Merge branch 'main' into fix-hang-github-mcp

Author: sicoyle

.github/workflows/shared.yml

@@ -70,6 +70,7 @@ jobs:
       - name: Run pytest with coverage
         shell: bash
         run: |
+          uv run --frozen --no-sync coverage erase
           uv run --frozen --no-sync coverage run -m pytest -n auto
           uv run --frozen --no-sync coverage combine
           uv run --frozen --no-sync coverage report

.github/workflows/weekly-lockfile-update.yml

@@ -32,6 +32,7 @@ jobs:
         uses: peter-evans/create-pull-request@c0f553fe549906ede9cf27b5156039d195d2ece0 # v7
         with:
           commit-message: "chore: update uv.lock with latest dependencies"
+          sign-commits: true
           title: "chore: weekly dependency update"
           body-path: pr_body.md
           branch: weekly-lockfile-update

CLAUDE.md

@@ -28,9 +28,19 @@ This document contains critical information about working with this codebase. Fo
    - Bug fixes require regression tests
    - IMPORTANT: The `tests/client/test_client.py` is the most well designed test file. Follow its patterns.
    - IMPORTANT: Be minimal, and focus on E2E tests: Use the `mcp.client.Client` whenever possible.
-   - IMPORTANT: Before pushing, verify 100% branch coverage on changed files by running
-     `uv run --frozen pytest -x` (coverage is configured in `pyproject.toml` with `fail_under = 100`
-     and `branch = true`). If any branch is uncovered, add a test for it before pushing.
+   - Coverage: CI requires 100% (`fail_under = 100`, `branch = true`).
+     - Full check: `./scripts/test` (~20s, matches CI exactly)
+     - Targeted check while iterating:
+
+       ```bash
+       uv run --frozen coverage erase
+       uv run --frozen coverage run -m pytest tests/path/test_foo.py
+       uv run --frozen coverage combine
+       uv run --frozen coverage report --include='src/mcp/path/foo.py' --fail-under=0
+       ```
+
+       Partial runs can't hit 100% (coverage tracks `tests/` too), so `--fail-under=0`
+       and `--include` scope the report to what you actually changed.
    - Avoid `anyio.sleep()` with a fixed duration to wait for async operations. Instead:
      - Use `anyio.Event` — set it in the callback/handler, `await event.wait()` in the test
      - For stream messages, use `await stream.receive()` instead of `sleep()` + `receive_nowait()`

README.v2.md

@@ -346,13 +346,12 @@ Tools can optionally receive a Context object by including a parameter with the
 <!-- snippet-source examples/snippets/servers/tool_progress.py -->
 ```python
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 
 mcp = MCPServer(name="Progress Example")
 
 
 @mcp.tool()
-async def long_running_task(task_name: str, ctx: Context[ServerSession, None], steps: int = 5) -> str:
+async def long_running_task(task_name: str, ctx: Context, steps: int = 5) -> str:
     """Execute a task with progress updates."""
     await ctx.info(f"Starting: {task_name}")
 
@@ -694,13 +693,12 @@ The Context object provides the following capabilities:
 <!-- snippet-source examples/snippets/servers/tool_progress.py -->
 ```python
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 
 mcp = MCPServer(name="Progress Example")
 
 
 @mcp.tool()
-async def long_running_task(task_name: str, ctx: Context[ServerSession, None], steps: int = 5) -> str:
+async def long_running_task(task_name: str, ctx: Context, steps: int = 5) -> str:
     """Execute a task with progress updates."""
     await ctx.info(f"Starting: {task_name}")
 
@@ -826,7 +824,6 @@ import uuid
 from pydantic import BaseModel, Field
 
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 from mcp.shared.exceptions import UrlElicitationRequiredError
 from mcp.types import ElicitRequestURLParams
 
@@ -844,7 +841,7 @@ class BookingPreferences(BaseModel):
 
 
 @mcp.tool()
-async def book_table(date: str, time: str, party_size: int, ctx: Context[ServerSession, None]) -> str:
+async def book_table(date: str, time: str, party_size: int, ctx: Context) -> str:
     """Book a table with date availability check.
 
