Replace httpx and httpx-sse with httpx2 (#2972)

Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com>

examples/clients/simple-auth-client/mcp_simple_auth_client/main.py

@@ -17,7 +17,7 @@ from http.server import BaseHTTPRequestHandler, HTTPServer
 from typing import Any
 from urllib.parse import parse_qs, urlparse
 
-import httpx
+import httpx2
 from mcp.client._transport import ReadStream, WriteStream
 from mcp.client.auth import AuthorizationCodeResult, OAuthClientProvider, TokenStorage
 from mcp.client.session import ClientSession
@@ -233,7 +233,7 @@ class SimpleAuthClient:
                     await self._run_session(read_stream, write_stream)
             else:
                 print("📡 Opening StreamableHTTP transport connection with auth...")
-                async with httpx.AsyncClient(auth=oauth_auth, follow_redirects=True) as custom_client:
+                async with httpx2.AsyncClient(auth=oauth_auth, follow_redirects=True) as custom_client:
                     async with streamable_http_client(url=self.server_url, http_client=custom_client) as (
                         read_stream,
                         write_stream,

examples/clients/simple-chatbot/mcp_simple_chatbot/main.py

@@ -8,7 +8,7 @@ import shutil
 from contextlib import AsyncExitStack
 from typing import Any
 
-import httpx
+import httpx2
 from dotenv import load_dotenv
 from mcp import ClientSession, StdioServerParameters
 from mcp.client.stdio import stdio_client
@@ -227,10 +227,7 @@ class LLMClient:
             messages: A list of message dictionaries.
 
         Returns:
-            The LLM's response as a string.
-
-        Raises:
-            httpx.RequestError: If the request to the LLM fails.
+            The LLM's response as a string, or an error message if the request fails.
         """
         url = "https://api.groq.com/openai/v1/chat/completions"
 
@@ -249,17 +246,17 @@ class LLMClient:
         }
 
         try:
-            with httpx.Client() as client:
+            with httpx2.Client() as client:
                 response = client.post(url, headers=headers, json=payload)
                 response.raise_for_status()
                 data = response.json()
                 return data["choices"][0]["message"]["content"]
 
-        except httpx.RequestError as e:
+        except httpx2.HTTPError as e:
             error_message = f"Error getting LLM response: {str(e)}"
             logging.error(error_message)
 
-            if isinstance(e, httpx.HTTPStatusError):
+            if isinstance(e, httpx2.HTTPStatusError):
                 status_code = e.response.status_code
                 logging.error(f"Status code: {status_code}")
                 logging.error(f"Response details: {e.response.text}")

examples/clients/sse-polling-client/mcp_sse_polling_client/main.py

@@ -92,8 +92,8 @@ def main(url: str, items: int, checkpoint_every: int, log_level: str) -> None:
         format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
     )
     # Suppress noisy HTTP client logging
-    logging.getLogger("httpx").setLevel(logging.WARNING)
-    logging.getLogger("httpcore").setLevel(logging.WARNING)
+    logging.getLogger("httpx2").setLevel(logging.WARNING)
+    logging.getLogger("httpcore2").setLevel(logging.WARNING)
 
     asyncio.run(run_demo(url, items, checkpoint_every))
 

examples/mcpserver/text_me.py

@@ -19,7 +19,7 @@ Visit https://surgemsg.com/ and click "Get Started" to obtain these values.
 
 from typing import Annotated
 
-import httpx
+import httpx2
 from pydantic import BeforeValidator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
@@ -44,7 +44,7 @@ surge_settings = SurgeSettings()  # type: ignore
 @mcp.tool(name="textme", description="Send a text message to me")
 def text_me(text_content: str) -> str:
     """Send a text message to a phone number via https://surgemsg.com/"""
-    with httpx.Client() as client:
+    with httpx2.Client() as client:
         response = client.post(
             "https://api.surgemsg.com/messages",
             headers={

examples/servers/everything-server/pyproject.toml

@@ -7,7 +7,7 @@ requires-python = ">=3.10"
 authors = [{ name = "Model Context Protocol a Series of LF Projects, LLC." }]
 keywords = ["mcp", "llm", "automation", "conformance", "testing"]
 license = { text = "MIT" }
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp", "starlette", "uvicorn"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp", "starlette", "uvicorn"]
 
