RandomCodeSpace
diff --git a/‎internal/api/similar_handler.go‎
Lines changed: 4 additions & 1 deletion b/‎internal/api/similar_handler.go‎
Lines changed: 4 additions & 1 deletion
diff --git a/‎internal/api/similar_handler_test.go‎
Lines changed: 117 additions & 0 deletions b/‎internal/api/similar_handler_test.go‎
Lines changed: 117 additions & 0 deletions
diff --git a/‎internal/graphrag/builder.go‎
Lines changed: 13 additions & 0 deletions b/‎internal/graphrag/builder.go‎
Lines changed: 13 additions & 0 deletions
diff --git a/‎internal/graphrag/clustering.go‎
Lines changed: 7 additions & 8 deletions b/‎internal/graphrag/clustering.go‎
Lines changed: 7 additions & 8 deletions
@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"net/http"
 	"strconv"
+
+	"github.com/RandomCodeSpace/otelcontext/internal/storage"
 )
 
 // handleGetSimilarLogs handles GET /api/logs/similar?q=<text>&limit=10
@@ -30,7 +32,8 @@ func (s *Server) handleGetSimilarLogs(w http.ResponseWriter, r *http.Request) {
 		limit = 50
 	}
 
-	results := s.vectorIdx.Search(query, limit)
+	tenant := storage.TenantFromContext(r.Context())
+	results := s.vectorIdx.Search(tenant, query, limit)
 
 	w.Header().Set("Content-Type", "application/json")
 	_ = json.NewEncoder(w).Encode(map[string]any{
 
@@ -0,0 +1,117 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/RandomCodeSpace/otelcontext/internal/config"
+	"github.com/RandomCodeSpace/otelcontext/internal/vectordb"
+)
+
+// TestSimilarHandler_TenantIsolation is the RAN-20 acceptance bar for the HTTP
+// surface. Two tenants with distinct corpora query /api/logs/similar; each
+// sees ZERO rows belonging to the other tenant.
+func TestSimilarHandler_TenantIsolation(t *testing.T) {
+	idx := vectordb.New(1_000)
+	idx.Add(101, "acme", "checkout", "ERROR", "payment gateway timeout charging customer")
+	idx.Add(102, "acme", "checkout", "ERROR", "payment gateway refused charge insufficient funds")
+	idx.Add(201, "globex", "auth", "ERROR", "payment gateway token expired for session")
+	idx.Add(202, "globex", "auth", "ERROR", "payment gateway 500 internal error while authenticating")
+
+	srv := &Server{vectorIdx: idx}
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /api/logs/similar", srv.handleGetSimilarLogs)
+	handler := TenantMiddleware(&config.Config{DefaultTenant: "default"})(mux)
+
+	acmeIDs := map[float64]bool{101: true, 102: true}
+	globexIDs := map[float64]bool{201: true, 202: true}
+
+	q := url.Values{}
+	q.Set("q", "payment gateway")
+	q.Set("limit", "50")
+	path := "/api/logs/similar?" + q.Encode()
+
+	// Tenant A
+	aRec := httptest.NewRecorder()
+	aReq := httptest.NewRequest(http.MethodGet, path, nil)
+	aReq.Header.Set(TenantHeader, "acme")
+	handler.ServeHTTP(aRec, aReq)
+	if aRec.Code != http.StatusOK {
+		t.Fatalf("acme: want 200, got %d body=%q", aRec.Code, aRec.Body.String())
+	}
+	acme := decodeResults(t, aRec)
+	if len(acme) == 0 {
+		t.Fatalf("acme got zero hits despite matching corpus")
+	}
+	for _, r := range acme {
+		if !acmeIDs[r.ID] {
+			t.Fatalf("acme leaked cross-tenant id=%v tenant=%q body=%q", r.ID, r.Tenant, r.Body)
+		}
+	}
+
+	// Tenant B
+	gRec := httptest.NewRecorder()
+	gReq := httptest.NewRequest(http.MethodGet, path, nil)
+	gReq.Header.Set(TenantHeader, "globex")
+	handler.ServeHTTP(gRec, gReq)
+	if gRec.Code != http.StatusOK {
+		t.Fatalf("globex: want 200, got %d", gRec.Code)
+	}
+	globex := decodeResults(t, gRec)
+	if len(globex) == 0 {
+		t.Fatalf("globex got zero hits despite matching corpus")
+	}
+	for _, r := range globex {
+		if !globexIDs[r.ID] {
+			t.Fatalf("globex leaked cross-tenant id=%v tenant=%q body=%q", r.ID, r.Tenant, r.Body)
+		}
+	}
+}
+
+// TestSimilarHandler_UnknownTenantReturnsEmpty confirms a request bearing an
+// unknown tenant header returns zero results — the handler must not silently
+// fall back to another tenant's rows.
+func TestSimilarHandler_UnknownTenantReturnsEmpty(t *testing.T) {
+	idx := vectordb.New(100)
+	idx.Add(1, "acme", "svc", "ERROR", "database connection refused upstream")
+
+	srv := &Server{vectorIdx: idx}
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /api/logs/similar", srv.handleGetSimilarLogs)
+	handler := TenantMiddleware(&config.Config{DefaultTenant: "default"})(mux)
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/logs/similar?q=database+connection", nil)
+	req.Header.Set(TenantHeader, "initech")
+	handler.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("want 200, got %d", rec.Code)
+	}
+	if r := decodeResults(t, rec); len(r) != 0 {
+		t.Fatalf("unknown tenant saw %d cross-tenant hits", len(r))
+	}
+}
+
+type similarResult struct {
+	ID          float64 `json:"LogID"`
+	Tenant      string  `json:"Tenant"`
+	ServiceName string  `json:"ServiceName"`
+	Severity    string  `json:"Severity"`
+	Body        string  `json:"Body"`
+	Score       float64 `json:"Score"`
+}
+
+func decodeResults(t *testing.T, rec *httptest.ResponseRecorder) []similarResult {
+	t.Helper()
+	var env struct {
+		Results []similarResult `json:"results"`
+	}
+	if err := json.Unmarshal(rec.Body.Bytes(), &env); err != nil {
+		t.Fatalf("decode response: %v (body=%q)", err, rec.Body.String())
+	}
+	return env.Results
+}
@@ -154,6 +154,19 @@ func (g *GraphRAG) DroppedMetricsCount() int64 { return g.droppedMetrics.Load()
 // tests to assert cooldown behavior without requiring a live repo.
 func (g *GraphRAG) InvestigationInsertCount() int64 { return g.invInserts.Load() }
 
