refactor(python-sdk): share the pyqwest transport plumbing with the envd RPC stack

With the envd RPC migration (#1558) on main, both stacks carried identical
copies of the transport pieces. Make e2b.api the canonical home: proxy_to_url
(with stack-neutral error messages) and the pool tuning move out of
e2b.envd.client_shared, and the flavor modules gain a shared
retrying_http_transport factory + ConnectionRetryTransport that
e2b.envd.client_sync/client_async now import instead of defining their own.
The stacks keep separate per-proxy pools (unification is a follow-up).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: mishushakov

packages/python-sdk/e2b/api/__init__.py

@@ -69,11 +69,11 @@ async def on_response(response: Response) -> None:
 
 connection_retries = int(os.getenv("E2B_CONNECTION_RETRIES") or "3")
 
-# Mirror the httpx pool tuning above with pyqwest's equivalents for the REST
-# API transports. `pool_max_idle_per_host` is per host rather than httpx's
-# global idle cap, but API traffic goes to a single host, so the values map
-# directly; reqwest has no counterpart to `E2B_MAX_CONNECTIONS` (it does not
-# cap concurrent connections).
+# Mirror the httpx pool tuning above with pyqwest's equivalents, shared by
+# the REST API and envd RPC transports. `pool_max_idle_per_host` is per host
+# rather than httpx's global idle cap, which suits both: API traffic goes to
+# a single host and each sandbox is its own host. reqwest has no counterpart
+# to `E2B_MAX_CONNECTIONS` (it does not cap concurrent connections).
 pool_idle_timeout = float(os.getenv("E2B_KEEPALIVE_EXPIRY") or "300")
 pool_max_idle_per_host = int(os.getenv("E2B_MAX_KEEPALIVE_CONNECTIONS") or "20")
 
@@ -109,9 +109,7 @@ def proxy_to_config(proxy: Optional[ProxyTypes]) -> Optional[ProxyConfig]:
         return ProxyConfig(str(proxy))
     if isinstance(proxy, httpx.Proxy):
         if proxy.ssl_context is not None:
-            raise InvalidArgumentException(
-                "E2B API calls don't support httpx.Proxy ssl_context"
-            )
+            raise InvalidArgumentException("httpx.Proxy ssl_context is not supported")
         # httpx.Proxy splits userinfo out of the URL into `.auth`; pyqwest
         # takes the credentials the same way, so they pass straight through.
         return ProxyConfig(
@@ -120,8 +118,8 @@ def proxy_to_config(proxy: Optional[ProxyTypes]) -> Optional[ProxyConfig]:
             headers=tuple(proxy.headers.items()),
         )
     raise InvalidArgumentException(
-        "E2B API calls support only URL-string, httpx.URL, and httpx.Proxy "
-        'proxies, e.g. proxy="http://user:pass@localhost:8030"'
+        "Only URL-string, httpx.URL, and httpx.Proxy proxies are supported, "
+        'e.g. proxy="http://user:pass@localhost:8030"'
     )
 
 

packages/python-sdk/e2b/api/client_async/__init__.py

@@ -53,19 +53,44 @@ async def handle_async_request(self, request: httpx.Request) -> httpx.Response:
 
 
 class ConnectionRetryTransport(RetryTransport):
-    """Retry only failures establishing the connection, matching the
-    connect-only ``retries`` of the httpx transport this replaced: pyqwest
-    raises the builtin ``ConnectionError`` only before the request was
-    written, so these retries can never replay a request the API may have
-    received. The retry middleware's default policy would otherwise also
-    retry I/O errors and 429/5xx responses for idempotent methods."""
+    """Retry only failures establishing the connection — shared by the REST
+    API and envd RPC stacks: pyqwest raises the builtin ``ConnectionError``
+    only before the request was written, so these retries can never replay a
+    request the server may have received (a delivered REST call or unary RPC
+    like ``SendInput``). This matches the connect-only ``retries`` of the
+    httpx transports this replaced; the retry middleware's default policy
+    would otherwise also retry I/O errors and 429/5xx responses for
+    idempotent methods."""
 
     def should_retry_response(
         self, request: Request, response: Union[Response, Exception]
     ) -> bool:
         return isinstance(response, ConnectionError)
 
