Add Vertex AI backend support and UI

Madzionator · Madzionator · commit 05f7f5fc4100 · 2026-03-26T00:08:15.000+01:00
Introduce Vertex AI support across the InferPage UI and settings plumbing. Changes include:

- Add a new BackendOption (id 9) for Vertex AI and corresponding selection/lookup logic in Settings.razor and Program.cs; Program warns that Vertex requires service account credentials.
- Extend the settings UI to collect Vertex auth fields (Project ID, Client Email, Private Key, Location), with toggleable key visibility and required-field validation to enable saving.
- Persist Vertex auth separately via SettingsService.SaveVertexAuthAsync/GetVertexAuthAsync and a VertexAuthStorage record; private_key is stored outside general settings. Also add VertexLocation to InferPageSettings.
- Pass a GoogleServiceAccountConfig (vertexAuth) through Utils.ApplySettings so MaINSettings.GoogleServiceAccountAuth can be set when selecting Vertex.
- Add model identifier constant for gemini-2.5-pro and fix a CloudModel reference to use Models.Gemini.Gemini2_5Pro.

These changes wire up UI, storage, and application settings so Vertex can be configured from the Settings page and applied at runtime.
diff --git a/src/MaIN.Domain/Models/Concrete/CloudModels.cs b/src/MaIN.Domain/Models/Concrete/CloudModels.cs
@@ -94,7 +94,7 @@ public sealed record Gemini2_0Flash() : CloudModel(
 }
 
 public sealed record Gemini2_5Pro() : CloudModel(
-    Models.Vertex.Gemini2_5Pro,
+    Models.Gemini.Gemini2_5Pro,
     BackendType.Gemini,
     "Gemini 2.5 Pro",
     1000000,
diff --git a/src/MaIN.Domain/Models/Models.cs b/src/MaIN.Domain/Models/Models.cs
@@ -23,6 +23,7 @@ public static class Anthropic
 
     public static class Gemini
     {
+        public const string Gemini2_5Pro = "gemini-2.5-pro";
         public const string Gemini2_5Flash = "gemini-2.5-flash";
         public const string Gemini2_0Flash = "gemini-2.0-flash";
     }
diff --git a/src/MaIN.InferPage/Components/Pages/Home.razor b/src/MaIN.InferPage/Components/Pages/Home.razor
@@ -428,11 +428,28 @@
         {
             var backendKey = backendType == BackendType.Ollama
                 ? (settings.IsOllamaCloud ? "OllamaCloud" : "OllamaLocal")
+                : backendType == BackendType.Vertex ? "Vertex"
                 : backendType.ToString();
 
             apiKey = await SettingsStorage.GetApiKeyForBackendAsync(backendKey);
         }
 
+        // Load Vertex auth from localStorage if applicable
+        Domain.Configuration.Vertex.GoogleServiceAccountConfig? vertexAuth = null;
+        if (backendType == BackendType.Vertex)
+        {
+            var stored = await SettingsStorage.GetVertexAuthAsync();
+            if (stored != null)
+            {
+                vertexAuth = new Domain.Configuration.Vertex.GoogleServiceAccountConfig
+                {
+                    ProjectId = stored.ProjectId,
+                    ClientEmail = stored.ClientEmail,
+                    PrivateKey = stored.PrivateKey
+                };
+            }
+        }
+
         Utils.ApplySettings(
             backendType,
             settings.Model!,
@@ -442,7 +459,8 @@
             settings.HasImageGen,
             settings.MmProjName,
             MaINSettings,
-            apiKey);
+            apiKey,
+            vertexAuth);
     }
 
     private void ShowSettingsFromGear()
diff --git a/src/MaIN.InferPage/Components/Pages/Settings.razor b/src/MaIN.InferPage/Components/Pages/Settings.razor
@@ -1,4 +1,5 @@
 @using MaIN.Domain.Configuration
+@using MaIN.Domain.Configuration.Vertex
 @using MaIN.Domain.Models.Abstract
 @inject SettingsService SettingsStorage
 @inject MaINSettings MaINSettings
@@ -64,6 +65,49 @@
                 </div>
             }
 
+            @if (_selectedBackend?.BackendType == BackendType.Vertex)
+            {
+                <div class="settings-field">
+                    <label class="settings-label">Project ID</label>
+                    <FluentTextField @bind-Value="_vertexProjectId"
+                                     Placeholder="my-google-cloud-project"
+                                     Style="width: 100%;" />
+                </div>
+
+                <div class="settings-field">
+                    <label class="settings-label">Client Email</label>
+                    <FluentTextField @bind-Value="_vertexClientEmail"
+                                     Placeholder="name@project.iam.gserviceaccount.com"
+                                     Style="width: 100%;" />
+                </div>
+
+                <div class="settings-field">
+                    <label class="settings-label">Private Key</label>
+                    <div class="api-key-row">
+                        <FluentTextField @bind-Value="_vertexPrivateKey"
+                                         Placeholder="Private key from service account JSON"
+                                         TextFieldType="@(_showVertexKey ? TextFieldType.Text : TextFieldType.Password)"
+                                         Style="flex: 1;" />
+                        <FluentButton Appearance="Appearance.Lightweight"
+                                      Style="--neutral-fill-stealth-rest: transparent; --neutral-fill-stealth-hover: rgba(128,128,128,0.15); --neutral-fill-stealth-active: rgba(128,128,128,0.25);"
+                                      OnClick="@(() => _showVertexKey = !_showVertexKey)"
+                                      IconStart="@(_showVertexKey
+                                          ? new Icons.Regular.Size20.EyeOff()
+                                          : (Icon)new Icons.Regular.Size20.Eye())">
+                        </FluentButton>
+                    </div>
+                    <span class="api-key-hint">private_key field from the service account JSON file</span>
+                </div>
+
+                <div class="settings-field">
+                    <label class="settings-label">Location</label>
+                    <FluentTextField @bind-Value="_vertexLocation"
+                                     Placeholder="us-central1"
+                                     Style="width: 100%;" />
+                    <span class="api-key-hint">Optional — defaults to us-central1</span>
+                </div>
+            }
+
             @if (_selectedBackend?.BackendType == BackendType.Self)
             {
                 <div class="settings-field">
@@ -155,6 +199,13 @@
     private string? _savedKeyPreview;
     private bool _showApiKey;
 
+    // Vertex AI auth fields
+    private string? _vertexProjectId;
+    private string? _vertexClientEmail;
+    private string? _vertexPrivateKey;
+    private string? _vertexLocation;
+    private bool _showVertexKey;
+
     // "Will load:" path preview shown below the model path field (Self backend only)
     private string? ResolvedModelPathPreview
     {
@@ -236,9 +287,14 @@
     private string? _mmProjName;
 
     private bool RequiresApiKey => _selectedBackend?.RequiresApiKey == true;
+    private bool IsVertexBackend => _selectedBackend?.BackendType == BackendType.Vertex;
+    private bool HasVertexRequiredFields => !string.IsNullOrWhiteSpace(_vertexProjectId)
+        && !string.IsNullOrWhiteSpace(_vertexClientEmail)
+        && !string.IsNullOrWhiteSpace(_vertexPrivateKey);
     private bool CanSave => !string.IsNullOrWhiteSpace(_modelName)
                             && _selectedBackend != null
-                            && (!RequiresApiKey || !string.IsNullOrEmpty(_apiKeyInput) || !string.IsNullOrEmpty(_savedKeyPreview));
+                            && (!RequiresApiKey || !string.IsNullOrEmpty(_apiKeyInput) || !string.IsNullOrEmpty(_savedKeyPreview))
+                            && (!IsVertexBackend || HasVertexRequiredFields);
 
     protected override async Task OnInitializedAsync()
     {
@@ -251,7 +307,8 @@
             new(5, "Anthropic", BackendType.Anthropic, true),
             new(6, "xAI", BackendType.Xai, true),
             new(7, "Ollama (Local)", BackendType.Ollama, false),
-            new(8, "Ollama (Cloud)", BackendType.Ollama, true)
+            new(8, "Ollama (Cloud)", BackendType.Ollama, true),
+            new(9, "Vertex AI", BackendType.Vertex, false)
         }.OrderBy(x => x.DisplayName)
          .Prepend(new BackendOption(0, "Local", BackendType.Self, false))
          .ToList();
@@ -281,6 +338,10 @@
                     ? _backendOptions.First(o => o.Id == 8)
                     : _backendOptions.First(o => o.Id == 7);
             }
+            else if (backendType == BackendType.Vertex)
+            {
+                _selectedBackend = _backendOptions.First(o => o.Id == 9);
+            }
             else
             {
                 _selectedBackend = _backendOptions.FirstOrDefault(o => o.BackendType == backendType && o.Id < 7);
@@ -293,6 +354,18 @@
             _manualImageGen = settings.HasImageGen;
             _mmProjName = settings.MmProjName;
 
