Merge branch 'main' into fweinberger/fix-transport-restart

Author: felixweinberger

.changeset/add-fastify-middleware.md

@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/fastify': minor
+---
+
+Add Fastify middleware adapter for MCP servers, following the same pattern as the Express and Hono adapters.

.changeset/fix-server-protocol-version.md

@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/server': patch
+---
+
+fix(server): propagate negotiated protocol version to transport in _oninitialize

.changeset/pre.json

@@ -0,0 +1,25 @@
+{
+  "mode": "pre",
+  "tag": "alpha",
+  "initialVersions": {
+    "@modelcontextprotocol/eslint-config": "2.0.0",
+    "@modelcontextprotocol/tsconfig": "2.0.0",
+    "@modelcontextprotocol/vitest-config": "2.0.0",
+    "@modelcontextprotocol/examples-client": "2.0.0-alpha.0",
+    "@modelcontextprotocol/examples-client-quickstart": "2.0.0-alpha.0",
+    "@modelcontextprotocol/examples-server": "2.0.0-alpha.0",
+    "@modelcontextprotocol/examples-server-quickstart": "2.0.0-alpha.0",
+    "@modelcontextprotocol/examples-shared": "2.0.0-alpha.0",
+    "@modelcontextprotocol/client": "2.0.0-alpha.0",
+    "@modelcontextprotocol/core": "2.0.0-alpha.0",
+    "@modelcontextprotocol/express": "2.0.0-alpha.0",
+    "@modelcontextprotocol/fastify": "2.0.0-alpha.0",
+    "@modelcontextprotocol/hono": "2.0.0-alpha.0",
+    "@modelcontextprotocol/node": "2.0.0-alpha.0",
+    "@modelcontextprotocol/server": "2.0.0-alpha.0",
+    "@modelcontextprotocol/test-conformance": "2.0.0-alpha.0",
+    "@modelcontextprotocol/test-helpers": "2.0.0-alpha.0",
+    "@modelcontextprotocol/test-integration": "2.0.0-alpha.0"
+  },
+  "changesets": []
+}

.github/workflows/main.yml

@@ -4,8 +4,6 @@ on:
             - main
     pull_request:
     workflow_dispatch:
-    release:
-        types: [published]
 
 concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}
@@ -94,53 +92,3 @@ jobs:
             - 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, test-runtimes]
-
-        permissions:
-            contents: read
-            id-token: write
-
-        steps:
-            - uses: actions/checkout@v6
-
-            - name: Install pnpm
-              uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5.0.0
-              id: pnpm-install
-              with:
-                  run_install: false
-            - uses: actions/setup-node@v6
-              with:
-                  node-version: 24
-                  cache: pnpm
-                  cache-dependency-path: pnpm-lock.yaml
-                  registry-url: 'https://registry.npmjs.org'
-            - run: pnpm install
-
-            - name: Determine npm tag
-              id: npm-tag
-              run: |
-                  VERSION=$(node -p "require('./package.json').version")
-                  # Check if this is a beta release
-                  if [[ "$VERSION" == *"-beta"* ]]; then
-                    echo "tag=--tag beta" >> $GITHUB_OUTPUT
-                  # Check if this release is from a non-primary branch (patch/maintenance release)
-                  elif [[ "${{ github.event.release.target_commitish }}" != "main" && "${{ github.event.release.target_commitish }}" != "v1.x" ]]; then
-                    # Use "release-X.Y" as tag for old branch releases (e.g., "release-1.23" for 1.23.x)
-                    # npm tags are mutable pointers to versions (like "latest" pointing to 1.24.3).
-                    # Using "release-1.23" means users can `npm install @modelcontextprotocol/sdk@release-1.23`
-                    # to get the latest patch on that minor version, and the tag updates if we
-                    # release 1.23.2, 1.23.3, etc.
-                    # Note: Can't use "v1.23" because npm rejects tags that look like semver ranges.
-                    MAJOR_MINOR=$(echo "$VERSION" | cut -d. -f1,2)
-                    echo "tag=--tag release-${MAJOR_MINOR}" >> $GITHUB_OUTPUT
-                  else
-                    echo "tag=" >> $GITHUB_OUTPUT
-                  fi
-
-            - run: pnpm publish --provenance --access public ${{ steps.npm-tag.outputs.tag }}
-              env:
-                  NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/publish.yml

