[v2] Мonorepo, sdk-client, sdk-server, sdk-core package split (#1279)

Author: KKonstantinov

.changeset/README.md

@@ -0,0 +1,6 @@
+# Changesets
+
+Hello and welcome! This folder has been automatically generated by `@changesets/cli`, a build tool that works with multi-package repos, or single-package repos to help you version and publish your code. You can find the full documentation for it
+[in our repository](https://github.com/changesets/changesets)
+
+We have a quick list of common questions to get you started engaging with this project in [our documentation](https://github.com/changesets/changesets/blob/main/docs/common-questions.md)

.changeset/config.json

@@ -0,0 +1,11 @@
+{
+    "$schema": "https://unpkg.com/@changesets/config@3.1.2/schema.json",
+    "changelog": ["@changesets/changelog-github", { "repo": "@modelcontextprotocol/typescript-sdk" }],
+    "commit": false,
+    "fixed": [],
+    "linked": [],
+    "access": "public",
+    "baseBranch": "main",
+    "updateInternalDependencies": "patch",
+    "ignore": ["@modelcontextprotocol/examples-client", "@modelcontextprotocol/examples-server", "@modelcontextprotocol/examples-shared"]
+}

.changeset/tender-snails-fold.md

@@ -0,0 +1,6 @@
+---
+'@modelcontextprotocol/client': patch
+'@modelcontextprotocol/server': patch
+---
+
+Initial 2.0.0-alpha.0 client and server package

.github/workflows/main.yml

@@ -16,32 +16,47 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
-            - uses: actions/checkout@v4
-            - uses: actions/setup-node@v4
+            - uses: actions/checkout@v6
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              id: pnpm-install
+              with:
+                  run_install: false
+            - uses: actions/setup-node@v6
               with:
                   node-version: 24
-                  cache: npm
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
 
-            - run: npm ci
-            - run: npm run check
-            - run: npm run build
+            - run: pnpm install
+            - run: pnpm run check:all
+            - run: pnpm run build:all
 
     test:
         runs-on: ubuntu-latest
         strategy:
             fail-fast: false
             matrix:
-                node-version: [18, 24]
+                node-version: [20, 22, 24]
 
         steps:
-            - uses: actions/checkout@v4
-            - uses: actions/setup-node@v4
+            - uses: actions/checkout@v6
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              id: pnpm-install
+              with:
+                  run_install: false
+            - uses: actions/setup-node@v6
               with:
                   node-version: ${{ matrix.node-version }}
-                  cache: npm
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
+
+            - run: pnpm install
 
-            - run: npm ci
-            - run: npm test
+            - run: pnpm test:all
 
     publish:
         runs-on: ubuntu-latest
@@ -55,13 +70,19 @@ jobs:
 
         steps:
             - uses: actions/checkout@v4
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              id: pnpm-install
+              with:
+                  run_install: false
             - uses: actions/setup-node@v4
               with:
                   node-version: 24
-                  cache: npm
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
                   registry-url: 'https://registry.npmjs.org'
-
-            - run: npm ci
+            - run: pnpm install
 
             - name: Determine npm tag
               id: npm-tag
@@ -84,6 +105,6 @@ jobs:
                     echo "tag=" >> $GITHUB_OUTPUT
                   fi
 
-            - run: npm publish --provenance --access public ${{ steps.npm-tag.outputs.tag }}
+            - run: pnpm publish --provenance --access public ${{ steps.npm-tag.outputs.tag }}
               env:
                   NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/publish.yml

@@ -1,6 +1,8 @@
 name: Publish Any Commit
+
 permissions:
     contents: read
+
 on:
     pull_request:
     push:
@@ -14,14 +16,26 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
-            - uses: actions/checkout@v4
-            - uses: actions/setup-node@v4
+            - uses: actions/checkout@v6
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              with:
+                  run_install: false
+
+            - name: Setup Node.js
+              uses: actions/setup-node@v6
               with:
                   node-version: 24
-                  cache: npm
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
+                  registry-url: 'https://registry.npmjs.org'
+
+            - name: Install dependencies
+              run: pnpm install
+
+            - name: Build packages
+              run: pnpm run build:all
 
