diff --git a/Dockerfile b/Dockerfile
index 38cf0762..1279d179 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -20,6 +20,7 @@ COPY internal/sigvalidate/ ../../internal/sigvalidate/
 COPY internal/packetpath/ ../../internal/packetpath/
 COPY internal/dbconfig/ ../../internal/dbconfig/
 COPY internal/perfio/ ../../internal/perfio/
+COPY internal/dbschema/ ../../internal/dbschema/
 RUN go mod download
 COPY cmd/server/ ./
 RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
@@ -33,6 +34,7 @@ COPY internal/sigvalidate/ ../../internal/sigvalidate/
 COPY internal/packetpath/ ../../internal/packetpath/
 COPY internal/dbconfig/ ../../internal/dbconfig/
 COPY internal/perfio/ ../../internal/perfio/
+COPY internal/dbschema/ ../../internal/dbschema/
 RUN go mod download
 COPY cmd/ingestor/ ./
 RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
diff --git a/cmd/server/config.go b/cmd/server/config.go
index 047ac041..93ecc7c5 100644
--- a/cmd/server/config.go
+++ b/cmd/server/config.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"log"
 	"os"
 	"path/filepath"
@@ -447,6 +448,68 @@ func (c *Config) IsBlacklisted(pubkey string) bool {
 	return c.blacklistSet()[strings.ToLower(strings.TrimSpace(pubkey))]
 }
 
+// SaveGeoFilter writes the geo_filter section back to config.json on disk.
+// Pass gf=nil to remove the filter. The rest of config.json is preserved as-is.
+func SaveGeoFilter(configDir string, gf *GeoFilterConfig) error {
+	var configPath string
+	for _, p := range []string{
+		filepath.Join(configDir, "config.json"),
+		filepath.Join(configDir, "data", "config.json"),
+	} {
+		if _, err := os.Stat(p); err == nil {
+			configPath = p
+			break
+		}
+	}
+	if configPath == "" {
+		return fmt.Errorf("config.json not found in %s", configDir)
+	}
+
+	data, err := os.ReadFile(configPath)
+	if err != nil {
+		return fmt.Errorf("read config: %w", err)
+	}
+
+	// Parse as a raw map so non-struct fields (_comment, etc.) are preserved.
+	var raw map[string]interface{}
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return fmt.Errorf("parse config: %w", err)
+	}
+
+	if gf == nil || len(gf.Polygon) == 0 {
+		delete(raw, "geo_filter")
+	} else {
+		// Round-trip through JSON to get a plain interface{} value.
+		b, _ := json.Marshal(gf)
+		var v interface{}
+		_ = json.Unmarshal(b, &v)
+		raw["geo_filter"] = v
+	}
+
+	out, err := json.MarshalIndent(raw, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshal config: %w", err)
+	}
+	out = append(out, '\n')
+
+	// Preserve the original file mode so operators' chmod 0600 survives the write.
+	origMode := os.FileMode(0644)
+	if fi, err := os.Stat(configPath); err == nil {
+		origMode = fi.Mode().Perm()
+	}
+
+	// Atomic write: temp file + rename.
+	tmp := configPath + ".tmp"
+	if err := os.WriteFile(tmp, out, origMode); err != nil {
+		return fmt.Errorf("write config: %w", err)
+	}
+	if err := os.Rename(tmp, configPath); err != nil {
+		os.Remove(tmp)
+		return fmt.Errorf("rename config: %w", err)
+	}
+	return nil
+}
+
 // obsBlacklistSet lazily builds and caches the observerBlacklist as a set for O(1) lookups.
 func (c *Config) obsBlacklistSet() map[string]bool {
 	c.obsBlacklistOnce.Do(func() {
@@ -485,8 +548,8 @@ func (c *Config) IsObserverBlacklisted(id string) bool {
 // RecomputeIntervalSeconds keys (all optional):
 //   topology, rf, distance, channels, hashCollisions, hashSizes, roles, observersClockSkew, nodesClockSkew
 type AnalyticsConfig struct {
-	DefaultIntervalSeconds    int            `json:"defaultIntervalSeconds,omitempty"`
-	RecomputeIntervalSeconds  map[string]int `json:"recomputeIntervalSeconds,omitempty"`
+	DefaultIntervalSeconds   int            `json:"defaultIntervalSeconds,omitempty"`
+	RecomputeIntervalSeconds map[string]int `json:"recomputeIntervalSeconds,omitempty"`
 }
 
 // AnalyticsDefaultRecomputeInterval returns the configured default
diff --git a/cmd/server/config_test.go b/cmd/server/config_test.go
index 36e59ea9..8323dbd2 100644
--- a/cmd/server/config_test.go
+++ b/cmd/server/config_test.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 )
 
@@ -387,3 +388,25 @@ func TestObserverDaysOrDefault(t *testing.T) {
 		})
 	}
 }
+
+func TestSaveGeoFilter_PreservesFileMode(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("Unix file permissions not supported on Windows")
+	}
+	dir := t.TempDir()
+	path := filepath.Join(dir, "config.json")
+	if err := os.WriteFile(path, []byte(`{"port":3000}`), 0600); err != nil {
+		t.Fatal(err)
+	}
+	gf := &GeoFilterConfig{Polygon: [][2]float64{{1, 2}, {3, 4}, {5, 6}}, BufferKm: 0}
+	if err := SaveGeoFilter(dir, gf); err != nil {
+		t.Fatal(err)
+	}
+	info, err := os.Stat(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := info.Mode().Perm(); got != 0600 {
+		t.Errorf("file mode downgraded: want 0600, got %04o", got)
+	}
+}
diff --git a/cmd/server/main.go b/cmd/server/main.go
index 7bb27b06..1a1dbce0 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -273,6 +273,7 @@ func main() {
 
 	// HTTP server
 	srv := NewServer(database, cfg, hub)
+	srv.configDir = configDir
 	srv.store = store
 	router := mux.NewRouter()
 	srv.RegisterRoutes(router)
diff --git a/cmd/server/routes.go b/cmd/server/routes.go
index 62d1d0ea..b72b06e2 100644
--- a/cmd/server/routes.go
+++ b/cmd/server/routes.go
@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"math"
 	"net/http"
 	"regexp"
 	"runtime"
@@ -25,12 +26,20 @@ type Server struct {
 	cfg       *Config
 	hub       *Hub
 	store     *PacketStore // in-memory packet store (nil = fallback to DB)
+	configDir string       // directory containing config.json (for write-back)
 	startedAt time.Time
 	perfStats *PerfStats
 	version   string
 	commit    string
 	buildTime string
 
+	// Guards s.cfg.GeoFilter — read by ingest/handler goroutines, written by PUT handler
+	cfgMu sync.RWMutex
+
+	// Serializes concurrent PUT /api/config/geo-filter disk writes so requests
+	// can't race on the .tmp file or interleave disk/memory updates.
+	saveMu sync.Mutex
+
 	// Cached runtime.MemStats to avoid stop-the-world pauses on every health check
 	memStatsMu   sync.Mutex
 	memStatsCache runtime.MemStats
@@ -59,6 +68,18 @@ type PerfStats struct {
 	StartedAt   time.Time
 }
 
+func (s *Server) getGeoFilter() *GeoFilterConfig {
+	s.cfgMu.RLock()
+	defer s.cfgMu.RUnlock()
+	return s.cfg.GeoFilter
+}
+
+func (s *Server) setGeoFilter(gf *GeoFilterConfig) {
+	s.cfgMu.Lock()
+	defer s.cfgMu.Unlock()
+	s.cfg.GeoFilter = gf
+}
+
 type EndpointPerf struct {
 	Count   int
 	TotalMs float64
@@ -120,6 +141,7 @@ func (s *Server) RegisterRoutes(r *mux.Router) {
 	r.HandleFunc("/api/config/theme", s.handleConfigTheme).Methods("GET")
 	r.HandleFunc("/api/config/map", s.handleConfigMap).Methods("GET")
 	r.HandleFunc("/api/config/geo-filter", s.handleConfigGeoFilter).Methods("GET")
+	r.Handle("/api/config/geo-filter", s.requireAPIKey(http.HandlerFunc(s.handlePutConfigGeoFilter))).Methods("PUT")
 
 	// Readiness endpoint (gated on background init completion)
 	r.HandleFunc("/api/healthz", s.handleHealthz).Methods("GET")
@@ -444,7 +466,11 @@ func (s *Server) handleConfigMap(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleConfigGeoFilter(w http.ResponseWriter, r *http.Request) {
-	gf := s.cfg.GeoFilter
+	gf := s.getGeoFilter()
+	// NOTE: do NOT include any field that derives from APIKey presence/strength here.
+	// This endpoint is intentionally public; leaking whether a write-capable key is
+	// configured is an info-disclosure. Clients that want to write should just try
+	// PUT and handle 401/403. See PR #736 review.
 	if gf == nil || len(gf.Polygon) == 0 {
 		writeJSON(w, map[string]interface{}{"polygon": nil, "bufferKm": 0})
 		return
@@ -452,6 +478,66 @@ func (s *Server) handleConfigGeoFilter(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, map[string]interface{}{"polygon": gf.Polygon, "bufferKm": gf.BufferKm})
 }
 
+func (s *Server) handlePutConfigGeoFilter(w http.ResponseWriter, r *http.Request) {
+	r.Body = http.MaxBytesReader(w, r.Body, 1<<20) // 1 MB cap
+
+	var body struct {
+		Polygon  [][2]float64 `json:"polygon"`
+		BufferKm float64      `json:"bufferKm"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid JSON")
+		return
+	}
+
+	// Allow clearing (empty/null polygon) or a valid polygon with ≥ 3 points.
+	if len(body.Polygon) > 0 && len(body.Polygon) < 3 {
+		writeError(w, http.StatusBadRequest, "polygon must have at least 3 points")
+		return
+	}
+	if len(body.Polygon) > 1000 {
+		writeError(w, http.StatusBadRequest, "polygon must have at most 1000 points")
+		return
+	}
+	for _, pt := range body.Polygon {
+		if math.IsNaN(pt[0]) || math.IsNaN(pt[1]) || math.IsInf(pt[0], 0) || math.IsInf(pt[1], 0) ||
+			pt[0] < -90 || pt[0] > 90 || pt[1] < -180 || pt[1] > 180 {
+			writeError(w, http.StatusBadRequest, "polygon point out of range: lat must be in [-90,90], lon in [-180,180]")
+			return
+		}
+	}
+
+	// bufferKm must be finite, non-negative, and ≤ 20000 km (half Earth circumference).
+	if math.IsNaN(body.BufferKm) || math.IsInf(body.BufferKm, 0) ||
+		body.BufferKm < 0 || body.BufferKm > 20000 {
+		writeError(w, http.StatusBadRequest, "bufferKm must be a finite number in [0, 20000]")
+		return
+	}
+
+	var gf *GeoFilterConfig
+	if len(body.Polygon) >= 3 {
+		gf = &GeoFilterConfig{Polygon: body.Polygon, BufferKm: body.BufferKm}
+	}
+
+	s.saveMu.Lock()
+	if s.configDir != "" {
+		if err := SaveGeoFilter(s.configDir, gf); err != nil {
+			s.saveMu.Unlock()
+			log.Printf("[geofilter] save failed: %v", err)
+			writeError(w, http.StatusInternalServerError, "failed to save config")
+			return
+		}
+	}
+	s.setGeoFilter(gf)
+	s.saveMu.Unlock()
+
+	if gf != nil {
+		writeJSON(w, map[string]interface{}{"polygon": gf.Polygon, "bufferKm": gf.BufferKm})
+	} else {
+		writeJSON(w, map[string]interface{}{"polygon": nil, "bufferKm": 0})
+	}
+}
+
 // --- System Handlers ---
 
