Fix MCP resources and improbe the sample project (#334)

Author: MikeAlhayek

src/Core/CrestApps.OrchardCore.AI.Mcp.Core/McpResourceUri.cs

@@ -23,11 +23,14 @@ public static bool TryMatch(string uriTemplate, string actualUri, out IReadOnlyD
     {
         variables = null;
 
-        if (string.IsNullOrEmpty(uriTemplate) || string.IsNullOrEmpty(actualUri))
+        if (string.IsNullOrWhiteSpace(uriTemplate) || string.IsNullOrWhiteSpace(actualUri))
         {
             return false;
         }
 
+        uriTemplate = uriTemplate.Trim();
+        actualUri = actualUri.Trim();
+
         // Collect all variable matches first so we know which is the last one.
         var matches = new List<(int Index, int Length, string Name)>();
 
@@ -101,7 +104,7 @@ public static bool TryMatch(string uriTemplate, string actualUri, out IReadOnlyD
     /// </summary>
     public static bool IsTemplate(string uri)
     {
-        return !string.IsNullOrEmpty(uri) && uri.Contains('{');
+        return !string.IsNullOrWhiteSpace(uri) && uri.AsSpan().Trim().Contains('{');
     }
 
     [GeneratedRegex(@"\{(\w+)\}")]

src/CrestApps.OrchardCore.Documentations/docs/ai/mcp/server.md

@@ -29,21 +29,53 @@ The MCP server exposes the following capabilities:
 
 ## Prompt Support
 
-The MCP server exposes MCP prompts registered in Orchard Core. Prompts can be:
+MCP **Prompts** are reusable prompt templates that MCP clients can discover and invoke. They allow you to define pre-configured system or user messages that external AI agents can request on demand — for example, a "summarize" prompt that instructs the model to summarize a given document, or a "translate" prompt that translates text into a target language.
 
-- Created and managed via the admin UI under **Artificial Intelligence → MCP Prompts**
-- Registered programmatically in code
-- Discovered by external MCP clients via `ListPrompts` and invoked via `GetPrompt`
+Prompts are listed by clients via `ListPrompts` and invoked via `GetPrompt`, which returns the prompt messages for the client to include in its conversation.
+
+### Managing Prompts via Admin UI
+
+1. Navigate to **Artificial Intelligence** → **MCP Prompts**
+2. Click **Add Prompt** to create a new prompt
+3. Fill in the required fields:
+   - **Name**: A unique identifier for the prompt (used by MCP clients to reference it)
+   - **Display Text**: A human-readable name shown in the admin list
+   - **Description**: Optional description that helps clients understand what the prompt does
+4. Add one or more **Messages** to the prompt:
+   - Each message has a **Role** (e.g., `system`, `user`) and **Content** (the message text)
+   - Messages are returned in order when a client calls `GetPrompt`
+5. Save the prompt
+
+Prompts can also be registered programmatically in code or imported via recipes.
 
 ## Resource Support
 
-The MCP server exposes MCP resources registered in Orchard Core, allowing clients to access various data sources through the MCP protocol.
+MCP **Resources** represent data that MCP clients can read. A resource has a URI that the client uses to request its content. Resources come in two flavors:
+
+- **Static Resources**: Have a fixed URI with no variable placeholders (e.g., `recipe-schema://abc123/recipe`). They return the same data every time and appear in `ListResources`.
+- **Templated Resources**: Have a URI containing `{variable}` placeholders (e.g., `file://abc123/{fileName}`). The client fills in the variables when reading the resource. These appear in `ListResourceTemplates` and allow dynamic content resolution.
 
