diff --git a/.changeset/express-request-types.md b/.changeset/express-request-types.md
new file mode 100644
index 0000000..d8b0bff
--- /dev/null
+++ b/.changeset/express-request-types.md
@@ -0,0 +1,5 @@
+---
+"@seamless-auth/express": patch
+---
+
+Ship the `Express.Request` augmentation. `req.user` (set by `requireAuth`) and `req.cookiePayload` (set by `createEnsureCookiesMiddleware`) now typecheck in a consumer that imports the package, without declaring the augmentation itself. It previously lived in an ambient `.d.ts` that tsc never copied into `dist`.
diff --git a/.changeset/fastify-request-types.md b/.changeset/fastify-request-types.md
new file mode 100644
index 0000000..b79fcb0
--- /dev/null
+++ b/.changeset/fastify-request-types.md
@@ -0,0 +1,5 @@
+---
+"@seamless-auth/fastify": patch
+---
+
+Load the `FastifyRequest` augmentation (`request.user`, `request.cookiePayload`) from the package entry through an import that resolves under `moduleResolution: "NodeNext"`. Consumers on NodeNext previously lost it because the entry reached it only through an extensionless relative import.
diff --git a/packages/express/src/index.ts b/packages/express/src/index.ts
index aec4c36..4909086 100644
--- a/packages/express/src/index.ts
+++ b/packages/express/src/index.ts
@@ -1,3 +1,6 @@
+// Loads the request type augmentation for anyone importing the package. The
+// .js extension keeps it resolvable under NodeNext as well as bundler.
+import "./types/express.js";
 import {
   createSeamlessAuthServer,
   SeamlessAuthServerOptions,
diff --git a/packages/express/src/types/express.d.ts b/packages/express/src/types/express.d.ts
deleted file mode 100644
index 84de5fa..0000000
--- a/packages/express/src/types/express.d.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-declare namespace Express {
-  interface Request {
-    user?: SeamlessAuthUser;
-  }
-}
diff --git a/packages/express/src/types/express.ts b/packages/express/src/types/express.ts
new file mode 100644
index 0000000..01fe392
--- /dev/null
+++ b/packages/express/src/types/express.ts
@@ -0,0 +1,16 @@
+import type { SeamlessAuthUser } from "@seamless-auth/core";
+
+// A module rather than an ambient .d.ts: tsc does not copy .d.ts sources into
+// dist, so an ambient file never reached consumers.
+declare global {
+  namespace Express {
+    interface Request {
+      /** Set by `requireAuth` once the access cookie or bearer token verifies. */
+      user?: SeamlessAuthUser;
+      /** Set by `createEnsureCookiesMiddleware` once a session cookie verifies. */
+      cookiePayload?: Record<string, any>;
+    }
+  }
+}
+
+export {};
diff --git a/packages/express/tests/consumerTypes.test.js b/packages/express/tests/consumerTypes.test.js
new file mode 100644
index 0000000..fb1802f
--- /dev/null
+++ b/packages/express/tests/consumerTypes.test.js
@@ -0,0 +1,46 @@
+// Type-checks a consumer against the built dist. Request augmentation that
+// lives only in source (an ambient .d.ts tsc never emits) fails here.
+import { execFileSync } from "node:child_process";
+import { createRequire } from "node:module";
+import { fileURLToPath } from "node:url";
+
+const require = createRequire(import.meta.url);
+const tsc = require.resolve("typescript/bin/tsc");
+const fixture = fileURLToPath(new URL("./types/consumer.ts", import.meta.url));
+
+const RESOLUTIONS = [
+  { module: "ESNext", moduleResolution: "bundler" },
+  { module: "NodeNext", moduleResolution: "NodeNext" },
+];
+
+describe("@seamless-auth/express consumer types", () => {
+  it.each(RESOLUTIONS)(
+    "types req.user and req.cookiePayload under moduleResolution $moduleResolution",
+    ({ module, moduleResolution }) => {
+      let output = "";
+      try {
+        execFileSync(
+          process.execPath,
+          [
+            tsc,
+            "--noEmit",
+            "--strict",
+            "--skipLibCheck",
+            "--target",
+            "ES2022",
+            "--module",
+            module,
+            "--moduleResolution",
+            moduleResolution,
+            fixture,
+          ],
+          { encoding: "utf8", stdio: "pipe" },
+        );
+      } catch (err) {
+        output = `${err.stdout ?? ""}${err.stderr ?? ""}`;
+      }
+      expect(output).toBe("");
+    },
+    60000,
+  );
+});
diff --git a/packages/express/tests/types/consumer.ts b/packages/express/tests/types/consumer.ts
new file mode 100644
index 0000000..66355bf
--- /dev/null
+++ b/packages/express/tests/types/consumer.ts
@@ -0,0 +1,18 @@
+// Resolves "@seamless-auth/express" by name through package.json `exports`, so
+// it sees the built dist exactly as an installed consumer does.
+import express from "express";
+import { requireAuth, requireRole } from "@seamless-auth/express";
+
+const app = express();
+
+app.get(
+  "/me",
+  requireAuth({ cookieSecret: "x".repeat(64) }),
+  requireRole("admin"),
+  (req, res) => {
+    const id: string | undefined = req.user?.id;
+    const roles: string[] | undefined = req.user?.roles;
+    const payload: Record<string, any> | undefined = req.cookiePayload;
+    res.json({ id, roles, payload });
+  },
+);
diff --git a/packages/express/tsconfig.json b/packages/express/tsconfig.json
index 7b4c8a6..1e68fb9 100644
--- a/packages/express/tsconfig.json
+++ b/packages/express/tsconfig.json
@@ -7,7 +7,6 @@
     "esModuleInterop": true,
     "strict": true,
     "skipLibCheck": true,
-    "typeRoots": ["src/types/express.d.types"],
     "declaration": true,
     "emitDeclarationOnly": false,
     "declarationMap": true
diff --git a/packages/fastify/src/index.ts b/packages/fastify/src/index.ts
index a6f15c9..e05496a 100644
--- a/packages/fastify/src/index.ts
+++ b/packages/fastify/src/index.ts
@@ -1,3 +1,6 @@
+// Loads the request type augmentation for anyone importing the package. The
+// .js extension keeps it resolvable under NodeNext as well as bundler.
+import "./types/fastify.js";
 import { seamlessAuth } from "./plugin";
 
 export { seamlessAuth };
diff --git a/packages/fastify/src/options.ts b/packages/fastify/src/options.ts
index 9c110d9..f376ba9 100644
--- a/packages/fastify/src/options.ts
+++ b/packages/fastify/src/options.ts
@@ -1,7 +1,6 @@
 import type {
   CookieSameSite,
   SeamlessAuthMessagingOptions,
-  SeamlessAuthUser,
 } from "@seamless-auth/core";
 
 import type { ClientIpResolver } from "./internal/buildForwardedClientIp";
@@ -54,12 +53,3 @@ export type ResolvedOptions = SeamlessAuthServerOptions & {
   refreshCookieName: string;
   preAuthCookieName: string;
 };
-
-declare module "fastify" {
-  interface FastifyRequest {
-    /** Set by the plugin's cookie hook once a session cookie has been verified. */
-    cookiePayload?: Record<string, any>;
-    /** Set by `requireAuth`. */
-    user?: SeamlessAuthUser;
-  }
-}
diff --git a/packages/fastify/src/types/fastify.ts b/packages/fastify/src/types/fastify.ts
new file mode 100644
index 0000000..fde86c9
--- /dev/null
+++ b/packages/fastify/src/types/fastify.ts
@@ -0,0 +1,12 @@
+import type { SeamlessAuthUser } from "@seamless-auth/core";
+
+declare module "fastify" {
+  interface FastifyRequest {
+    /** Set by the plugin's cookie hook once a session cookie has been verified. */
+    cookiePayload?: Record<string, any>;
+    /** Set by `requireAuth`. */
+    user?: SeamlessAuthUser;
+  }
+}
+
+export {};
diff --git a/packages/fastify/tests/consumerTypes.test.js b/packages/fastify/tests/consumerTypes.test.js
new file mode 100644
index 0000000..37bf74b
--- /dev/null
+++ b/packages/fastify/tests/consumerTypes.test.js
@@ -0,0 +1,46 @@
+// Type-checks a consumer against the built dist. Request augmentation that
+// lives only in source (an ambient .d.ts tsc never emits) fails here.
+import { execFileSync } from "node:child_process";
+import { createRequire } from "node:module";
+import { fileURLToPath } from "node:url";
+
+const require = createRequire(import.meta.url);
+const tsc = require.resolve("typescript/bin/tsc");
+const fixture = fileURLToPath(new URL("./types/consumer.ts", import.meta.url));
+
+const RESOLUTIONS = [
+  { module: "ESNext", moduleResolution: "bundler" },
+  { module: "NodeNext", moduleResolution: "NodeNext" },
+];
+
+describe("@seamless-auth/fastify consumer types", () => {
+  it.each(RESOLUTIONS)(
+    "types req.user and req.cookiePayload under moduleResolution $moduleResolution",
+    ({ module, moduleResolution }) => {
+      let output = "";
+      try {
+        execFileSync(
+          process.execPath,
+          [
+            tsc,
+            "--noEmit",
+            "--strict",
+            "--skipLibCheck",
+            "--target",
+            "ES2022",
+            "--module",
+            module,
+            "--moduleResolution",
+            moduleResolution,
+            fixture,
+          ],
+          { encoding: "utf8", stdio: "pipe" },
+        );
+      } catch (err) {
+        output = `${err.stdout ?? ""}${err.stderr ?? ""}`;
+      }
+      expect(output).toBe("");
+    },
+    60000,
+  );
+});
diff --git a/packages/fastify/tests/types/consumer.ts b/packages/fastify/tests/types/consumer.ts
new file mode 100644
index 0000000..1264795
--- /dev/null
+++ b/packages/fastify/tests/types/consumer.ts
@@ -0,0 +1,22 @@
+// Resolves "@seamless-auth/fastify" by name through package.json `exports`, so
+// it sees the built dist exactly as an installed consumer does.
+import Fastify from "fastify";
+import { requireAuth, requireRole } from "@seamless-auth/fastify";
+
+const app = Fastify();
+
+app.get(
+  "/me",
+  {
+    preHandler: [
+      requireAuth({ cookieSecret: "x".repeat(64) }),
+      requireRole("admin"),
+    ],
+  },
+  async (req) => {
+    const id: string | undefined = req.user?.id;
+    const roles: string[] | undefined = req.user?.roles;
+    const payload: Record<string, any> | undefined = req.cookiePayload;
+    return { id, roles, payload };
+  },
+);