 func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
@@ -1145,20 +1231,17 @@ func (s *Server) handleNodes(w http.ResponseWriter, r *http.Request) {
 			}
 		}
 	}
-	if s.cfg.GeoFilter != nil {
+	if gf := s.getGeoFilter(); gf != nil {
 		filtered := nodes[:0]
 		for _, node := range nodes {
 			// Foreign-flagged nodes (#730) are kept even when their GPS lies
-			// outside the geofilter polygon — that's the whole point of the
-			// flag: operators need to SEE bridged/leaked nodes, not have them
-			// filtered away. The ingestor sets foreign_advert=1 when its
-			// configured geo_filter rejected the advert; the server must
-			// surface those.
+			// outside the geofilter polygon — operators need to SEE bridged/
+			// leaked nodes, not have them filtered away.
 			if isForeign, _ := node["foreign"].(bool); isForeign {
 				filtered = append(filtered, node)
 				continue
 			}
-			if NodePassesGeoFilter(node["lat"], node["lon"], s.cfg.GeoFilter) {
+			if NodePassesGeoFilter(node["lat"], node["lon"], gf) {
 				filtered = append(filtered, node)
 			}
 		}
diff --git a/cmd/server/routes_test.go b/cmd/server/routes_test.go
index b0bd6195..2ddc5b2e 100644
--- a/cmd/server/routes_test.go
+++ b/cmd/server/routes_test.go
@@ -3,10 +3,14 @@ package main
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -2839,6 +2843,32 @@ func TestConfigGeoFilterEndpoint(t *testing.T) {
 		if body["bufferKm"] == nil {
 			t.Error("expected bufferKm in response")
 		}
+		// writeEnabled must NOT be leaked: the public GET endpoint should not
+		// disclose whether a strong apiKey is configured to unauthenticated callers.
+		if _, ok := body["writeEnabled"]; ok {
+			t.Errorf("writeEnabled must not be present in public GET response (info disclosure), got %v", body["writeEnabled"])
+		}
+	})
+
+	t.Run("writeEnabled is not exposed even when strong apiKey configured", func(t *testing.T) {
+		db := setupTestDB(t)
+		cfg := &Config{Port: 3000, APIKey: "a-strong-api-key-1234"}
+		hub := NewHub()
+		srv := NewServer(db, cfg, hub)
+		srv.store = NewPacketStore(db, nil)
+		srv.store.Load()
+		router := mux.NewRouter()
+		srv.RegisterRoutes(router)
+
+		req := httptest.NewRequest("GET", "/api/config/geo-filter", nil)
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		var body map[string]interface{}
+		json.Unmarshal(w.Body.Bytes(), &body)
+		if _, ok := body["writeEnabled"]; ok {
+			t.Errorf("writeEnabled must not be present (would leak apiKey presence), got %v", body["writeEnabled"])
+		}
 	})
 }
 