 [project.scripts]
 mcp-everything-server = "mcp_everything_server.server:main"

examples/servers/simple-auth/mcp_simple_auth/token_verifier.py

@@ -33,7 +33,7 @@ class IntrospectionTokenVerifier(TokenVerifier):
 
     async def verify_token(self, token: str) -> AccessToken | None:
         """Verify token via introspection endpoint."""
-        import httpx
+        import httpx2
 
         # Validate URL to prevent SSRF attacks
         if not self.introspection_endpoint.startswith(("https://", "http://localhost", "http://127.0.0.1")):
@@ -41,10 +41,10 @@ class IntrospectionTokenVerifier(TokenVerifier):
             return None
 
         # Configure secure HTTP client
-        timeout = httpx.Timeout(10.0, connect=5.0)
-        limits = httpx.Limits(max_connections=10, max_keepalive_connections=5)
+        timeout = httpx2.Timeout(10.0, connect=5.0)
+        limits = httpx2.Limits(max_connections=10, max_keepalive_connections=5)
 
-        async with httpx.AsyncClient(
+        async with httpx2.AsyncClient(
             timeout=timeout,
             limits=limits,
             verify=True,  # Enforce SSL verification

examples/servers/simple-auth/pyproject.toml

@@ -9,7 +9,7 @@ license = { text = "MIT" }
 dependencies = [
     "anyio>=4.5",
     "click>=8.2.0",
-    "httpx>=0.27",
+    "httpx2>=2.5.0",
     "mcp",
     "pydantic>=2.0",
     "pydantic-settings>=2.5.2",

examples/servers/simple-pagination/pyproject.toml

@@ -14,7 +14,7 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.10",
 ]
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp"]
 
 [project.scripts]
 mcp-simple-pagination = "mcp_simple_pagination.server:main"

examples/servers/simple-prompt/pyproject.toml

@@ -14,7 +14,7 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.10",
 ]
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp"]
 
 [project.scripts]
 mcp-simple-prompt = "mcp_simple_prompt.server:main"

examples/servers/simple-resource/pyproject.toml

@@ -14,7 +14,7 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.10",
 ]
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp"]
 
 [project.scripts]
 mcp-simple-resource = "mcp_simple_resource.server:main"

examples/servers/simple-streamablehttp-stateless/pyproject.toml

@@ -7,7 +7,7 @@ requires-python = ">=3.10"
 authors = [{ name = "Model Context Protocol a Series of LF Projects, LLC." }]
 keywords = ["mcp", "llm", "automation", "web", "fetch", "http", "streamable", "stateless"]
 license = { text = "MIT" }
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp", "starlette", "uvicorn"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp", "starlette", "uvicorn"]
 
 [project.scripts]
 mcp-simple-streamablehttp-stateless = "mcp_simple_streamablehttp_stateless.server:main"

examples/servers/simple-streamablehttp/pyproject.toml

@@ -7,7 +7,7 @@ requires-python = ">=3.10"
 authors = [{ name = "Model Context Protocol a Series of LF Projects, LLC." }]
 keywords = ["mcp", "llm", "automation", "web", "fetch", "http", "streamable"]
 license = { text = "MIT" }
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp", "starlette", "uvicorn"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp", "starlette", "uvicorn"]
 
 [project.scripts]
 mcp-simple-streamablehttp = "mcp_simple_streamablehttp.server:main"

examples/servers/simple-tool/pyproject.toml

@@ -14,7 +14,7 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.10",
 ]
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp"]
 
 [project.scripts]
 mcp-simple-tool = "mcp_simple_tool.server:main"

examples/servers/sse-polling-demo/pyproject.toml

@@ -7,7 +7,7 @@ requires-python = ">=3.10"
 authors = [{ name = "Model Context Protocol a Series of LF Projects, LLC." }]
 keywords = ["mcp", "sse", "polling", "streamable", "http"]
 license = { text = "MIT" }
-dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp", "starlette", "uvicorn"]
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx2>=2.5.0", "mcp", "starlette", "uvicorn"]
 