 
+def retrying_http_transport(
+    proxy: Optional[ProxyConfig],
+) -> ConnectionRetryTransport:
+    """A fresh pyqwest transport (= its own connection pool) with the SDK's
+    shared tuning — system CA certs (without which TLS through an
+    intercepting proxy fails), the httpx-equivalent pool limits, and
+    connect-only retries. The REST API and envd RPC stacks each cache their
+    own instances (pool unification is a follow-up).
+    Requests are logged by pyqwest itself on the ``pyqwest.access`` and
+    ``pyqwest`` loggers at ``DEBUG`` (off unless enabled) — the transport-level
+    diagnostics httpcore used to provide. The SDK's own ``logger`` option is
+    separate and sits above this, on the httpx client."""
+    return ConnectionRetryTransport(
+        HTTPTransport(
+            tls_include_system_certs=True,
+            proxy=proxy.to_pyqwest() if proxy is not None else None,
+            pool_idle_timeout=pool_idle_timeout,
+            pool_max_idle_per_host=pool_max_idle_per_host,
+        ),
+        max_retries=connection_retries,
+    )
+
+
 _transport_lock = threading.Lock()
 # One transport (= one connection pool) per proxy; None is the direct pool.
 # pyqwest's I/O runs on its own Rust runtime, so unlike the httpx envd
@@ -77,27 +102,12 @@ def should_retry_response(
 def get_transport(config: ConnectionConfig) -> "AsyncApiPyqwestTransport":
     """The shared pyqwest-backed httpx transport for REST API calls. For TLS
     connections ALPN negotiates the HTTP version (HTTP/2 against the E2B
-    API), like the http2-enabled httpx transport this replaced.
-
-    Requests are logged by pyqwest itself on the ``pyqwest.access`` and
-    ``pyqwest`` loggers at ``DEBUG`` (off unless enabled) — the transport-level
-    diagnostics httpcore used to provide. The SDK's own ``logger`` option is
-    separate and sits above this, on the httpx client."""
+    API), like the http2-enabled httpx transport this replaced."""
     proxy = proxy_to_config(config.proxy)
     with _transport_lock:
         transport = _transports.get(proxy)
         if transport is None:
-            transport = AsyncApiPyqwestTransport(
-                ConnectionRetryTransport(
-                    HTTPTransport(
-                        tls_include_system_certs=True,
-                        proxy=proxy.to_pyqwest() if proxy is not None else None,
-                        pool_idle_timeout=pool_idle_timeout,
-                        pool_max_idle_per_host=pool_max_idle_per_host,
-                    ),
-                    max_retries=connection_retries,
-                )
-            )
+            transport = AsyncApiPyqwestTransport(retrying_http_transport(proxy))
             _transports[proxy] = transport
         return transport
 

packages/python-sdk/e2b/api/client_sync/__init__.py

@@ -49,19 +49,44 @@ def handle_request(self, request: httpx.Request) -> httpx.Response:
 
 
 class ConnectionRetryTransport(SyncRetryTransport):
-    """Retry only failures establishing the connection, matching the
-    connect-only ``retries`` of the httpx transport this replaced: pyqwest
-    raises the builtin ``ConnectionError`` only before the request was
-    written, so these retries can never replay a request the API may have
-    received. The retry middleware's default policy would otherwise also
-    retry I/O errors and 429/5xx responses for idempotent methods."""
+    """Retry only failures establishing the connection — shared by the REST
+    API and envd RPC stacks: pyqwest raises the builtin ``ConnectionError``
+    only before the request was written, so these retries can never replay a
+    request the server may have received (a delivered REST call or unary RPC
+    like ``SendInput``). This matches the connect-only ``retries`` of the
+    httpx transports this replaced; the retry middleware's default policy
+    would otherwise also retry I/O errors and 429/5xx responses for
+    idempotent methods."""
 
     def should_retry_response(
         self, request: SyncRequest, response: Union[SyncResponse, Exception]
     ) -> bool:
         return isinstance(response, ConnectionError)
 
 
+def retrying_http_transport(
+    proxy: Optional[ProxyConfig],
+) -> ConnectionRetryTransport:
+    """A fresh pyqwest transport (= its own connection pool) with the SDK's
+    shared tuning — system CA certs (without which TLS through an
+    intercepting proxy fails), the httpx-equivalent pool limits, and
+    connect-only retries. The REST API and envd RPC stacks each cache their
+    own instances (pool unification is a follow-up).
+    Requests are logged by pyqwest itself on the ``pyqwest.access`` and
+    ``pyqwest`` loggers at ``DEBUG`` (off unless enabled) — the transport-level
+    diagnostics httpcore used to provide. The SDK's own ``logger`` option is
+    separate and sits above this, on the httpx client."""
+    return ConnectionRetryTransport(
+        SyncHTTPTransport(
+            tls_include_system_certs=True,
+            proxy=proxy.to_pyqwest() if proxy is not None else None,
+            pool_idle_timeout=pool_idle_timeout,
+            pool_max_idle_per_host=pool_max_idle_per_host,
+        ),
+        max_retries=connection_retries,
+    )
+
+
 _transport_lock = threading.Lock()
 # One transport (= one connection pool) per proxy; None is the direct pool.
 # pyqwest transports are thread-safe, so unlike the httpx envd transports
@@ -72,27 +97,12 @@ def should_retry_response(
 def get_transport(config: ConnectionConfig) -> "ApiPyqwestTransport":
     """The shared pyqwest-backed httpx transport for REST API calls. For TLS
     connections ALPN negotiates the HTTP version (HTTP/2 against the E2B
-    API), like the http2-enabled httpx transport this replaced.
-
-    Requests are logged by pyqwest itself on the ``pyqwest.access`` and
-    ``pyqwest`` loggers at ``DEBUG`` (off unless enabled) — the transport-level
-    diagnostics httpcore used to provide. The SDK's own ``logger`` option is
-    separate and sits above this, on the httpx client."""
+    API), like the http2-enabled httpx transport this replaced."""
     proxy = proxy_to_config(config.proxy)
     with _transport_lock:
         transport = _transports.get(proxy)
         if transport is None:
-            transport = ApiPyqwestTransport(
-                ConnectionRetryTransport(
-                    SyncHTTPTransport(
-                        tls_include_system_certs=True,
-                        proxy=proxy.to_pyqwest() if proxy is not None else None,
-                        pool_idle_timeout=pool_idle_timeout,
-                        pool_max_idle_per_host=pool_max_idle_per_host,
-                    ),
-                    max_retries=connection_retries,
-                )
-            )
+            transport = ApiPyqwestTransport(retrying_http_transport(proxy))
             _transports[proxy] = transport
         return transport
 