 Resources can be:
-- Created and managed via the admin UI under **Artificial Intelligence → MCP Resources**
+- Created and managed via the admin UI under **Artificial Intelligence** → **MCP Resources**
 - Registered programmatically in code
 - Discovered and accessed by external MCP clients
 
+### Managing Resources via Admin UI
+
+1. Navigate to **Artificial Intelligence** → **MCP Resources**
+2. Click **Add Resource** to create a new resource
+3. Select a **Resource Type** (e.g., File, Content Item, Recipe Step Schema). Each type defines what kind of data the resource serves and which URI variables are available.
+4. Fill in the required fields:
+   - **Display Text**: A friendly name for the resource shown in the admin list
+   - **Path**: The path portion of the URI. For templated resources, include variable placeholders from the supported variables list shown in the UI (e.g., `{fileName}`, `{contentType}`)
+   - **Name**: The MCP resource name (used by clients to identify the resource)
+   - **Title**: Optional human-readable title
+   - **Description**: Optional description that helps clients understand the resource
+   - **MIME Type**: The content type of the resource (e.g., `application/json`, `text/plain`)
+5. Save the resource
+
+The system automatically constructs the full URI by prepending the scheme and a unique resource ID to your path. For example, if you select the **File** resource type and enter `{fileName}` as the path, the full URI might be `file://abc123/{fileName}`.
+
 ### Built-in Resource Types
 
 | Type | Supported Variables | Description |
@@ -72,20 +104,6 @@ Each resource instance has a URI that is auto-constructed by the system as:
 
 When creating a resource in the admin UI, you only provide the **path** portion. The system automatically prepends the scheme and resource ID.
 
-### Creating Resources via Admin UI
-
-1. Navigate to **Artificial Intelligence** → **MCP Resources**
-2. Click **Add Resource**
-3. Select a resource type (e.g., File, Content Item, Recipe Step Schema)
-4. Fill in the required fields:
-   - **Display Text**: A friendly name for the resource
-   - **Path**: The path portion of the URI, using any supported variables shown in the UI
-   - **Name**: The MCP resource name (used by clients)
-   - **Title**: Optional human-readable title
-   - **Description**: Optional description
-   - **MIME Type**: Content type of the resource
-5. Save the resource
-
 ### Registering Custom Resource Types
 
 You can register custom resource types with their handlers:

src/CrestApps.OrchardCore.Documentations/docs/changelog/v2.0.0.md

@@ -90,6 +90,8 @@ A new suite of modules for multi-channel communication:
 - **MCP Prompts and Resources** — Prompts and resources can be added and managed via the admin UI.
 - **Templated Resources** — Support for dynamic MCP resources defined with URI templates.
 - **Stdio Transport** — Connect to local MCP servers (e.g., Docker containers) via Standard Input/Output.
+- **Template URI Whitespace Handling** — Resource URI templates and incoming URIs are now trimmed of leading/trailing whitespace before matching, preventing mismatches caused by accidental spaces in URI definitions.
+- **File Resource Directory Rejection** — The file resource handler now returns a descriptive error when the resolved path is a directory instead of a file, rather than attempting to read directory content.
 
 ### AI Agent (`CrestApps.OrchardCore.AI.Agent`)
 

src/Modules/CrestApps.OrchardCore.AI.Mcp/Drivers/McpResourceDisplayDriver.cs

@@ -95,7 +95,7 @@ public override async Task<IDisplayResult> UpdateAsync(McpResource entry, Update
         };
 
         // Build the full URI from the user-provided path.
-        entry.Resource.Uri = Handlers.McpResourceHandler.BuildUri(entry.Source, entry.ItemId, model.Path);
+        entry.Resource.Uri = Handlers.McpResourceHandler.BuildUri(entry.Source, entry.ItemId, model.Path?.Trim());
 
         entry.Resource.Name = model.Name ?? string.Empty;
         entry.Resource.Title = entry.DisplayText;

src/Modules/CrestApps.OrchardCore.AI.Mcp/Handlers/FileResourceTypeHandler.cs

@@ -59,6 +59,11 @@ protected override async Task<ReadResourceResult> GetResultAsync(McpResource res
             return CreateErrorResult(resource.Resource.Uri, $"File not found: {fileName}");
         }
 