-            - run: npm ci
-            - name: Build
-              run: npm run build
-            - name: Publish
-              run: npx pkg-pr-new publish
+            - name: Publish preview packages
+              run: pnpm dlx pkg-pr-new publish --packageManager=npm --pnpm './packages/server' './packages/client'

.github/workflows/release.yml

@@ -0,0 +1,45 @@
+name: Release
+
+permissions:
+    contents: write
+    pull-requests: write
+
+on:
+    push:
+        branches:
+            - main
+
+concurrency: ${{ github.workflow }}-${{ github.ref }}
+
+jobs:
+    release:
+        name: Release
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v6
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              with:
+                  run_install: false
+
+            - name: Setup Node.js
+              uses: actions/setup-node@v6
+              with:
+                  node-version: 24
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
+                  registry-url: 'https://registry.npmjs.org'
+
+            - name: Install dependencies
+              run: pnpm install
+
+            - name: Create Release Pull Request or Publish to npm
+              id: changesets
+              uses: changesets/action@v1
+              with:
+                  publish: pnpm run build:all && pnpm changeset publish
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+                  NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+                  NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/update-spec-types.yml

@@ -15,27 +15,35 @@ jobs:
         runs-on: ubuntu-latest
         steps:
             - name: Checkout repository
-              uses: actions/checkout@v4
+              uses: actions/checkout@v6
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              id: pnpm-install
+              with:
+                  run_install: false
 
             - name: Setup Node.js
-              uses: actions/setup-node@v4
+              uses: actions/setup-node@v6
               with:
-                  node-version: '24'
+                  node-version: 24
+                  cache: pnpm
+                  cache-dependency-path: pnpm-lock.yaml
 
             - name: Install dependencies
-              run: npm ci
+              run: pnpm install
 
             - name: Fetch latest spec types
-              run: npm run fetch:spec-types
+              run: pnpm run fetch:spec-types
 
             - name: Check for changes
               id: check_changes
               run: |
-                  if git diff --quiet src/spec.types.ts; then
+                  if git diff --quiet packages/core/src/types/spec.types.ts; then
                     echo "has_changes=false" >> $GITHUB_OUTPUT
                   else
                     echo "has_changes=true" >> $GITHUB_OUTPUT
-                    LATEST_SHA=$(grep "Last updated from commit:" src/spec.types.ts | cut -d: -f2 | tr -d ' ')
+                    LATEST_SHA=$(grep "Last updated from commit:" packages/core/src/types/spec.types.ts | cut -d: -f2 | tr -d ' ')
                     echo "sha=$LATEST_SHA" >> $GITHUB_OUTPUT
                   fi
 
@@ -48,12 +56,12 @@ jobs:
                   git config user.email "github-actions[bot]@users.noreply.github.com"
 
                   git checkout -B update-spec-types
-                  git add src/spec.types.ts
+                  git add packages/core/src/types/spec.types.ts
                   git commit -m "chore: update spec.types.ts from upstream"
                   git push -f origin update-spec-types
 
                   # Create PR if it doesn't exist, or update if it does
-                  PR_BODY="This PR updates \`src/spec.types.ts\` from the Model Context Protocol specification.
+                  PR_BODY="This PR updates \`packages/core/src/types/spec.types.ts\` from the Model Context Protocol specification.
 
                   Source file: https://github.com/modelcontextprotocol/modelcontextprotocol/blob/${{ steps.check_changes.outputs.sha }}/schema/draft/schema.ts
 

CLAUDE.md

@@ -5,14 +5,21 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 ## Build & Test Commands
 
 ```sh
-npm run build        # Build ESM and CJS versions
-npm run lint         # Run ESLint and Prettier check
-npm run lint:fix     # Auto-fix lint and formatting issues
-npm test             # Run all tests (vitest)
-npm run test:watch   # Run tests in watch mode
-npx vitest path/to/file.test.ts  # Run specific test file
-npx vitest -t "test name"        # Run tests matching pattern
-npm run typecheck    # Type-check without emitting
+pnpm install         # Install all workspace dependencies
+
+pnpm build:all       # Build all packages
+pnpm lint:all        # Run ESLint + Prettier checks across all packages
+pnpm lint:fix:all    # Auto-fix lint and formatting issues across all packages
+pnpm typecheck:all   # Type-check all packages
+pnpm test:all        # Run all tests (vitest) across all packages
+pnpm check:all       # typecheck + lint across all packages
+
+# Run a single package script (examples)
+# Run a single package script from the repo root with pnpm filter
+pnpm --filter @modelcontextprotocol/core test                # vitest run (core)
+pnpm --filter @modelcontextprotocol/core test:watch          # vitest (watch)
+pnpm --filter @modelcontextprotocol/core test -- path/to/file.test.ts
+pnpm --filter @modelcontextprotocol/core test -- -t "test name"
 ```
 
 ## Code Style Guidelines
@@ -31,64 +38,64 @@ npm run typecheck    # Type-check without emitting
 
 The SDK is organized into three main layers:
 
-1. **Types Layer** (`src/types.ts`) - Protocol types generated from the MCP specification. All JSON-RPC message types, schemas, and protocol constants are defined here using Zod v4.
+1. **Types Layer** (`packages/core/src/types/types.ts`) - Protocol types generated from the MCP specification. All JSON-RPC message types, schemas, and protocol constants are defined here using Zod v4.
 
-2. **Protocol Layer** (`src/shared/protocol.ts`) - The abstract `Protocol` class that handles JSON-RPC message routing, request/response correlation, capability negotiation, and transport management. Both `Client` and `Server` extend this class.
+2. **Protocol Layer** (`packages/core/src/shared/protocol.ts`) - The abstract `Protocol` class that handles JSON-RPC message routing, request/response correlation, capability negotiation, and transport management. Both `Client` and `Server` extend this class.
 
 3. **High-Level APIs**:
-    - `Client` (`src/client/index.ts`) - Low-level client extending Protocol with typed methods for all MCP operations
-    - `Server` (`src/server/index.ts`) - Low-level server extending Protocol with request handler registration
-    - `McpServer` (`src/server/mcp.ts`) - High-level server API with simplified resource/tool/prompt registration
+    - `Client` (`packages/client/src/client/client.ts`) - Client implementation extending Protocol with typed methods for MCP operations
+    - `Server` (`packages/server/src/server/server.ts`) - Server implementation extending Protocol with request handler registration
+    - `McpServer` (`packages/server/src/server/mcp.ts`) - High-level server API with simplified resource/tool/prompt registration
 
 ### Transport System
 
-Transports (`src/shared/transport.ts`) provide the communication layer:
+Transports (`packages/core/src/shared/transport.ts`) provide the communication layer:
 
-- **Streamable HTTP** (`src/server/streamableHttp.ts`, `src/client/streamableHttp.ts`) - Recommended transport for remote servers, supports SSE for streaming
-- **SSE** (`src/server/sse.ts`, `src/client/sse.ts`) - Legacy HTTP+SSE transport for backwards compatibility
-- **stdio** (`src/server/stdio.ts`, `src/client/stdio.ts`) - For local process-spawned integrations
+- **Streamable HTTP** (`packages/server/src/server/streamableHttp.ts`, `packages/client/src/client/streamableHttp.ts`) - Recommended transport for remote servers, supports SSE for streaming
+- **SSE** (`packages/server/src/server/sse.ts`, `packages/client/src/client/sse.ts`) - Legacy HTTP+SSE transport for backwards compatibility
+- **stdio** (`packages/server/src/server/stdio.ts`, `packages/client/src/client/stdio.ts`) - For local process-spawned integrations
 