packages/python-sdk/e2b/envd/client_async/__init__.py

@@ -9,25 +9,20 @@
     Callable,
     Optional,
     TypeVar,
-    Union,
     cast,
 )
 
 from connectrpc.code import Code
 from connectrpc.errors import ConnectError
-from pyqwest import Client, HTTPTransport, Request, Response, Transport
-from pyqwest.middleware.retry import RetryTransport
+from pyqwest import Client, Request, Response, Transport
 
-from e2b.api import connection_retries
+from e2b.api import ProxyConfig, proxy_to_config
+from e2b.api.client_async import retrying_http_transport
 from e2b.connection_config import ConnectionConfig
 from e2b.envd.client_shared import (
     ENVD_JSON_CODEC,
     ENVD_RPC_COMPRESSION,
     plain_http_error,
-    pool_idle_timeout,
-    pool_max_idle_per_host,
-    proxy_to_url,
-    should_retry_connection,
 )
 from e2b.envd.interceptors import build_interceptors
 from e2b.exceptions import TimeoutException
@@ -37,7 +32,7 @@
 
 _transport_lock = threading.Lock()
 # One transport (= one connection pool) per proxy; None is the direct pool.
-_transports: dict[Optional[str], "PlainHTTPErrorTransport"] = {}
+_transports: dict[Optional[ProxyConfig], "PlainHTTPErrorTransport"] = {}
 
 
 class PlainHTTPErrorTransport:
@@ -70,37 +65,16 @@ async def execute(self, request: Request) -> Response:
         raise error
 
 
-class ConnectionRetryTransport(RetryTransport):
-    """Retry only failures establishing the connection; see
-    :func:`e2b.envd.client_shared.should_retry_connection` for the policy
-    rationale."""
-
-    def should_retry_response(
-        self, request: Request, response: Union[Response, Exception]
-    ) -> bool:
-        return should_retry_connection(response)
-
-
-def get_transport(proxy_url: Optional[str]) -> "PlainHTTPErrorTransport":
+def get_transport(proxy: Optional[ProxyConfig]) -> "PlainHTTPErrorTransport":
     with _transport_lock:
-        transport = _transports.get(proxy_url)
+        transport = _transports.get(proxy)
         if transport is None:
             # connectrpc arms the per-call deadline around the transport, so
             # retry backoff counts against the request timeout. The plain-
             # error normalization sits outside the retries so it converts
             # the settled response once.
-            transport = PlainHTTPErrorTransport(
-                ConnectionRetryTransport(
-                    HTTPTransport(
-                        tls_include_system_certs=True,
-                        proxy=proxy_url,
-                        pool_idle_timeout=pool_idle_timeout,
-                        pool_max_idle_per_host=pool_max_idle_per_host,
-                    ),
-                    max_retries=connection_retries,
-                )
-            )
-            _transports[proxy_url] = transport
+            transport = PlainHTTPErrorTransport(retrying_http_transport(proxy))
+            _transports[proxy] = transport
         return transport
 
 
@@ -111,11 +85,11 @@ def create_rpc_client(
 ) -> TClient:
     """Build a generated async connectrpc client (e.g. ``ProcessClient``)
     wired with the shared pyqwest transport (which retries failed connects,
-    see :class:`ConnectionRetryTransport`), the envd JSON codec, and the
-    SDK's default-header and logging interceptors. Compression is disabled
-    (see ``ENVD_RPC_COMPRESSION``).
+    see :class:`e2b.api.client_async.ConnectionRetryTransport`), the envd
+    JSON codec, and the SDK's default-header and logging interceptors.
+    Compression is disabled (see ``ENVD_RPC_COMPRESSION``).
     """
-    http_client = Client(get_transport(proxy_to_url(config.proxy)))
+    http_client = Client(get_transport(proxy_to_config(config.proxy)))
     return client_cls(
         base_url,
         codec=ENVD_JSON_CODEC,