diff --git a/server/auth-session.ts b/server/auth-session.ts
index 726981e..06114b1 100644
--- a/server/auth-session.ts
+++ b/server/auth-session.ts
@@ -70,6 +70,96 @@ export async function getAuthenticatedUser(
   return null;
 }
 
+/**
+ * Helper to get an application by host.
+ * Checks Valkey cache first, falls back to PostgreSQL, and populates Valkey.
+ */
+export async function getAppByHost(
+  host: string,
+): Promise<{ id: string; name: string } | null> {
+  const cacheKey = `auth:app_by_host:${host}`;
+
+  // 1. Try Valkey cache
+  try {
+    const cachedStr = await valkey.get(cacheKey);
+    if (cachedStr) {
+      return JSON.parse(cachedStr);
+    }
+  } catch (_err) {
+    // Valkey cache miss or connection error
+  }
+
+  // 2. Fallback to PostgreSQL
+  try {
+    // Search by domain first
+    let app = await sqlWrapper.sql`
+      SELECT id, name FROM apps WHERE domain = ${host}
+    `.then((res: any) => res[0]);
+
+    // Fallback: match name against the first subdomain segment
+    if (!app) {
+      const subdomain = host.split(".")[0];
+      if (subdomain) {
+        app = await sqlWrapper.sql`
+          SELECT id, name FROM apps WHERE name = ${subdomain}
+        `.then((res: any) => res[0]);
+      }
+    }
+
+    if (app) {
+      // Repopulate Valkey
+      try {
+        await valkey.setex(cacheKey, 3600, JSON.stringify(app)); // Cache for 1 hour
+      } catch (_e) {}
+      return app;
+    }
+  } catch (_err) {
+    return null;
+  }
+
+  return null;
+}
+
+/**
+ * Helper to get a user's role grant for a specific app.
+ * Checks Valkey cache first, falls back to PostgreSQL, and populates Valkey.
+ */
+export async function getUserGrant(
+  userId: string,
+  appId: string,
+): Promise<string | null> {
+  const cacheKey = `auth:grants:${userId}:${appId}`;
+
+  // 1. Try Valkey cache
+  try {
+    const cachedRole = await valkey.get(cacheKey);
+    if (cachedRole) {
+      return cachedRole;
+    }
+  } catch (_err) {
+    // Valkey cache miss or connection error
+  }
+
+  // 2. Fallback to PostgreSQL
+  try {
+    const grant = await sqlWrapper.sql`
+      SELECT role FROM grants WHERE user_id = ${userId} AND app_id = ${appId}
+    `.then((res: any) => res[0]);
+
+    if (grant && grant.role) {
+      // Repopulate Valkey
+      try {
+        await valkey.setex(cacheKey, 3600, grant.role); // Cache for 1 hour
+      } catch (_e) {}
+      return grant.role;
+    }
+  } catch (_err) {
+    return null;
+  }
+
+  return null;
+}
+
 /**
  * Helper to check if user has global admin privileges.
  * Strict check: Requires an explicit 'admin' grant on the Management Console
diff --git a/server/db.ts b/server/db.ts
index 539d94e..e795cbe 100644
--- a/server/db.ts
+++ b/server/db.ts
@@ -62,6 +62,13 @@ export async function initDb(): Promise<void> {
     // Ignore and check next
   }
 
+  // Ensure domain column exists for Edge authorization routing
+  try {
+    await sql`ALTER TABLE apps ADD COLUMN IF NOT EXISTS domain TEXT UNIQUE`;
+  } catch {
+    // Soft ignore if column already exists
+  }
+
   await sql`
     CREATE TABLE IF NOT EXISTS roles (
       id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
diff --git a/server/main.test.ts b/server/main.test.ts
index 72331d5..89fdc78 100644
--- a/server/main.test.ts
+++ b/server/main.test.ts
@@ -30,7 +30,24 @@ Deno.test("Tier 1 & 2: GET /api/forward-auth - Valid session", async () => {
 
   setMockSql(() => Promise.resolve([mockUser]));
 
-  const valkeyStub = stub(valkey, "get", () => {
+  let queryCount = 0;
+
+  setMockSql(() => {
+    queryCount++;
+    if (queryCount === 1) return Promise.resolve([mockUser]); // User lookup
+    return Promise.resolve([]); // isGlobalAdmin lookup
+  });
+
+  const valkeyStub = stub(valkey, "get", (key: any) => {
+    const k = String(key);
+    if (k.startsWith("auth:app_by_host:")) {
+      return Promise.resolve(
+        JSON.stringify({ id: "app-id-1", name: "test-app" }),
+      );
+    }
+    if (k.startsWith("auth:grants:")) {
+      return Promise.resolve("viewer");
+    }
     return Promise.resolve(
       JSON.stringify({ uuid: "user-id-1", username: "alice" }),
     );
@@ -39,6 +56,7 @@ Deno.test("Tier 1 & 2: GET /api/forward-auth - Valid session", async () => {
   const req = new Request("http://localhost/api/forward-auth", {
     headers: {
       Cookie: "session_id=mock-session-id",
+      "X-Forwarded-Host": "test.app.local",
     },
   });
 
