diff --git a/src/gateway/proxy.ts b/src/gateway/proxy.ts
index 748f12d5..1ab64dfc 100644
--- a/src/gateway/proxy.ts
+++ b/src/gateway/proxy.ts
@@ -29,7 +29,11 @@ import type { GatewayAuthEnv } from "./service-key-auth.js";
 import { proxySSEStream } from "./streaming.js";
 import type { FetchFn, GatewayConfig, ProviderConfig } from "./types.js";
 
-const DEFAULT_MARGIN = 1.3;
+/**
+ * Fallback only used when resolveMargin is not provided (tests only).
+ * Production MUST provide resolveMargin — mountRoutes enforces this.
+ */
+const TEST_ONLY_MARGIN = 1.3;
 
 /** Max call duration cap: 4 hours = 240 minutes. */
 const MAX_CALL_DURATION_MINUTES = 240;
@@ -96,7 +100,10 @@ export function buildProxyDeps(config: GatewayConfig): ProxyDeps {
     providers: config.providers,
     defaultModel: config.defaultModel,
     resolveDefaultModel: config.resolveDefaultModel,
-    defaultMargin: config.defaultMargin ?? DEFAULT_MARGIN,
+    get defaultMargin() {
+      if (config.resolveMargin) return config.resolveMargin();
+      return config.defaultMargin ?? TEST_ONLY_MARGIN;
+    },
     fetchFn: config.fetchFn ?? fetch,
     arbitrageRouter: config.arbitrageRouter,
     rateLookupFn: config.rateLookupFn,
diff --git a/src/gateway/types.ts b/src/gateway/types.ts
index f497ea23..87f63a38 100644
--- a/src/gateway/types.ts
+++ b/src/gateway/types.ts
@@ -115,8 +115,10 @@ export interface GatewayConfig {
   graceBufferCents?: number;
   /** Upstream provider credentials */
   providers: ProviderConfig;
-  /** Default margin multiplier (default: 1.3 = 30%) */
+  /** Static margin (for tests only). Production should use resolveMargin. */
   defaultMargin?: number;
+  /** Live margin resolver — called per-request, reads from DB. Takes priority over defaultMargin. */
+  resolveMargin?: () => number;
   /** Optional arbitrage router for multi-provider cost optimization (WOP-463) */
   arbitrageRouter?: import("../monetization/arbitrage/router.js").ArbitrageRouter;
   /** Injectable fetch for testing */
diff --git a/src/index.ts b/src/index.ts
index 4997d29f..b1513c6c 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -48,3 +48,7 @@ export * from "./tenancy/index.js";
 
 // tRPC
 export * from "./trpc/index.js";
+// monorepo e2e cutover test
+// hybrid dockerfile e2e
+// sequential build test
+// lockfile build
diff --git a/src/server/__tests__/container.test.ts b/src/server/__tests__/container.test.ts
index 6beb3bb0..4949c8db 100644
--- a/src/server/__tests__/container.test.ts
+++ b/src/server/__tests__/container.test.ts
@@ -169,6 +169,8 @@ describe("createTestContainer", () => {
 
     const gateway: GatewayServices = {
       serviceKeyRepo: {} as never,
+      meter: {} as never,
+      budgetChecker: {} as never,
     };
 
     const hotPool: HotPoolServices = {
@@ -189,7 +191,9 @@ describe("createTestContainer", () => {
   });
 
   it("overrides merge without affecting other defaults", () => {
-    const c = createTestContainer({ gateway: { serviceKeyRepo: {} as never } });
+    const c = createTestContainer({
+      gateway: { serviceKeyRepo: {} as never, meter: {} as never, budgetChecker: {} as never },
+    });
 
     // Overridden field
     expect(c.gateway).not.toBeNull();
diff --git a/src/server/container.ts b/src/server/container.ts
index 17fabe9e..54f77090 100644
--- a/src/server/container.ts
+++ b/src/server/container.ts
@@ -51,6 +51,8 @@ export interface StripeServices {
 
 export interface GatewayServices {
   serviceKeyRepo: IServiceKeyRepository;
+  meter: import("../metering/emitter.js").MeterEmitter;
+  budgetChecker: import("../monetization/budget/budget-checker.js").IBudgetChecker;
 }
 
 export interface HotPoolServices {
@@ -239,8 +241,14 @@ export async function buildContainer(bootConfig: BootConfig): Promise<PlatformCo
   let gateway: GatewayServices | null = null;
   if (bootConfig.features.gateway) {
     const { DrizzleServiceKeyRepository } = await import("../gateway/service-key-repository.js");
+    const { MeterEmitter } = await import("../metering/emitter.js");
+    const { DrizzleMeterEventRepository } = await import("../metering/meter-event-repository.js");
+    const { DrizzleBudgetChecker } = await import("../monetization/budget/budget-checker.js");
+
     const serviceKeyRepo: IServiceKeyRepository = new DrizzleServiceKeyRepository(db as never);
-    gateway = { serviceKeyRepo };
+    const meter = new MeterEmitter(new DrizzleMeterEventRepository(db as never), { flushIntervalMs: 5_000 });
+    const budgetChecker = new DrizzleBudgetChecker(db as never, { cacheTtlMs: 30_000 });
+    gateway = { serviceKeyRepo, meter, budgetChecker };
   }
 