+            if (backendType == BackendType.Vertex)
+            {
+                var vertexAuth = await SettingsStorage.GetVertexAuthAsync();
+                if (vertexAuth != null)
+                {
+                    _vertexProjectId = vertexAuth.ProjectId;
+                    _vertexClientEmail = vertexAuth.ClientEmail;
+                    _vertexPrivateKey = vertexAuth.PrivateKey;
+                }
+                _vertexLocation = settings.VertexLocation;
+            }
+
             OnModelNameChanged();
         }
         else if (!Utils.NeedsConfiguration)
@@ -302,7 +375,9 @@
                 ? (Utils.HasApiKey
                     ? _backendOptions.First(o => o.Id == 8)
                     : _backendOptions.First(o => o.Id == 7))
-                : _backendOptions.FirstOrDefault(o => o.BackendType == Utils.BackendType && o.Id < 7);
+                : Utils.BackendType == BackendType.Vertex
+                    ? _backendOptions.First(o => o.Id == 9)
+                    : _backendOptions.FirstOrDefault(o => o.BackendType == Utils.BackendType && o.Id < 7);
 
             _modelName = Utils.Model;
             _modelPath = Utils.Path;
@@ -343,6 +418,26 @@
             }
         }
 
+        if (IsVertexBackend)
+        {
+            var vertexAuth = await SettingsStorage.GetVertexAuthAsync();
+            if (vertexAuth != null)
+            {
+                _vertexProjectId = vertexAuth.ProjectId;
+                _vertexClientEmail = vertexAuth.ClientEmail;
+                _vertexPrivateKey = vertexAuth.PrivateKey;
+            }
+            else
+            {
+                _vertexProjectId = null;
+                _vertexClientEmail = null;
+                _vertexPrivateKey = null;
+            }
+
+            var settings = await SettingsStorage.LoadSettingsAsync();
+            _vertexLocation = settings?.VertexLocation;
+        }
+
         await LoadApiKeyPreview();
         _apiKeyInput = null;
     }
@@ -425,7 +520,8 @@
             HasReasoning = hasReasoning,
             HasImageGen = hasImageGen,
             ModelPath = _modelPath,
-            MmProjName = _mmProjName
+            MmProjName = _mmProjName,
+            VertexLocation = IsVertexBackend ? _vertexLocation : null
         };
         await SettingsStorage.SaveSettingsAsync(settings);
 
@@ -447,6 +543,19 @@
             }
         }
 
+        // Vertex AI: persist auth and build config
+        GoogleServiceAccountConfig? vertexAuth = null;
+        if (IsVertexBackend && HasVertexRequiredFields)
+        {
+            await SettingsStorage.SaveVertexAuthAsync(_vertexProjectId!, _vertexClientEmail!, _vertexPrivateKey!);
+            vertexAuth = new GoogleServiceAccountConfig
+            {
+                ProjectId = _vertexProjectId!,
+                ClientEmail = _vertexClientEmail!,
+                PrivateKey = _vertexPrivateKey!
+            };
+        }
+
         Utils.ApplySettings(
             _selectedBackend.BackendType,
             _modelName,
@@ -456,7 +565,8 @@
             hasImageGen,
             _mmProjName,
             MaINSettings,
-            apiKey);
+            apiKey,
+            vertexAuth);
 
         await OnSettingsApplied.InvokeAsync();
     }
@@ -466,6 +576,7 @@
         if (_selectedBackend == null) return "Self";
         if (_selectedBackend.Id == 7) return "OllamaLocal";
         if (_selectedBackend.Id == 8) return "OllamaCloud";
+        if (_selectedBackend.Id == 9) return "Vertex";
         return _selectedBackend.BackendType.ToString();
     }
 
diff --git a/src/MaIN.InferPage/Program.cs b/src/MaIN.InferPage/Program.cs
@@ -39,10 +39,15 @@
                 "anthropic" => BackendType.Anthropic,
                 "xai" => BackendType.Xai,
                 "ollama" => BackendType.Ollama,
+                "vertex" => BackendType.Vertex,
                 _ => BackendType.Self
             };
 
