diff --git a/packages/polymech/src/components/sidebar/Sidebar.astro b/packages/polymech/src/components/sidebar/Sidebar.astro
index 4f284f4..0ee75bc 100644
--- a/packages/polymech/src/components/sidebar/Sidebar.astro
+++ b/packages/polymech/src/components/sidebar/Sidebar.astro
@@ -6,6 +6,7 @@ import type { SidebarGroup as SidebarGroupType } from './types';
 import type { MarkdownHeading } from 'astro';
 import Translate from "@polymech/astro-base/components/i18n.astro";
 import SidebarPersister from './SidebarPersister.astro';
+import { I18N_SOURCE_LANGUAGE } from "config/config.js";
 
 interface Props {
   config: SidebarGroupType[];
@@ -17,14 +18,24 @@ interface Props {
 const { config, currentUrl, headings = [], pageNavigation = [] } = Astro.props;
 const currentPath = currentUrl ? getCurrentPath(currentUrl) : '';
 
+// Extract locale from URL path (e.g., /es/resources/ -> 'es')
+let locale: string = I18N_SOURCE_LANGUAGE; // Default to source language
+if (currentPath) {
+  const pathSegments = currentPath.split('/').filter(segment => segment);
+  // Check if first segment is a language code (2 letters)
+  if (pathSegments.length > 0 && /^[a-z]{2}$/.test(pathSegments[0])) {
+    locale = pathSegments[0];
+  }
+}
+
 // Process all sidebar groups
 const processedGroups = await Promise.all(
-  config.map(group => processSidebarGroup(group, currentPath))
+  config.map(group => processSidebarGroup(group, currentPath, locale))
 );
 
 // Process page-level navigation
 const processedPageNav = await Promise.all(
-  pageNavigation.map(group => processSidebarGroup({...group, isPageLevel: true}, currentPath))
+  pageNavigation.map(group => processSidebarGroup({...group, isPageLevel: true}, currentPath, locale))
 );
 ---
 
diff --git a/packages/polymech/src/components/sidebar/utils.ts b/packages/polymech/src/components/sidebar/utils.ts
index 54a91d3..6bd2dd6 100644
--- a/packages/polymech/src/components/sidebar/utils.ts
+++ b/packages/polymech/src/components/sidebar/utils.ts
@@ -2,6 +2,7 @@ import { getCollection } from 'astro:content';
 import type { SidebarGroup, SidebarLink, SortFunction } from './types.js';
 import { filterCollection, defaultFilters, type CollectionFilter } from '../../base/collections.js';
 import { z } from 'zod';
+import { I18N_SOURCE_LANGUAGE } from "config/config.js";
 
 interface DirectoryStructure {
   [key: string]: {
@@ -19,6 +20,7 @@ export const SidebarGenerationOptionsSchema = z.object({
   sortBy: z.enum(['alphabetical', 'date', 'custom']).default('alphabetical'),
   customSort: z.any().optional(), // We'll validate this at runtime
   filters: z.array(z.any()).optional(), // We'll validate this at runtime
+  locale: z.string().default(I18N_SOURCE_LANGUAGE), // Language code for URL generation, defaults to source language
 }).strict();
 
 // Define the proper TypeScript types
@@ -30,6 +32,7 @@ export interface SidebarGenerationOptions {
   sortBy: 'alphabetical' | 'date' | 'custom';
   customSort?: (a: SidebarLink | SidebarGroup, b: SidebarLink | SidebarGroup) => number;
   filters?: CollectionFilter[];
+  locale: string; // Required, defaults to I18N_SOURCE_LANGUAGE
 }
 