@@ -46,24 +64,58 @@ Deno.test("Tier 1 & 2: GET /api/forward-auth - Valid session", async () => {
   assertEquals(res.status, 200);
   assertEquals(res.headers.get("X-Forwarded-User"), "alice");
   assertEquals(res.headers.get("X-Forwarded-User-Id"), "user-id-1");
+  assertEquals(res.headers.get("X-Forwarded-Scopes"), "viewer");
+  assertEquals(res.headers.get("X-Forwarded-App-Id"), "app-id-1");
 
   restoreMockSql();
   valkeyStub.restore();
 });
 
 Deno.test("Tier 1 & 2: GET /api/forward-auth - Missing session", async () => {
-  const req = new Request("http://localhost/api/forward-auth");
+  const req = new Request("http://localhost/api/forward-auth", {
+    headers: { "X-Forwarded-Host": "test.app.local" },
+  });
+
+  let valkeyStub: any;
+  if ((valkey.get as any).restore) {
+    valkeyStub = valkey.get as any;
+  } else {
+    valkeyStub = stub(valkey, "get", (key: any) => {
+      const k = String(key);
+      if (k.startsWith("auth:app_by_host:")) {
+        return Promise.resolve(
+          JSON.stringify({ id: "app-id-1", name: "test-app" }),
+        );
+      }
+      return Promise.resolve(null);
+    });
+  }
   const res = await app.request(req);
   assertEquals(res.status, 401);
+  valkeyStub.restore();
 });
 
 Deno.test("Tier 1 & 2: GET /api/forward-auth - Expired session", async () => {
-  const valkeyStub = stub(valkey, "get", () => {
-    return Promise.resolve(null);
-  });
+  let valkeyStub: any;
+  if ((valkey.get as any).restore) {
+    valkeyStub = valkey.get as any;
+  } else {
+    valkeyStub = stub(valkey, "get", (key: any) => {
+      const k = String(key);
+      if (k.startsWith("auth:app_by_host:")) {
+        return Promise.resolve(
+          JSON.stringify({ id: "app-id-1", name: "test-app" }),
+        );
+      }
+      return Promise.resolve(null);
+    });
+  }
 
   const req = new Request("http://localhost/api/forward-auth", {
-    headers: { Cookie: "session_id=expired-session-id" },
+    headers: {
+      Cookie: "session_id=expired-session-id",
+      "X-Forwarded-Host": "test.app.local",
+    },
   });
   const res = await app.request(req);
   assertEquals(res.status, 401);
@@ -79,14 +131,28 @@ Deno.test("Tier 1 & 2: GET /api/forward-auth - Suspended account", async () => {
 
   setMockSql(() => Promise.resolve([mockUser]));
 
-  const valkeyStub = stub(valkey, "get", () => {
-    return Promise.resolve(
-      JSON.stringify({ uuid: "user-id-1", username: "alice" }),
-    );
-  });
+  let valkeyStub: any;
+  if ((valkey.get as any).restore) {
+    valkeyStub = valkey.get as any;
+  } else {
+    valkeyStub = stub(valkey, "get", (key: any) => {
+      const k = String(key);
+      if (k.startsWith("auth:app_by_host:")) {
+        return Promise.resolve(
+          JSON.stringify({ id: "app-id-1", name: "test-app" }),
+        );
+      }
+      return Promise.resolve(
+        JSON.stringify({ uuid: "user-id-1", username: "alice" }),
+      );
+    });
+  }
 
   const req = new Request("http://localhost/api/forward-auth", {
-    headers: { Cookie: "session_id=mock-session-id" },
+    headers: {
+      Cookie: "session_id=mock-session-id",
+      "X-Forwarded-Host": "test.app.local",
+    },
   });
   const res = await app.request(req);
   assertEquals(res.status, 403);
@@ -112,12 +178,16 @@ Deno.test("Tier 3: ValidateSession ConnectRPC - Default-Deny", async () => {
 
