diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7edf1eb0..7513a94d 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -100,6 +100,24 @@ sqlc generate
 
 ## API changes
 
+### Router configuration and optional admin endpoints
+
+Keep `router.New`'s signature stable. Pass startup settings by name in
+`router.Options`; a new optional setting must not require unrelated callers and
+tests to supply another positional argument.
+
+An optional admin feature owns its subrouter, dependencies and HTTP methods.
+Register it once through `Options.AdminRoutes` in the startup wiring, using a
+literal path such as `/accounts`. The parent admin router applies bearer
+authentication to the entire subtree; the feature must not mount itself beside
+that boundary. `/config` remains owned by the shared admin router. No global
+registration or `init` side effects are needed.
+
+When concurrent PRs touch the same startup wiring, stack them in an explicit
+merge order and link each feature-only comparison. Rebase the stack together
+after prerequisite merges, regenerate Swagger rather than hand-merging it, and
+compile the combined result even when GitHub reports it as mergeable.
+
 Any new or modified REST endpoint must have swagger annotations and regenerated
 docs:
 
diff --git a/cmd/beacon/main.go b/cmd/beacon/main.go
index f2a9294c..b518ab1f 100644
--- a/cmd/beacon/main.go
+++ b/cmd/beacon/main.go
@@ -303,7 +303,11 @@ func main() {
 	// Wrap after wiring cache invalidators and cleanup callbacks to the actual
 	// CachedReader. Only response projections receive the geographic annotation.
 	reader = api.WithLocalBorders(reader, localBorders)
-	r := router.New(h, reader, []*ingest.Worker{broker1, broker2}, resolved.MaxConnsPerIP, resolved.MaxConnectsPerMinute, cfg.CORS, cfg.Server, cfg.Auth, resolved.RateLimit)
+	r := router.New(h, reader, []*ingest.Worker{broker1, broker2}, router.Options{
+		MaxConnsPerIP:        resolved.MaxConnsPerIP,
+		MaxConnectsPerMinute: resolved.MaxConnectsPerMinute,
+		CORS:                 cfg.CORS, Server: cfg.Server, Auth: cfg.Auth, RateLimit: resolved.RateLimit,
+	})
 
 	srv := &http.Server{
 		Addr:     addr,
diff --git a/internal/api/handlers/admin.go b/internal/api/handlers/admin.go
index b775a515..cf4f0d6a 100644
--- a/internal/api/handlers/admin.go
+++ b/internal/api/handlers/admin.go
@@ -17,10 +17,13 @@ import (
 
 // AdminRouter mounts operator endpoints. Its caller must wrap the
 // entire subrouter with BearerAuth, including unknown paths and methods.
-func AdminRouter(runtime *mw.RuntimeConfig) http.Handler {
+func AdminRouter(runtime *mw.RuntimeConfig, routes map[string]http.Handler) http.Handler {
 	r := chi.NewRouter()
 	r.Get("/config", getAdminConfig(runtime))
 	r.Put("/config", updateAdminConfig(runtime))
+	for path, handler := range routes {
+		r.Mount(path, handler)
+	}
 	return r
 }
 
