `[D:8.4,8.5,8.8]` | **IN PROGRESS.** Pure Go queue domain enforces one active ticket per verified player under concurrent mutation, 10 s heartbeat/30 s expiry, retry-safe create/heartbeat/cancel, owner-only recovery reads and deterministic candidate projection; store layer adds a rebuildable candidate-cache boundary and authenticated HTTP queue adapter with playlist/build/protocol compatibility metadata | `server/domain/queue.go`, `server/store/candidates.go`, `server/store/queue_sql.go`, `server/store/redis_candidates.go` and `server/api/service.go` cover ownership/expiry/idempotency, concurrent create fencing, candidate/player ownership binding, owner/revision-scoped SQL heartbeat/cancel/recovery, injectable PostgreSQL queue backend selected by the HTTP service, authoritative queue-to-cache rebuild, expired recovery as a terminal error, owner-scoped SQL recovery with authoritative expiry handling, server-owned candidate resolution, strict compatibility metadata, TTL-bound Redis upsert/remove/snapshot, API create/heartbeat/cancel projection hooks, optional control-plane Redis configuration and atomic durable-source repair on partial/malformed cache state; opt-in real PostgreSQL execution now covers create/replay/active-player fencing, owner recovery, revision-fenced heartbeat/cancel and expiry, while miniredis covers Redis behavior and repair-source failure; live Redis restart/failover and worker integration remain |
-| 8.15 `[D:7.8,8.3]` | **IN PROGRESS.** Pure Go probe validation treats Steam location as opaque, requires nonce/freshness/region and server-computed RTT, and implements discrepancy quarantine/release; authenticated HTTP now accepts only opaque location/nonce input through a server-owned probe provider; durable queue projections now have a server-derived RTT JSON field for matcher reads | `server/domain/probes.go`, `server/migrations/0003_queue_probe_metadata.sql`, adversarial fixtures and `server/api/service.go`/`store/queue_sql.go` cover stale/wrong/forged evidence, the 25 ms/30% threshold, three-sample quarantine, five-clean release, authenticated provider arguments, rejection of client RTT fields, playlist-scoped candidate reads and bounded metadata decoding; Steam coordinator, regional probe adapters and API-to-queue probe population remain |
+| 8.15 `[D:7.8,8.3]` | **IN PROGRESS.** Pure Go probe validation treats Steam location as opaque, requires nonce/freshness/region and server-computed RTT, and implements discrepancy quarantine/release; authenticated HTTP now accepts only opaque location/nonce input through a server-owned probe provider and records validated RTT into the active player's durable queue ticket; durable queue projections have a server-derived RTT JSON field for matcher reads | `server/domain/probes.go`, `server/migrations/0003_queue_probe_metadata.sql`, adversarial fixtures and `server/api/service.go`/`store/queue_sql.go` cover stale/wrong/forged evidence, the 25 ms/30% threshold, three-sample quarantine, five-clean release, authenticated provider arguments, rejection of client RTT fields, player/ticket/expiry binding, persistence failure, playlist-scoped candidate reads and bounded metadata decoding; Steam coordinator, regional probe adapters and multi-region probe population remain |
 | 8.16 `[D:8.14,8.15]` | **IN PROGRESS.** Pure Go candidate/team selection implements the <=100 ms ceiling, pairwise widening tolerance, anchor inclusion, deterministic set/region scoring and balanced team partitioning; queue-backed formation now consumes the server-owned projection, fences duplicate player identities and rejects playlist/build/protocol mixing; the matcher worker performs bounded formation and delegates the final claim to the durable proposal transaction | `server/domain/matcher.go`, `teams.go`, `server/matcher/worker.go` and adversarial fixtures cover no-common-region, tolerance boundaries, lexical ties, mean-rating balance, malformed candidates, duplicate identities, compatibility mismatches, incomplete batches, source failure, durable claim failure and queue-backed oldest-anchor formation; ranked provider and long-running worker integration remain |
 | 8.17 `[D:8.14,8.16]` | **IN PROGRESS.** Pure Go proposal policy sends a 10-second response window to every selected human, requires unanimous acceptance, applies exact decline/timeout cooldowns and ranked escalation; authenticated API exposes revisioned accept/decline mutations; formed matches now pass through a playlist-aware proposal boundary | `server/domain/proposal.go`, `formation.go` and `server/api/service.go` plus adversarial fixtures cover partial/unanimous response, expiry, replay/conflict, stale API revision, casual lineup preparation and ranked metadata validation; queue precedence and allocation integration remain |
 | 8.18 `[D:8.5,8.14,8.17]` | **IN PROGRESS.** Go store layer defines PostgreSQL SERIALIZABLE whole-transaction retries and queue candidate/proposal claim SQL using `FOR UPDATE SKIP LOCKED` plus durable uniqueness/revision fences; proposal creation now inserts proposal/participants and promotes every ticket in one rollback-safe transaction with player- and playlist-bound claim predicates, queue creation has a durable idempotency/owner-read adapter, participant-scoped proposal recovery now expires OPEN proposals and pending participants transactionally at read time, and proposal accept/decline now uses participant/proposal locks, revision fencing and durable idempotency; response attempts also advance expired proposals and pending participants before returning closed; runnable casual matcher polling now reads an authoritative PostgreSQL candidate batch and delegates its final claim to this transaction | `server/store/serializable.go`, `queue_sql.go`, `proposal_sql.go`, `proposal_recovery_sql.go`, `server/matcher/worker.go` and tests cover retry classification, claim-boundary invariants, player/ticket/playlist mapping, durable queue replay/conflict, owner-scoped queue/proposal recovery, expiry at read and mutation boundaries, response replay/conflict, stale revisions, zero-row claim aborts, atomic statement ordering, incomplete matcher batches and source/claim failures; opt-in PostgreSQL execution now covers queue create/replay/fencing, assignment persistence, proposal claim/promotion, participant recovery, unanimous response and rollback of partial claims; ranked provider, Redis-backed worker repair, worker-failure and concurrent two-matcher integration tests remain |

server/api/service.go

@@ -26,6 +26,9 @@ const maxBodyBytes = 8 << 10
 type CandidateProvider func(playerID, ticketID string) (domain.Candidate, error)
 type CandidateProviderV2 func(playerID, ticketID string, spec domain.QueueSpec) (domain.Candidate, error)
 type ProbeProvider func(playerID, region string, opaqueLocation, nonce []byte, receivedAt time.Time) (domain.ProbeEvidence, []byte, error)
+type ProbeRecorder interface {
+	RecordProbe(context.Context, string, string, time.Duration, time.Time) error
+}
 
 type QueueBackend interface {
 	Create(context.Context, string, string, string, domain.QueueSpec, time.Time) (domain.QueueTicket, error)
@@ -86,6 +89,7 @@ type Service struct {
 	QueueBackend    QueueBackend
 	CandidateIndex  CandidateIndex
 	Probe           ProbeProvider
+	ProbeRecorder   ProbeRecorder
 	Assignment      AssignmentProvider
 	Now             func() time.Time
 	Proposals       map[string]*domain.Proposal
@@ -653,6 +657,12 @@ func (s *Service) probe(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusUnprocessableEntity, "invalid_probe")
 		return
 	}
+	if s.ProbeRecorder != nil {
+		if err := s.ProbeRecorder.RecordProbe(r.Context(), playerID, region, evidence.ServerRTT, receivedAt); err != nil {
+			writeError(w, http.StatusServiceUnavailable, "probe_persistence_failed")
+			return
+		}
+	}
 	writeJSON(w, http.StatusAccepted, map[string]any{"region": region, "server_rtt_ms": evidence.ServerRTT.Milliseconds(), "status": "accepted"})
 }
 

server/api/service_test.go

@@ -25,6 +25,21 @@ type candidateIndexSpy struct {
 	last                     domain.Candidate
 }
 
+type probeRecorderSpy struct {
+	calls int
+	err   error
+	last  struct {
+		player, region string
+		rtt            time.Duration
+	}
+}
+
+func (p *probeRecorderSpy) RecordProbe(_ context.Context, player, region string, rtt time.Duration, _ time.Time) error {
+	p.calls++
+	p.last.player, p.last.region, p.last.rtt = player, region, rtt
+	return p.err
+}
+
 func (i *candidateIndexSpy) Upsert(_ context.Context, candidate domain.Candidate) error {
 	i.upsertCalls++
 	i.last = candidate
@@ -936,6 +951,36 @@ func TestProbeAPIUsesServerEvidenceAndRejectsClientRTTField(t *testing.T) {
 	_ = response.Body.Close()
 }
 
+func TestProbeAPIRecordsOnlyValidatedServerEvidence(t *testing.T) {
+	now := time.Unix(1000, 0).UTC()
+	sessions := domain.NewSessionStore()
+	session, token, _ := sessions.Issue("player-a", time.Hour, now)
+	recorder := &probeRecorderSpy{}
+	service := &Service{Sessions: sessions, Now: func() time.Time { return now }, ProbeRecorder: recorder, Probe: func(_ string, region string, location, nonce []byte, _ time.Time) (domain.ProbeEvidence, []byte, error) {
+		return domain.ProbeEvidence{OpaqueLocation: location, Nonce: nonce, IssuedAt: now, Region: region, ServerRTT: 37 * time.Millisecond}, nonce, nil
+	}}
+	server := httptest.NewServer(service.Handler())
+	defer server.Close()
+	req, _ := http.NewRequest(http.MethodPost, server.URL+"/v1/probes/NA", strings.NewReader(`{"opaque_location":"b3BhcXVl","nonce":"bm9uY2U="}`))
+	req.Header.Set("Authorization", "Bearer "+session.SessionID+":"+token)
+	response, err := http.DefaultClient.Do(req)
+	if err != nil || response.StatusCode != http.StatusAccepted {
+		t.Fatalf("status=%v err=%v", response.StatusCode, err)
+	}
+	response.Body.Close()
+	if recorder.calls != 1 || recorder.last.player != "player-a" || recorder.last.region != "NA" || recorder.last.rtt != 37*time.Millisecond {
+		t.Fatalf("recorded probe=%+v calls=%d", recorder.last, recorder.calls)
+	}
+	recorder.err = errors.New("database unavailable")
+	req, _ = http.NewRequest(http.MethodPost, server.URL+"/v1/probes/NA", strings.NewReader(`{"opaque_location":"b3BhcXVl","nonce":"bm9uY2U="}`))
+	req.Header.Set("Authorization", "Bearer "+session.SessionID+":"+token)
+	response, err = http.DefaultClient.Do(req)
+	if err != nil || response.StatusCode != http.StatusServiceUnavailable {
+		t.Fatalf("persistence status=%v err=%v", response.StatusCode, err)
+	}
+	response.Body.Close()
+}
+
 func TestProposalRecoveryIsParticipantScopedAndExpiresAtReadBoundary(t *testing.T) {
 	now := time.Unix(1000, 0).UTC()
 	sessions := domain.NewSessionStore()

server/domain/queue.go

@@ -163,6 +163,34 @@ func (q *Queue) Expire(now time.Time) []QueueTicket {
 	return q.expireLocked(now)
 }
 
