smp: Simple Management Protocol

4.0.2 verified Fri May 01 auth: no python

smp is a Python implementation of the Simple Management Protocol (SMP) for remotely managing MCU firmware, commonly used with Zephyr and MCUboot. Version 4.0.2 is current, supporting Python >=3.9. The library provides client and server functionality for MCU management including image upload, shell, file system, and task statistics. Releases occur every few months.

pip install smp

Common errors

error ModuleNotFoundError: No module named 'smp.client' ↓

cause Import path changed in v4.0.0.

fix

Use 'from smp import SMPClient' instead.

error ValueError: Fragment size 8192 exceeds maximum 127 ↓

cause Default fragment size reduced to 127 in v4.0.0. An explicit large value is rejected.

fix

Set fragment_size to a value <= 127 or use the default.

error TypeError: object NoneType can't be used in 'await' expression ↓

cause Trying to await a synchronous method or missing client.connect() call.

fix

Ensure you call 'await client.connect()' before other operations.

error smp.exceptions.SMPError: No response received ↓

cause MCU not reachable or wrong transport address.

fix

Verify the MCU is running and the port is correct; check network connectivity.

Warnings

breaking v4.0.0 dropped Python 3.8 support. Upgrade to Python >=3.9. ↓

fix Ensure Python 3.9+ is installed.

breaking v4.0.0 changed default line length from 8192 to 127 bytes for encode(). Override if using larger frames. ↓

fix Use `SMPClient.encode(data, fragment_size=8192)` if 8192 bytes is required.

gotcha Top-level imports changed in v4; 'from smp.client import SMPClient' no longer works. ↓

fix Use 'from smp import SMPClient' instead.

deprecated The 'session' module is deprecated in favor of the new client interface. ↓

fix Migrate to SMPClient (import from smp).

Imports

SMPClient
wrong
```
from smp.client import SMPClient
```
correct
```
from smp import SMPClient
```
SMPClient is exported directly from smp package since v4

Group

wrong

from smp.group import Group

correct

from smp import Group

Group moved to top-level in v4

Quickstart

Connect to a remote MCU over TCP, send an echo request, and list management groups.

import asyncio
from smp import SMPClient, Group

async def main():
    client = SMPClient("tcp://localhost:6500")
    await client.connect()
    # Get echo response
    echo = await client.echo(data=b"hello")
    print("Echo:", echo)
    # List groups
    groups = await client.get_group_list()
    print("Groups:", groups)
    await client.disconnect()

asyncio.run(main())