diff --git a/internal/api/router/admin_config_test.go b/internal/api/router/admin_config_test.go
index 43ee7cfb..9acd524c 100644
--- a/internal/api/router/admin_config_test.go
+++ b/internal/api/router/admin_config_test.go
@@ -32,7 +32,7 @@ func TestAdminConfig(t *testing.T) {
 			want = map[string]any{"allowed_origins": []any{"https://example.test"}, "allowed_methods": []any{"GET"},
 				"allowed_headers": []any{"Authorization", "X-Operator"}, "allow_credentials": true, "max_age": float64(600)}
 		}
-		handler := New(nil, nil, []*ingest.Worker{{}, {}}, 5, 1000, cfg, config.ServerConfig{}, config.AuthConfig{APIKey: key}, config.ResolvedRateLimitConfig{})
+		handler := New(nil, nil, []*ingest.Worker{{}, {}}, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, CORS: cfg, Auth: config.AuthConfig{APIKey: key}})
 		if custom {
 			cfg.AllowedOrigins[0] = "https://changed.test"
 			cfg.AllowedMethods[0] = "DELETE"
diff --git a/internal/api/router/admin_routes_test.go b/internal/api/router/admin_routes_test.go
new file mode 100644
index 00000000..c017236c
--- /dev/null
+++ b/internal/api/router/admin_routes_test.go
@@ -0,0 +1,54 @@
+// Copyright 2026 Beacon Contributors
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package router
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/MeshCore-Beacon/beacon-server/internal/config"
+)
+
+func TestAdditionalAdminRoutesStayAuthenticated(t *testing.T) {
+	for _, key := range []string{"", "fixture-key"} {
+		calls := 0
+		opts := Options{Auth: config.AuthConfig{APIKey: key}, AdminRoutes: map[string]http.Handler{
+			"/feature": http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+				calls++
+				w.WriteHeader(http.StatusNoContent)
+			}),
+		}}
+		handler := New(nil, nil, nil, opts)
+		// Registration happens at startup; later edits to the caller's map must
+		// not replace the registered handler or create a new unprotected route.
+		delete(opts.AdminRoutes, "/feature")
+		for _, path := range []string{"/api/v1/admin/feature", "/api/v1/admin/feature/nested"} {
+			for _, method := range []string{"GET", "POST", "DELETE"} {
+				for _, token := range []string{"", "wrong", "fixture-key"} {
+					request := httptest.NewRequest(method, path, nil)
+					if token != "" {
+						request.Header.Set("Authorization", "Bearer "+token)
+					}
+					response := httptest.NewRecorder()
+					before := calls
+					handler.ServeHTTP(response, request)
+					want := http.StatusServiceUnavailable
+					if key != "" {
+						want = http.StatusUnauthorized
+						if token == key {
+							want = http.StatusNoContent
+						}
+					}
+					if response.Code != want || response.Header().Get("Cache-Control") != "no-store" {
+						t.Fatalf("%s %s: status=%d want=%d", method, path, response.Code, want)
+					}
+					if (calls != before) != (want == http.StatusNoContent) {
+						t.Fatal("authentication boundary bypassed")
+					}
+				}
+			}
+		}
+	}
+}
diff --git a/internal/api/router/auth_test.go b/internal/api/router/auth_test.go
index 66c9614e..d8796f79 100644
--- a/internal/api/router/auth_test.go
+++ b/internal/api/router/auth_test.go
@@ -13,7 +13,7 @@ import (
 
 func TestAdminAuthBoundary(t *testing.T) {
 	for _, key := range []string{"", "synthetic-test-key"} {
-		handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, config.ServerConfig{}, config.AuthConfig{APIKey: key}, config.ResolvedRateLimitConfig{})
+		handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, Auth: config.AuthConfig{APIKey: key}})
 		for _, path := range []string{"/api/v1/admin", "/api/v1/admin/", "/api/v1/admin/config", "/api/v1/admin//config"} {
 			for _, method := range []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"} {
 				for _, token := range []string{"", "wrong", "synthetic-test-key"} {
diff --git a/internal/api/router/options.go b/internal/api/router/options.go
new file mode 100644
index 00000000..ec9e1fbf
--- /dev/null
+++ b/internal/api/router/options.go
@@ -0,0 +1,25 @@
+// Copyright 2026 Beacon Contributors
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package router
+
+import (
+	"net/http"
+
+	"github.com/MeshCore-Beacon/beacon-server/internal/config"
+)
+
+// Options names the startup settings used by the router. Adding an optional
+// route does not change New's signature or require unrelated callers to change.
+type Options struct {
+	MaxConnsPerIP        int
+	MaxConnectsPerMinute int
+	CORS                 config.CORSConfig
+	Server               config.ServerConfig
+	Auth                 config.AuthConfig
+	RateLimit            config.ResolvedRateLimitConfig
+	// AdminRoutes mounts operator-only subrouters at literal paths such as
+	// "/accounts". Each feature owns its dependencies, methods and handlers.
+	// The router applies authentication to every path and method in this group.
+	AdminRoutes map[string]http.Handler
+}
diff --git a/internal/api/router/rate_limit_test.go b/internal/api/router/rate_limit_test.go
index 95ab42f2..b0e1cd86 100644
--- a/internal/api/router/rate_limit_test.go
+++ b/internal/api/router/rate_limit_test.go
@@ -22,7 +22,7 @@ import (
 )
 