   // 12. Build the container (hotPool bound after construction)
diff --git a/src/server/index.ts b/src/server/index.ts
index 7da8f25a..412a1d7f 100644
--- a/src/server/index.ts
+++ b/src/server/index.ts
@@ -56,7 +56,7 @@ export async function bootPlatformServer(config: BootConfig): Promise<BootResult
   const container = await buildContainer(config);
   const app = new Hono();
 
-  mountRoutes(
+  await mountRoutes(
     app,
     container,
     {
diff --git a/src/server/mount-routes.ts b/src/server/mount-routes.ts
index f420d20b..5daa69f6 100644
--- a/src/server/mount-routes.ts
+++ b/src/server/mount-routes.ts
@@ -44,12 +44,12 @@ export interface MountConfig {
  *   6. Product-specific route plugins
  *   7. Tenant proxy middleware (catch-all — must be last)
  */
-export function mountRoutes(
+export async function mountRoutes(
   app: Hono,
   container: PlatformContainer,
   config: MountConfig,
   plugins: RoutePlugin[] = [],
-): void {
+): Promise<void> {
   // 1. CORS middleware
   const origins = deriveCorsOrigins(container.productConfig.product, container.productConfig.domains);
   app.use(
@@ -95,7 +95,45 @@ export function mountRoutes(
     );
   }
 
-  // 6. Product-specific route plugins
+  // 6. Metered inference gateway (when gateway is enabled)
+  if (container.gateway) {
+    // Validate billing config exists in DB — fail hard, no silent defaults
+    const billingConfig = container.productConfig.billing;
+    const marginConfig = billingConfig?.marginConfig as { default?: number } | null;
+    if (!marginConfig?.default) {
+      throw new Error(
+        "Gateway enabled but product_billing_config.margin_config.default is not set. " +
+          "Seed the DB: INSERT INTO product_billing_config (product_id, margin_config) VALUES ('<id>', '{\"default\": 4.0}')",
+      );
+    }
+
+    // Live margin — reads from productConfig per-request (DB-cached with TTL)
+    const initialMargin = marginConfig.default;
+    const resolveMargin = (): number => {
+      const cfg = container.productConfig.billing?.marginConfig as { default?: number } | null;
+      return cfg?.default ?? initialMargin;
+    };
+
+    const gw = container.gateway;
+    const { mountGateway } = await import("../gateway/index.js");
+    mountGateway(app, {
+      meter: gw.meter,
+      budgetChecker: gw.budgetChecker,
+      creditLedger: container.creditLedger,
+      resolveMargin,
+      providers: {
+        openrouter: process.env.OPENROUTER_API_KEY
+          ? { apiKey: process.env.OPENROUTER_API_KEY, baseUrl: process.env.OPENROUTER_BASE_URL || undefined }
+          : undefined,
+      },
+      resolveServiceKey: async (key: string) => {
+        const tenant = await gw.serviceKeyRepo.resolve(key);
+        return tenant ?? null;
+      },
+    });
+  }
+
+  // 7. Product-specific route plugins
   for (const plugin of plugins) {
     app.route(plugin.path, plugin.handler(container));
   }
diff --git a/src/server/routes/__tests__/admin.test.ts b/src/server/routes/__tests__/admin.test.ts
index 13a0c7e5..6528d498 100644
--- a/src/server/routes/__tests__/admin.test.ts
+++ b/src/server/routes/__tests__/admin.test.ts
@@ -173,6 +173,7 @@ describe("createAdminRouter", () => {
           },
           serviceKeyRepo: {} as never,
         },
+        gateway: { serviceKeyRepo: {} as never, meter: {} as never, budgetChecker: {} as never },
       });
 
       const caller = makeCaller(container);
@@ -220,6 +221,7 @@ describe("createAdminRouter", () => {
           },
           serviceKeyRepo: {} as never,
         },
+        gateway: { serviceKeyRepo: {} as never, meter: {} as never, budgetChecker: {} as never },
       });
 
       const caller = makeCaller(container);
@@ -273,9 +275,7 @@ describe("createAdminRouter", () => {
 
       const container = createTestContainer({
         pool: mockPool as never,
-        gateway: {
-          serviceKeyRepo: {} as never,
-        },
+        gateway: { serviceKeyRepo: {} as never, meter: {} as never, budgetChecker: {} as never },
       });
 
       const caller = makeCaller(container);