     This demonstrates form mode elicitation for collecting non-sensitive user input.
@@ -868,7 +865,7 @@ async def book_table(date: str, time: str, party_size: int, ctx: Context[ServerS
 
 
 @mcp.tool()
-async def secure_payment(amount: float, ctx: Context[ServerSession, None]) -> str:
+async def secure_payment(amount: float, ctx: Context) -> str:
     """Process a secure payment requiring URL confirmation.
 
     This demonstrates URL mode elicitation using ctx.elicit_url() for
@@ -892,7 +889,7 @@ async def secure_payment(amount: float, ctx: Context[ServerSession, None]) -> st
 
 
 @mcp.tool()
-async def connect_service(service_name: str, ctx: Context[ServerSession, None]) -> str:
+async def connect_service(service_name: str, ctx: Context) -> str:
     """Connect to a third-party service requiring OAuth authorization.
 
     This demonstrates the "throw error" pattern using UrlElicitationRequiredError.
@@ -933,14 +930,13 @@ Tools can interact with LLMs through sampling (generating text):
 <!-- snippet-source examples/snippets/servers/sampling.py -->
 ```python
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 from mcp.types import SamplingMessage, TextContent
 
 mcp = MCPServer(name="Sampling Example")
 
 
 @mcp.tool()
-async def generate_poem(topic: str, ctx: Context[ServerSession, None]) -> str:
+async def generate_poem(topic: str, ctx: Context) -> str:
     """Generate a poem using LLM sampling."""
     prompt = f"Write a short poem about {topic}"
 
@@ -970,13 +966,12 @@ Tools can send logs and notifications through the context:
 <!-- snippet-source examples/snippets/servers/notifications.py -->
 ```python
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 
 mcp = MCPServer(name="Notifications Example")
 
 
 @mcp.tool()
-async def process_data(data: str, ctx: Context[ServerSession, None]) -> str:
+async def process_data(data: str, ctx: Context) -> str:
     """Process data with logging."""
     # Different log levels
     await ctx.debug(f"Debug: Processing '{data}'")

docs/experimental/tasks-server.md

@@ -408,16 +408,10 @@ For custom error messages, call `task.fail()` before raising.
 For web applications, use the Streamable HTTP transport:
 
 ```python
-from collections.abc import AsyncIterator
-from contextlib import asynccontextmanager
-
 import uvicorn
-from starlette.applications import Starlette
-from starlette.routing import Mount
 
 from mcp.server import Server
 from mcp.server.experimental.task_context import ServerTaskContext
-from mcp.server.streamable_http_manager import StreamableHTTPSessionManager
 from mcp.types import (
     CallToolResult, CreateTaskResult, TextContent, Tool, ToolExecution, TASK_REQUIRED,
 )
@@ -462,22 +456,8 @@ async def handle_tool(name: str, arguments: dict) -> CallToolResult | CreateTask
     return CallToolResult(content=[TextContent(type="text", text=f"Unknown: {name}")], isError=True)
 
 
-def create_app():
-    session_manager = StreamableHTTPSessionManager(app=server)
-
-    @asynccontextmanager
-    async def lifespan(app: Starlette) -> AsyncIterator[None]:
-        async with session_manager.run():
-            yield
-
-    return Starlette(
-        routes=[Mount("/mcp", app=session_manager.handle_request)],
-        lifespan=lifespan,
-    )
-
-
 if __name__ == "__main__":
-    uvicorn.run(create_app(), host="127.0.0.1", port=8000)
+    uvicorn.run(server.streamable_http_app(), host="127.0.0.1", port=8000)
 ```
 
 ## Testing Task Servers

docs/migration.md

@@ -288,6 +288,37 @@ app = Starlette(routes=[Mount("/", app=mcp.streamable_http_app(json_response=Tru
 
 **Note:** DNS rebinding protection is automatically enabled when `host` is `127.0.0.1`, `localhost`, or `::1`. This now happens in `sse_app()` and `streamable_http_app()` instead of the constructor.
 