 func TestDefaultAPIRateLimit(t *testing.T) {
-	handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, config.ServerConfig{}, config.AuthConfig{}, config.Resolve(&config.Config{}).RateLimit)
+	handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, RateLimit: config.Resolve(&config.Config{}).RateLimit})
 	for i := 0; i <= 300; i++ {
 		request := httptest.NewRequest(http.MethodGet, "/api/v1/brokers", nil)
 		request.RemoteAddr = "198.51.100.1:1234"
@@ -56,7 +56,7 @@ func TestAPIRateLimitContractAndLogging(t *testing.T) {
 	slog.SetDefault(slog.New(slog.NewJSONHandler(&logs, nil)))
 	t.Cleanup(func() { slog.SetDefault(previous); log.SetOutput(writer); log.SetFlags(flags) })
 	proxy := config.ServerConfig{TrustedProxies: []netip.Prefix{netip.MustParsePrefix("127.0.0.1/32")}}
-	handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, proxy, config.AuthConfig{}, config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 2, Burst: 10})
+	handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, Server: proxy, RateLimit: config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 2, Burst: 10}})
 	for _, path := range []string{"/api/v1/brokers", "/api/v1/packets?limit=0"} {
 		response := rateRequest(handler, path, "127.0.0.1:1234", "198.51.100.25")
 		if response.Code != http.StatusOK && response.Code != http.StatusBadRequest {
@@ -111,7 +111,7 @@ func TestAPIRateLimitClientIdentity(t *testing.T) {
 			if tc.trusted {
 				proxy.TrustedProxies = []netip.Prefix{netip.MustParsePrefix("127.0.0.1/32")}
 			}
-			handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, proxy, config.AuthConfig{}, config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 1, Burst: 1})
+			handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, Server: proxy, RateLimit: config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 1, Burst: 1}})
 			if response := rateRequest(handler, "/api/v1/brokers", tc.firstPeer, tc.firstHeader); response.Code != http.StatusOK {
 				t.Fatalf("first client: %d", response.Code)
 			}
@@ -128,7 +128,7 @@ func TestAPIRateLimitClientIdentity(t *testing.T) {
 
 func TestAPIRateLimitWindowsAndExclusions(t *testing.T) {
 	synctest.Test(t, func(t *testing.T) {
-		handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, config.ServerConfig{}, config.AuthConfig{}, config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 4, Burst: 2})
+		handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, RateLimit: config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 4, Burst: 2}})
 		request := func() *httptest.ResponseRecorder {
 			return rateRequest(handler, "/api/v1/brokers", "198.51.100.1:1", "")
 		}
@@ -164,7 +164,7 @@ func TestAPIRateLimitWindowsAndExclusions(t *testing.T) {
 			t.Fatal("minute budget did not recover")
 		}
 	})
-	handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, config.ServerConfig{}, config.AuthConfig{}, config.ResolvedRateLimitConfig{Enabled: false, RequestsPerMinute: 1, Burst: 1})
+	handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, RateLimit: config.ResolvedRateLimitConfig{Enabled: false, RequestsPerMinute: 1, Burst: 1}})
 	for range 5 {
 		if response := rateRequest(handler, "/api/v1/brokers", "198.51.100.1:1", ""); response.Code != http.StatusOK || response.Header().Get("Retry-After") != "" {
 			t.Fatal("disabled limiter still applied")
@@ -173,7 +173,7 @@ func TestAPIRateLimitWindowsAndExclusions(t *testing.T) {
 }
 
 func TestAPIRateLimitConcurrentRequests(t *testing.T) {
-	handler := New(nil, nil, nil, 5, 1000, config.CORSConfig{}, config.ServerConfig{}, config.AuthConfig{}, config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 5, Burst: 5})
+	handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, RateLimit: config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 5, Burst: 5}})
 	var accepted, rejected atomic.Int32
 	var group sync.WaitGroup
 	for range 20 {
diff --git a/internal/api/router/router.go b/internal/api/router/router.go
index d58e8b71..447d407e 100644
--- a/internal/api/router/router.go
+++ b/internal/api/router/router.go
@@ -15,7 +15,6 @@ import (
 	"github.com/MeshCore-Beacon/beacon-server/internal/api"
 	"github.com/MeshCore-Beacon/beacon-server/internal/api/handlers"
 	mw "github.com/MeshCore-Beacon/beacon-server/internal/api/middleware"
-	"github.com/MeshCore-Beacon/beacon-server/internal/config"
 	"github.com/MeshCore-Beacon/beacon-server/internal/hub"
 	"github.com/MeshCore-Beacon/beacon-server/internal/ingest"
 	"github.com/MeshCore-Beacon/beacon-server/internal/ws"
@@ -38,35 +37,35 @@ import (
 //	  /stats           → stats subrouter
 //
 // Admin endpoints require a configured bearer key.
-func New(h *hub.Hub, reader api.Reader, workers []*ingest.Worker, maxConnsPerIP, maxConnectsPerMinute int, corsCfg config.CORSConfig, serverCfg config.ServerConfig, authCfg config.AuthConfig, rateLimitCfg config.ResolvedRateLimitConfig) http.Handler {
+func New(h *hub.Hub, reader api.Reader, workers []*ingest.Worker, opts Options) http.Handler {
 	r := chi.NewRouter()
 
 	// ── CORS ─────────────────────────────────────────────────────────────────
-	allowedOrigins := corsCfg.AllowedOrigins
+	allowedOrigins := opts.CORS.AllowedOrigins
 	if len(allowedOrigins) == 0 {
 		allowedOrigins = []string{"*"}
 	}
-	allowedMethods := corsCfg.AllowedMethods
+	allowedMethods := opts.CORS.AllowedMethods
 	if len(allowedMethods) == 0 {
 		allowedMethods = []string{"GET", "HEAD", "OPTIONS"}
 	}
-	allowedHeaders := corsCfg.AllowedHeaders
+	allowedHeaders := opts.CORS.AllowedHeaders
 	if len(allowedHeaders) == 0 {
 		allowedHeaders = []string{"Accept", "Authorization", "Content-Type"}
 	}
-	maxAge := corsCfg.MaxAge
+	maxAge := opts.CORS.MaxAge
 	if maxAge == 0 {
 		maxAge = 300
 	}
 	// Capture only values used by this router. Do not retain Config, credentials
 	// or caller-owned slices in the admin response.
 	adminConfig := api.AdminConfig{
-		Auth: api.AdminAuthConfig{Configured: authCfg.APIKey != ""},
+		Auth: api.AdminAuthConfig{Configured: opts.Auth.APIKey != ""},
 		CORS: api.AdminCORSConfig{
 			AllowedOrigins:   append([]string{}, allowedOrigins...),
 			AllowedMethods:   append([]string{}, allowedMethods...),
 			AllowedHeaders:   append([]string{}, allowedHeaders...),
-			AllowCredentials: corsCfg.AllowCredentials,
+			AllowCredentials: opts.CORS.AllowCredentials,
 			MaxAge:           maxAge,
 		},
 		Ingest: api.AdminIngestConfig{BrokerCount: len(workers)},
@@ -76,7 +75,7 @@ func New(h *hub.Hub, reader api.Reader, workers []*ingest.Worker, maxConnsPerIP,
 
 	// ── Global middleware ────────────────────────────────────────────────────
 	r.Use(middleware.RequestID)
-	r.Use(mw.TrustedProxyIP(serverCfg.TrustedProxies))
+	r.Use(mw.TrustedProxyIP(opts.Server.TrustedProxies))
 	r.Use(mw.RequestLogger)
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.CleanPath)
@@ -92,11 +91,11 @@ func New(h *hub.Hub, reader api.Reader, workers []*ingest.Worker, maxConnsPerIP,
 	))
 
 	// ── WebSocket ────────────────────────────────────────────────────────────
-	r.Get("/ws", ws.Handler(h, reader, maxConnsPerIP, maxConnectsPerMinute))
+	r.Get("/ws", ws.Handler(h, reader, opts.MaxConnsPerIP, opts.MaxConnectsPerMinute))
 