   // Re-define valkey stub
 
-  const originalValkeyGet = valkey.get;
-  valkey.get = () => {
-    return Promise.resolve(
-      JSON.stringify({ uuid: "user-1", username: "alice" }),
-    );
-  };
+  let valkeyStub: any;
+  if ((valkey.get as any).restore) {
+    valkeyStub = valkey.get as any;
+  } else {
+    valkeyStub = stub(valkey, "get", () => {
+      return Promise.resolve(
+        JSON.stringify({ uuid: "user-1", username: "alice" }),
+      );
+    });
+  }
 
   let auditCalled = false;
   const originalAudit = auditWrapper.auditLog;
@@ -158,7 +228,7 @@ Deno.test("Tier 3: ValidateSession ConnectRPC - Default-Deny", async () => {
 
   spireWrapper.extractSpiffeIdFromCert = originalExtract;
   restoreMockSql();
-  valkey.get = originalValkeyGet;
+  valkeyStub.restore();
   auditWrapper.auditLog = originalAudit;
 });
 
@@ -176,12 +246,16 @@ Deno.test("Tier 3: ValidateSession ConnectRPC - Valid RBAC Grant", async () => {
     }
   });
 
-  const originalValkeyGet = valkey.get;
-  valkey.get = () => {
-    return Promise.resolve(
-      JSON.stringify({ uuid: "user-1", username: "alice" }),
-    );
-  };
+  let valkeyStub: any;
+  if ((valkey.get as any).restore) {
+    valkeyStub = valkey.get as any;
+  } else {
+    valkeyStub = stub(valkey, "get", () => {
+      return Promise.resolve(
+        JSON.stringify({ uuid: "user-1", username: "alice" }),
+      );
+    });
+  }
 
   const req = new Request(
     "http://localhost/auth.v1.AuthService/ValidateSession",
@@ -206,7 +280,7 @@ Deno.test("Tier 3: ValidateSession ConnectRPC - Valid RBAC Grant", async () => {
 
   spireWrapper.extractSpiffeIdFromCert = originalExtract;
   restoreMockSql();
-  valkey.get = originalValkeyGet;
+  valkeyStub.restore();
 });
 
 Deno.test("Tier 3: ValidateSession ConnectRPC - SPIFFE Attestation Failure", async () => {
diff --git a/server/main.ts b/server/main.ts
index e959541..36c22bb 100644
--- a/server/main.ts
+++ b/server/main.ts
@@ -962,12 +962,29 @@ app.post("/api/admin/users/:id/status", async (c) => {
 // Traefik ForwardAuth Edge Proxy Route (Tier 2)
 // ---------------------------------------------------------
 
+import { getAppByHost, getUserGrant } from "./auth-session.ts";
+
 app.get("/api/forward-auth", async (c) => {
+  const host = c.req.header("X-Forwarded-Host");
+  if (!host) {
+    return c.text("Bad Request: Missing X-Forwarded-Host header", 400);
+  }
+
+  // 1. Resolve Target App (Valkey -> DB)
+  const appRecord = await getAppByHost(host);
+  if (!appRecord) {
+    // Default-Deny if app is not registered
+    return c.text("Forbidden: Application not registered", 403);
+  }
+
+  // 2. Validate Session
   const auth = await getAuthenticatedUser(c);
   if (!auth) {
     return c.text("Unauthorized", 401);
   }
 
+  // Cache lookup for user status can be added later; hitting DB to be safe for now,
+  // but let's just make sure account is active.
   const user = await sqlWrapper.sql`
     SELECT id, username, account_status
     FROM users
@@ -978,8 +995,26 @@ app.get("/api/forward-auth", async (c) => {
     return c.text("Forbidden: Account inactive", 403);
   }
 
+  // 3. Resolve Grants and Roles
+  const globalAdmin = await isGlobalAdmin(auth.userId);
+  const grantRole = await getUserGrant(auth.userId, appRecord.id);
+
+  if (!globalAdmin && !grantRole) {
+    // Enforce Default-Deny if no app-specific grants and not global admin
+    return c.text("Forbidden: Access denied to this application", 403);
+  }
+
+  // Combine scopes, ensuring no duplicates and formatting as comma-separated string
+  const scopes = [
+    ...new Set([grantRole, globalAdmin ? "admin" : null].filter(Boolean)),
+  ].join(",");
+
+  // 4. Inject Headers
   c.header("X-Forwarded-User", user.username);
   c.header("X-Forwarded-User-Id", user.id);
+  c.header("X-Forwarded-Scopes", scopes);
+  c.header("X-Forwarded-App-Id", appRecord.id);
+
   return c.text("OK", 200);
 });
 
diff --git a/tasks/new/2026-0824.03.jul.feat.auth-api.ingress-grant-injection-1200.md b/tasks/complete/2026-0824.03.jul.feat.auth-api.ingress-grant-injection-1200.md
similarity index 100%
rename from tasks/new/2026-0824.03.jul.feat.auth-api.ingress-grant-injection-1200.md
rename to tasks/complete/2026-0824.03.jul.feat.auth-api.ingress-grant-injection-1200.md