+### `MCPServer.get_context()` removed
+
+`MCPServer.get_context()` has been removed. Context is now injected by the framework and passed explicitly — there is no ambient ContextVar to read from.
+
+**If you were calling `get_context()` from inside a tool/resource/prompt:** use the `ctx: Context` parameter injection instead.
+
+**Before (v1):**
+
+```python
+@mcp.tool()
+async def my_tool(x: int) -> str:
+    ctx = mcp.get_context()
+    await ctx.info("Processing...")
+    return str(x)
+```
+
+**After (v2):**
+
+```python
+@mcp.tool()
+async def my_tool(x: int, ctx: Context) -> str:
+    await ctx.info("Processing...")
+    return str(x)
+```
+
+### `MCPServer.call_tool()`, `read_resource()`, `get_prompt()` now accept a `context` parameter
+
+`MCPServer.call_tool()`, `MCPServer.read_resource()`, and `MCPServer.get_prompt()` now accept an optional `context: Context | None = None` parameter. The framework passes this automatically during normal request handling. If you call these methods directly and omit `context`, a Context with no active request is constructed for you — tools that don't use `ctx` work normally, but any attempt to use `ctx.session`, `ctx.request_id`, etc. will raise.
+
+The internal layers (`ToolManager.call_tool`, `Tool.run`, `Prompt.render`, `ResourceTemplate.create_resource`, etc.) now require `context` as a positional argument.
+
 ### Replace `RootModel` by union types with `TypeAdapter` validation
 
 The following union types are no longer `RootModel` subclasses:
@@ -694,7 +725,7 @@ If you prefer the convenience of automatic wrapping, use `MCPServer` which still
 
 ### Lowlevel `Server`: `request_context` property removed
 
-The `server.request_context` property has been removed. Request context is now passed directly to handlers as the first argument (`ctx`). The `request_ctx` module-level contextvar is now an internal implementation detail and should not be relied upon.
+The `server.request_context` property has been removed. Request context is now passed directly to handlers as the first argument (`ctx`). The `request_ctx` module-level contextvar has been removed entirely.
 
 **Before (v1):**
 

examples/servers/everything-server/mcp_everything_server/server.py

@@ -13,7 +13,6 @@
 from mcp.server import ServerRequestContext
 from mcp.server.mcpserver import Context, MCPServer
 from mcp.server.mcpserver.prompts.base import UserMessage
-from mcp.server.session import ServerSession
 from mcp.server.streamable_http import EventCallback, EventMessage, EventStore
 from mcp.types import (
     AudioContent,
@@ -142,7 +141,7 @@ def test_multiple_content_types() -> list[TextContent | ImageContent | EmbeddedR
 
 
 @mcp.tool()
-async def test_tool_with_logging(ctx: Context[ServerSession, None]) -> str:
+async def test_tool_with_logging(ctx: Context) -> str:
     """Tests tool that emits log messages during execution"""
     await ctx.info("Tool execution started")
     await asyncio.sleep(0.05)
@@ -155,7 +154,7 @@ async def test_tool_with_logging(ctx: Context[ServerSession, None]) -> str:
 
 
 @mcp.tool()
-async def test_tool_with_progress(ctx: Context[ServerSession, None]) -> str:
+async def test_tool_with_progress(ctx: Context) -> str:
     """Tests tool that reports progress notifications"""
     await ctx.report_progress(progress=0, total=100, message="Completed step 0 of 100")
     await asyncio.sleep(0.05)
@@ -173,7 +172,7 @@ async def test_tool_with_progress(ctx: Context[ServerSession, None]) -> str:
 
 
 @mcp.tool()
-async def test_sampling(prompt: str, ctx: Context[ServerSession, None]) -> str:
+async def test_sampling(prompt: str, ctx: Context) -> str:
     """Tests server-initiated sampling (LLM completion request)"""
     try:
         # Request sampling from client
@@ -198,7 +197,7 @@ class UserResponse(BaseModel):
 
 
 @mcp.tool()
-async def test_elicitation(message: str, ctx: Context[ServerSession, None]) -> str:
+async def test_elicitation(message: str, ctx: Context) -> str:
     """Tests server-initiated elicitation (user input request)"""
     try:
         # Request user input from client
@@ -230,7 +229,7 @@ class SEP1034DefaultsSchema(BaseModel):
 