+        if (fileInfo.IsDirectory)
+        {
+            return CreateErrorResult(resource.Resource.Uri, $"The path '{fileName}' is a directory, not a file. Only file resources are supported.");
+        }
+
         if (_logger.IsEnabled(LogLevel.Debug))
         {
             _logger.LogDebug("Reading file resource from provider '{ProviderName}': {FileName}", providerName, fileName);

src/Startup/CrestApps.OrchardCore.Samples.McpClient/Pages/Prompts.cshtml

@@ -11,7 +11,7 @@
 }
 
 <div class="d-flex align-items-center gap-3 mb-3">
-    <p class="text-muted mb-0">Prompts registered on the MCP server. Click "Get Prompt" to retrieve details.</p>
+    <p class="text-muted mb-0">Prompts registered on the MCP server. Click "Get" to retrieve details.</p>
     <form method="post" asp-page-handler="Refresh" class="d-inline">
         <button class="btn btn-secondary btn-sm" type="submit">Refresh</button>
     </form>
@@ -24,8 +24,11 @@
     </div>
 
     <ul class="list-group" id="promptsList">
-        @foreach (var prompt in Model.Prompts)
+        @for (var i = 0; i < Model.Prompts.Count; i++)
         {
+            var prompt = Model.Prompts[i];
+            var resultId = $"result-prompt-{i}";
+
             <li class="list-group-item searchable-item" data-search-text="@prompt.Name?.ToLowerInvariant() @prompt.Description?.ToLowerInvariant()">
                 <div class="d-flex justify-content-between align-items-start">
                     <div>
@@ -35,10 +38,11 @@
                             <div class="text-muted">@prompt.Description</div>
                         }
                     </div>
-                    <form method="post" asp-page-handler="GetPrompt">
-                        <input type="hidden" name="promptName" value="@prompt.Name" />
-                        <button class="btn btn-primary btn-sm" type="submit">Get Prompt</button>
-                    </form>
+                    <div class="prompt-form" data-prompt-name="@prompt.Name" data-result-target="#@resultId">
+                        <button class="btn btn-primary btn-sm btn-get-prompt" type="button">Get</button>
+                    </div>
+                </div>
+                <div id="@resultId" class="mt-3" style="display:none">
                 </div>
             </li>
         }
@@ -51,39 +55,68 @@ else
     <p class="text-muted">No prompts were returned by the MCP server.</p>
 }
 
-@if (Model.PromptResult is not null)
-{
-    <div class="card mt-4">
-        <div class="card-header">Prompt Details: @Model.SelectedPromptName</div>
-        <div class="card-body">
-            @if (!string.IsNullOrWhiteSpace(Model.PromptResult.Description))
-            {
-                <p><strong>Description:</strong> @Model.PromptResult.Description</p>
-            }
-
-            @if (Model.PromptResult.Messages?.Count > 0)
-            {
-                <h6>Messages</h6>
-                @foreach (var message in Model.PromptResult.Messages)
-                {
-                    <div class="card mb-2">
-                        <div class="card-body p-2">
-                            <span class="badge bg-secondary me-1">@message.Role</span>
-                            <span>@message.Content</span>
-                        </div>
-                    </div>
-                }
-            }
-            else
-            {
-                <p class="text-muted">No messages returned for this prompt.</p>
-            }
-        </div>
-    </div>
-}
-
 <script>
     (function () {
+        // Handle Get button clicks via AJAX.
+        document.querySelectorAll('.btn-get-prompt').forEach(function (btn) {
+            btn.addEventListener('click', function () {
+                var container = btn.closest('.prompt-form');
+                var promptName = container.dataset.promptName;
+                var resultDiv = document.querySelector(container.dataset.resultTarget);
+
+                btn.disabled = true;
+                btn.textContent = 'Loading…';
+                resultDiv.style.display = 'block';
+                resultDiv.innerHTML = '<p class="text-muted">Loading…</p>';
+
+                var formData = new FormData();
+                formData.append('promptName', promptName);
+
+                fetch('?handler=GetPrompt', {
+                    method: 'POST',
+                    headers: {
+                        'RequestVerificationToken': document.querySelector('input[name="__RequestVerificationToken"]')?.value || ''
+                    },
+                    body: formData
+                })
+                .then(function (response) { return response.json(); })
+                .then(function (data) {
+                    if (data.error) {
+                        resultDiv.innerHTML = '<div class="alert alert-danger mb-0">' + escapeHtml(data.error) + '</div>';
+                        return;
+                    }
+
+                    var html = '';
+
+                    if (data.description) {
+                        html += '<p><strong>Description:</strong> ' + escapeHtml(data.description) + '</p>';
+                    }
+
+                    if (data.messages && data.messages.length > 0) {
+                        html += '<h6>Messages</h6>';
+                        data.messages.forEach(function (msg) {
+                            html += '<div class="card mb-2"><div class="card-body p-2">';
+                            html += '<span class="badge bg-secondary me-1">' + escapeHtml(msg.role) + '</span>';
+                            html += '<span>' + escapeHtml(msg.content || '') + '</span>';
+                            html += '</div></div>';
+                        });
+                    } else {
+                        html += '<p class="text-muted mb-0">No messages returned for this prompt.</p>';
+                    }
+
+                    resultDiv.innerHTML = html;
+                })
+                .catch(function (err) {
+                    resultDiv.innerHTML = '<div class="alert alert-danger mb-0">' + escapeHtml(err.message || 'An error occurred.') + '</div>';
+                })
+                .finally(function () {
+                    btn.disabled = false;
+                    btn.textContent = 'Get';
+                });
+            });
+        });
+
+        // Client-side search.
         var searchInput = document.getElementById('promptSearch');
         if (!searchInput) return;
         var items = document.querySelectorAll('#promptsList .searchable-item');
@@ -98,5 +131,15 @@ else
             });
             noResults.style.display = visible === 0 && query ? '' : 'none';
         });
+
+        function escapeHtml(text) {
+            var div = document.createElement('div');
+            div.appendChild(document.createTextNode(text));
+            return div.innerHTML;
+        }
     })();
 </script>
+
+@* Antiforgery token for AJAX calls *@
+<form id="__AjaxAntiForgeryForm" method="post" style="display:none">
+</form>

src/Startup/CrestApps.OrchardCore.Samples.McpClient/Pages/Prompts.cshtml.cs

@@ -17,10 +17,6 @@ public PromptsModel(McpClientFactory clientFactory)
 
     public IList<McpClientPrompt> Prompts { get; private set; } = [];
 
-    public string SelectedPromptName { get; private set; }
-
-    public GetPromptResult PromptResult { get; private set; }
-
     public string ErrorMessage { get; private set; }
 
     public async Task OnGetAsync(CancellationToken cancellationToken)
@@ -39,31 +35,35 @@ public async Task<IActionResult> OnPostGetPromptAsync(string promptName, Cancell
     {
         if (string.IsNullOrWhiteSpace(promptName))
         {
-            ErrorMessage = "Prompt name is required.";
-            await LoadPromptsAsync(cancellationToken);
-
-            return Page();
+            return new JsonResult(new { error = "Prompt name is required." });
         }
 
         try
         {
             var client = await _clientFactory.CreateAsync(cancellationToken);
 
-            SelectedPromptName = promptName;
-            PromptResult = await client.GetPromptAsync(
+            var result = await client.GetPromptAsync(
                 promptName,
                 new Dictionary<string, object>(),
                 options: null,
                 cancellationToken);
+
+            var messages = new List<object>();
+
+            if (result.Messages?.Count > 0)
+            {
+                foreach (var message in result.Messages)
+                {
+                    messages.Add(new { role = message.Role.ToString(), content = message.Content?.ToString() });
+                }
+            }
+
+            return new JsonResult(new { description = result.Description, messages });
         }
         catch (Exception ex)
         {
-            ErrorMessage = ex.Message;
+            return new JsonResult(new { error = ex.Message });
         }
-
-        await LoadPromptsAsync(cancellationToken);
-
-        return Page();
     }
 
     private async Task LoadPromptsAsync(CancellationToken cancellationToken)