BREAKING: ble and serial dependencies are optional

Use [ble], [serial], or [all] to enable the transports that
are required.

Existing projects are encouraged to use [all] to minimize
migration friction.

Author: JPHutchins

.github/workflows/test.yaml

@@ -35,6 +35,56 @@ jobs:
             dist/*.tar.gz
             dist/*.whl
 
+  transport-extras:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - name: no-extras
+            extras: ""
+            expect-serial: fail
+            expect-ble: fail
+          - name: serial-only
+            extras: "[serial]"
+            expect-serial: pass
+            expect-ble: fail
+          - name: ble-only
+            extras: "[ble]"
+            expect-serial: fail
+            expect-ble: pass
+          - name: all
+            extras: "[all]"
+            expect-serial: pass
+            expect-ble: pass
+    name: transport-extras (${{ matrix.name }})
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: astral-sh/setup-uv@v6
+
+      - run: uv venv && uv pip install .${{ matrix.extras }}
+
+      - name: serial transport should ${{ matrix.expect-serial }}
+        run: |
+          if [ "${{ matrix.expect-serial }}" = "pass" ]; then
+            .venv/bin/python -c "from smpclient.transport.serial import SMPSerialTransport"
+          else
+            ! .venv/bin/python -c "from smpclient.transport.serial import SMPSerialTransport" 2>/dev/null
+          fi
+
+      - name: ble transport should ${{ matrix.expect-ble }}
+        run: |
+          if [ "${{ matrix.expect-ble }}" = "pass" ]; then
+            .venv/bin/python -c "from smpclient.transport.ble import SMPBLETransport"
+          else
+            ! .venv/bin/python -c "from smpclient.transport.ble import SMPBLETransport" 2>/dev/null
+          fi
+
+      - name: udp transport should pass
+        run: .venv/bin/python -c "from smpclient.transport.udp import SMPUDPTransport"
+
   coverage:
     runs-on: ubuntu-latest
     steps:

README.md

@@ -16,6 +16,28 @@ If you'd like an SMP CLI application instead of a library, then you should try
 
 `smpclient` is [distributed by PyPI](https://pypi.org/project/smpclient/) and can be installed with `uv`, `pip`, and other dependency managers.
 
+Build with all transports:
+
+```
+smpclient[all]
+```
+
+Or none (UDP transport only):
+
+```
+smpclient
+```
+
+Or build with only the transports you need:
+
+```
+smpclient[serial] # Serial (UART, USB, CAN)
+smpclient[ble] # Bluetooth Low Energy
+smpclient[serial,ble] # Serial + BLE
+```
+
+The UDP transport has no additional dependencies and is always available.
+
 ## User Documentation
 
 Documentation is in the source code so that it is available to your editor.

pyproject.toml

@@ -21,13 +21,17 @@ classifiers = [
 "Operating System :: MacOS :: MacOS X",
 ]
 dependencies = [
-"pyserial>=3.5",
 "smp>=4.0.2",
 "intelhex>=2.3.0",
-"bleak>=2.0.0",
 "async-timeout>=4.0.3; python_version < '3.11'",
 ]
 
+[project.optional-dependencies]
+serial = ["pyserial>=3.5"]
+ble = ["bleak>=2.0.0"]
+udp = []
+all = ["smpclient[serial,ble,udp]"]
+
 [project.urls]
 Homepage = "https://www.intercreate.io"
 Documentation = "https://intercreate.github.io/smpclient"
@@ -46,6 +50,7 @@ source = "vcs"
 
 [dependency-groups]
 dev = [
+"smpclient[all]",
 "hatch>=1.14.1",
 "mypy>=1.7.0",
 "mypy-extensions>=1.0.0",

src/smpclient/__init__.py

@@ -7,6 +7,18 @@
 Additionally, SMP is extensible, allowing for custom commands to be defined to
 meet the specific needs of the product.
 
+### Transports
+
+Transports are optional extras.  Install only the transports you need, or all:
+
+```
+smpclient[serial]
+smpclient[ble]
+smpclient[all]
+```
+
+The UDP transport has no additional dependencies and is always available.
+
 ### Operating Systems
 
 |   | Windows 11 (x86) | Ubuntu (Arm/x86) | macOS (Arm/x86) |

src/smpclient/transport/ble.py

@@ -7,10 +7,15 @@
 from typing import Final, Protocol, TypeGuard
 from uuid import UUID
 
-from bleak import BleakClient, BleakGATTCharacteristic, BleakScanner
-from bleak.args.winrt import WinRTClientArgs
-from bleak.backends.client import BaseBleakClient
-from bleak.backends.device import BLEDevice
+try:
+    from bleak import BleakClient, BleakGATTCharacteristic, BleakScanner
+    from bleak.args.winrt import WinRTClientArgs
+    from bleak.backends.client import BaseBleakClient
+    from bleak.backends.device import BLEDevice
+except ImportError as _e:
+    raise ImportError(
+        "BLE transport requires the 'ble' extra. Install with: pip install smpclient[ble]"
+    ) from _e
 from smp import header as smphdr
 from typing_extensions import override
 

src/smpclient/transport/serial.py

@@ -11,7 +11,12 @@
 from functools import cached_property
 from typing import Final
 
-from serial import Serial, SerialException
+try:
+    from serial import Serial, SerialException
+except ImportError as _e:
+    raise ImportError(
+        "Serial transport requires the 'serial' extra. Install with: pip install smpclient[serial]"
+    ) from _e
 from smp import packet as smppacket
 from typing_extensions import override