@@ -40,4 +40,4 @@ jobs:
             - name: Publish preview packages
               run:
                   pnpm dlx pkg-pr-new publish --packageManager=npm --pnpm './packages/server' './packages/client'
-                  './packages/middleware/express' './packages/middleware/hono' './packages/middleware/node'
+                  './packages/middleware/express' './packages/middleware/fastify' './packages/middleware/hono' './packages/middleware/node'

packages/client/README.md

@@ -0,0 +1,20 @@
+# `@modelcontextprotocol/client`
+
+The MCP (Model Context Protocol) TypeScript client SDK. Build MCP clients that connect to MCP servers.
+
+> [!WARNING] **This is an alpha release.** Expect breaking changes until v2 stabilizes. We're publishing early to gather feedback — please try it and open issues — but we can't guarantee API stability yet. We'll aim to minimize disruption between alphas.
+
+> [!NOTE] This is **v2** of the MCP TypeScript SDK. It replaces the monolithic `@modelcontextprotocol/sdk` package from v1. See the **[migration guide](https://github.com/modelcontextprotocol/typescript-sdk/blob/main/docs/migration.md)** if you're coming from v1.
+
+## Install
+
+```bash
+npm install @modelcontextprotocol/client@alpha
+```
+
+## Documentation
+
+- **[Repository README](https://github.com/modelcontextprotocol/typescript-sdk#readme)** — overview, package layout, examples
+- **[Client guide](https://github.com/modelcontextprotocol/typescript-sdk/blob/main/docs/client.md)**
+- **[API reference](https://ts.sdk.modelcontextprotocol.io/v2/)**
+- **[MCP specification](https://modelcontextprotocol.io)**

packages/middleware/fastify/README.md

@@ -0,0 +1,70 @@
+# `@modelcontextprotocol/fastify`
+
+Fastify adapters for the MCP TypeScript server SDK.
+
+This package is a thin Fastify integration layer for [`@modelcontextprotocol/server`](https://github.com/modelcontextprotocol/typescript-sdk/tree/main/packages/server).
+
+It does **not** implement MCP itself. Instead, it helps you:
+
+- create a Fastify app with sensible defaults for MCP servers
+- add DNS rebinding protection via Host header validation (recommended for localhost servers)
+
+## Install
+
+```bash
+npm install @modelcontextprotocol/server @modelcontextprotocol/fastify fastify
+
+# For MCP Streamable HTTP over Node.js (IncomingMessage/ServerResponse):
+npm install @modelcontextprotocol/node
+```
+
+## Exports
+
+- `createMcpFastifyApp(options?)`
+- `hostHeaderValidation(allowedHostnames)`
+- `localhostHostValidation()`
+
+## Usage
+
+### Create a Fastify app (localhost DNS rebinding protection by default)
+
+```ts
+import { createMcpFastifyApp } from '@modelcontextprotocol/fastify';
+
+const app = createMcpFastifyApp(); // default host is 127.0.0.1; protection enabled
+```
+
+### Streamable HTTP endpoint (Fastify)
+
+```ts
+import { createMcpFastifyApp } from '@modelcontextprotocol/fastify';
+import { NodeStreamableHTTPServerTransport } from '@modelcontextprotocol/node';
+import { McpServer } from '@modelcontextprotocol/server';
+
+const app = createMcpFastifyApp();
+const mcpServer = new McpServer({ name: 'my-server', version: '1.0.0' });
+
+app.post('/mcp', async (request, reply) => {
+    // Stateless example: create a transport per request.
+    // For stateful mode (sessions), keep a transport instance around and reuse it.
+    const transport = new NodeStreamableHTTPServerTransport({ sessionIdGenerator: undefined });
+    await mcpServer.connect(transport);
+
+    // Clean up when the client closes the connection (e.g. during SSE streaming).
+    reply.raw.on('close', () => {
+        transport.close();
+    });
+
+    await transport.handleRequest(request.raw, reply.raw, request.body);
+});
+```
+
+If you create a new `McpServer` per request in stateless mode, also call `mcpServer.close()` in the `close` handler. To reject non-POST requests with 405 Method Not Allowed, add routes for GET and DELETE that send a JSON-RPC error response.
+
+### Host header validation (DNS rebinding protection)
+
+```ts
+import { hostHeaderValidation } from '@modelcontextprotocol/fastify';
+
+app.addHook('onRequest', hostHeaderValidation(['localhost', '127.0.0.1', '[::1]']));
+```

packages/middleware/fastify/eslint.config.mjs

@@ -0,0 +1,12 @@
+// @ts-check
+
+import baseConfig from '@modelcontextprotocol/eslint-config';
+
+export default [
+    ...baseConfig,
+    {
+        settings: {
+            'import/internal-regex': '^@modelcontextprotocol/(server|core)'
+        }
+    }
+];