@@ -3973,3 +4003,262 @@ func TestPacketDetailPrefersStoreOverDB(t *testing.T) {
 		t.Errorf("expected observation_count=2 (from store), got %v", body["observation_count"])
 	}
 }
+
+// --- geo-filter write-back tests ---
+
+func setupGeoFilterServer(t *testing.T, apiKey string) (*Server, *mux.Router, string) {
+	t.Helper()
+	dir := t.TempDir()
+	cfgJSON := `{"port":3000,"apiKey":"` + apiKey + `"}`
+	if err := os.WriteFile(filepath.Join(dir, "config.json"), []byte(cfgJSON), 0644); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+	db := setupTestDB(t)
+	seedTestData(t, db)
+	cfg := &Config{Port: 3000, APIKey: apiKey}
+	hub := NewHub()
+	srv := NewServer(db, cfg, hub)
+	srv.configDir = dir
+	store := NewPacketStore(db, nil)
+	if err := store.Load(); err != nil {
+		t.Fatalf("store.Load: %v", err)
+	}
+	srv.store = store
+	router := mux.NewRouter()
+	srv.RegisterRoutes(router)
+	return srv, router, dir
+}
+
+func TestPutConfigGeoFilter(t *testing.T) {
+	const apiKey = "a-strong-api-key-for-testing"
+
+	t.Run("saves valid polygon and updates in-memory config", func(t *testing.T) {
+		srv, router, dir := setupGeoFilterServer(t, apiKey)
+
+		body := `{"polygon":[[51.0,4.0],[51.0,5.0],[50.5,5.0],[50.5,4.0]],"bufferKm":15}`
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		if w.Code != 200 {
+			t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+		}
+
+		// In-memory config updated
+		if srv.cfg.GeoFilter == nil {
+			t.Fatal("expected in-memory GeoFilter to be set")
+		}
+		if len(srv.cfg.GeoFilter.Polygon) != 4 {
+			t.Errorf("expected 4 polygon points, got %d", len(srv.cfg.GeoFilter.Polygon))
+		}
+		if srv.cfg.GeoFilter.BufferKm != 15 {
+			t.Errorf("expected bufferKm=15, got %v", srv.cfg.GeoFilter.BufferKm)
+		}
+
+		// config.json updated on disk
+		data, _ := os.ReadFile(filepath.Join(dir, "config.json"))
+		if !bytes.Contains(data, []byte("geo_filter")) {
+			t.Error("expected geo_filter key in saved config.json")
+		}
+	})
+
+	t.Run("clears filter when polygon is empty", func(t *testing.T) {
+		srv, router, dir := setupGeoFilterServer(t, apiKey)
+		// Pre-set a filter so we can clear it
+		srv.setGeoFilter(&GeoFilterConfig{Polygon: [][2]float64{{51.0, 4.0}, {51.0, 5.0}, {50.5, 4.0}}, BufferKm: 10})
+
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(`{"polygon":null}`))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		if w.Code != 200 {
+			t.Fatalf("expected 200, got %d", w.Code)
+		}
+		if srv.cfg.GeoFilter != nil {
+			t.Error("expected in-memory GeoFilter to be cleared")
+		}
+		data, _ := os.ReadFile(filepath.Join(dir, "config.json"))
+		if bytes.Contains(data, []byte("geo_filter")) {
+			t.Error("expected geo_filter to be removed from config.json")
+		}
+	})
+
+	t.Run("rejects polygon with fewer than 3 points", func(t *testing.T) {
+		_, router, _ := setupGeoFilterServer(t, apiKey)
+
+		body := `{"polygon":[[51.0,4.0],[51.0,5.0]],"bufferKm":0}`
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		if w.Code != http.StatusBadRequest {
+			t.Fatalf("expected 400, got %d", w.Code)
+		}
+	})
+
+	t.Run("rejects out-of-range coordinates", func(t *testing.T) {
+		_, router, _ := setupGeoFilterServer(t, apiKey)
+
+		body := `{"polygon":[[91.0,4.0],[51.0,5.0],[50.5,4.0]],"bufferKm":0}`
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		if w.Code != http.StatusBadRequest {
+			t.Fatalf("expected 400 for out-of-range lat, got %d", w.Code)
+		}
+	})
+
+	t.Run("rejects polygon exceeding 1000 points", func(t *testing.T) {
+		_, router, _ := setupGeoFilterServer(t, apiKey)
+
+		pts := make([][2]float64, 1001)
+		for i := range pts {
+			pts[i] = [2]float64{51.0 + float64(i)*0.0001, 4.0}
+		}
+		b, _ := json.Marshal(map[string]interface{}{"polygon": pts, "bufferKm": 0})
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(string(b)))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		if w.Code != http.StatusBadRequest {
+			t.Fatalf("expected 400 for oversized polygon, got %d", w.Code)
+		}
+	})
+
+	t.Run("rejects missing API key", func(t *testing.T) {
+		_, router, _ := setupGeoFilterServer(t, apiKey)
+
+		body := `{"polygon":[[51.0,4.0],[51.0,5.0],[50.5,4.0]],"bufferKm":0}`
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+
+		if w.Code != http.StatusUnauthorized {
+			t.Fatalf("expected 401, got %d", w.Code)
+		}
+	})
+
+	t.Run("rejects negative bufferKm", func(t *testing.T) {
+		_, router, _ := setupGeoFilterServer(t, apiKey)
+		body := `{"polygon":[[51.0,4.0],[51.0,5.0],[50.5,4.0]],"bufferKm":-1}`
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+		if w.Code != http.StatusBadRequest {
+			t.Fatalf("expected 400 for negative bufferKm, got %d: %s", w.Code, w.Body.String())
+		}
+	})
+
+	t.Run("rejects excessive bufferKm", func(t *testing.T) {
+		_, router, _ := setupGeoFilterServer(t, apiKey)
+		body := `{"polygon":[[51.0,4.0],[51.0,5.0],[50.5,4.0]],"bufferKm":99999999}`
+		req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+		req.Header.Set("X-API-Key", apiKey)
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, req)
+		if w.Code != http.StatusBadRequest {
+			t.Fatalf("expected 400 for excessive bufferKm, got %d: %s", w.Code, w.Body.String())
+		}
+	})
+}
+
+func TestPutConfigGeoFilter_ConcurrentSafe(t *testing.T) {
+	const apiKey = "a-strong-api-key-for-testing"
+	srv, router, dir := setupGeoFilterServer(t, apiKey)
+	_ = srv
+
+	const n = 10
+	var wg sync.WaitGroup
+	errs := make(chan string, n)
+	for i := 0; i < n; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			lat := 51.0 + float64(i)*0.001
+			body := fmt.Sprintf(`{"polygon":[[%f,4.0],[%f,5.0],[50.5,4.0]],"bufferKm":0}`, lat, lat)
+			req := httptest.NewRequest("PUT", "/api/config/geo-filter", strings.NewReader(body))
+			req.Header.Set("X-API-Key", apiKey)
+			req.Header.Set("Content-Type", "application/json")
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+			if w.Code != 200 {
+				errs <- fmt.Sprintf("goroutine %d: got %d: %s", i, w.Code, w.Body.String())
+			}
+		}(i)
+	}
+	wg.Wait()
+	close(errs)
+	for e := range errs {
+		t.Error(e)
+	}
+	// config.json must be valid JSON after concurrent writes
+	data, err := os.ReadFile(filepath.Join(dir, "config.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var v interface{}
+	if err := json.Unmarshal(data, &v); err != nil {
+		t.Errorf("config.json corrupted after concurrent PUTs: %v\ncontents: %s", err, data)
+	}
+}
+
+func TestSaveGeoFilter(t *testing.T) {
+	t.Run("saves and reads back", func(t *testing.T) {
+		dir := t.TempDir()
+		if err := os.WriteFile(filepath.Join(dir, "config.json"), []byte(`{"port":3000}`), 0644); err != nil {
+			t.Fatal(err)
+		}
+		gf := &GeoFilterConfig{
+			Polygon:  [][2]float64{{51.0, 4.0}, {51.0, 5.0}, {50.5, 4.0}},
+			BufferKm: 20,
+		}
+		if err := SaveGeoFilter(dir, gf); err != nil {
+			t.Fatalf("SaveGeoFilter: %v", err)
+		}
+		data, _ := os.ReadFile(filepath.Join(dir, "config.json"))
+		if !bytes.Contains(data, []byte("geo_filter")) {
+			t.Error("expected geo_filter in saved config")
+		}
+		if !bytes.Contains(data, []byte(`"bufferKm"`)) {
+			t.Error("expected bufferKm in saved config")
+		}
+	})
+
+	t.Run("removes geo_filter key when gf is nil", func(t *testing.T) {
+		dir := t.TempDir()
+		initial := `{"port":3000,"geo_filter":{"polygon":[[1,2],[3,4],[5,6]],"bufferKm":5}}`
+		if err := os.WriteFile(filepath.Join(dir, "config.json"), []byte(initial), 0644); err != nil {
+			t.Fatal(err)
+		}
+		if err := SaveGeoFilter(dir, nil); err != nil {
+			t.Fatalf("SaveGeoFilter: %v", err)
+		}
+		data, _ := os.ReadFile(filepath.Join(dir, "config.json"))
+		if bytes.Contains(data, []byte("geo_filter")) {
+			t.Error("expected geo_filter to be removed")
+		}
+	})
+
+	t.Run("returns error when config.json not found", func(t *testing.T) {
+		dir := t.TempDir()
+		err := SaveGeoFilter(dir, nil)
+		if err == nil {
+			t.Error("expected error when config.json not found")
+		}
+	})
+}
diff --git a/config.example.json b/config.example.json
index 64b23f03..ae15cab0 100644
--- a/config.example.json
+++ b/config.example.json
@@ -175,7 +175,7 @@
       [37.20, -122.52]
     ],
     "bufferKm": 20,
-    "_comment": "Optional. Restricts ingestion and API responses to nodes within the polygon + bufferKm. Polygon is an array of [lat, lon] pairs (minimum 3). Use the GeoFilter Builder (`/geofilter-builder.html`) to draw a polygon, save drafts to localStorage with Save Draft, and export a config snippet with Download — paste the snippet here as the `geo_filter` block. Remove this section to disable filtering. Nodes with no GPS fix are always allowed through."
+    "_comment": "Optional. Restricts ingestion and API responses to nodes within the polygon + bufferKm. Polygon is an array of [lat, lon] pairs (minimum 3). Use the GeoFilter tab in the Customizer (requires apiKey) or the GeoFilter Builder (`/geofilter-builder.html`) to draw a polygon visually. Remove this section to disable filtering. Nodes with no GPS fix are always allowed through."
   },
   "foreignAdverts": {
     "mode": "flag",
diff --git a/docs/superpowers/plans/2026-04-05-deep-linking-p1.md b/docs/superpowers/plans/2026-04-05-deep-linking-p1.md
deleted file mode 100644
index 23a23ba4..00000000
--- a/docs/superpowers/plans/2026-04-05-deep-linking-p1.md
+++ /dev/null
@@ -1,674 +0,0 @@
-# Deep Linking P1 Implementation Plan
-
-> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
-
-**Goal:** Make P1 UI states in nodes, packets, and channels URL-addressable so they survive refresh and can be shared.
-
-**Architecture:** Each page reads URL params from `location.hash.split('?')[1]` on init (router strips query string before passing `routeParam`, so pages must read `location.hash` directly). State changes call `history.replaceState` to keep the URL in sync. localStorage remains the fallback default; URL params override when present.
-
-**Tech Stack:** Vanilla JS (ES5/6), browser History API, URLSearchParams
-
----
-
-## Files Changed
-
-| File | Changes |
-|---|---|
-| `public/region-filter.js` | Add `setSelected(codesArray)`, track `_container` for re-render |
-| `public/nodes.js` | Read `?tab=`/`?search=` on init; `updateNodesUrl()` on tab/search change; expose `buildNodesQuery` on `window` |
-| `public/packets.js` | Read `?timeWindow=`/`?region=` on init; `updatePacketsUrl()` on timeWindow/region change; expose `buildPacketsUrl` on `window` |
-| `public/channels.js` | Read `?node=` on init; update URL in `showNodeDetail`/`closeNodeDetail` |
-| `test-frontend-helpers.js` | Add unit tests for `buildNodesQuery` and `buildPacketsUrl` |
-| `test-e2e-playwright.js` | Add Playwright tests: tab URL persistence, timeWindow URL persistence |
-
----
-
-## Task 1: Add `setSelected` to RegionFilter
-
-**Files:**
-- Modify: `public/region-filter.js`
-
-- [ ] **Step 1: Write the failing unit test**
-
-Add to `test-frontend-helpers.js` before the `// ===== SUMMARY =====` line:
-
-```javascript
-// ===== REGION-FILTER.JS: setSelected =====
-console.log('\n=== region-filter.js: setSelected ===');
-{
-  const ctx = makeSandbox();
-  ctx.fetch = () => Promise.resolve({ json: () => Promise.resolve({ 'US-SFO': 'San Jose', 'US-LAX': 'Los Angeles' }) });
-  loadInCtx(ctx, 'public/region-filter.js');
-
-  const RF = ctx.RegionFilter;
-  RF.init(document.createElement('div'));
-
-  test('setSelected sets region codes', async () => {
-    await RF.init(document.createElement('div'));
-    RF.setSelected(['US-SFO', 'US-LAX']);
-    assert.strictEqual(RF.getRegionParam(), 'US-SFO,US-LAX');
-  });
-
-  test('setSelected with null clears selection', async () => {
-    await RF.init(document.createElement('div'));
-    RF.setSelected(['US-SFO']);
-    RF.setSelected(null);
-    assert.strictEqual(RF.getRegionParam(), '');
-  });
-
-  test('setSelected with empty array clears selection', async () => {
-    await RF.init(document.createElement('div'));
-    RF.setSelected(['US-SFO']);
-    RF.setSelected([]);
-    assert.strictEqual(RF.getRegionParam(), '');
-  });
-}
-```
-
-- [ ] **Step 2: Run test to verify it fails**
-
-```bash
-node test-frontend-helpers.js 2>&1 | grep -A2 "setSelected"
-```
-
-Expected: `❌ setSelected sets region codes: RF.setSelected is not a function`
-
-- [ ] **Step 3: Add `_container` tracking and `setSelected` to region-filter.js**
-
-In `region-filter.js`, add `var _container = null;` after the existing module-level vars (after line 9 `var _listeners = [];`):
-
-```javascript
-  var _listeners = [];
-  var _container = null;   // ← add this line
-  var _loaded = false;
-```
-
-In `initFilter`, save the container:
-
-```javascript
-  async function initFilter(container, opts) {
-    _container = container;          // ← add this line
-    if (opts && opts.dropdown) container._forceDropdown = true;
-    await fetchRegions();
-    render(container);
-  }
-```
-
-Add `setSelected` function before `// Expose globally`:
-
-```javascript
-  /** Override selected regions (e.g. from URL param). Persists to localStorage and re-renders. */
-  function setSelected(codesArray) {
-    _selected = (codesArray && codesArray.length > 0) ? new Set(codesArray) : null;
-    saveToStorage();
-    if (_container) render(_container);
-  }
-```
-
-Add `setSelected` to the public API object:
-
-```javascript
-  window.RegionFilter = {
-    init: initFilter,
-    render: render,
-    getSelected: getSelected,
-    getRegionParam: getRegionParam,
-    regionQueryString: regionQueryString,
-    onChange: onChange,
-    offChange: offChange,
-    fetchRegions: fetchRegions,
-    setSelected: setSelected,    // ← add this line
-  };
-```
-
-- [ ] **Step 4: Run test to verify it passes**
