diff --git a/CHANGELOG.md b/CHANGELOG.md
index a23af6e..d579fc0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.35.1] - 2026-02-09
+
+### Fixed
+
+- **MCP Apps: Fix UI not rendering for some tools in Claude**: Added legacy flat `_meta["ui/resourceUri"]` key alongside the nested `_meta.ui.resourceUri` in tool definitions. Claude.ai reads the flat key format; without it, tools like `n8n_health_check` and `n8n_list_workflows` showed as collapsed accordions instead of rendering their rich UI apps. Both key formats are now set by `injectToolMeta()`, matching the behavior of the official `registerAppTool` helper from `@modelcontextprotocol/ext-apps/server`.
+
+Conceived by Romuald Czlonkowski - https://www.aiadvisors.pl/en
+
 ## [2.35.0] - 2026-02-09
 
 ### Added
diff --git a/package.json b/package.json
index fdbd5d2..d20d3f0 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.35.0",
+  "version": "2.35.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/src/mcp/ui/registry.ts b/src/mcp/ui/registry.ts
index 846891b..4698e29 100644
--- a/src/mcp/ui/registry.ts
+++ b/src/mcp/ui/registry.ts
@@ -64,13 +64,19 @@ export class UIAppRegistry {
    * Enrich tool definitions with _meta.ui.resourceUri for tools that have
    * a matching UI app. Per MCP ext-apps spec, this goes on the tool
    * definition (tools/list), not the tool call response.
+   *
+   * Sets both nested (_meta.ui.resourceUri) and flat (_meta["ui/resourceUri"])
+   * keys for compatibility with hosts that read either format.
    */
   static injectToolMeta(tools: Array<{ name: string; [key: string]: any }>): void {
     if (!this.loaded) return;
     for (const tool of tools) {
       const entry = this.toolIndex.get(tool.name);
       if (entry && entry.html) {
-        tool._meta = { ui: { resourceUri: entry.config.uri } };
+        tool._meta = {
+          ui: { resourceUri: entry.config.uri },
+          'ui/resourceUri': entry.config.uri,
+        };
       }
     }
   }
diff --git a/tests/unit/mcp/ui/meta-injection.test.ts b/tests/unit/mcp/ui/meta-injection.test.ts
index 54956ee..f626f3d 100644
--- a/tests/unit/mcp/ui/meta-injection.test.ts
+++ b/tests/unit/mcp/ui/meta-injection.test.ts
@@ -72,7 +72,7 @@ describe('UI Meta Injection on Tool Definitions', () => {
       expect(tools[2]._meta.ui.resourceUri).toBe('ui://n8n-mcp/validation-summary');
     });
 
-    it('should produce _meta with exact shape { ui: { resourceUri: string } }', () => {
+    it('should produce _meta with both nested and flat resourceUri keys', () => {
       const tools: any[] = [
         { name: 'n8n_create_workflow', description: 'Create', inputSchema: { type: 'object', properties: {} } },
       ];
@@ -83,10 +83,10 @@ describe('UI Meta Injection on Tool Definitions', () => {
         ui: {
           resourceUri: 'ui://n8n-mcp/operation-result',
         },
+        'ui/resourceUri': 'ui://n8n-mcp/operation-result',
       });
-      expect(Object.keys(tools[0]._meta)).toEqual(['ui']);
-      expect(Object.keys(tools[0]._meta.ui)).toEqual(['resourceUri']);
-      expect(typeof tools[0]._meta.ui.resourceUri).toBe('string');
+      expect(tools[0]._meta.ui.resourceUri).toBe('ui://n8n-mcp/operation-result');
+      expect(tools[0]._meta['ui/resourceUri']).toBe('ui://n8n-mcp/operation-result');
     });
   });
 
diff --git a/tests/unit/mcp/ui/registry.test.ts b/tests/unit/mcp/ui/registry.test.ts
index 7bb1cc8..3d85167 100644
--- a/tests/unit/mcp/ui/registry.test.ts
+++ b/tests/unit/mcp/ui/registry.test.ts
@@ -308,7 +308,7 @@ describe('UIAppRegistry', () => {
           { name: 'n8n_create_workflow', description: 'Create', inputSchema: { type: 'object', properties: {} } },
         ];
         UIAppRegistry.injectToolMeta(tools);
-        expect(tools[0]._meta).toEqual({ ui: { resourceUri: 'ui://n8n-mcp/operation-result' } });
+        expect(tools[0]._meta).toEqual({ ui: { resourceUri: 'ui://n8n-mcp/operation-result' }, 'ui/resourceUri': 'ui://n8n-mcp/operation-result' });
       });
 
       it('should set _meta.ui.resourceUri on matching validation tools', () => {
@@ -316,7 +316,7 @@ describe('UIAppRegistry', () => {
           { name: 'validate_node', description: 'Validate', inputSchema: { type: 'object', properties: {} } },
         ];
         UIAppRegistry.injectToolMeta(tools);
-        expect(tools[0]._meta).toEqual({ ui: { resourceUri: 'ui://n8n-mcp/validation-summary' } });
+        expect(tools[0]._meta).toEqual({ ui: { resourceUri: 'ui://n8n-mcp/validation-summary' }, 'ui/resourceUri': 'ui://n8n-mcp/validation-summary' });
       });
 
       it('should not set _meta on tools without a matching UI app', () => {