diff --git a/.gitignore b/.gitignore
index 85c491c..453b3dc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 uv.lock
 .venv
 **/node_modules
+**/dist
diff --git a/rest/nodejs/src/api/checkout.ts b/rest/nodejs/src/api/checkout.ts
index 840b3d0..a1dafaa 100644
--- a/rest/nodejs/src/api/checkout.ts
+++ b/rest/nodejs/src/api/checkout.ts
@@ -1,5 +1,5 @@
 import { createHash } from "crypto";
-import { type Context } from "hono";
+import type { Context } from "hono";
 import { v4 as uuidv4 } from "uuid";
 import { z } from "zod";
 
@@ -15,7 +15,7 @@ import {
   saveCheckout,
   saveIdempotencyRecord,
   saveOrder,
-} from "../data";
+} from "../data/index.js";
 import {
   CheckoutResponseStatusSchema,
   type Expectation,
@@ -36,7 +36,7 @@ import {
   type PaymentCreateRequest,
   PaymentDataSchema,
   type PostalAddress,
-} from "../models";
+} from "../models/index.js";
 
 /**
  * Schema for the request body when completing a checkout session.
diff --git a/rest/nodejs/src/api/discovery.ts b/rest/nodejs/src/api/discovery.ts
index 14b992f..cbcd60e 100644
--- a/rest/nodejs/src/api/discovery.ts
+++ b/rest/nodejs/src/api/discovery.ts
@@ -1,5 +1,5 @@
-import { type Context } from "hono";
-import { type UcpDiscoveryProfile } from "../models";
+import type { Context } from "hono";
+import type { UcpDiscoveryProfile } from "../models";
 
 /**
  * Service for handling UCP discovery requests.
diff --git a/rest/nodejs/src/api/order.ts b/rest/nodejs/src/api/order.ts
index a65f25c..d55f028 100644
--- a/rest/nodejs/src/api/order.ts
+++ b/rest/nodejs/src/api/order.ts
@@ -1,6 +1,6 @@
-import { type Context } from "hono";
-import { getOrder, logRequest, saveOrder } from "../data";
-import { type Order } from "../models";
+import type { Context } from "hono";
+import { getOrder, logRequest, saveOrder } from "../data/index.js";
+import type { Order } from "../models";
 
 /**
  * Service for managing orders.
diff --git a/rest/nodejs/src/api/testing.ts b/rest/nodejs/src/api/testing.ts
index 00b2144..a850d77 100644
--- a/rest/nodejs/src/api/testing.ts
+++ b/rest/nodejs/src/api/testing.ts
@@ -1,6 +1,6 @@
-import { type Context } from "hono";
+import type { Context } from "hono";
 
-import { CheckoutService } from "./checkout";
+import { CheckoutService } from "./checkout.js";
 
 export class TestingService {
   constructor(private readonly checkoutService: CheckoutService) {}
diff --git a/rest/nodejs/src/data/index.ts b/rest/nodejs/src/data/index.ts
index 4d5e042..ac57414 100644
--- a/rest/nodejs/src/data/index.ts
+++ b/rest/nodejs/src/data/index.ts
@@ -4,7 +4,7 @@
  * transactions databases (SQLite).
  */
 
-export * from "./db";
-export * from "./inventory";
-export * from "./products";
-export * from "./transactions";
+export * from "./db.js";
+export * from "./inventory.js";
+export * from "./products.js";
+export * from "./transactions.js";
diff --git a/rest/nodejs/src/data/inventory.ts b/rest/nodejs/src/data/inventory.ts
index d23d373..ca4b97c 100644
--- a/rest/nodejs/src/data/inventory.ts
+++ b/rest/nodejs/src/data/inventory.ts
@@ -1,4 +1,4 @@
-import { getTransactionsDb } from "./db";
+import { getTransactionsDb } from "./db.js";
 