+// RegisterAnomaly inserts an anomaly into the AnomalyStore for tenant.
+// Mirrors PersistInvestigation's "tenant accepted explicitly" shape so
+// out-of-band anomaly producers (synthetic detectors, integration tests,
+// future external anomaly feeds) can land directly on the right tenant
+// slice without going through the metric/error detection loops. Empty
+// tenant collapses to storage.DefaultTenantID.
+func (g *GraphRAG) RegisterAnomaly(tenant string, anomaly AnomalyNode) {
+	if tenant == "" {
+		tenant = storage.DefaultTenantID
+	}
+	g.storesForTenant(tenant).anomalies.AddAnomaly(anomaly)
+}
+
 // recordEventDrop increments the per-signal atomic counter and — when
 // a telemetry registry is wired — the Prometheus counter vec.
 func (g *GraphRAG) recordEventDrop(signal string) {
 
@@ -9,6 +9,8 @@ import (
 	"context"
 	"fmt"
 	"time"
+
+	"github.com/RandomCodeSpace/otelcontext/internal/storage"
 )
 
 // clusterLog runs the log body through Drain and upserts a LogClusterNode
@@ -78,14 +80,11 @@ func (g *GraphRAG) SimilarErrors(ctx context.Context, clusterID string, k int) [
 	if query == "" && len(cluster.TemplateTokens) > 0 {
 		query = joinTokens(cluster.TemplateTokens)
 	}
-	// TODO(RAN-20): vectordb.Index.Search itself is not yet tenant-scoped on
-	// `main`, so we call the 2-arg signature here. Tenant isolation for the
-	// SignalStore lookup above is already enforced via storesFor(ctx); the
-	// vector hits are then narrowed by the EmittedBy edges in this tenant's
-	// SignalStore on lines below, so cross-tenant hits cannot surface even
-	// while the underlying vector index is shared.
-	_ = ctx
-	results := g.vectorIdx.Search(query, k*2) // over-fetch to filter
+	// vectordb.Index.Search takes the tenant string directly; resolve it
+	// from ctx via the same storage helper used by storesFor so both sides
+	// agree on coercion rules (empty → DefaultTenantID).
+	tenant := storage.TenantFromContext(ctx)
+	results := g.vectorIdx.Search(tenant, query, k*2) // over-fetch to filter
 
 	// Map results back to log clusters.
 	seen := map[string]bool{clusterID: true}