 	// ── Public REST API (v1) ─────────────────────────────────────────────────
 	r.Route("/api/v1", func(r chi.Router) {
-		r.Use(mw.RateLimit(rateLimitCfg))
+		r.Use(mw.RateLimit(opts.RateLimit))
 		// Public group — no authentication required.
 		r.Group(func(r chi.Router) {
 			r.Mount("/packets", handlers.PacketsRouter(reader))
@@ -114,7 +113,7 @@ func New(h *hub.Hub, reader api.Reader, workers []*ingest.Worker, maxConnsPerIP,
 		})
 
 		// Protect the entire subtree, including its root and unknown paths.
-		r.Mount("/admin", mw.BearerAuth(authCfg.APIKey, handlers.AdminRouter(runtimeConfig)))
+		r.Mount("/admin", mw.BearerAuth(opts.Auth.APIKey, handlers.AdminRouter(runtimeConfig, opts.AdminRoutes)))
 	})
 
 	return r
diff --git a/internal/api/router/router_test.go b/internal/api/router/router_test.go
index 88927e29..bbb434dd 100644
--- a/internal/api/router/router_test.go
+++ b/internal/api/router/router_test.go
@@ -36,7 +36,7 @@ func TestWebSocketLimitUsesTrustedClientIP(t *testing.T) {
 
 func checkWebSocketLimit(t *testing.T, cfg config.ServerConfig, secondIP string, wantShed bool) {
 	t.Helper()
-	server := httptest.NewServer(New(hub.New(), nil, nil, 1, 10, config.CORSConfig{}, cfg, config.AuthConfig{}, config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 1, Burst: 1}))
+	server := httptest.NewServer(New(hub.New(), nil, nil, Options{MaxConnsPerIP: 1, MaxConnectsPerMinute: 10, Server: cfg, RateLimit: config.ResolvedRateLimitConfig{Enabled: true, RequestsPerMinute: 1, Burst: 1}}))
 	defer server.Close()
 	// Exhaust this client's REST budget before checking its independent WS cap.
 	for _, want := range []int{http.StatusOK, http.StatusTooManyRequests} {
diff --git a/internal/api/router/runtime_config_test.go b/internal/api/router/runtime_config_test.go
index 17dc67b9..6ac6073e 100644
--- a/internal/api/router/runtime_config_test.go
+++ b/internal/api/router/runtime_config_test.go
@@ -16,7 +16,7 @@ import (
 
 func TestRuntimeConfigUpdate(t *testing.T) {
 	newRouter := func() http.Handler {
-		return New(nil, nil, nil, 5, 1000, config.CORSConfig{AllowedOrigins: []string{"https://before.test"}}, config.ServerConfig{}, config.AuthConfig{APIKey: "test-key"}, config.ResolvedRateLimitConfig{})
+		return New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1000, CORS: config.CORSConfig{AllowedOrigins: []string{"https://before.test"}}, Auth: config.AuthConfig{APIKey: "test-key"}})
 	}
 	handler := newRouter()
 	request := func(method, path, body, token, media, origin string) *httptest.ResponseRecorder {
diff --git a/internal/api/router/ws_attempt_test.go b/internal/api/router/ws_attempt_test.go
index b0f73982..853ecde6 100644
--- a/internal/api/router/ws_attempt_test.go
+++ b/internal/api/router/ws_attempt_test.go
@@ -29,7 +29,7 @@ func TestWebSocketAttemptClientIdentity(t *testing.T) {
 			if tc.trusted {
 				cfg.TrustedProxies = []netip.Prefix{netip.MustParsePrefix("127.0.0.1/32")}
 			}
-			handler := New(nil, nil, nil, 5, 1, config.CORSConfig{}, cfg, config.AuthConfig{}, config.ResolvedRateLimitConfig{})
+			handler := New(nil, nil, nil, Options{MaxConnsPerIP: 5, MaxConnectsPerMinute: 1, Server: cfg})
 			attempt := func(peer, header string) int {
 				request := httptest.NewRequest(http.MethodGet, "/ws", nil)
 				request.RemoteAddr = peer