 /**
  * Retrieves the available inventory quantity for a given product.
diff --git a/rest/nodejs/src/data/products.ts b/rest/nodejs/src/data/products.ts
index f6c3623..5923896 100644
--- a/rest/nodejs/src/data/products.ts
+++ b/rest/nodejs/src/data/products.ts
@@ -1,4 +1,4 @@
-import { getProductsDb } from "./db";
+import { getProductsDb } from "./db.js";
 
 /**
  * Represents a product in the catalog.
diff --git a/rest/nodejs/src/data/transactions.ts b/rest/nodejs/src/data/transactions.ts
index c2369a8..17e3816 100644
--- a/rest/nodejs/src/data/transactions.ts
+++ b/rest/nodejs/src/data/transactions.ts
@@ -1,6 +1,6 @@
-import { type ExtendedCheckoutResponse, type Order } from "../models";
+import type { ExtendedCheckoutResponse, Order } from "../models";
 
-import { getTransactionsDb } from "./db";
+import { getTransactionsDb } from "./db.js";
 
 /**
  * Represents the structure of a checkout session stored in the database.
diff --git a/rest/nodejs/src/index.ts b/rest/nodejs/src/index.ts
index 7ffdf3d..8d03f9b 100644
--- a/rest/nodejs/src/index.ts
+++ b/rest/nodejs/src/index.ts
@@ -4,17 +4,17 @@ import { type Context, Hono } from "hono";
 import { requestId } from "hono/request-id";
 import { pinoHttp } from "pino-http";
 
-import { CheckoutService, zCompleteCheckoutRequest } from "./api/checkout";
-import { DiscoveryService } from "./api/discovery";
-import { OrderService } from "./api/order";
-import { TestingService } from "./api/testing";
-import { initDbs } from "./data/db";
+import { CheckoutService, zCompleteCheckoutRequest } from "./api/checkout.js";
+import { DiscoveryService } from "./api/discovery.js";
+import { OrderService } from "./api/order.js";
+import { TestingService } from "./api/testing.js";
+import { initDbs } from "./data/db.js";
 import {
   ExtendedCheckoutCreateRequestSchema,
   ExtendedCheckoutUpdateRequestSchema,
   OrderSchema,
-} from "./models";
-import { IdParamSchema, prettyValidation } from "./utils/validation";
+} from "./models/index.js";
+import { IdParamSchema, prettyValidation } from "./utils/validation.js";
 
 const app = new Hono();
 
diff --git a/rest/nodejs/src/models/extensions.ts b/rest/nodejs/src/models/extensions.ts
index 7c2b3f5..88eb037 100644
--- a/rest/nodejs/src/models/extensions.ts
+++ b/rest/nodejs/src/models/extensions.ts
@@ -11,7 +11,7 @@ import {
   FulfillmentDestinationResponseSchema,
   OrderSchema,
   PaymentCredentialSchema,
-} from "./spec_generated";
+} from "./spec_generated.js";
 
 export const ExtendedPaymentCredentialSchema = PaymentCredentialSchema.extend({
   token: z.string().optional(),
diff --git a/rest/nodejs/src/models/index.ts b/rest/nodejs/src/models/index.ts
index 28e9880..8adad2d 100644
--- a/rest/nodejs/src/models/index.ts
+++ b/rest/nodejs/src/models/index.ts
@@ -1,2 +1,2 @@
-export * from "./extensions";
-export * from "./spec_generated";
+export * from "./extensions.js";
+export * from "./spec_generated.js";
diff --git a/rest/nodejs/src/utils/validation.ts b/rest/nodejs/src/utils/validation.ts
index 093d18a..b7a5426 100644
--- a/rest/nodejs/src/utils/validation.ts
+++ b/rest/nodejs/src/utils/validation.ts
@@ -1,4 +1,4 @@
-import { type Context } from "hono";
+import type { Context } from "hono";
 import * as z from "zod";
 
 /**