How to send a value update in SignalK in Python

[gpenot]

After two days of research, I am not able to code a python program to update a value of my signalk. Someone can help me? Thank

• Console dialog is:

**> cd_ /home/pi ; /usr/bin/env /bin/python /home/pi/.vscode/extensions/ms-python.debugpy-2025.10.0-linux-arm64/bundled/libs/debugpy/adapter/../../debugpy/launcher 35883 -- /home/pi/import\ websocket.py
Connexion ouverte. Envoi de la mise à jour...
<websocket._app.WebSocketApp object at 0x7fac14ecd0>
Mise à jour envoyée. Fermeture de la connexion dans 3 secondes...
Erreur : 'NoneType' object has no attribute 'sock'

Connexion fermée ###__**

• Here is my program:

import websocket
import json
import time
def on_error(ws, error):
    print(f"Erreur : {error}")

def on_close(ws, close_status_code, close_msg):
    print("### Connexion fermée ###")

def on_open(ws):
    print("Connexion ouverte. Envoi de la mise à jour...")
    # Le message delta au format JSON
    # 'vessels.self' se réfère à l'entité par défaut (le bateau lui-même)
    # L'unité de la vitesse du vent est en mètres par seconde (m/s)
    delta_message = {
        "context": "vessels.self",
        "updates": [
            {
                "source": {
                    "label": "demo-sensor",
                    "type": "custom"
                },
                "timestamp": "2025-08-22T11:32:08.570Z", # Utilisez la date et l'heure actuelles
                "values": [
                    {
                        "path": "environment.wind.speedApparent",
                        "value": 5.2 # Vitesse du vent en m/s
                    }
                ]
            }
        ]
    }
    
    # Envoi du message
    
    ws.send(json.dumps(delta_message))
    print("Mise à jour envoyée. Fermeture de la connexion dans 3 secondes...")
    time.sleep(3)
    ws.close()

if __name__ == "__main__":
    # URL de votre serveur Signal K
    # Assurez-vous que le serveur est configuré pour accepter les mises à jour
    # 'ws://' est pour une connexion non sécurisée. Pour WSS, utilisez 'wss://' et le port 2446
    SERVER_URL = "ws://localhost:3000/signalk/v1/stream/"
    
    ws = websocket.WebSocketApp(SERVER_URL,
                              on_open=on_open,
                              on_error=on_error,
                              on_close=on_close)
    ws.run_forever()_

[tkurki]

I don't really know any Python, but there seem to be several WebSocket implementations for it. If I pip install websockets this works on my machine

import json
from websockets.sync.client import connect

delta_message = {
    "updates": [
        {
            "values": [
                {
                    "path": "navigation.speedOverGround",
                    "value": 3.5
                }
            ]
        }
    ]
}

def sendOnce():
    with connect("ws://localhost:3001/signalk/v1/stream?subscribe=none") as websocket:
        websocket.send(json.dumps(delta_message))

sendOnce()

Context defaults to self and the server will fill in $source and timestamp.

[gpenot]

Thank a lot but nothing appear, but i think i need an authentification Le ven. 22 août 2025, 21:09, Teppo Kurki ***@***.***> a écrit :

…

I don't really know any Python, but there seem to be several WebSocket implementations for it. If I pip install websockets this works on my machine import json from websockets.sync.client import connect delta_message = { "updates": [ { "values": [ { "path": "navigation.speedOverGround", "value": 3.5 } ] } ] } def sendOnce(): with connect("ws://localhost:3001/signalk/v1/stream?subscribe=none") as websocket: websocket.send(json.dumps(delta_message)) sendOnce() Context defaults to self and the server will fill in $source and timestamp. — Reply to this email directly, view it on GitHub <#196 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANP45XANMTCCNS4OWAS7DP33O5TIJAVCNFSM6AAAAACER2GLMWVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTIMJZGI3TONI> . You are receiving this because you authored the thread.Message ID: ***@***.***>