 /**
@@ -84,7 +87,8 @@ export async function generateLinksFromDirectory(
  *   maxDepth: 3,
  *   collapsedByDefault: true,
  *   sortBy: 'date',
- *   filters: [hasTitle, isNotDraft]
+ *   filters: [hasTitle, isNotDraft],
+ *   locale: 'es' // Include language code in URLs
  * });
  * 
  * // Using the helper function
@@ -119,7 +123,8 @@ export async function generateLinksFromDirectoryWithConfig(
       validatedOptions.collapsedByDefault,
       validatedOptions.sortBy,
       validatedOptions.customSort,
-      entries
+      entries,
+      validatedOptions.locale
     );
   } catch (error) {
     console.warn(`Could not load collection "${directory}":`, error);
@@ -176,14 +181,15 @@ function buildSidebarFromStructure(
   collapsedByDefault: boolean = false,
   sortBy: SortFunction = 'alphabetical',
   customSort?: (a: SidebarLink | SidebarGroup, b: SidebarLink | SidebarGroup) => number,
-  entries?: any[]
+  entries?: any[],
+  locale: string
 ): (SidebarLink | SidebarGroup)[] {
   const items: (SidebarLink | SidebarGroup)[] = [];
   // Process root level files first
   if (structure['']?.files) {
     const rootFiles = structure[''].files
       .filter(entry => !isPageHidden(entry))
-      .map(entry => createSidebarLink(entry, baseDirectory, currentPath));
+      .map(entry => createSidebarLink(entry, baseDirectory, locale, currentPath));
     
     // Add root files without sorting (will be sorted at the end)
     items.push(...rootFiles);
@@ -201,7 +207,7 @@ function buildSidebarFromStructure(
       if (dirData.files.length > 0) {
         const subFiles = dirData.files
           .filter(entry => !isPageHidden(entry))
-          .map(entry => createSidebarLink(entry, baseDirectory, currentPath));
+          .map(entry => createSidebarLink(entry, baseDirectory, locale, currentPath));
         subItems.push(...subFiles);
       }
       
@@ -217,7 +223,8 @@ function buildSidebarFromStructure(
           collapsedByDefault,
           sortBy,
           customSort,
-          entries
+          entries,
+          locale
         );
         subItems.push(...nestedItems);
       }
@@ -249,7 +256,7 @@ function isPageHidden(entry: any): boolean {
 /**
  * Create a sidebar link from an entry
  */
-function createSidebarLink(entry: any, baseDirectory: string, currentPath?: string): SidebarLink {
+function createSidebarLink(entry: any, baseDirectory: string, locale: string, currentPath?: string): SidebarLink {
   // Handle different collection schemas
   let label = entry.id;
   if (entry.data.title) {
@@ -268,9 +275,12 @@ function createSidebarLink(entry: any, baseDirectory: string, currentPath?: stri
   // Remove file extension from entry.id for clean URLs
   const cleanId = entry.id.replace(/\.(md|mdx)$/, '');
   
+  // Generate href with locale if provided
+  const href = locale ? `/${locale}/${baseDirectory}/${cleanId}/` : `/${baseDirectory}/${cleanId}/`;
+  
   return {
     label,
-    href: `/${baseDirectory}/${cleanId}/`,
+    href,
     isCurrent: currentPath?.includes(`/${baseDirectory}/${cleanId}`) || false,
   };
 }
@@ -349,7 +359,7 @@ function applySorting(
 /**
  * Process a sidebar group and generate links
  */
-export async function processSidebarGroup(group: SidebarGroup, currentPath?: string): Promise<SidebarGroup> {
+export async function processSidebarGroup(group: SidebarGroup, currentPath?: string, locale?: string): Promise<SidebarGroup> {
   const processedGroup: SidebarGroup = {
     label: group.label,
     collapsed: group.collapsed,
@@ -368,7 +378,8 @@ export async function processSidebarGroup(group: SidebarGroup, currentPath?: str
         collapsedByDefault: group.autogenerate.collapsed ?? false,
         currentDepth: 0,
         sortBy,
-        customSort: group.autogenerate.customSort
+        customSort: group.autogenerate.customSort,
+        locale
       }
     );
     processedGroup.items = items;