pondsocket-client 0.0.4

PondSocket Python client — connect to a PondSocket server from Python.

pondsocket-client

Python client for the PondSocket server. Connects to PondSocket servers (Python, Go, or TypeScript implementation) over WebSocket.

Modeled after the JavaScript client architecture (@eleven-am/pondsocket-client) rather than the Go one — the JS client fixes several bugs the Go client has (see Parity notes below).

Install

pip install pondsocket-client

Quick start

import asyncio
from pondsocket_client import PondClient


async def main() -> None:
    client = PondClient("ws://localhost:8000/ws", {"token": "secret"})
    await client.connect()

    channel = client.create_channel("/chat/42", {"username": "alice"})
    channel.on_message_event("message", lambda m: print(m.payload))
    channel.on_join(lambda user: print("joined:", user))
    channel.join()

    channel.send_message("message", {"text": "hello"})

    response = await channel.send_for_response("ping", {"text": "abc"})
    print("got pong:", response)

    await asyncio.sleep(10)
    await client.disconnect()


asyncio.run(main())

Architecture

BaseClient (abstract)
  ├── channel registry
  ├── inbound event routing (ACK / UNAUTHORIZED / CONNECTION / per-channel)
  ├── connection state machine: DISCONNECTED → CONNECTING → CONNECTED
  └── exponential reconnect

WebSocketClient(BaseClient)  (abstract)
  ├── opens via `websockets` library
  └── receive loop pumps inbound to BaseClient

PondClient(WebSocketClient)  (concrete)
  ├── URL handling (http → ws, https → wss)
  └── appends query-string params

The Channel class holds the per-channel state machine (IDLE → JOINING → JOINED → STALLED → CLOSED/DECLINED), a bounded outbound queue (drops oldest on overflow), and a send_for_response that correlates inbound replies by requestId.

Connection states

Subscribe via client.on_connection_change(handler):

State	When
DISCONNECTED	initial; after disconnect or socket close
CONNECTING	connect() called; socket handshake in flight
CONNECTED	socket open AND server sent the CONNECTION event

Channel states

Subscribe via channel.on_channel_state_change(handler):

State	Meaning
IDLE	created but join() not called
JOINING	join() called; awaiting ACKNOWLEDGE
JOINED	server acknowledged; messages flow
STALLED	socket dropped while JOINED; will rejoin on reconnect
CLOSED	leave() called
DECLINED	server sent UNAUTHORIZED; channel is terminal — create a new one

Parity notes

Compared to the Go client (go/pondsocket-client/):

Behavior	Go	Python
send_for_response correlation	event name (buggy)	requestId (correct)
Reconnect backoff	linear despite comment	true exponential, capped
UNAUTHORIZED handling	not implemented	→ DECLINED state
Connection state	bool (no CONNECTING)	three-state enum
Outbound queue	unbounded	bounded, drops oldest
Join while disconnected	dropped silently	deferred until CONNECTED

The Python client follows the JS client design where the two diverge.

Public API

from pondsocket_client import (
    PondClient,
    Channel,
    ConnectionState,
    ClientOptions,
    ResponseTimeoutError,
)

Also exposed for adapter authors: BaseClient, WebSocketClient, Publisher (type alias).

License

GPL-3.0-or-later.