-
-```bash
-node test-frontend-helpers.js 2>&1 | grep -E "(setSelected|FAIL|passed|failed)"
-```
-
-Expected: 3 passing `setSelected` tests, overall pass.
-
-- [ ] **Step 5: Commit**
-
-```bash
-git add public/region-filter.js test-frontend-helpers.js
-git commit -m "feat: add RegionFilter.setSelected for URL param initialization (#536)"
-```
-
----
-
-## Task 2: nodes.js — tab and search deep linking
-
-**Files:**
-- Modify: `public/nodes.js`
-- Test: `test-frontend-helpers.js`
-- Test: `test-e2e-playwright.js`
-
-- [ ] **Step 1: Write the unit test (add to test-frontend-helpers.js)**
-
-Add before the `// ===== SUMMARY =====` line:
-
-```javascript
-// ===== NODES.JS: buildNodesQuery =====
-console.log('\n=== nodes.js: buildNodesQuery ===');
-{
-  const ctx = makeSandbox();
-  loadInCtx(ctx, 'public/roles.js');
-  loadInCtx(ctx, 'public/app.js');
-
-  // Provide required globals for nodes.js IIFE to execute
-  ctx.registerPage = () => {};
-  ctx.RegionFilter = { init: () => Promise.resolve(), onChange: () => () => {}, offChange: () => {}, getSelected: () => null, getRegionParam: () => '' };
-  ctx.onWS = () => {};
-  ctx.offWS = () => {};
-  ctx.debouncedOnWS = () => () => {};
-  ctx.invalidateApiCache = () => {};
-  ctx.favStar = () => '';
-  ctx.bindFavStars = () => {};
-  ctx.getFavorites = () => [];
-  ctx.isFavorite = () => false;
-  ctx.connectWS = () => {};
-  ctx.HopResolver = { init: () => {}, resolve: () => ({}), ready: () => false };
-  ctx.initTabBar = () => {};
-  ctx.debounce = (fn) => fn;
-  ctx.copyToClipboard = () => {};
-  ctx.api = () => Promise.resolve({});
-  ctx.escapeHtml = (s) => s;
-  ctx.timeAgo = () => '';
-  ctx.formatTimestampWithTooltip = () => '';
-  ctx.getTimestampMode = () => 'ago';
-  ctx.CLIENT_TTL = {};
-  ctx.qrcode = null;
-
-  try {
-    const src = fs.readFileSync('public/nodes.js', 'utf8');
-    vm.runInContext(src, ctx);
-    for (const k of Object.keys(ctx.window)) ctx[k] = ctx.window[k];
-  } catch (e) {
-    console.log('  ⚠️ nodes.js sandbox load failed:', e.message.slice(0, 120));
-  }
-
-  const buildNodesQuery = ctx.buildNodesQuery;
-
-  if (buildNodesQuery) {
-    test('buildNodesQuery: all tab + no search = empty', () => {
-      assert.strictEqual(buildNodesQuery('all', ''), '');
-    });
-    test('buildNodesQuery: repeater tab only', () => {
-      assert.strictEqual(buildNodesQuery('repeater', ''), '?tab=repeater');
-    });
-    test('buildNodesQuery: search only (all tab)', () => {
-      assert.strictEqual(buildNodesQuery('all', 'foo'), '?search=foo');
-    });
-    test('buildNodesQuery: tab + search combined', () => {
-      assert.strictEqual(buildNodesQuery('companion', 'bar'), '?tab=companion&search=bar');
-    });
-    test('buildNodesQuery: null search treated as empty', () => {
-      assert.strictEqual(buildNodesQuery('all', null), '');
-    });
-    test('buildNodesQuery: sensor tab', () => {
-      assert.strictEqual(buildNodesQuery('sensor', ''), '?tab=sensor');
-    });
-  } else {
-    console.log('  ⚠️ buildNodesQuery not exposed — skipping');
-  }
-}
-```
-
-- [ ] **Step 2: Run test to verify it fails (or skips)**
-
-```bash
-node test-frontend-helpers.js 2>&1 | grep -A3 "buildNodesQuery"
-```
-
-Expected: `⚠️ buildNodesQuery not exposed — skipping`
-
-- [ ] **Step 3: Add URL param reading and helpers to nodes.js**
-
-**3a.** Add `buildNodesQuery` and `updateNodesUrl` functions inside the nodes.js IIFE, after the `TABS` definition (around line 86, before `function renderNodeTimestampHtml`):
-
-```javascript
-  function buildNodesQuery(tab, searchStr) {
-    var parts = [];
-    if (tab && tab !== 'all') parts.push('tab=' + encodeURIComponent(tab));
-    if (searchStr) parts.push('search=' + encodeURIComponent(searchStr));
-    return parts.length ? '?' + parts.join('&') : '';
-  }
-  window.buildNodesQuery = buildNodesQuery;
-
-  function updateNodesUrl() {
-    history.replaceState(null, '', '#/nodes' + buildNodesQuery(activeTab, search));
-  }
-```
-
-**3b.** In the list-view branch of `init` (after the `return;` that ends the full-screen block at line 317), add URL param reading before `app.innerHTML`:
-
-```javascript
-    // Read URL params for list view (router strips query string from routeParam)
-    const _listUrlParams = new URLSearchParams(location.hash.split('?')[1] || '');
-    const _urlTab = _listUrlParams.get('tab');
-    const _urlSearch = _listUrlParams.get('search');
-    if (_urlTab && TABS.some(function(t) { return t.key === _urlTab; })) activeTab = _urlTab;
-    if (_urlSearch) search = _urlSearch;
-
-    app.innerHTML = `<div class="nodes-page">
-```
-
-**3c.** After `app.innerHTML = ...` (after the closing backtick at line ~330), populate the search input:
-
-```javascript
-    if (search) {
-      var _si = document.getElementById('nodeSearch');
-      if (_si) _si.value = search;
-    }
-```
-
-**3d.** In the search input event listener (around line 335), add `updateNodesUrl()`:
-
-```javascript
-    document.getElementById('nodeSearch').addEventListener('input', debounce(e => {
-      search = e.target.value;
-      updateNodesUrl();
-      loadNodes();
-    }, 250));
-```
-
-**3e.** In the tab click handler inside `renderLeft` (around line 875), add `updateNodesUrl()`:
-
-```javascript
-      btn.addEventListener('click', () => { activeTab = btn.dataset.tab; updateNodesUrl(); loadNodes(); });
-```
-
-- [ ] **Step 4: Run unit tests**
-
-```bash
-node test-frontend-helpers.js 2>&1 | grep -E "(buildNodesQuery|✅|❌)" | grep -v "helpers"
-```
-
-Expected: 6 passing `buildNodesQuery` tests.
-
-- [ ] **Step 5: Write Playwright test (add to test-e2e-playwright.js)**
-
-Add before the closing `await browser.close()` line:
-
-```javascript
-  // --- Group: Deep linking (#536) ---
-
-  // Test: nodes tab deep link
-  await test('Nodes tab deep link restores active tab', async () => {
-    await page.goto(BASE + '#/nodes?tab=repeater', { waitUntil: 'domcontentloaded' });
-    await page.waitForSelector('.node-tab', { timeout: 8000 });
-    const activeTab = await page.$('.node-tab.active');
-    assert(activeTab, 'No active tab found');
-    const tabText = await activeTab.textContent();
-    assert(tabText.includes('Repeater'), `Expected Repeater tab active, got: ${tabText}`);
-    const url = page.url();
-    assert(url.includes('tab=repeater'), `URL should contain tab=repeater, got: ${url}`);
-  });
-
-  // Test: nodes tab click updates URL
-  await test('Nodes tab click updates URL', async () => {
-    await page.goto(BASE + '#/nodes', { waitUntil: 'domcontentloaded' });
-    await page.waitForSelector('.node-tab', { timeout: 8000 });
-    const roomTab = await page.$('.node-tab[data-tab="room"]');
-    if (roomTab) {
-      await roomTab.click();
-      await page.waitForTimeout(300);
-      const url = page.url();
-      assert(url.includes('tab=room'), `URL should contain tab=room after click, got: ${url}`);
-    }
-  });
-```
-
-- [ ] **Step 6: Run full test suite**
-
-```bash
-node test-frontend-helpers.js
-```
-
-Expected: all tests pass.
-
-- [ ] **Step 7: Commit**
-
-```bash
-git add public/nodes.js test-frontend-helpers.js test-e2e-playwright.js
-git commit -m "feat: deep link nodes tab and search query (#536)"
-```
-
----
-
-## Task 3: packets.js — timeWindow and region deep linking
-
-**Files:**
-- Modify: `public/packets.js`
-- Test: `test-frontend-helpers.js`
-- Test: `test-e2e-playwright.js`
-
-> Depends on Task 1 (RegionFilter.setSelected).
-
-- [ ] **Step 1: Write the unit test**
-
-Add to `test-frontend-helpers.js` before `// ===== SUMMARY =====`:
-
-```javascript
-// ===== PACKETS.JS: buildPacketsUrl =====
-console.log('\n=== packets.js: buildPacketsUrl ===');
-{
-  // Test the pure helper function
-  // (loaded via packets.js after it exposes window.buildPacketsUrl)
-  const ctx = makeSandbox();
-  loadInCtx(ctx, 'public/roles.js');
-  loadInCtx(ctx, 'public/app.js');
-
-  ctx.registerPage = () => {};
-  ctx.RegionFilter = { init: () => Promise.resolve(), onChange: () => () => {}, offChange: () => {}, getSelected: () => null, getRegionParam: () => '', setSelected: () => {} };
-  ctx.onWS = () => {};
-  ctx.offWS = () => {};
-  ctx.debouncedOnWS = () => () => {};
-  ctx.invalidateApiCache = () => {};
-  ctx.api = () => Promise.resolve({});
-  ctx.observerMap = new Map();
-  ctx.getParsedPath = () => [];
-  ctx.getParsedDecoded = () => ({});
-  ctx.clearParsedCache = () => {};
-  ctx.escapeHtml = (s) => s;
-  ctx.timeAgo = () => '';
-  ctx.formatTimestampWithTooltip = () => '';
-  ctx.getTimestampMode = () => 'ago';
-  ctx.copyToClipboard = () => {};
-  ctx.CLIENT_TTL = {};
-  ctx.debounce = (fn) => fn;
-  ctx.initTabBar = () => {};
-
-  try {
-    const src = fs.readFileSync('public/packet-helpers.js', 'utf8');
-    vm.runInContext(src, ctx);
-    for (const k of Object.keys(ctx.window)) ctx[k] = ctx.window[k];
-    const src2 = fs.readFileSync('public/packets.js', 'utf8');
-    vm.runInContext(src2, ctx);
-    for (const k of Object.keys(ctx.window)) ctx[k] = ctx.window[k];
-  } catch (e) {
-    console.log('  ⚠️ packets.js sandbox load failed:', e.message.slice(0, 120));
-  }
-
-  const buildPacketsUrl = ctx.buildPacketsUrl;
-
-  if (buildPacketsUrl) {
-    test('buildPacketsUrl: default (15min, no region) = bare #/packets', () => {
-      assert.strictEqual(buildPacketsUrl(15, ''), '#/packets');
-    });
-    test('buildPacketsUrl: non-default timeWindow', () => {
-      assert.strictEqual(buildPacketsUrl(60, ''), '#/packets?timeWindow=60');
-    });
-    test('buildPacketsUrl: region only', () => {
-      assert.strictEqual(buildPacketsUrl(15, 'US-SFO'), '#/packets?region=US-SFO');
-    });
-    test('buildPacketsUrl: timeWindow + region', () => {
-      assert.strictEqual(buildPacketsUrl(30, 'US-SFO,US-LAX'), '#/packets?timeWindow=30&region=US-SFO%2CUS-LAX');
-    });
-    test('buildPacketsUrl: timeWindow=0 treated as default', () => {
-      assert.strictEqual(buildPacketsUrl(0, ''), '#/packets');
-    });
-  } else {
-    console.log('  ⚠️ buildPacketsUrl not exposed — skipping');
-  }
-}
-```
-
-- [ ] **Step 2: Run to verify it skips**
-
-```bash
-node test-frontend-helpers.js 2>&1 | grep -A2 "buildPacketsUrl"
-```
-
-Expected: `⚠️ buildPacketsUrl not exposed — skipping`
-
-- [ ] **Step 3: Add helpers and URL param reading to packets.js**
-
-**3a.** Add `buildPacketsUrl` and `updatePacketsUrl` inside the packets.js IIFE, after the existing constants at the top (around line 36, after `let showHexHashes`):
-
-```javascript
-  function buildPacketsUrl(timeWindowMin, regionParam) {
-    var parts = [];
-    if (timeWindowMin && timeWindowMin !== 15) parts.push('timeWindow=' + timeWindowMin);
-    if (regionParam) parts.push('region=' + encodeURIComponent(regionParam));
-    return '#/packets' + (parts.length ? '?' + parts.join('&') : '');
-  }
-  window.buildPacketsUrl = buildPacketsUrl;
-
-  function updatePacketsUrl() {
-    history.replaceState(null, '', buildPacketsUrl(savedTimeWindowMin, RegionFilter.getRegionParam()));
-  }
-```
-
-**3b.** In the `init` function (around line 263), add URL param reading after the existing `routeParam`/`directObsId` parsing and before `app.innerHTML`:
-
-```javascript
-    // Read URL params for filter state (router strips query from routeParam; read from location.hash)
-    var _initUrlParams = new URLSearchParams(location.hash.split('?')[1] || '');
-    var _urlTimeWindow = Number(_initUrlParams.get('timeWindow'));
-    if (Number.isFinite(_urlTimeWindow) && _urlTimeWindow > 0) {
-      savedTimeWindowMin = _urlTimeWindow;
-      localStorage.setItem('meshcore-time-window', String(_urlTimeWindow));
-    }
-    var _urlRegion = _initUrlParams.get('region');
-    if (_urlRegion) {
-      RegionFilter.setSelected(_urlRegion.split(',').filter(Boolean));
-    }
-
-    app.innerHTML = `<div class="split-layout detail-collapsed">
-```
-
-**3c.** In the time window change handler (around line 865), add `updatePacketsUrl()`:
-
-```javascript
-    fTimeWindow.addEventListener('change', () => {
-      savedTimeWindowMin = Number(fTimeWindow.value);
-      if (!Number.isFinite(savedTimeWindowMin) || savedTimeWindowMin <= 0) savedTimeWindowMin = 15;
-      localStorage.setItem('meshcore-time-window', fTimeWindow.value);
-      updatePacketsUrl();
-      loadPackets();
-    });
-```
-
-**3d.** In the RegionFilter.onChange callback (around line 719), add `updatePacketsUrl()`:
-
-```javascript
-    RegionFilter.onChange(function() { updatePacketsUrl(); loadPackets(); });
-```
-
-- [ ] **Step 4: Run unit tests**
-
-```bash
-node test-frontend-helpers.js 2>&1 | grep -E "(buildPacketsUrl|✅|❌)" | grep -v "helpers"
-```
-
-Expected: 5 passing `buildPacketsUrl` tests.
-
-- [ ] **Step 5: Write Playwright test (add to test-e2e-playwright.js, inside the deep-linking group)**
-
-```javascript
-  // Test: packets timeWindow deep link
-  await test('Packets timeWindow deep link restores dropdown', async () => {
-    await page.goto(BASE + '#/packets?timeWindow=60', { waitUntil: 'domcontentloaded' });
-    await page.waitForSelector('#fTimeWindow', { timeout: 8000 });
-    const val = await page.$eval('#fTimeWindow', el => el.value);
-    assert(val === '60', `Expected timeWindow dropdown = 60, got: ${val}`);
-    const url = page.url();
-    assert(url.includes('timeWindow=60'), `URL should still contain timeWindow=60, got: ${url}`);
-  });
-
-  // Test: timeWindow change updates URL
-  await test('Packets timeWindow change updates URL', async () => {
-    await page.goto(BASE + '#/packets', { waitUntil: 'domcontentloaded' });