 [project.scripts]
 mcp-sse-polling-demo = "mcp_sse_polling_demo.server:main"

examples/snippets/clients/identity_assertion_client.py

@@ -16,7 +16,7 @@ to use.
 
 import asyncio
 
-import httpx
+import httpx2
 
 from mcp import ClientSession
 from mcp.client.auth.extensions.identity_assertion import IdentityAssertionOAuthProvider
@@ -66,7 +66,7 @@ async def main() -> None:
         scope="user",
     )
 
-    async with httpx.AsyncClient(auth=oauth_auth, follow_redirects=True) as http_client:
+    async with httpx2.AsyncClient(auth=oauth_auth, follow_redirects=True) as http_client:
         async with streamable_http_client("http://localhost:8001/mcp", http_client=http_client) as (read, write):
             async with ClientSession(read, write) as session:
                 await session.initialize()

examples/snippets/clients/oauth_client.py

@@ -9,7 +9,7 @@ cd to the `examples/snippets` directory and run:
 import asyncio
 from urllib.parse import parse_qs, urlparse
 
-import httpx
+import httpx2
 from pydantic import AnyUrl
 
 from mcp import ClientSession
@@ -72,7 +72,7 @@ async def main():
         callback_handler=handle_callback,
     )
 
-    async with httpx.AsyncClient(auth=oauth_auth, follow_redirects=True) as custom_client:
+    async with httpx2.AsyncClient(auth=oauth_auth, follow_redirects=True) as custom_client:
         async with streamable_http_client("http://localhost:8001/mcp", http_client=custom_client) as (read, write):
             async with ClientSession(read, write) as session:
                 await session.initialize()

examples/stories/_harness.py

@@ -18,7 +18,7 @@ from typing import Any, TypeAlias
 from urllib.parse import urlsplit
 
 import anyio
-import httpx
+import httpx2
 from mcp_types.version import LATEST_MODERN_VERSION
 
 from mcp import StdioServerParameters, stdio_client
@@ -38,8 +38,8 @@ Target: TypeAlias = "Server[Any] | MCPServer | Transport | str"
 TargetFactory = Callable[[], Target]
 """Yields a FRESH target against the same server/app on every call (``multi_connection`` stories)."""
 
-AuthBuilder = Callable[[httpx.AsyncClient], httpx.Auth]
-"""Builds an ``httpx.Auth`` bound to the in-process HTTP client (auth-story harness seam)."""
+AuthBuilder = Callable[[httpx2.AsyncClient], httpx2.Auth]
+"""Builds an ``httpx2.Auth`` bound to the in-process HTTP client (auth-story harness seam)."""
 
 
 def argv_after(flag: str, *, default: str | None = None) -> str:
@@ -127,8 +127,8 @@ def _story_cfg(name: str) -> dict[str, Any]:
     return manifest["defaults"] | manifest["story"].get(name, {})
 
 
-def _authed_targets(url: str, http: httpx.AsyncClient) -> TargetFactory:
-    """Fresh streamable-HTTP transports over an already-authed ``httpx`` client."""
+def _authed_targets(url: str, http: httpx2.AsyncClient) -> TargetFactory:
+    """Fresh streamable-HTTP transports over an already-authed ``httpx2`` client."""
     return lambda: streamable_http_client(url, http_client=http)
 
 
@@ -176,13 +176,13 @@ def run_client(main: Callable[..., Awaitable[None]]) -> None:
                 if url is None or (build_auth is None and not cfg["needs_http"]):
                     await main(targets if cfg["multi_connection"] else targets(), mode=mode)
                     return
-                # Auth and needs_http stories want the raw httpx client underneath the transport:
-                # build_auth threads an httpx.Auth onto it (Client(url, auth=...) doesn't exist
+                # Auth and needs_http stories want the raw httpx2 client underneath the transport:
+                # build_auth threads an httpx2.Auth onto it (Client(url, auth=...) doesn't exist
                 # yet), and needs_http stories assert on raw responses, so root the client at the
                 # server origin and relative paths like "/mcp" resolve.
                 parts = urlsplit(url)
                 base = f"{parts.scheme}://{parts.netloc}"
-                http = await stack.enter_async_context(httpx.AsyncClient(base_url=base))
+                http = await stack.enter_async_context(httpx2.AsyncClient(base_url=base))
                 make = targets
                 if build_auth is not None:
                     http.auth = build_auth(http)

