v2 ci: add Bun and Deno integration tests (#1607)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/main.yml

@@ -58,11 +58,47 @@ jobs:
 
             - run: pnpm test:all
 
+    test-runtimes:
+        runs-on: ubuntu-latest
+        strategy:
+            fail-fast: false
+            matrix:
+                include:
+                    - runtime: bun
+                      version: "1.x"
+                    - runtime: deno
+                      version: v2.x
+        steps:
+            - uses: actions/checkout@v6
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              with:
+                  run_install: false
+            - uses: actions/setup-node@v6
+              with:
+                  node-version: 24
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
+            - name: Set up Bun
+              if: matrix.runtime == 'bun'
+              uses: oven-sh/setup-bun@v2
+              with:
+                  bun-version: ${{ matrix.version }}
+            - name: Set up Deno
+              if: matrix.runtime == 'deno'
+              uses: denoland/setup-deno@v2
+              with:
+                  deno-version: ${{ matrix.version }}
+            - run: pnpm install
+            - run: pnpm build:all
+            - name: Run ${{ matrix.runtime }} integration tests
+              run: pnpm --filter @modelcontextprotocol/test-integration test:integration:${{ matrix.runtime }}
+
     publish:
         runs-on: ubuntu-latest
         if: github.event_name == 'release'
         environment: release
-        needs: [build, test]
+        needs: [build, test, test-runtimes]
 
         permissions:
             contents: read

README.md

@@ -25,7 +25,7 @@
 
 The Model Context Protocol (MCP) allows applications to provide context for LLMs in a standardized way, separating the concerns of providing context from the actual LLM interaction.
 
-This repository contains the TypeScript SDK implementation of the MCP specification and ships:
+This repository contains the TypeScript SDK implementation of the MCP specification. It runs on **Node.js**, **Bun**, and **Deno**, and ships:
 
 - MCP **server** libraries (tools/resources/prompts, Streamable HTTP, stdio, auth helpers)
 - MCP **client** libraries (transports, high-level helpers, OAuth helpers)
@@ -57,12 +57,20 @@ They are intentionally thin adapters: they should not introduce new MCP function
 
 ```bash
 npm install @modelcontextprotocol/server zod
+# or
+bun add @modelcontextprotocol/server zod
+# or
+deno add npm:@modelcontextprotocol/server npm:zod
 ```
 
 ### Client
 
 ```bash
 npm install @modelcontextprotocol/client zod
+# or
+bun add @modelcontextprotocol/client zod
+# or
+deno add npm:@modelcontextprotocol/client npm:zod
 ```
 
 ### Optional middleware packages

docs/client-quickstart.md

@@ -19,10 +19,13 @@ This quickstart assumes you have familiarity with:
 
 Before starting, ensure your system meets these requirements:
 
-- Node.js 20 or higher installed
+- Node.js 20 or higher installed (or **Bun** / **Deno** — the SDK supports all three runtimes)
 - Latest version of `npm` installed
 - An Anthropic API key from the [Anthropic Console](https://console.anthropic.com/settings/keys)
 
+> [!TIP]
+> This tutorial uses Node.js and npm, but you can substitute `bun` or `deno` commands where appropriate. For example, use `bun add` instead of `npm install`, or run the client with `bun run` / `deno run`.
+
 ## Set up your environment
 
 First, let's create and set up our project:

docs/server-quickstart.md

@@ -36,6 +36,9 @@ node --version
 npm --version
 ```
 
+> [!TIP]
+> The MCP SDK also works with **Bun** and **Deno**. This tutorial uses Node.js, but you can substitute `bun` or `deno` commands where appropriate. For HTTP-based servers on Bun or Deno, use `WebStandardStreamableHTTPServerTransport` instead of the Node.js-specific transport — see the [server guide](./server.md) for details.
+
 ## Set up your environment
 
 First, let's install Node.js and npm if you haven't already. You can download them from [nodejs.org](https://nodejs.org/).

test/integration/package.json

@@ -29,7 +29,9 @@
         "test:watch": "vitest",
         "start": "npm run server",
         "server": "tsx watch --clear-screen=false scripts/cli.ts server",
-        "client": "tsx scripts/cli.ts client"
+        "client": "tsx scripts/cli.ts client",
+        "test:integration:bun": "bun test test/server/bun.test.ts",
+        "test:integration:deno": "deno test --no-check --allow-net --allow-read --allow-env test/server/deno.test.ts"
     },
     "devDependencies": {
         "@modelcontextprotocol/core": "workspace:^",

test/integration/test/server/bun.test.ts

@@ -0,0 +1,57 @@
+/**
+ * Bun integration test
+ *
+ * Verifies the MCP server and client packages work natively on Bun.
+ * Run with: bun test test/server/bun.test.ts
+ */
+
+import { Client, StreamableHTTPClientTransport } from '@modelcontextprotocol/client';
+import { McpServer, WebStandardStreamableHTTPServerTransport } from '@modelcontextprotocol/server';
+// eslint-disable-next-line import/no-unresolved
+import { afterAll, beforeAll, describe, expect, it } from 'bun:test';
+import * as z from 'zod/v4';
+
+describe('MCP on Bun', () => {
+    let httpServer: ReturnType<typeof Bun.serve>;
+    let transport: WebStandardStreamableHTTPServerTransport;
+
+    beforeAll(async () => {
+        const mcpServer = new McpServer({ name: 'test-server', version: '1.0.0' });
+
+        mcpServer.registerTool(
+            'greet',
+            {
+                description: 'Greet someone',
+                inputSchema: z.object({ name: z.string() })
+            },
+            async ({ name }) => ({
+                content: [{ type: 'text' as const, text: `Hello, ${name}!` }]
+            })
+        );
+
+        transport = new WebStandardStreamableHTTPServerTransport();
+        await mcpServer.connect(transport);
+
+        httpServer = Bun.serve({
+            port: 0,
+            fetch: req => transport.handleRequest(req)
+        });
+    });
+
+    afterAll(async () => {
+        await transport?.close();
+        httpServer?.stop();
+    });
+
+    it('should handle MCP tool calls', async () => {
+        const client = new Client({ name: 'test-client', version: '1.0.0' });
+        const clientTransport = new StreamableHTTPClientTransport(new URL(`http://localhost:${httpServer.port}`));
+
+        await client.connect(clientTransport);
+
+        const result = await client.callTool({ name: 'greet', arguments: { name: 'Bun' } });
+        expect(result.content).toEqual([{ type: 'text', text: 'Hello, Bun!' }]);
+
+        await client.close();
+    });
+});

test/integration/test/server/deno.test.ts

@@ -0,0 +1,53 @@
+/**
+ * Deno integration test
+ *
+ * Verifies the MCP server and client packages work natively on Deno.
+ * Run with: deno test --no-check --allow-net --allow-read --allow-env test/server/deno.test.ts
+ */
+
+import assert from 'node:assert/strict';
+
+import { Client, StreamableHTTPClientTransport } from '@modelcontextprotocol/client';
+import { McpServer, WebStandardStreamableHTTPServerTransport } from '@modelcontextprotocol/server';
+import * as z from 'zod/v4';
+
+Deno.test({
+    name: 'MCP tool calls work on Deno',
+    sanitizeOps: false,
+    sanitizeResources: false,
+    async fn() {
+        const mcpServer = new McpServer({ name: 'test-server', version: '1.0.0' });
+
+        mcpServer.registerTool(
+            'greet',
+            {
+                description: 'Greet someone',
+                inputSchema: z.object({ name: z.string() })
+            },
+            async ({ name }) => ({
+                content: [{ type: 'text' as const, text: `Hello, ${name}!` }]
+            })
+        );
+
+        const transport = new WebStandardStreamableHTTPServerTransport();
+        await mcpServer.connect(transport);
+
+        const httpServer = Deno.serve({ port: 0 }, req => transport.handleRequest(req));
+        const port = httpServer.addr.port;
+
+        try {
+            const client = new Client({ name: 'test-client', version: '1.0.0' });
+            const clientTransport = new StreamableHTTPClientTransport(new URL(`http://localhost:${port}`));
+
+            await client.connect(clientTransport);
+
+            const result = await client.callTool({ name: 'greet', arguments: { name: 'Deno' } });
+            assert.deepStrictEqual(result.content, [{ type: 'text', text: 'Hello, Deno!' }]);
+
+            await client.close();
+        } finally {
+            await transport.close();
+            await httpServer.shutdown();
+        }
+    }
+});

test/integration/tsconfig.json

@@ -1,7 +1,7 @@
 {
     "extends": "@modelcontextprotocol/tsconfig",
     "include": ["./"],
-    "exclude": ["node_modules", "dist"],
+    "exclude": ["node_modules", "dist", "test/server/bun.test.ts", "test/server/deno.test.ts"],
     "compilerOptions": {
         "paths": {
             "*": ["./*"],

test/integration/vitest.config.js

@@ -1,3 +1,11 @@
+import { defineConfig, mergeConfig } from 'vitest/config';
 import baseConfig from '../../common/vitest-config/vitest.config.js';
 
-export default baseConfig;
+export default mergeConfig(
+    baseConfig,
+    defineConfig({
+        test: {
+            exclude: ['**/dist/**', '**/bun.test.ts', '**/deno.test.ts']
+        }
+    })
+);