-    await page.waitForSelector('#fTimeWindow', { timeout: 8000 });
-    await page.selectOption('#fTimeWindow', '30');
-    await page.waitForTimeout(300);
-    const url = page.url();
-    assert(url.includes('timeWindow=30'), `URL should contain timeWindow=30 after change, got: ${url}`);
-  });
-```
-
-- [ ] **Step 6: Run full test suite**
-
-```bash
-node test-frontend-helpers.js
-```
-
-Expected: all tests pass.
-
-- [ ] **Step 7: Commit**
-
-```bash
-git add public/packets.js test-frontend-helpers.js test-e2e-playwright.js
-git commit -m "feat: deep link packets timeWindow and region filter (#536)"
-```
-
----
-
-## Task 4: channels.js — node panel deep linking
-
-**Files:**
-- Modify: `public/channels.js`
-
-No unit tests needed for this task — the URL manipulation is side-effectful (DOM + History API). Playwright tests cover it.
-
-- [ ] **Step 1: Write the Playwright test (add to test-e2e-playwright.js, inside the deep-linking group)**
-
-```javascript
-  // Test: channels selected channel survives refresh (already implemented, verify it still works)
-  await test('Channels channel selection is URL-addressable', async () => {
-    await page.goto(BASE + '#/channels', { waitUntil: 'domcontentloaded' });
-    await page.waitForSelector('.ch-item', { timeout: 8000 }).catch(() => null);
-    const firstChannel = await page.$('.ch-item');
-    if (firstChannel) {
-      await firstChannel.click();
-      await page.waitForTimeout(500);
-      const url = page.url();
-      assert(url.includes('#/channels/') || url.includes('#/channels'), `URL should reflect channel selection, got: ${url}`);
-    }
-  });
-```
-
-- [ ] **Step 2: Update `showNodeDetail` to write `?node=` to the URL**
-
-In `channels.js`, in `showNodeDetail` (around line 171), add the URL update right after `selectedNode = name;`:
-
-```javascript
-  async function showNodeDetail(name) {
-    _nodePanelTrigger = document.activeElement;
-    if (_focusTrapCleanup) { _focusTrapCleanup(); _focusTrapCleanup = null; }
-    const node = await lookupNode(name);
-    selectedNode = name;
-    var _chBase = selectedHash ? '#/channels/' + encodeURIComponent(selectedHash) : '#/channels';
-    history.replaceState(null, '', _chBase + '?node=' + encodeURIComponent(name));
-
-    let panel = document.getElementById('chNodePanel');
-```
-
-- [ ] **Step 3: Update `closeNodeDetail` to strip `?node=` from the URL**
-
-In `closeNodeDetail` (around line 232), add URL restore right after `selectedNode = null;`:
-
-```javascript
-  function closeNodeDetail() {
-    if (_focusTrapCleanup) { _focusTrapCleanup(); _focusTrapCleanup = null; }
-    const panel = document.getElementById('chNodePanel');
-    if (panel) panel.classList.remove('open');
-    selectedNode = null;
-    var _chRestoreUrl = selectedHash ? '#/channels/' + encodeURIComponent(selectedHash) : '#/channels';
-    history.replaceState(null, '', _chRestoreUrl);
-    if (_nodePanelTrigger && typeof _nodePanelTrigger.focus === 'function') {
-```
-
-- [ ] **Step 4: Read `?node=` on init and auto-open panel**
-
-In `channels.js` `init` (line 316), add URL param reading at the very top of the function (before `app.innerHTML`):
-
-```javascript
-  function init(app, routeParam) {
-    var _initUrlParams = new URLSearchParams(location.hash.split('?')[1] || '');
-    var _pendingNode = _initUrlParams.get('node');
-
-    app.innerHTML = `<div class="ch-layout">
-```
-
-Then update the `loadChannels().then(...)` call (around line 350) to auto-open the node panel:
-
-```javascript
-    loadChannels().then(async function () {
-      if (routeParam) await selectChannel(routeParam);
-      if (_pendingNode) showNodeDetail(_pendingNode);
-    });
-```
-
-- [ ] **Step 5: Run full test suite**
-
-```bash
-node test-frontend-helpers.js
-```
-
-Expected: all tests pass (no channels unit tests, but regression tests still pass).
-
-- [ ] **Step 6: Commit**
-
-```bash
-git add public/channels.js
-git commit -m "feat: deep link channels node panel via ?node= (#536)"
-```
-
----
-
-## Task 5: Run E2E Playwright tests
-
-- [ ] **Step 1: Start the local server**
-
-```bash
-cd cmd/server && go run . &
-```
-
-Wait for it to be ready (check `http://localhost:3000`).
-
-- [ ] **Step 2: Run Playwright tests**
-
-```bash
-node test-e2e-playwright.js
-```
-
-Expected: all tests pass including the new deep-linking group.
-
-- [ ] **Step 3: If any deep-linking test fails, debug**
-
-Common failures:
-- Selector `.node-tab.active` not found: check that nodes.js correctly reads `?tab=` from URL before rendering
-- `#fTimeWindow` value wrong: check that `savedTimeWindowMin` is overridden before the DOM is built
-- URL doesn't update: check `history.replaceState` calls in the change handlers
-
-- [ ] **Step 4: Final commit (if any fixes needed)**
-
-```bash
-git add public/nodes.js public/packets.js public/channels.js
-git commit -m "fix: deep linking E2E adjustments (#536)"
-```
-
----
-
-## Self-Review
-
-**Spec coverage check:**
-- ✅ P1: Nodes role tab → Task 2
-- ✅ P1: Packets time window → Task 3
-- ✅ P1: Packets region filter → Task 3 (depends on Task 1)
-- ✅ P1: Channels selected channel → Already implemented via `#/channels/{hash}` (verified in channels.js init line 351)
-- ✅ P1: Channels node panel → Task 4
-- ✅ P2+ items → explicitly out of scope per issue
-
-**Architecture note:** The router in `app.js` strips the query string at line 422 (`const route = hash.split('?')[0]`) before computing `basePage` and `routeParam`. Therefore `#/nodes?tab=repeater` gives `routeParam=null` (not `?tab=repeater`). All pages must read URL params from `location.hash` directly, not from `routeParam`. This is the established pattern in `analytics.js` and `nodes.js` (section scroll).
-
-**Placeholder scan:** No TBDs, no "implement later", all code blocks complete. ✅
-
-**Type consistency:**
-- `buildNodesQuery(tab, searchStr)` — used consistently in `updateNodesUrl()` and in tests ✅
-- `buildPacketsUrl(timeWindowMin, regionParam)` — used consistently in `updatePacketsUrl()` and in tests ✅
-- `RegionFilter.setSelected(codesArray)` — defined in Task 1, used in Task 3 ✅
diff --git a/docs/superpowers/specs/2026-04-23-scope-stats-design.md b/docs/superpowers/specs/2026-04-23-scope-stats-design.md
deleted file mode 100644
index 22a310bd..00000000
--- a/docs/superpowers/specs/2026-04-23-scope-stats-design.md
+++ /dev/null
@@ -1,204 +0,0 @@
-# Scope Stats Page — Design Spec
-
-**Issue**: Kpa-clawbot/CoreScope#899  
-**Date**: 2026-04-23  
-**Branch target**: `master`
-
----
-
-## Overview
-
-Add a dedicated **Scopes** page showing scope/region statistics for MeshCore transport-route packets. Scope filtering in MeshCore uses `TRANSPORT_FLOOD` (route_type 0) and `TRANSPORT_DIRECT` (route_type 3) packets that carry two 16-bit transport codes. Code1 ≠ `0000` means the packet is region-scoped.
-
-Feature 3 from the issue (default scope per client via advert) is **not implemented** — the advert format has no scope field in the current firmware.
-
----
-
-## How Scopes Work (Firmware)
-
-Transport code derivation (authoritative source: `meshcore-dev/MeshCore`):
-
-```
-key  = SHA256("#regionname")[:16]          // TransportKeyStore::getAutoKeyFor
-Code1 = HMAC-SHA256(key, type || payload)  // TransportKey::calcTransportCode, 2-byte output
-```
-
-Code1 is a **per-message** HMAC — the same region produces a different Code1 for every message. Identifying a region from Code1 requires knowing the region name in advance and recomputing the HMAC.
-
-`Code1 = 0000` is the "no scope" sentinel (also `FFFF` is reserved). Packets with route_type 1 or 2 (plain FLOOD/DIRECT) carry no transport codes.
-
----
-
-## Config
-
-Add `hashRegions` to the ingestor `Config` struct in `cmd/ingestor/config.go`, mirroring `hashChannels`:
-
-```json
-"hashRegions": ["#belgium", "#eu", "#brussels"]
-```
-
-Normalization (same rules as `hashChannels`):
-- Trim whitespace
-- Prepend `#` if missing
-- Skip empty entries
-
----
-
-## Ingestor Changes
-
-### Key derivation (`loadRegionKeys`)
-
-```go
-func loadRegionKeys(cfg *Config) map[string][]byte {
-    // key = first 16 bytes of SHA256("#regionname")
-}
-```
-
-Returns `map[string][]byte` (region name → 16-byte HMAC key). Called once at startup, stored on the `Store`.
-
-### Decoder: expose raw payload bytes
-
-Add `PayloadRaw []byte` to `DecodedPacket` in `cmd/ingestor/decoder.go`. Populated from the raw `buf` slice at the payload offset — zero-copy slice, no allocation. This is the **encrypted** payload bytes, matching what the firmware feeds into `calcTransportCode`.
-
-### At-ingest region matching
-
-In `BuildPacketData`:
-- Skip if `route_type` not in `{0, 3}` → `scope_name` stays `nil`
-- If `Code1 == "0000"` → `scope_name = nil` (unscoped transport, no scope involvement)
-- If `Code1 != "0000"` → try each region key:
-  ```
-  HMAC-SHA256(key, payloadType_byte || PayloadRaw)  → first 2 bytes as uint16
-  ```
-  First match → `scope_name = "#regionname"`. No match → `scope_name = ""` (unknown scope).
-
-Add `ScopeName *string` to `PacketData`.
-
-### MQTT-sourced packets (DM / CHAN paths in main.go)
-
-These are injected directly without going through `BuildPacketData`. They use `route_type = 1` (FLOOD), so they are never transport-route packets. No scope matching needed for these paths.
-
----
-
-## Database
-
-### Migration
-
-```sql
-ALTER TABLE transmissions ADD COLUMN scope_name TEXT DEFAULT NULL;
-CREATE INDEX idx_tx_scope_name ON transmissions(scope_name) WHERE scope_name IS NOT NULL;
-```
-
-### Column semantics
-
-| Value | Meaning |
-|-------|---------|
-| `NULL` | Either: non-transport-route packet (route_type 1/2), or transport-route with Code1=0000 |
-| `""` (empty string) | Transport-route, Code1 ≠ 0000, but no configured region matched |
-| `"#belgium"` | Matched named region |
-
-The API stats queries resolve the NULL ambiguity by always filtering `route_type IN (0, 3)` first:
-- `unscoped` count = `route_type IN (0,3) AND scope_name IS NULL`
-- `scoped` count = `route_type IN (0,3) AND scope_name IS NOT NULL`
-
-### Backfill
-
-On migration, re-decode `raw_hex` for all rows where `route_type IN (0, 3)` and `scope_name IS NULL`. Run the same HMAC matching logic. Rows with `Code1 = 0000` remain `NULL`.
-
-The backfill runs in the existing migration framework in `cmd/ingestor/db.go`. If no regions are configured, backfill is skipped.
-
----
-
-## API
-
-### `GET /api/scope-stats`
-
-**Query param**: `window` — one of `1h`, `24h` (default), `7d`
-
-**Time-series bucket sizes**:
-| Window | Bucket |
-|--------|--------|
-| `1h`   | 5 min  |
-| `24h`  | 1 hour |
-| `7d`   | 6 hours|
-
-**Response**:
-```json
-{
-  "window": "24h",
-  "summary": {
-    "transportTotal": 1240,
-    "scoped": 890,
-    "unscoped": 350,
-    "unknownScope": 42
-  },
-  "byRegion": [
-    { "name": "#belgium", "count": 612 },
-    { "name": "#eu",      "count": 236 }
-  ],
-  "timeSeries": [
-    { "t": "2026-04-23T10:00:00Z", "scoped": 45, "unscoped": 18 },
-    { "t": "2026-04-23T11:00:00Z", "scoped": 51, "unscoped": 22 }
-  ]
-}
-```
-
-- `transportTotal` = `scoped + unscoped` (transport-route packets only)
-- `scoped` = Code1 ≠ 0000 (named + unknown)
-- `unscoped` = transport-route with Code1 = 0000
-- `unknownScope` = scoped but no region name matched (subset of `scoped`)
-- `byRegion` sorted by count descending, excludes unknown
-- `timeSeries` covers the full window at the bucket granularity
-
-Route: `GET /api/scope-stats` registered in `cmd/server/routes.go`.  
-No auth required (same as other read endpoints).  
-TTL cache: 30 seconds (heavier query than `/api/stats`).
-
----
-
-## Frontend
-
-### Navigation
-
-Add nav link between Channels and Nodes in `public/index.html`:
-```html
-<a href="#/scopes" class="nav-link" data-route="scopes">Scopes</a>
-```
-
-### `public/scopes.js`
-
-Three sections on the page:
-
-**1. Summary cards** (reuse existing card CSS pattern from home/analytics pages)  
-- Transport total, Scoped, Unscoped, Unknown scope  
-- Each card shows count + percentage of transport total
-
-**2. Per-region table**  
-Columns: Region, Messages, % of Scoped  
-Sorted by count descending. Last row: "Unknown scope" (italic) if unknownScope > 0.  
-Shows "No regions configured" message if `byRegion` is empty and `unknownScope = 0`.
-
-**3. Time-series chart**  
-- Window selector: `1h / 24h / 7d` (default 24h)  
-- Two lines: **Scoped** (blue) and **Unscoped** (grey)  
-- Uses the same lightweight canvas chart pattern as other pages (no external chart lib)
-
-### Cache buster
-
-`scopes.js` added to the `__BUST__` entries in `index.html` in the same commit.
-
----
-
-## Testing
-
-- Unit tests for `loadRegionKeys`: normalization, key bytes match firmware SHA256 derivation
-- Unit tests for HMAC matching: known Code1 value computed from firmware logic, verified against Go implementation
-- Integration test: ingest a synthetic transport-route packet with a known region, assert `scope_name` column is set correctly
-- API test: `GET /api/scope-stats` returns correct summary counts against fixture DB
-
----
-
-## Out of Scope
-
-- Feature 3 (default scope per client via advert) — firmware has no advert scope field
-- Drill-down from region row to filtered packet list (deferred)
-- Private regions (`$`-prefixed) — use secret keys not publicly derivable
diff --git a/docs/user-guide/configuration.md b/docs/user-guide/configuration.md
index 7ff59d94..7435fd3f 100644
--- a/docs/user-guide/configuration.md
+++ b/docs/user-guide/configuration.md
@@ -206,7 +206,9 @@ Provide cert and key paths to enable HTTPS.
 