 ### Server-Side Features
 
 - **Tools/Resources/Prompts**: Registered via `McpServer.tool()`, `.resource()`, `.prompt()` methods
-- **OAuth/Auth**: Full OAuth 2.0 server implementation in `src/server/auth/`
-- **Completions**: Auto-completion support via `src/server/completable.ts`
+- **OAuth/Auth**: Full OAuth 2.0 server implementation in `packages/server/src/server/auth/`
+- **Completions**: Auto-completion support via `packages/server/src/server/completable.ts`
 
 ### Client-Side Features
 
-- **Auth**: OAuth client support in `src/client/auth.ts` and `src/client/auth-extensions.ts`
-- **Middleware**: Request middleware in `src/client/middleware.ts`
+- **Auth**: OAuth client support in `packages/client/src/client/auth.ts` and `packages/client/src/client/auth-extensions.ts`
+- **Middleware**: Request middleware in `packages/client/src/client/middleware.ts`
 - **Sampling**: Clients can handle `sampling/createMessage` requests from servers (LLM completions)
 - **Elicitation**: Clients can handle `elicitation/create` requests for user input (form or URL mode)
 - **Roots**: Clients can expose filesystem roots to servers via `roots/list`
 
 ### Experimental Features
 
-Located in `src/experimental/`:
+Located in `packages/*/src/experimental/`:
 
-- **Tasks**: Long-running task support with polling/resumption (`src/experimental/tasks/`)
+- **Tasks**: Long-running task support with polling/resumption (`packages/core/src/experimental/tasks/`)
 
 ### Zod Compatibility
 
 The SDK uses `zod/v4` internally but supports both v3 and v4 APIs. Compatibility utilities:
 
-- `src/server/zod-compat.ts` - Schema parsing helpers that work across versions
-- `src/server/zod-json-schema-compat.ts` - Converts Zod schemas to JSON Schema
+- `packages/core/src/util/zod-compat.ts` - Schema parsing helpers that work across versions
+- `packages/core/src/util/zod-json-schema-compat.ts` - Converts Zod schemas to JSON Schema
 
 ### Validation
 
-Pluggable JSON Schema validation (`src/validation/`):
+Pluggable JSON Schema validation (`packages/core/src/validation/`):
 
 - `ajv-provider.ts` - Default Ajv-based validator
 - `cfworker-provider.ts` - Cloudflare Workers-compatible alternative
 
 ### Examples
 
-Runnable examples in `src/examples/`:
+Runnable examples in `examples/`:
 
-- `server/` - Various server configurations (stateful, stateless, OAuth, etc.)
-- `client/` - Client examples (basic, OAuth, parallel calls, etc.)
-- `shared/` - Shared utilities like in-memory event store
+- `examples/server/src/` - Various server configurations (stateful, stateless, OAuth, etc.)
+- `examples/client/src/` - Client examples (basic, OAuth, parallel calls, etc.)
+- `examples/shared/src/` - Shared utilities (OAuth demo provider, etc.)
 
 ## Message Flow (Bidirectional Protocol)
 
@@ -98,9 +105,9 @@ MCP is bidirectional: both client and server can send requests. Understanding th
 
 ```
 Protocol (abstract base)
-├── Client (src/client/index.ts)     - can send requests TO server, handle requests FROM server
-└── Server (src/server/index.ts)     - can send requests TO client, handle requests FROM client
-    └── McpServer (src/server/mcp.ts) - high-level wrapper around Server
+├── Client (packages/client/src/client/client.ts)     - can send requests TO server, handle requests FROM server
+└── Server (packages/server/src/server/server.ts)     - can send requests TO client, handle requests FROM client
+    └── McpServer (packages/server/src/server/mcp.ts) - high-level wrapper around Server
 ```
 
 ### Outbound Flow: Sending Requests