Support for MCP Tool Triggers (#4790)

nturinski · web-flow · commit 2c486c22697a · 2025-11-13T18:06:31.000-08:00
* Support for creating self-hosted mcp server projects

* Add file that I forgot to include

* Work for creating MCP triggers via Functions mcp extensions
diff --git a/src/commands/createFunction/FunctionCreateStepBase.ts b/src/commands/createFunction/FunctionCreateStepBase.ts
@@ -3,23 +3,26 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { AzExtFsExtra, AzureWizardExecuteStepWithActivityOutput, callWithTelemetryAndErrorHandling, nonNullValue, type IActionContext } from '@microsoft/vscode-azext-utils';
+import { AzExtFsExtra, AzureWizardExecuteStepWithActivityOutput, callWithTelemetryAndErrorHandling, nonNullProp, nonNullValue, type IActionContext } from '@microsoft/vscode-azext-utils';
 import * as path from 'path';
 import { Uri, window, workspace, type Progress } from 'vscode';
-import { hostFileName } from '../../constants';
+import { hostFileName, McpProjectType, mcpProjectTypeSetting } from '../../constants';
 import { ext } from '../../extensionVariables';
 import { type IHostJsonV2 } from '../../funcConfig/host';
 import { localize } from '../../localize';
 import { type FunctionTemplateBase } from '../../templates/IFunctionTemplate';
+import { addLocalMcpServer, checkIfMcpServerExists, getLocalServerName, getOrCreateMcpJson, saveMcpJson } from '../../utils/mcpUtils';
 import { verifyTemplateIsV1 } from '../../utils/templateVersionUtils';
 import { verifyExtensionBundle } from '../../utils/verifyExtensionBundle';
 import { getContainingWorkspace } from '../../utils/workspace';
+import { updateWorkspaceSetting } from '../../vsCodeConfig/settings';
 import { type IFunctionWizardContext } from './IFunctionWizardContext';
 
 interface ICachedFunction {
     projectPath: string;
     newFilePath: string;
     isHttpTrigger: boolean;
+    isMcpTrigger: boolean;
 }
 
 const cacheKey: string = 'azFuncPostFunctionCreate';
@@ -68,9 +71,23 @@ export abstract class FunctionCreateStepBase<T extends IFunctionWizardContext> e
         progress.report({ message: localize('creatingFunction', 'Creating new {0}...', template.name) });
 
         const newFilePath: string = await this.executeCore(context);
+        if (context.functionTemplate?.isMcpTrigger) {
+            // indicate that this is a MCP Extension Server project
+            await updateWorkspaceSetting(mcpProjectTypeSetting, McpProjectType.McpExtensionServer, context.workspacePath);
+            // add the local server to the mcp.json if it doesn't already exist
+            const workspace = nonNullProp(context, 'workspaceFolder');
+            const mcpJson = await getOrCreateMcpJson(workspace);
+            const serverName = getLocalServerName(workspace);
+            // only add if it doesn't already exist
+            if (!checkIfMcpServerExists(mcpJson, serverName)) {
+                const newMcpJson = await addLocalMcpServer(mcpJson, serverName, McpProjectType.McpExtensionServer);
+                await saveMcpJson(workspace, newMcpJson);
+            }
+        }
+
         await verifyExtensionBundle(context, template);
 
-        const cachedFunc: ICachedFunction = { projectPath: context.projectPath, newFilePath, isHttpTrigger: template.isHttpTrigger };
+        const cachedFunc: ICachedFunction = { projectPath: context.projectPath, newFilePath, isHttpTrigger: template.isHttpTrigger, isMcpTrigger: template.isMcpTrigger };
         const hostFilePath: string = path.join(context.projectPath, hostFileName);
         if (await AzExtFsExtra.pathExists(hostFilePath)) {
             if (verifyTemplateIsV1(context.functionTemplate) && context.functionTemplate?.isDynamicConcurrent) {
@@ -80,6 +97,24 @@ export abstract class FunctionCreateStepBase<T extends IFunctionWizardContext> e
                     snapshotPersistenceEnabled: true
                 }
                 await AzExtFsExtra.writeJSON(hostFilePath, hostJson);
+            } else if (context.functionTemplate?.isMcpTrigger) {
+                const hostJson = await AzExtFsExtra.readJSON<IHostJsonV2>(hostFilePath);
+                hostJson.extensions = hostJson.extensions ?? {};
+                if (!hostJson.extensions.mcp) {
+                    hostJson.extensions.mcp = {
+                        instructions: "Some test instructions on how to use the server",
+                        serverName: "TestServer",
+                        serverVersion: "2.0.0",
+                        encryptClientState: true,
+                        messageOptions: {
+                            useAbsoluteUriForEndpoint: false
+                        },
+                        system: {
+                            webhookAuthorizationLevel: "System"
+                        }
+                    }
+                }
+                await AzExtFsExtra.writeJSON(hostFilePath, hostJson);
             }
         }
 
@@ -105,7 +140,15 @@ function runPostFunctionCreateSteps(func: ICachedFunction): void {
 
         // If function creation created a new file, open it in an editor...
         if (func.newFilePath && getContainingWorkspace(func.projectPath)) {
-            if (await AzExtFsExtra.pathExists(func.newFilePath)) {
+            const mcpJsonFilePath: string = path.join(func.projectPath, '.vscode', 'mcp.json');
+            if (await AzExtFsExtra.pathExists(func.newFilePath) && await AzExtFsExtra.pathExists(mcpJsonFilePath) && func.isMcpTrigger) {
+                // show the func new file path and the mcp json file in a split editor
+                const templateFile = await workspace.openTextDocument(Uri.file(func.newFilePath));
+                const mcpJsonFile = await workspace.openTextDocument(Uri.file(mcpJsonFilePath));
+                await window.showTextDocument(templateFile, { viewColumn: 1, preserveFocus: false });
+                await window.showTextDocument(mcpJsonFile, { viewColumn: 2, preserveFocus: true });
+            }
+            else if (await AzExtFsExtra.pathExists(func.newFilePath)) {
                 await window.showTextDocument(await workspace.openTextDocument(Uri.file(func.newFilePath)));
             }
         }
diff --git a/src/commands/createFunction/actionStepsV2/WriteToFileExecuteStep.ts b/src/commands/createFunction/actionStepsV2/WriteToFileExecuteStep.ts
@@ -3,10 +3,15 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { AzExtFsExtra, nonNullProp } from "@microsoft/vscode-azext-utils";
+import { AzExtFsExtra, nonNullProp, nonNullValue } from "@microsoft/vscode-azext-utils";
 import * as path from 'path';
 import { Uri, window, workspace } from "vscode";
+import { hostFileName, McpProjectType, mcpProjectTypeSetting } from "../../../constants";
+import { type IHostJsonV2 } from "../../../funcConfig/host";
+import { type FunctionTemplateBase } from "../../../templates/IFunctionTemplate";
 import { isDocumentOpened } from "../../../utils/textUtils";
+import { verifyExtensionBundle } from "../../../utils/verifyExtensionBundle";
+import { updateWorkspaceSetting } from "../../../vsCodeConfig/settings";
 import { type FunctionV2WizardContext } from "../IFunctionWizardContext";
 import { getFileExtensionFromLanguage } from "../scriptSteps/ScriptFunctionCreateStep";
 import { ActionSchemaStepBase } from "./ActionSchemaStepBase";
@@ -25,6 +30,33 @@ export class WriteToFileExecuteStep<T extends FunctionV2WizardContext> extends A
         const source = context[sourceKey] as string;
 
         await AzExtFsExtra.writeFile(filePath, source);
+        if (context.functionTemplate?.isMcpTrigger) {
+            // indicate that this is a MCP Extension Server project
+            await updateWorkspaceSetting(mcpProjectTypeSetting, McpProjectType.McpExtensionServer, context.workspacePath);
+            const template: FunctionTemplateBase = nonNullValue(context.functionTemplate);
+            await verifyExtensionBundle(context, template);
+
+            const hostFilePath: string = path.join(context.projectPath, hostFileName);
+            if (await AzExtFsExtra.pathExists(hostFilePath)) {
+                const hostJson = await AzExtFsExtra.readJSON<IHostJsonV2>(hostFilePath);
+                hostJson.extensions = hostJson.extensions ?? {};
+                if (!hostJson.extensions.mcp) {
+                    hostJson.extensions.mcp = {
+                        instructions: "Some test instructions on how to use the server",
+                        serverName: "TestServer",
+                        serverVersion: "2.0.0",
+                        encryptClientState: true,
+                        messageOptions: {
+                            useAbsoluteUriForEndpoint: false
+                        },
+                        system: {
+                            webhookAuthorizationLevel: "System"
+                        }
+                    }
+                }
+                await AzExtFsExtra.writeJSON(hostFilePath, hostJson);
+            }
+        }
     }
 
     protected async getFilePath(context: T): Promise<string> {
diff --git a/src/funcConfig/function.ts b/src/funcConfig/function.ts
@@ -3,6 +3,9 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+import { type IFunctionTemplate } from "../templates/IFunctionTemplate";
+
+
 export interface IFunctionJson {
     disabled?: boolean;
     scriptFile?: string;
@@ -32,12 +35,20 @@ export enum HttpAuthLevel {
  */
 export class ParsedFunctionJson {
     public readonly data: IFunctionJson;
+    public readonly template: IFunctionTemplate | undefined;
 
     // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types, @typescript-eslint/no-explicit-any
     public constructor(data: any) {
         // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-        if (typeof data === 'object' && data !== null && (data.bindings === undefined || data.bindings instanceof Array)) {
-            this.data = <IFunctionJson>data;
+        if (typeof data === 'object' && data !== null && (data.functions?.bindings !== undefined || data.functions?.bindings instanceof Array)) {
+            // this is to preserve the old template structure where function.json was nested under 'functions'
+            // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+            this.data = <IFunctionJson>data.functions;
+            // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+        } else if (typeof data === 'object' && data !== null && (data.metadata) !== undefined) {
+            // for Node.js programming model v4, there is no function.json so use the template metadata
+            // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+            this.template = <IFunctionTemplate>data.metadata;
         } else {
             this.data = {};
         }
@@ -60,13 +71,30 @@ export class ParsedFunctionJson {
     }
 
     public get isHttpTrigger(): boolean {
+        if (this.template?.triggerType) {
+            return /^http/i.test(this.template.triggerType);
+        }
         return !!this.triggerBinding && !!this.triggerBinding.type && /^http/i.test(this.triggerBinding.type);
     }
 
     public get isTimerTrigger(): boolean {
+        if (this.template?.triggerType) {
+            return /^timer/i.test(this.template.triggerType);
+        }
         return !!this.triggerBinding && !!this.triggerBinding.type && /^timer/i.test(this.triggerBinding.type);
     }
 
+    public get isMcpTrigger(): boolean {
+        if (this.template?.triggerType) {
+            return /^mcptooltrigger/i.test(this.template.triggerType) || /^mcptrigger/i.test(this.template.triggerType);
+        }
+        if (this.triggerBinding && this.triggerBinding.type) {
+            return /^mcptooltrigger/i.test(this.triggerBinding.type) || /^mcptrigger/i.test(this.triggerBinding.type);
+        }
+
+        return false;
+    }
+
     public get authLevel(): HttpAuthLevel | undefined {
         if (this.triggerBinding && this.triggerBinding.authLevel) {
             return HttpAuthLevel[this.triggerBinding.authLevel.toLowerCase() as HttpAuthLevel];
diff --git a/src/templates/IFunctionTemplate.ts b/src/templates/IFunctionTemplate.ts
@@ -44,5 +44,6 @@ export interface FunctionTemplateBase {
     language: ProjectLanguage;
     isHttpTrigger: boolean;
     isTimerTrigger: boolean;
+    isMcpTrigger: boolean;
     templateSchemaVersion: TemplateSchemaVersion
 }
diff --git a/src/templates/dotnet/getDotnetVerifiedTemplateIds.ts b/src/templates/dotnet/getDotnetVerifiedTemplateIds.ts
@@ -21,7 +21,8 @@ export function getDotnetVerifiedTemplateIds(version: string): RegExp[] {
         //TODO: Add unit test for EventGridBlobTrigger
         'EventGridBlobTrigger',
         'SqlInputBinding',
-        'SqlOutputBinding'
+        'SqlOutputBinding',
+        'McpToolTrigger'
     ];
 
     if (version === FuncVersion.v1) {
diff --git a/src/templates/dotnet/parseDotnetTemplates.ts b/src/templates/dotnet/parseDotnetTemplates.ts
@@ -77,6 +77,7 @@ function parseDotnetTemplate(rawTemplate: IRawTemplate): IFunctionTemplate {
     return {
         isHttpTrigger: /^http/i.test(rawTemplate.Name) || /webhook$/i.test(rawTemplate.Name),
         isTimerTrigger: /^timer/i.test(rawTemplate.Name),
+        isMcpTrigger: /^mcptooltrigger/i.test(rawTemplate.Name),
         isSqlBindingTemplate: sqlBindingTemplateRegex.test(rawTemplate.Name),
         id: rawTemplate.Identity,
         name: rawTemplate.Name,
diff --git a/src/templates/script/getScriptVerifiedTemplateIds.ts b/src/templates/script/getScriptVerifiedTemplateIds.ts
@@ -37,7 +37,9 @@ export function getScriptVerifiedTemplateIds(version: string): (string | RegExp)
             'IoTHubTrigger',
             //TODO: Add unit test for EventGridBlobTrigger
             'EventGridBlobTrigger',
-            'SqlTrigger'
+            'SqlTrigger',
+            'McpToolTrigger',
+            'MCPTrigger'
         ]);
 
         // These languages are only supported in v2+ - same functions as JavaScript, with a few minor exceptions that aren't worth distinguishing here
diff --git a/src/templates/script/parseScriptTemplates.ts b/src/templates/script/parseScriptTemplates.ts
@@ -197,7 +197,7 @@ export function parseScriptTemplate(rawTemplate: IRawTemplate, resources: IResou
         return undefined;
     }
 
-    const functionJson: ParsedFunctionJson = new ParsedFunctionJson(rawTemplate.function);
+    const functionJson: ParsedFunctionJson = new ParsedFunctionJson(rawTemplate);
 
     let language: ProjectLanguage = rawTemplate.metadata.language;
     // The templateApiZip only supports script languages, and thus incorrectly defines 'C#Script' as 'C#', etc.
@@ -251,6 +251,7 @@ export function parseScriptTemplate(rawTemplate: IRawTemplate, resources: IResou
         functionJson,
         isHttpTrigger: functionJson.isHttpTrigger,
         isTimerTrigger: functionJson.isTimerTrigger,
+        isMcpTrigger: functionJson.isMcpTrigger,
         isSqlBindingTemplate: sqlBindingTemplateRegex.test(rawTemplate.id),
         id: rawTemplate.id,
         name: getResourceValue(resources, rawTemplate.metadata.name),
diff --git a/src/templates/script/parseScriptTemplatesV2.ts b/src/templates/script/parseScriptTemplatesV2.ts
@@ -121,12 +121,16 @@ export function parseScriptTemplates(rawTemplates: RawTemplateV2[], rawBindings:
         }
         const isHttpTrigger = !!templateV2.id?.toLowerCase().includes('httptrigger-');
         const isTimerTrigger = !!templateV2.id?.toLowerCase().includes('timertrigger-');
+        // python and node.js use 2 different IDs for Mcp Triggers... because of course they do
+        const isMcpTrigger = !!templateV2.id?.toLowerCase().includes('mcptooltrigger') ||
+            templateV2.id?.toLowerCase().includes('mcptrigger');
 
         templates.push(Object.assign(templateV2, {
             wizards: parsedJobs,
             id: nonNullValue(templateV2.id),
             isHttpTrigger,
             isTimerTrigger,
+            isMcpTrigger,
             templateSchemaVersion: TemplateSchemaVersion.v2
         }));
     }
diff --git a/src/utils/bundleFeedUtils.ts b/src/utils/bundleFeedUtils.ts
@@ -14,7 +14,7 @@ import { nugetUtils } from './nugetUtils';
 
 export namespace bundleFeedUtils {
     export const defaultBundleId: string = 'Microsoft.Azure.Functions.ExtensionBundle';
-    export const defaultVersionRange: string = '[1.*, 2.0.0)';
+    export const defaultVersionRange: string = '[4.*, 5.0.0)';
 
     interface IBundleFeed {
         defaultVersionRange: string;

Original file line number	Diff line number	Diff line change
`@@ -44,5 +44,6 @@ export interface FunctionTemplateBase {`
`44`	`44`	`language: ProjectLanguage;`
`45`	`45`	`isHttpTrigger: boolean;`
`46`	`46`	`isTimerTrigger: boolean;`
	`47`	`+ isMcpTrigger: boolean;`
`47`	`48`	`templateSchemaVersion: TemplateSchemaVersion`
`48`	`49`	`}`