 Restricts ingestion and API responses to nodes within the polygon plus a buffer margin. Remove the block to disable filtering. Nodes with no GPS fix always pass through.
 
-See [Geographic Filtering](geofilter.md) for the full guide including the visual polygon builder and the prune script for cleaning up historical data.
+Can also be configured live via the **🗺️ GeoFilter** tab in the Customizer (requires `apiKey`).
+
+See [Geographic Filtering](geofilter.md) for the full guide.
 
 ## Home page
 
diff --git a/docs/user-guide/customization.md b/docs/user-guide/customization.md
index 888761e2..c4d982de 100644
--- a/docs/user-guide/customization.md
+++ b/docs/user-guide/customization.md
@@ -66,11 +66,13 @@ Click **Import JSON** and paste a previously exported theme. The customizer load
 
 Click **Reset to Defaults** to restore all settings to the built-in defaults.
 
-## GeoFilter Builder
+## GeoFilter (admin only)
 
-The Export tab includes a **GeoFilter Builder →** link. Click it to open a Leaflet map where you can draw a polygon boundary for your deployment area. The tool generates a `geo_filter` block you can paste directly into `config.json`.
+The **🗺️ GeoFilter** tab lets operators configure geographic filtering directly from the customizer. It shows the active polygon on a Leaflet map and — on servers with a write-capable `apiKey` — allows editing the polygon and saving back to `config.json` without a restart.
 
-See [Geographic Filtering](geofilter.md) for full details on what geo filtering does and how to configure it.
+The editing controls are only revealed after the server confirms write access. On public deployments without an `apiKey`, the tab is read-only.
+
+See [Geographic Filtering](geofilter.md) for the full guide, including the API, the prune script, and the standalone GeoFilter Builder.
 
 ## How it works
 
diff --git a/docs/user-guide/geofilter.md b/docs/user-guide/geofilter.md
index 27d20b41..f17d7a62 100644
--- a/docs/user-guide/geofilter.md
+++ b/docs/user-guide/geofilter.md
@@ -30,9 +30,9 @@ Add a `geo_filter` block to `config.json`:
 | Field | Type | Description |
 |-------|------|-------------|
 | `polygon` | `[[lat, lon], ...]` | Array of at least 3 coordinate pairs defining the boundary |
-| `bufferKm` | number | Extra distance (km) around the polygon edge that is also accepted. `0` = exact boundary |
+| `bufferKm` | number | Extra distance (km) outside the polygon edge that is also accepted. `0` = exact boundary |
 
-Both the server and the ingestor read `geo_filter` from `config.json`. Restart both after changing this section.
+Both the server and the ingestor read `geo_filter` from `config.json`. Restart both after changing this section manually.
 
 To disable filtering entirely, remove the `geo_filter` block.
 
@@ -51,50 +51,64 @@ An older bounding box format is also supported as a fallback when no `polygon` i
 
 Prefer the polygon format — it supports irregular shapes and the `bufferKm` margin.
 
-## API endpoint
+## Configuring via the customizer
 
-The current geo filter configuration is exposed at:
+If your server has an `apiKey` configured, the **GeoFilter tab** in the Customizer lets you edit the polygon visually without touching `config.json`:
 
-```
-GET /api/config/geo-filter
-```
+1. Open the Customizer (nav bar → customize icon)
+2. Click the **🗺️ GeoFilter** tab
+3. Click on the map to draw your polygon (at least 3 points)
+4. Adjust **Buffer km**
+5. Enter your **Server API Key** (the `apiKey` value from `config.json`)
+6. Click **Save to server** — the filter is applied immediately, no restart needed
 
-The frontend reads this endpoint to display the active filter. No authentication is required (the endpoint returns config, not private data).
+The editing controls are always visible. Saving requires entering the server's `apiKey`; on servers without one (or with a weak key), the save request returns `401`/`403` and the error is shown inline.
 
-## GeoFilter Builder
+To remove the filter, click **Remove filter** (also requires the API key).
 
-The simplest way to create a polygon is the included visual builder:
+## GeoFilter Builder (standalone tool)
 
-**File:** `tools/geofilter-builder.html`
+For a full-screen editing experience, use the built-in GeoFilter Builder at `/geofilter-builder.html`:
 
-Open it directly in a browser — it runs entirely client-side, no server required:
+1. Navigate to `http://your-server/geofilter-builder.html`
+2. Click on the map to add polygon vertices
+3. Adjust **Buffer km** (default 20)
+4. Copy the generated JSON from the output panel
+5. Paste it as a top-level key into `config.json` and restart the server
+
+The builder is also accessible from the Customizer's Export tab via the **GeoFilter Builder →** link.
+
+For local/offline use without a running server, open `tools/geofilter-builder.html` directly in a browser.
+
+## API endpoint
 
-```bash
-# From the project root
-open tools/geofilter-builder.html          # macOS
-xdg-open tools/geofilter-builder.html     # Linux
-start tools/geofilter-builder.html        # Windows
+```
+GET /api/config/geo-filter
+```
+
+Returns the current geo filter configuration (`polygon`, `bufferKm`). Whether the `PUT` endpoint will accept a write depends on whether the server has an `apiKey` configured; clients should attempt the write and handle `401`/`403` if it isn't.
+
+```
+PUT /api/config/geo-filter
 ```
 
-**Workflow:**
+Requires `X-API-Key` header. Saves the polygon to `config.json` and applies it in-memory immediately.
 
-1. The map opens centered on Belgium by default. Navigate to your region.
-2. Click on the map to add polygon vertices. Each click adds a numbered point.
-3. Add at least 3 points to form a closed polygon.
-4. Adjust **Buffer km** (default 20) to add a margin around the polygon edge.
-5. The generated JSON block appears at the bottom of the page — copy it directly into `config.json`.
-6. Use **↩ Undo** to remove the last point, **✕ Clear** to start over.
+Request body:
+```json
+{"polygon": [[lat, lon], ...], "bufferKm": 20}
+```
 
-The output is a complete `{ "geo_filter": { ... } }` block ready to paste into `config.json`.
+To clear the filter, send `{"polygon": null}`.
 
 ## Cleaning up historical nodes
 
-The ingestor prevents new out-of-bounds nodes from being ingested, but it does not retroactively remove nodes that were stored before the filter was configured. For that, use the prune script.
+The ingestor prevents new out-of-bounds nodes from being ingested, but it does not retroactively remove nodes stored before the filter was configured. For that, use the prune script:
 
 **File:** `scripts/prune-nodes-outside-geo-filter.py`
 
 ```bash
-# Dry run — shows what would be deleted without making any changes
+# Dry run — shows what would be deleted without making changes
 python3 scripts/prune-nodes-outside-geo-filter.py --dry-run
 
 # Default paths: /app/data/meshcore.db and /app/config.json
@@ -104,11 +118,11 @@ python3 scripts/prune-nodes-outside-geo-filter.py
 python3 scripts/prune-nodes-outside-geo-filter.py /path/to/meshcore.db \
   --config /path/to/config.json
 