+// RecordProbe stores server-computed RTT metadata on the player's active
+// ticket. It never accepts client-provided latency and refuses expired or
+// non-queueable tickets.
+func (q *Queue) RecordProbe(playerID, region string, rtt time.Duration, now time.Time) error {
+	if playerID == "" || (region != "EU" && region != "NA") || rtt < 0 || now.IsZero() {
+		return fmt.Errorf("invalid probe recording")
+	}
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	ticketID, ok := q.byPlayer[playerID]
+	if !ok {
+		return ErrTicketNotFound
+	}
+	ticket, ok := q.tickets[ticketID]
+	if !ok || (ticket.State != Queued && ticket.State != Proposed) {
+		return ErrTicketNotFound
+	}
+	if !now.Before(ticket.ExpiresAt) {
+		return ErrTicketExpired
+	}
+	if ticket.Candidate.PredictedRTT == nil {
+		ticket.Candidate.PredictedRTT = make(map[string]float64)
+	}
+	ticket.Candidate.PredictedRTT[region] = float64(rtt) / float64(time.Millisecond)
+	q.tickets[ticketID] = ticket
+	return nil
+}
+
 func (q *Queue) expireLocked(now time.Time) []QueueTicket {
 	var expired []QueueTicket
 	for id, ticket := range q.tickets {

server/domain/queue_test.go

@@ -136,3 +136,24 @@ func TestQueueConcurrentCreateKeepsOneActiveTicketPerPlayer(t *testing.T) {
 		t.Fatalf("concurrent creates succeeded %d times", succeeded)
 	}
 }
+
+func TestQueueRecordProbeBindsServerRTTToActivePlayerTicket(t *testing.T) {
+	now := time.Unix(1000, 0).UTC()
+	queue := NewQueue()
+	if _, err := queue.Create("player-a", "ticket-a", "create-key-123456", Candidate{PlayerID: "player-a", TicketID: "ticket-a", Playlist: Casual, EnqueuedAt: now}, now); err != nil {
+		t.Fatal(err)
+	}
+	if err := queue.RecordProbe("player-a", "EU", 42*time.Millisecond, now); err != nil {
+		t.Fatal(err)
+	}
+	ticket, err := queue.Get("player-a", "ticket-a", now)
+	if err != nil || ticket.Candidate.PredictedRTT["EU"] != 42 {
+		t.Fatalf("ticket=%+v err=%v", ticket, err)
+	}
+	if err := queue.RecordProbe("player-a", "NA", time.Millisecond, now.Add(QueueExpiryWindow)); err != ErrTicketExpired {
+		t.Fatalf("expired record err=%v", err)
+	}
+	if err := queue.RecordProbe("player-other", "EU", time.Millisecond, now); err != ErrTicketNotFound {
+		t.Fatalf("unknown player err=%v", err)
+	}
+}

server/store/queue_sql.go

@@ -137,6 +137,28 @@ type queueTicketRecord struct {
 
 type PostgresQueue struct{ DB *sql.DB }
 
+const QueueProbeRecordSQL = `UPDATE queue_tickets
+SET predicted_rtt = jsonb_set(COALESCE(predicted_rtt, '{}'::jsonb), ARRAY[$2], to_jsonb($3::double precision), true)
+WHERE player_id = $1 AND state IN ('QUEUED', 'PROPOSED') AND expires_at > $4`
+
+func (q PostgresQueue) RecordProbe(ctx context.Context, playerID, region string, rtt time.Duration, now time.Time) error {
+	if q.DB == nil || playerID == "" || (region != "EU" && region != "NA") || rtt < 0 || now.IsZero() {
+		return fmt.Errorf("invalid probe recording")
+	}
+	result, err := q.DB.ExecContext(ctx, QueueProbeRecordSQL, playerID, region, float64(rtt)/float64(time.Millisecond), now)
+	if err != nil {
+		return err
+	}
+	changed, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if changed == 0 {
+		return domain.ErrTicketNotFound
+	}
+	return nil
+}
+
 func (q PostgresQueue) Create(ctx context.Context, playerID, ticketID, idempotencyKey string, spec domain.QueueSpec, now time.Time) (domain.QueueTicket, error) {
 	return CreateQueueTicket(ctx, q.DB, ticketID, playerID, idempotencyKey, spec, now)
 }