Configuration

Table of Contents

1. Logging
   1. Socket Trace
   2. Custom Handler
2. Reconnection
   1. Raw Interval Strategy
   2. Interval Backoff Strategy
   3. Keep-Alive (Ping)
3. Headers
4. Query String Parameters
5. Skip Negotiation
6. Transport
   1. WebSockets (default)
   2. Server-Sent Events
   3. Long Polling
7. MessagePack Encoding
8. Custom SSL Context

---

Logging

HubConnectionBuilder()\
    .with_url(server_url)\
    .configure_logging(logging.DEBUG)\
    ...

Socket Trace

HubConnectionBuilder()\
    .with_url(server_url)\
    .configure_logging(logging.DEBUG, socket_trace=True)\
    ...

Custom Handler

import logging

handler = logging.StreamHandler()
handler.setLevel(logging.DEBUG)

HubConnectionBuilder()\
    .with_url(server_url, options={"verify_ssl": False})\
    .configure_logging(logging.DEBUG, socket_trace=True, handler=handler)\
    ...

---

Reconnection

After reaching max_attempts, an exception is thrown and the on_close event fires.

Raw Interval Strategy

Reconnects at a fixed interval:

hub_connection = HubConnectionBuilder()\
    .with_url(server_url)\
    .with_automatic_reconnect({
        "type": "raw",
        "keep_alive_interval": 10,
        "reconnect_interval": 5,
        "max_attempts": 5
    }).build()

Interval Backoff Strategy

Reconnects using a list of increasing intervals:

hub_connection = HubConnectionBuilder()\
    .with_url(server_url)\
    .with_automatic_reconnect({
        "type": "interval",
        "keep_alive_interval": 10,
        "intervals": [1, 3, 5, 6, 7, 87, 3]
    }).build()

Keep-Alive (Ping)

keep_alive_interval sets the number of seconds between ping messages sent to the server.

---

Headers

hub_connection = HubConnectionBuilder()\
    .with_url(server_url, options={
        "headers": {
            "mycustomheader": "mycustomheadervalue"
        }
    })\
    .build()

---

Query String Parameters

Pass parameters directly in the URL:

server_url = "http://.../?myQueryStringParam=134&foo=bar"

connection = HubConnectionBuilder()\
    .with_url(server_url)\
    .build()

---

Skip Negotiation

hub_connection = HubConnectionBuilder()\
    .with_url("ws://" + server_url, options={
        "verify_ssl": False,
        "skip_negotiation": False,
        "headers": {}
    })\
    .configure_logging(logging.DEBUG, socket_trace=True, handler=handler)\
    .build()

---

Transport

WebSockets (default)

Used by default — no explicit configuration needed.

from signalrcore.hub_connection_builder import HubConnectionBuilder
from signalrcore.transport.websockets.websocket_transport import HttpTransportType

HubConnectionBuilder()\
    .with_url(server_url, options={
        "transport": HttpTransportType.web_sockets
    })\
    .configure_logging(logging.ERROR)\
    .build()

Server-Sent Events

HubConnectionBuilder()\
    .with_url(server_url, options={
        "transport": HttpTransportType.server_sent_events
    })\
    .configure_logging(logging.ERROR)\
    .build()

Long Polling

HubConnectionBuilder()\
    .with_url(server_url, options={
        "transport": HttpTransportType.long_polling
    })\
    .configure_logging(logging.ERROR)\
    .build()

---

MessagePack Encoding

By default, JSON encoding is used. To switch to binary MessagePack:

from signalrcore.protocol.messagepack_protocol import MessagePackHubProtocol

HubConnectionBuilder()\
    .with_url(server_url, options={"verify_ssl": False})\
    .with_hub_protocol(MessagePackHubProtocol())\
    .build()

---

Custom SSL Context

Pass a custom SSL context to all requests and socket connections:

import ssl

MY_CA_FILE_PATH = "ca.crt"
context = ssl.create_default_context(cafile=MY_CA_FILE_PATH)

options = {"ssl_context": context}

connection = HubConnectionBuilder()\
    .with_url(server_url, options=options)\
    .configure_logging(logging.INFO, socket_trace=True)\
    .build()

For full certificate setup instructions, see the Custom Client Certificates article.