-# In Docker — run inside the container
+# In Docker
 docker exec -it meshcore-analyzer \
   python3 /app/scripts/prune-nodes-outside-geo-filter.py --dry-run
 ```
 
-The script reads `geo_filter.polygon` and `geo_filter.bufferKm` from config, lists the nodes that fall outside, then asks for `yes` confirmation before deleting. Nodes without coordinates are always kept.
+The script reads `geo_filter.polygon` and `geo_filter.bufferKm` from config, lists nodes that fall outside, then asks for `yes` confirmation before deleting. Nodes without coordinates are always kept.
 
-This is a **one-time migration tool** — run it once after first configuring `geo_filter` to clean up pre-filter data. The ingestor handles all subsequent filtering automatically at ingest time.
+This is a **one-time migration tool** — run it once after first configuring `geo_filter` to clean up pre-filter data. The ingestor handles all subsequent filtering automatically.
diff --git a/public/customize-v2.js b/public/customize-v2.js
index 3e50d532..1e9ef4c9 100644
--- a/public/customize-v2.js
+++ b/public/customize-v2.js
@@ -878,6 +878,16 @@
   var _activeTab = 'branding';
   var _styleEl = null;
 
+  // GeoFilter tab state
+  var _gfMap = null;
+  var _gfModalMap = null;
+  var _gfWriteEnabled = false;
+  var _gfPoints = [];
+  var _gfMarkers = [];
+  var _gfPolygon = null;
+  var _gfClosingLine = null;
+  var _gfLoaded = false; // true after initial server load
+
   function esc(s) { var d = document.createElement('div'); d.textContent = s || ''; return d.innerHTML; }
   function escAttr(s) { return (s || '').replace(/&/g, '&amp;').replace(/"/g, '&quot;').replace(/</g, '&lt;'); }
 
@@ -1004,6 +1014,7 @@
       { id: 'nodes', label: '🎯', title: 'Colors', badge: (function () { var n = _countOverrides('nodeColors') + _countOverrides('typeColors'); return n ? ' <span class="cv2-tab-badge">' + n + '</span>' : ''; })() },
       { id: 'home', label: '🏠', title: 'Home', badge: _tabBadge('home') },
       { id: 'display', label: '🖥️', title: 'Display', badge: (function () { var n = _countOverrides('timestamps') + (_isOverridden(null, 'distanceUnit') ? 1 : 0); return n ? ' <span class="cv2-tab-badge">' + n + '</span>' : ''; })() },
+      { id: 'geofilter', label: '🗺️', title: 'GeoFilter' },
       { id: 'export', label: '📤', title: 'Export' }
     ];
     return '<div class="cust-tabs">' + tabs.map(function (t) {
@@ -1256,6 +1267,293 @@
     '</div>';
   }
 
+  function _renderGeoFilter() {
+    return '<div class="cust-panel' + (_activeTab === 'geofilter' ? ' active' : '') + '" data-panel="geofilter">' +
+      '<p class="cust-section-title">Geographic Filter</p>' +
+      '<p style="font-size:12px;color:var(--text-muted);margin-bottom:12px">Shows the active geographic filter. Nodes outside this area are excluded at ingest time and in API responses.</p>' +
+      '<div style="position:relative;margin-bottom:8px">' +
+        '<div id="cv2-gf-map" style="height:200px;border-radius:6px;border:1px solid var(--border);background:var(--surface-1);cursor:pointer"></div>' +
+        '<div style="position:absolute;top:7px;right:7px;background:rgba(255,255,255,0.88);border-radius:4px;padding:3px 8px;font-size:11px;color:#444;pointer-events:none;box-shadow:0 1px 3px rgba(0,0,0,0.15)">🔍 click to expand</div>' +
+      '</div>' +
+      '<div id="cv2-gf-status" style="font-size:12px;color:var(--text-muted);margin-bottom:10px">Loading current filter…</div>' +
+      // Edit controls — hidden until server confirms write access (writeEnabled=true)
+      '<div id="cv2-gf-edit" style="display:none">' +
+        '<div style="display:flex;gap:8px;margin-bottom:10px;align-items:center">' +
+          '<label style="font-size:12px;color:var(--text-muted)">Buffer km:</label>' +
+          '<input type="number" id="cv2-gf-buffer" value="20" min="0" max="500" style="width:64px;padding:4px 8px;border:1px solid var(--border);border-radius:6px;background:var(--input-bg);color:var(--text);font-size:12px">' +
+        '</div>' +
+        '<div class="cust-field"><label>Server API Key</label>' +
+          '<input type="password" id="cv2-gf-apikey" placeholder="apiKey from config.json" style="width:100%;padding:5px 8px;border:1px solid var(--border);border-radius:6px;background:var(--input-bg);color:var(--text);font-size:12px">' +
+        '</div>' +
+        '<div style="display:flex;gap:8px;margin-top:12px">' +
+          '<button id="cv2-gf-save" style="padding:7px 16px;background:var(--accent);color:#fff;border:none;border-radius:6px;cursor:pointer;font-size:13px;font-weight:500">Save to server</button>' +
+          '<button id="cv2-gf-remove" style="padding:7px 14px;background:var(--surface-1);color:var(--status-red);border:1px solid var(--border);border-radius:6px;cursor:pointer;font-size:13px">Remove filter</button>' +
+        '</div>' +
+        '<div id="cv2-gf-msg" style="margin-top:8px;font-size:12px;display:none"></div>' +
+      '</div>' +
+    '</div>';
+  }
+
+  function _gfOpenModal(container) {
+    var existing = document.getElementById('cv2-gf-modal-overlay');
+    if (existing) existing.remove();
+    if (_gfModalMap) { _gfModalMap.remove(); _gfModalMap = null; }
+
+    var overlay = document.createElement('div');
+    overlay.id = 'cv2-gf-modal-overlay';
+    overlay.style.cssText = 'position:fixed;inset:0;background:rgba(0,0,0,0.65);z-index:99999;display:flex;align-items:center;justify-content:center;';
+
+    var dialog = document.createElement('div');
+    dialog.style.cssText = 'width:92vw;height:86vh;background:#fff;border-radius:10px;display:flex;flex-direction:column;overflow:hidden;box-shadow:0 8px 32px rgba(0,0,0,0.4);';
+
+    var toolbarEl = document.createElement('div');
+    toolbarEl.style.cssText = 'padding:10px 14px;display:flex;gap:8px;align-items:center;border-bottom:1px solid #e0e0e0;background:#f5f5f5;flex-shrink:0;';
+    var title = document.createElement('span');
+    title.style.cssText = 'font-weight:600;color:#333;font-size:14px;';
+    title.textContent = _gfWriteEnabled ? 'Edit GeoFilter — click map to add points' : 'GeoFilter — read only';
+    toolbarEl.appendChild(title);
+
+    if (_gfWriteEnabled) {
+      var undoBtn = document.createElement('button');
+      undoBtn.id = 'cv2-gfm-undo';
+      undoBtn.textContent = '↩ Undo';
+      undoBtn.style.cssText = 'padding:5px 10px;background:#eee;color:#555;border:1px solid #ccc;border-radius:6px;cursor:pointer;font-size:12px;';
+      var clearBtn = document.createElement('button');
+      clearBtn.id = 'cv2-gfm-clear';
+      clearBtn.textContent = '✕ Clear';
+      clearBtn.style.cssText = 'padding:5px 10px;background:#fee;color:#c44;border:1px solid #fcc;border-radius:6px;cursor:pointer;font-size:12px;';
+      var countEl = document.createElement('span');
+      countEl.id = 'cv2-gfm-count';
+      countEl.style.cssText = 'font-size:12px;color:#888;';
+      var spacer = document.createElement('span');
+      spacer.style.cssText = 'flex:1;';
+      var doneBtn = document.createElement('button');
+      doneBtn.id = 'cv2-gfm-done';
+      doneBtn.textContent = 'Done';
+      doneBtn.style.cssText = 'padding:7px 18px;background:#4a9eff;color:#fff;border:none;border-radius:6px;cursor:pointer;font-size:13px;font-weight:500;';
+      toolbarEl.appendChild(undoBtn);
+      toolbarEl.appendChild(clearBtn);
+      toolbarEl.appendChild(countEl);
+      toolbarEl.appendChild(spacer);
+      toolbarEl.appendChild(doneBtn);
+    } else {
+      var spacer2 = document.createElement('span');
+      spacer2.style.cssText = 'flex:1;';
+      toolbarEl.appendChild(spacer2);
+    }
+
+    var closeBtn = document.createElement('button');
+    closeBtn.id = 'cv2-gfm-close';
+    closeBtn.textContent = _gfWriteEnabled ? 'Cancel' : 'Close';
+    closeBtn.style.cssText = 'padding:7px 14px;background:#eee;color:#555;border:1px solid #ccc;border-radius:6px;cursor:pointer;font-size:13px;';
+    toolbarEl.appendChild(closeBtn);
+
+    var mapDiv = document.createElement('div');
+    mapDiv.id = 'cv2-gf-modal-map';
+    mapDiv.style.cssText = 'flex:1;';
+
+    dialog.appendChild(toolbarEl);
+    dialog.appendChild(mapDiv);
+    overlay.appendChild(dialog);
+    document.body.appendChild(overlay);
+
+    var modalPoints = _gfPoints.map(function (p) { return [p[0], p[1]]; });
+    var modalMarkers = [];
+    var modalPolygon = null;
+    var modalClosingLine = null;
+
+    _gfModalMap = L.map(mapDiv, { zoomControl: true });
+    L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png', {
+      attribution: '© OpenStreetMap © CartoDB', maxZoom: 19
+    }).addTo(_gfModalMap);
+
+    function renderModal() {
+      if (modalPolygon) { _gfModalMap.removeLayer(modalPolygon); modalPolygon = null; }
+      if (modalClosingLine) { _gfModalMap.removeLayer(modalClosingLine); modalClosingLine = null; }
+      modalMarkers.forEach(function (m) { _gfModalMap.removeLayer(m); });
+      modalMarkers = [];
+      modalPoints.forEach(function (pt, i) {
+        var m = L.circleMarker(pt, { radius: 6, color: '#4a9eff', weight: 2, fillColor: '#4a9eff', fillOpacity: 0.9 })
+          .addTo(_gfModalMap)
+          .bindTooltip(String(i + 1), { permanent: true, direction: 'top', offset: [0, -8] });
+        modalMarkers.push(m);
+      });
+      if (modalPoints.length >= 3) {
+        modalPolygon = L.polygon(modalPoints, { color: '#4a9eff', weight: 2, fillColor: '#4a9eff', fillOpacity: 0.12 }).addTo(_gfModalMap);
+      } else if (modalPoints.length === 2) {
+        modalClosingLine = L.polyline(modalPoints, { color: '#4a9eff', weight: 2, dashArray: '5,5' }).addTo(_gfModalMap);
+      }
+      var ce = document.getElementById('cv2-gfm-count');
+      if (ce) ce.textContent = modalPoints.length + ' point' + (modalPoints.length !== 1 ? 's' : '');
+    }
+
+    function closeModal() {
+      if (_gfModalMap) { _gfModalMap.remove(); _gfModalMap = null; }
+      overlay.remove();
+    }
+
+    setTimeout(function () {
+      _gfModalMap.invalidateSize();
+      renderModal();
+      if (modalPoints.length >= 3) {
+        _gfModalMap.fitBounds(L.latLngBounds(modalPoints), { padding: [40, 40] });
+      } else {
+        _gfModalMap.setView([50.5, 4.4], 5);
+      }
+    }, 80);
+
+    if (_gfWriteEnabled) {
+      _gfModalMap.on('click', function (e) {
+        modalPoints.push([parseFloat(e.latlng.lat.toFixed(6)), parseFloat(e.latlng.lng.toFixed(6))]);
+        renderModal();
+      });
+      document.getElementById('cv2-gfm-undo').addEventListener('click', function () {
+        if (!modalPoints.length) return;
+        modalPoints.pop();
+        renderModal();
+      });
+      document.getElementById('cv2-gfm-clear').addEventListener('click', function () {
+        modalPoints = [];
+        renderModal();
+      });
+      document.getElementById('cv2-gfm-done').addEventListener('click', function () {
+        _gfPoints = modalPoints;
+        _gfRender();
+        var prune = container.querySelector('#cv2-gf-prune-section');
+        if (prune) prune.style.display = _gfPoints.length >= 3 ? '' : 'none';
+        _gfStatus(container, _gfPoints.length + ' point' + (_gfPoints.length !== 1 ? 's' : '') + '.');
+        closeModal();
+      });
+    }
+
+    closeBtn.addEventListener('click', closeModal);
+    overlay.addEventListener('click', function (e) { if (e.target === overlay) closeModal(); });
+  }
+
+  function _gfRender() {
+    if (!_gfMap) return;
+    if (_gfPolygon) { _gfMap.removeLayer(_gfPolygon); _gfPolygon = null; }
+    if (_gfClosingLine) { _gfMap.removeLayer(_gfClosingLine); _gfClosingLine = null; }
+    _gfMarkers.forEach(function (m) { _gfMap.removeLayer(m); });
+    _gfMarkers = [];
+
+    _gfPoints.forEach(function (pt, i) {
+      var m = L.circleMarker(pt, { radius: 6, color: '#4a9eff', weight: 2, fillColor: '#4a9eff', fillOpacity: 0.9 })
+        .addTo(_gfMap)
+        .bindTooltip(String(i + 1), { permanent: true, direction: 'top', offset: [0, -8] });
+      _gfMarkers.push(m);
+    });
+
+    if (_gfPoints.length >= 3) {
+      _gfPolygon = L.polygon(_gfPoints, { color: '#4a9eff', weight: 2, fillColor: '#4a9eff', fillOpacity: 0.12 }).addTo(_gfMap);