-            if (Utils.BackendType != BackendType.Self)
+            if (Utils.BackendType == BackendType.Vertex)
+            {
+                Console.WriteLine("Vertex AI requires service account credentials. Configure them via the Settings page.");
+            }
+            else if (Utils.BackendType != BackendType.Self)
             {
                 var apiKeyVariable = LLMApiRegistry.GetEntry(Utils.BackendType)?.ApiKeyEnvName ?? string.Empty;
                 var key = Environment.GetEnvironmentVariable(apiKeyVariable);
diff --git a/src/MaIN.InferPage/Services/InferPageSettings.cs b/src/MaIN.InferPage/Services/InferPageSettings.cs
@@ -10,4 +10,5 @@ public class InferPageSettings
     public bool HasImageGen { get; set; }
     public string? ModelPath { get; set; }
     public string? MmProjName { get; set; }
+    public string? VertexLocation { get; set; }
 }
diff --git a/src/MaIN.InferPage/Services/SettingsService.cs b/src/MaIN.InferPage/Services/SettingsService.cs
@@ -41,6 +41,18 @@ public async Task SaveProfileForBackendAsync(string backend, string model,
         return profiles?.GetValueOrDefault(backend);
     }
 
+    // Vertex AI auth (stored separately — PrivateKey should not be in general settings)
+    private const string VertexAuthKey = "inferpage-vertex-auth";
+
+    public async Task SaveVertexAuthAsync(string projectId, string clientEmail, string privateKey)
+    {
+        var auth = new VertexAuthStorage(projectId, clientEmail, privateKey);
+        await js.InvokeVoidAsync("settingsManager.save", VertexAuthKey, auth);
+    }
+
+    public async Task<VertexAuthStorage?> GetVertexAuthAsync()
+        => await js.InvokeAsync<VertexAuthStorage?>("settingsManager.load", VertexAuthKey);
+
     private async Task SetInDictAsync(string storageKey, string key, string value)
     {
         var dict = await LoadDictAsync(storageKey);
@@ -56,3 +68,5 @@ private async Task<Dictionary<string, string>> LoadDictAsync(string storageKey)
 }
 
 public record BackendProfile(string Model, bool Vision, bool Reasoning, bool ImageGen, string? MmProjName = null);
+
+public record VertexAuthStorage(string ProjectId, string ClientEmail, string PrivateKey);
diff --git a/src/MaIN.InferPage/Utils.cs b/src/MaIN.InferPage/Utils.cs
@@ -1,4 +1,5 @@
 using MaIN.Domain.Configuration;
+using MaIN.Domain.Configuration.Vertex;
 using MaIN.Domain.Entities;
 using MaIN.Domain.Models.Abstract;
 using MaIN.Domain.Models.Concrete;
@@ -45,7 +46,8 @@ public static void ApplySettings(
         bool hasImageGen,
         string? mmProjName,
         MaINSettings mainSettings,
-        string? apiKey)
+        string? apiKey,
+        GoogleServiceAccountConfig? vertexAuth = null)
     {
         BackendType = backendType;
         Model = model;
@@ -89,6 +91,10 @@ public static void ApplySettings(
             case BackendType.GroqCloud: mainSettings.GroqCloudKey = apiKey; break;
             case BackendType.Ollama: mainSettings.OllamaKey = apiKey; break;
             case BackendType.Xai: mainSettings.XaiKey = apiKey; break;
+            case BackendType.Vertex:
+                if (vertexAuth != null)
+                    mainSettings.GoogleServiceAccountAuth = vertexAuth;
+                break;
         }
     }
 
diff --git a/src/MaIN.Services/Services/LLMService/VertexService.cs b/src/MaIN.Services/Services/LLMService/VertexService.cs
@@ -54,8 +54,12 @@ protected override string GetApiKey()
 
         _tokenProvider ??= new GoogleServiceAccountTokenProvider(auth);
 