examples/stories/_hosting.py

@@ -25,7 +25,7 @@ ServerFactory = Callable[[], AnyServer]
 AppFactory = Callable[[], Starlette]
 
 NO_DNS_REBIND = TransportSecuritySettings(enable_dns_rebinding_protection=False)
-"""Harness servers bind 127.0.0.1 and the in-process httpx client sends no Origin header."""
+"""Harness servers bind 127.0.0.1 and the in-process httpx2 client sends no Origin header."""
 
 
 def argv_after(flag: str, *, default: str | None = None) -> str:

examples/stories/_shared/auth.py

@@ -10,7 +10,7 @@ import secrets
 import time
 from urllib.parse import parse_qs, urlsplit
 
-import httpx
+import httpx2
 from pydantic import AnyHttpUrl
 
 from mcp.server.auth.provider import (
@@ -49,14 +49,14 @@ class InMemoryTokenStorage:
 
 
 class HeadlessOAuth:
-    """Completes the authorize redirect in-process via the bound ``httpx`` client."""
+    """Completes the authorize redirect in-process via the bound ``httpx2`` client."""
 
     def __init__(self) -> None:
         self.authorize_url: str | None = None
-        self._http: httpx.AsyncClient | None = None
+        self._http: httpx2.AsyncClient | None = None
         self._result = AuthorizationCodeResult(code="", state=None)
 
-    def bind(self, http_client: httpx.AsyncClient) -> None:
+    def bind(self, http_client: httpx2.AsyncClient) -> None:
         self._http = http_client
 
     async def redirect_handler(self, authorization_url: str) -> None:

examples/stories/bearer_auth/README.md

@@ -31,7 +31,7 @@ uv run python -m stories.bearer_auth.client --http http://127.0.0.1:8000/mcp
 `Client(url)` has no `auth=` passthrough, so a target built from a bare URL
 can't carry the token. Both runners close that gap the same way: `run_client`
 (above) and the pytest harness thread the module's `build_auth` export onto the
-`httpx.AsyncClient` underneath the transport and hand `main` a target that is
+`httpx2.AsyncClient` underneath the transport and hand `main` a target that is
 already routed through it.
 
 ## Try it without the SDK client
@@ -56,9 +56,9 @@ kill "$SERVER_PID"
   transport that already carries the bearer token; nothing in the body knows
   auth exists.
 - `client.py` `build_auth` / `StaticBearerAuth` — bearer auth client-side is
-  five lines of `httpx.Auth`. `Client(url, auth=...)` is the ergonomic the SDK
+  five lines of `httpx2.Auth`. `Client(url, auth=...)` is the ergonomic the SDK
   is missing; until it lands, the auth has to be threaded onto the
-  `httpx.AsyncClient` underneath the transport, outside `main`.
+  `httpx2.AsyncClient` underneath the transport, outside `main`.
 - `server.py` — `MCPServer(token_verifier=..., auth=AuthSettings(...))` is the
   whole recipe; `streamable_http_app()` reads those constructor kwargs and
   mounts the bearer gate + PRM route.
@@ -73,7 +73,7 @@ kill "$SERVER_PID"
 ## Caveats
 
 - `transport_security=NO_DNS_REBIND` — DNS-rebinding protection is on by default
-  for localhost binds; the harness disables it because the in-process httpx
+  for localhost binds; the harness disables it because the in-process httpx2
   client sends no `Origin` header. Drop the kwarg for a real deployment.
 - `RESOURCE_URL` is hard-coded to port 8000 (the harness's in-process origin).
   If you change `--port`, edit `RESOURCE_URL` to match or the PRM document's