+    } else if (_gfPoints.length === 2) {
+      _gfClosingLine = L.polyline(_gfPoints, { color: '#4a9eff', weight: 2, dashArray: '5,5' }).addTo(_gfMap);
+    }
+  }
+
+  function _gfStatus(container, msg) {
+    var el = container.querySelector('#cv2-gf-status');
+    if (el) el.textContent = msg;
+  }
+
+  function _gfMsg(container, msg, ok) {
+    var el = container.querySelector('#cv2-gf-msg');
+    if (!el) return;
+    el.textContent = msg;
+    el.style.display = msg ? '' : 'none';
+    el.style.color = ok ? 'var(--status-green)' : 'var(--status-red)';
+  }
+
+  function _gfSave(container) {
+    if (_gfPoints.length < 3) { _gfMsg(container, 'Need at least 3 polygon points.', false); return; }
+    var apiKey = (container.querySelector('#cv2-gf-apikey') || {}).value || '';
+    if (!apiKey) { _gfMsg(container, 'API key required to save.', false); return; }
+    var bufferKm = parseFloat((container.querySelector('#cv2-gf-buffer') || {}).value) || 0;
+    fetch('/api/config/geo-filter', {
+      method: 'PUT',
+      headers: { 'Content-Type': 'application/json', 'X-API-Key': apiKey },
+      body: JSON.stringify({ polygon: _gfPoints, bufferKm: bufferKm })
+    }).then(function (r) {
+      if (!r.ok) return r.json().then(function (e) { throw new Error(e.error || ('HTTP ' + r.status)); });
+      _gfMsg(container, 'Saved. Filter is active immediately.', true);
+      _gfStatus(container, _gfPoints.length + ' points · bufferKm=' + bufferKm + ' · saved');
+    }).catch(function (e) { _gfMsg(container, 'Error: ' + e.message, false); });
+  }
+
+  function _gfRemove(container) {
+    var apiKey = (container.querySelector('#cv2-gf-apikey') || {}).value || '';
+    if (!apiKey) { _gfMsg(container, 'API key required.', false); return; }
+    if (!confirm('Remove geo filter? All nodes will be allowed through.')) return;
+    fetch('/api/config/geo-filter', {
+      method: 'PUT',
+      headers: { 'Content-Type': 'application/json', 'X-API-Key': apiKey },
+      body: JSON.stringify({ polygon: null })
+    }).then(function (r) {
+      if (!r.ok) return r.json().then(function (e) { throw new Error(e.error || ('HTTP ' + r.status)); });
+      _gfPoints = []; _gfLoaded = true;
+      _gfRender();
+      _gfStatus(container, 'No geo filter. Click the map to draw a polygon.');
+      _gfMsg(container, 'Geo filter removed.', true);
+    }).catch(function (e) { _gfMsg(container, 'Error: ' + e.message, false); });
+  }
+
+  function _initGeoFilterTab(container) {
+    var mapEl = container.querySelector('#cv2-gf-map');
+    if (!mapEl || typeof L === 'undefined') return;
+
+    _gfMap = L.map(mapEl, { zoomControl: false, dragging: false, scrollWheelZoom: false, doubleClickZoom: false, touchZoom: false });
+    L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png', {
+      attribution: '© OpenStreetMap © CartoDB', maxZoom: 19
+    }).addTo(_gfMap);
+
+    if (!_gfLoaded) {
+      api('/config/geo-filter', { ttl: 0 }).then(function (gf) {
+        // Always expose edit controls. The server no longer leaks apiKey presence
+        // via writeEnabled (info-disclosure on a public endpoint); instead, the
+        // user enters their API key into the editor and writes either succeed or
+        // get a 401/403 surfaced as an inline error.
+        _gfWriteEnabled = true;
+        var editEl = container.querySelector('#cv2-gf-edit');
+        if (editEl) editEl.style.display = '';
+        if (gf && gf.polygon && gf.polygon.length >= 3) {
+          _gfPoints = gf.polygon.map(function (p) { return [p[0], p[1]]; });
+          var buf = container.querySelector('#cv2-gf-buffer');
+          if (buf) buf.value = gf.bufferKm || 0;
+          _gfRender();
+          if (_gfPolygon) _gfMap.fitBounds(_gfPolygon.getBounds(), { padding: [20, 20] });
+          _gfStatus(container, gf.polygon.length + ' points · bufferKm=' + (gf.bufferKm || 0));
+        } else {
+          _gfPoints = [];
+          _gfStatus(container, 'No geo filter. Click the map to open the editor.');
+          _gfMap.setView([50.5, 4.4], 5);
+        }
+        _gfLoaded = true;
+        setTimeout(function () { if (_gfMap) _gfMap.invalidateSize(); }, 100);
+      }).catch(function () {
+        _gfStatus(container, 'Could not load current filter.');
+        _gfMap.setView([50.5, 4.4], 5);
+        _gfLoaded = true;
+        setTimeout(function () { if (_gfMap) _gfMap.invalidateSize(); }, 100);
+      });
+    } else {
+      if (_gfPoints.length >= 3) {
+        _gfRender();
+        if (_gfPolygon) _gfMap.fitBounds(_gfPolygon.getBounds(), { padding: [20, 20] });
+        _gfStatus(container, _gfPoints.length + ' points.');
+      } else {
+        _gfMap.setView([50.5, 4.4], 5);
+        _gfStatus(container, _gfPoints.length ? _gfPoints.length + ' points (need at least 3).' : 'Click the map to draw a polygon.');
+        _gfRender();
+      }
+      setTimeout(function () { if (_gfMap) _gfMap.invalidateSize(); }, 100);
+    }
+
+    _gfMap.on('click', function () { _gfOpenModal(container); });
+
+    container.querySelector('#cv2-gf-save').addEventListener('click', function () { _gfSave(container); });
+    container.querySelector('#cv2-gf-remove').addEventListener('click', function () { _gfRemove(container); });
+  }
+
   function _renderExport() {
     var delta = readOverrides();
     var json = JSON.stringify(delta, null, 2);
@@ -1290,6 +1588,7 @@
         _renderNodes() +
         _renderHome() +
         _renderDisplay() +
+        _renderGeoFilter() +
         _renderExport() +
       '</div>';
     _bindEvents(container);
@@ -1358,11 +1657,15 @@
     // Tab switching
     container.querySelectorAll('.cust-tab').forEach(function (btn) {
       btn.addEventListener('click', function () {
+        if (_gfMap) { _gfMap.remove(); _gfMap = null; _gfMarkers = []; _gfPolygon = null; _gfClosingLine = null; } if (_gfModalMap) { _gfModalMap.remove(); _gfModalMap = null; } var _ov = document.getElementById('cv2-gf-modal-overlay'); if (_ov) _ov.remove();
         _activeTab = btn.dataset.tab;
         _renderPanel(container);
       });
     });
 
+    // GeoFilter tab init
+    if (_activeTab === 'geofilter') _initGeoFilterTab(container);
+
     // Preset buttons
     container.querySelectorAll('.cust-preset-btn').forEach(function (btn) {
       btn.addEventListener('click', function () {
@@ -1645,7 +1948,10 @@
       '<div class="cv2-footer"><span id="cv2-save-status">All changes saved</span></div>';
     document.body.appendChild(_panelEl);
 
-    _panelEl.querySelector('.cust-close').addEventListener('click', function () { _panelEl.classList.add('hidden'); });
+    _panelEl.querySelector('.cust-close').addEventListener('click', function () {
+      if (_gfMap) { _gfMap.remove(); _gfMap = null; _gfMarkers = []; _gfPolygon = null; _gfClosingLine = null; } if (_gfModalMap) { _gfModalMap.remove(); _gfModalMap = null; } var _ov = document.getElementById('cv2-gf-modal-overlay'); if (_ov) _ov.remove();
+      _panelEl.classList.add('hidden');
+    });
 
     // Drag support
     var header = _panelEl.querySelector('.cust-header');
diff --git a/public/geofilter-builder.html b/public/geofilter-builder.html
index 1d970118..a34d0449 100644
--- a/public/geofilter-builder.html
+++ b/public/geofilter-builder.html
@@ -8,18 +8,18 @@
 <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
 <style>
   * { box-sizing: border-box; margin: 0; padding: 0; }
-  body { font-family: system-ui, sans-serif; background: #1a1a2e; color: #e0e0e0; height: 100vh; display: flex; flex-direction: column; }
-  header { padding: 12px 16px; background: #0f0f23; border-bottom: 1px solid #333; display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
-  header h1 { font-size: 1rem; font-weight: 600; color: #4a9eff; white-space: nowrap; }
+  body { font-family: system-ui, sans-serif; background: #f5f5f5; color: #222; height: 100vh; display: flex; flex-direction: column; }
+  header { padding: 12px 16px; background: #fff; border-bottom: 1px solid #ddd; display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
+  header h1 { font-size: 1rem; font-weight: 600; color: #1a6abf; white-space: nowrap; }
   .controls { display: flex; gap: 8px; flex-wrap: wrap; }
   button { padding: 6px 14px; border: none; border-radius: 6px; cursor: pointer; font-size: 0.85rem; font-weight: 500; }
-  #btnUndo  { background: #333; color: #ccc; }
-  #btnClear { background: #5a2020; color: #ffaaaa; }
-  #btnUndo:hover  { background: #444; }
-  #btnClear:hover { background: #7a2020; }
+  #btnUndo  { background: #eee; color: #555; border: 1px solid #ccc; }
+  #btnClear { background: #fee; color: #c44; border: 1px solid #fcc; }
+  #btnUndo:hover  { background: #e0e0e0; }
+  #btnClear:hover { background: #fdd; }
   .hint { font-size: 0.8rem; color: #888; margin-left: auto; }
   #map { flex: 1; }
-  #output-panel { background: #0f0f23; border-top: 1px solid #333; padding: 12px 16px; display: flex; gap: 12px; align-items: flex-start; }
+  #output-panel { background: #fff; border-top: 1px solid #ddd; padding: 12px 16px; display: flex; gap: 12px; align-items: flex-start; }
   #output-panel label { font-size: 0.75rem; color: #888; white-space: nowrap; padding-top: 6px; }
   #output { flex: 1; background: #111; border: 1px solid #333; border-radius: 6px; padding: 10px 12px; font-family: monospace; font-size: 0.78rem; color: #7ec8e3; white-space: pre; overflow-x: auto; min-height: 54px; max-height: 140px; overflow-y: auto; cursor: text; }
   #output.empty { color: #555; font-style: italic; }
@@ -34,12 +34,12 @@
   #btnDownload:hover { background: #2a6aaa; }
   #counter { font-size: 0.8rem; color: #888; padding-top: 6px; white-space: nowrap; }
   .bufferRow { display: flex; align-items: center; gap: 8px; }
-  .bufferRow label { font-size: 0.85rem; color: #aaa; }
-  .bufferRow input { width: 60px; padding: 5px 8px; background: #222; border: 1px solid #444; border-radius: 6px; color: #eee; font-size: 0.85rem; }
-  #help-bar { background: #0f0f23; padding: 6px 16px; font-size: 0.75rem; color: #666; border-top: 1px solid #222; }
-  #help-bar a { color: #4a9eff; text-decoration: none; }
+  .bufferRow label { font-size: 0.85rem; color: #555; }
+  .bufferRow input { width: 60px; padding: 5px 8px; background: #fff; border: 1px solid #ccc; border-radius: 6px; color: #222; font-size: 0.85rem; }
+  #help-bar { background: #fff; padding: 6px 16px; font-size: 0.75rem; color: #888; border-top: 1px solid #e0e0e0; }
+  #help-bar a { color: #1a6abf; text-decoration: none; }
   #help-bar a:hover { text-decoration: underline; }
-  #back-link { font-size: 0.8rem; color: #4a9eff; text-decoration: none; white-space: nowrap; }
+  #back-link { font-size: 0.8rem; color: #1a6abf; text-decoration: none; white-space: nowrap; }
   #back-link:hover { text-decoration: underline; }
 </style>
 </head>
@@ -79,14 +79,14 @@ <h1>GeoFilter Builder</h1>
 <div id="help-bar">
   <strong>Save Draft</strong> preserves your polygon across sessions. <strong>Download</strong> exports a JSON snippet → paste as a top-level key in <code>config.json</code> → restart the server.
   Nodes with no GPS fix always pass through. Remove the <code>geo_filter</code> block to disable filtering.
-  &nbsp;·&nbsp; <a href="/geofilter-docs.html">Documentation</a>
+  &nbsp;·&nbsp; <a href="https://github.com/Kpa-clawbot/CoreScope/blob/master/docs/user-guide/geofilter.md" target="_blank">Documentation ↗</a>
 </div>
 
 <script src="geofilter-draft.js"></script>
 <script>
 const map = L.map('map').setView([50.5, 4.4], 8);
 
-L.tileLayer('https://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png', {
+L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png', {
   attribution: '© OpenStreetMap © CartoDB',
   maxZoom: 19
 }).addTo(map);
@@ -97,8 +97,7 @@ <h1>GeoFilter Builder</h1>
 let closingLine = null;
 
 function latLonPair(latlng) {
-  const w = latlng.wrap();
-  return [parseFloat(w.lat.toFixed(6)), parseFloat(w.lng.toFixed(6))];
+  return [parseFloat(latlng.lat.toFixed(6)), parseFloat(latlng.lng.toFixed(6))];
 }
 
 function render() {