packages/middleware/fastify/package.json

@@ -0,0 +1,67 @@
+{
+    "name": "@modelcontextprotocol/fastify",
+    "private": false,
+    "version": "2.0.0-alpha.0",
+    "description": "Fastify adapters for the Model Context Protocol TypeScript server SDK - Fastify middleware",
+    "license": "MIT",
+    "author": "Anthropic, PBC (https://anthropic.com)",
+    "homepage": "https://modelcontextprotocol.io",
+    "bugs": "https://github.com/modelcontextprotocol/typescript-sdk/issues",
+    "type": "module",
+    "repository": {
+        "type": "git",
+        "url": "git+https://github.com/modelcontextprotocol/typescript-sdk.git"
+    },
+    "engines": {
+        "node": ">=20",
+        "pnpm": ">=10.24.0"
+    },
+    "packageManager": "pnpm@10.24.0",
+    "keywords": [
+        "modelcontextprotocol",
+        "mcp",
+        "fastify",
+        "middleware"
+    ],
+    "exports": {
+        ".": {
+            "types": "./dist/index.d.mts",
+            "import": "./dist/index.mjs"
+        }
+    },
+    "files": [
+        "dist"
+    ],
+    "scripts": {
+        "typecheck": "tsgo -p tsconfig.json --noEmit",
+        "build": "tsdown",
+        "build:watch": "tsdown --watch",
+        "prepack": "npm run build",
+        "lint": "eslint src/ && prettier --ignore-path ../../../.prettierignore --check .",
+        "lint:fix": "eslint src/ --fix && prettier --ignore-path ../../../.prettierignore --write .",
+        "check": "npm run typecheck && npm run lint",
+        "test": "vitest run",
+        "test:watch": "vitest"
+    },
+    "dependencies": {},
+    "peerDependencies": {
+        "@modelcontextprotocol/server": "workspace:^",
+        "fastify": "catalog:runtimeServerOnly"
+    },
+    "devDependencies": {
+        "@modelcontextprotocol/server": "workspace:^",
+        "@modelcontextprotocol/tsconfig": "workspace:^",
+        "@modelcontextprotocol/vitest-config": "workspace:^",
+        "@modelcontextprotocol/eslint-config": "workspace:^",
+        "@eslint/js": "catalog:devTools",
+        "@typescript/native-preview": "catalog:devTools",
+        "eslint": "catalog:devTools",
+        "eslint-config-prettier": "catalog:devTools",
+        "eslint-plugin-n": "catalog:devTools",
+        "prettier": "catalog:devTools",
+        "tsdown": "catalog:devTools",
+        "typescript": "catalog:devTools",
+        "typescript-eslint": "catalog:devTools",
+        "vitest": "catalog:devTools"
+    }
+}

packages/middleware/fastify/src/fastify.examples.ts

@@ -0,0 +1,41 @@
+/**
+ * Type-checked examples for `fastify.ts`.
+ *
+ * These examples are synced into JSDoc comments via the sync-snippets script.
+ * Each function's region markers define the code snippet that appears in the docs.
+ *
+ * @module
+ */
+
+import { createMcpFastifyApp } from './fastify.js';
+
+/**
+ * Example: Basic usage with default DNS rebinding protection.
+ */
+function createMcpFastifyApp_default() {
+    //#region createMcpFastifyApp_default
+    const app = createMcpFastifyApp();
+    //#endregion createMcpFastifyApp_default
+    return app;
+}
+
+/**
+ * Example: Custom host binding with and without DNS rebinding protection.
+ */
+function createMcpFastifyApp_customHost() {
+    //#region createMcpFastifyApp_customHost
+    const appOpen = createMcpFastifyApp({ host: '0.0.0.0' }); // No automatic DNS rebinding protection
+    const appLocal = createMcpFastifyApp({ host: 'localhost' }); // DNS rebinding protection enabled
+    //#endregion createMcpFastifyApp_customHost
+    return { appOpen, appLocal };
+}
+
+/**
+ * Example: Custom allowed hosts for non-localhost binding.
+ */
+function createMcpFastifyApp_allowedHosts() {
+    //#region createMcpFastifyApp_allowedHosts
+    const app = createMcpFastifyApp({ host: '0.0.0.0', allowedHosts: ['myapp.local', 'localhost'] });
+    //#endregion createMcpFastifyApp_allowedHosts
+    return app;
+}