+        logger?.LogInformation("Vertex: Requesting access token for {ClientEmail}...", auth.ClientEmail);
         var httpClient = _httpClientFactory.CreateClient(HttpClientName);
-        return _tokenProvider.GetAccessTokenAsync(httpClient).GetAwaiter().GetResult();
+        // Use Task.Run to avoid deadlocking on Blazor Server's SynchronizationContext
+        var token = Task.Run(() => _tokenProvider.GetAccessTokenAsync(httpClient)).GetAwaiter().GetResult();
+        logger?.LogInformation("Vertex: Access token obtained (length={Length})", token?.Length ?? 0);
+        return token;
     }
 
     protected override string GetApiName() => LLMApiRegistry.Vertex.ApiName;
@@ -88,6 +92,8 @@ protected override void ApplyBackendParams(Dictionary<string, object> requestBod
         CancellationToken cancellationToken = default)
     {
         ExtractLocation(chat);
+        logger?.LogInformation("Vertex: Send called, model={Model}, location={Location}, url={Url}",
+            chat.ModelId, _location, ChatCompletionsUrl);
         return await base.Send(chat, options, cancellationToken);
     }
 

Original file line number	Diff line number	Diff line change
`@@ -94,7 +94,7 @@ public sealed record Gemini2_0Flash() : CloudModel(`
`94`	`94`	`}`
`95`	`95`
`96`	`96`	`public sealed record Gemini2_5Pro() : CloudModel(`
`97`		`- Models.Vertex.Gemini2_5Pro,`
	`97`	`+ Models.Gemini.Gemini2_5Pro,`
`98`	`98`	`BackendType.Gemini,`
`99`	`99`	`"Gemini 2.5 Pro",`
`100`	`100`	`1000000,`
Original file line number	Diff line number	Diff line change
`@@ -23,6 +23,7 @@ public static class Anthropic`
`23`	`23`
`24`	`24`	`public static class Gemini`
`25`	`25`	`{`
	`26`	`+ public const string Gemini2_5Pro = "gemini-2.5-pro";`
`26`	`27`	`public const string Gemini2_5Flash = "gemini-2.5-flash";`
`27`	`28`	`public const string Gemini2_0Flash = "gemini-2.0-flash";`
`28`	`29`	`}`
Original file line number	Diff line number	Diff line change
`@@ -10,4 +10,5 @@ public class InferPageSettings`
`10`	`10`	`public bool HasImageGen { get; set; }`
`11`	`11`	`public string? ModelPath { get; set; }`
`12`	`12`	`public string? MmProjName { get; set; }`
	`13`	`+ public string? VertexLocation { get; set; }`
`13`	`14`	`}`
Original file line number	Diff line number	Diff line change
`@@ -54,8 +54,12 @@ protected override string GetApiKey()`
`54`	`54`
`55`	`55`	`_tokenProvider ??= new GoogleServiceAccountTokenProvider(auth);`
`56`	`56`
	`57`	`+ logger?.LogInformation("Vertex: Requesting access token for {ClientEmail}...", auth.ClientEmail);`
`57`	`58`	`var httpClient = _httpClientFactory.CreateClient(HttpClientName);`
`58`		`- return _tokenProvider.GetAccessTokenAsync(httpClient).GetAwaiter().GetResult();`
	`59`	`+ // Use Task.Run to avoid deadlocking on Blazor Server's SynchronizationContext`
	`60`	`+ var token = Task.Run(() => _tokenProvider.GetAccessTokenAsync(httpClient)).GetAwaiter().GetResult();`
	`61`	`+ logger?.LogInformation("Vertex: Access token obtained (length={Length})", token?.Length ?? 0);`
	`62`	`+ return token;`
`59`	`63`	`}`
`60`	`64`
`61`	`65`	`protected override string GetApiName() => LLMApiRegistry.Vertex.ApiName;`
`@@ -88,6 +92,8 @@ protected override void ApplyBackendParams(Dictionary<string, object> requestBod`
`88`	`92`	`CancellationToken cancellationToken = default)`
`89`	`93`	`{`
`90`	`94`	`ExtractLocation(chat);`
	`95`	`+ logger?.LogInformation("Vertex: Send called, model={Model}, location={Location}, url={Url}",`
	`96`	`+ chat.ModelId, _location, ChatCompletionsUrl);`
`91`	`97`	`return await base.Send(chat, options, cancellationToken);`
`92`	`98`	`}`
`93`	`99`