 
 @mcp.tool()
-async def test_elicitation_sep1034_defaults(ctx: Context[ServerSession, None]) -> str:
+async def test_elicitation_sep1034_defaults(ctx: Context) -> str:
     """Tests elicitation with default values for all primitive types (SEP-1034)"""
     try:
         # Request user input with defaults for all primitive types
@@ -289,7 +288,7 @@ class EnumSchemasTestSchema(BaseModel):
 
 
 @mcp.tool()
-async def test_elicitation_sep1330_enums(ctx: Context[ServerSession, None]) -> str:
+async def test_elicitation_sep1330_enums(ctx: Context) -> str:
     """Tests elicitation with enum schema variations per SEP-1330"""
     try:
         result = await ctx.elicit(
@@ -313,7 +312,7 @@ def test_error_handling() -> str:
 
 
 @mcp.tool()
-async def test_reconnection(ctx: Context[ServerSession, None]) -> str:
+async def test_reconnection(ctx: Context) -> str:
     """Tests SSE polling by closing stream mid-call (SEP-1699)"""
     await ctx.info("Before disconnect")
 

examples/servers/simple-pagination/README.md

@@ -4,14 +4,14 @@ A simple MCP server demonstrating pagination for tools, resources, and prompts u
 
 ## Usage
 
-Start the server using either stdio (default) or SSE transport:
+Start the server using either stdio (default) or Streamable HTTP transport:
 
 ```bash
 # Using stdio transport (default)
 uv run mcp-simple-pagination
 
-# Using SSE transport on custom port
-uv run mcp-simple-pagination --transport sse --port 8000
+# Using Streamable HTTP transport on custom port
+uv run mcp-simple-pagination --transport streamable-http --port 8000
 ```
 
 The server exposes:

examples/servers/simple-pagination/mcp_simple_pagination/server.py

@@ -10,7 +10,6 @@
 import click
 from mcp import types
 from mcp.server import Server, ServerRequestContext
-from starlette.requests import Request
 
 T = TypeVar("T")
 
@@ -143,10 +142,10 @@ async def handle_get_prompt(ctx: ServerRequestContext, params: types.GetPromptRe
 
 
 @click.command()
-@click.option("--port", default=8000, help="Port to listen on for SSE")
+@click.option("--port", default=8000, help="Port to listen on for HTTP")
 @click.option(
     "--transport",
-    type=click.Choice(["stdio", "sse"]),
+    type=click.Choice(["stdio", "streamable-http"]),
     default="stdio",
     help="Transport type",
 )
@@ -161,30 +160,10 @@ def main(port: int, transport: str) -> int:
         on_get_prompt=handle_get_prompt,
     )
 
-    if transport == "sse":
-        from mcp.server.sse import SseServerTransport
-        from starlette.applications import Starlette
-        from starlette.responses import Response
-        from starlette.routing import Mount, Route
-
-        sse = SseServerTransport("/messages/")
-
-        async def handle_sse(request: Request):
-            async with sse.connect_sse(request.scope, request.receive, request._send) as streams:  # type: ignore[reportPrivateUsage]
-                await app.run(streams[0], streams[1], app.create_initialization_options())
-            return Response()
-
-        starlette_app = Starlette(
-            debug=True,
-            routes=[
-                Route("/sse", endpoint=handle_sse, methods=["GET"]),
-                Mount("/messages/", app=sse.handle_post_message),
-            ],
-        )
-
+    if transport == "streamable-http":
         import uvicorn
 
-        uvicorn.run(starlette_app, host="127.0.0.1", port=port)
+        uvicorn.run(app.streamable_http_app(), host="127.0.0.1", port=port)
     else:
         from mcp.server.stdio import stdio_server
 

examples/servers/simple-prompt/README.md

@@ -4,14 +4,14 @@ A simple MCP server that exposes a customizable prompt template with optional co
 
 ## Usage
 
-Start the server using either stdio (default) or SSE transport:
+Start the server using either stdio (default) or Streamable HTTP transport:
 
 ```bash
 # Using stdio transport (default)
 uv run mcp-simple-prompt
 
-# Using SSE transport on custom port
-uv run mcp-simple-prompt --transport sse --port 8000
+# Using Streamable HTTP transport on custom port
+uv run mcp-simple-prompt --transport streamable-http --port 8000
 ```
 
 The server exposes a prompt named "simple" that accepts two optional arguments: