DISCLAIMER:
Production use of v3.0.0b1 (and all future beta versions) is HIGHLY discouraged.
Beta versions should not be used in applications which require user authentication.
Provide your API-KEY/API-SECRET, and manage your account and funds at your own risk.

Features

User-friendly implementations for 75+ public and authenticated REST endpoints.
- A complete list of available REST endpoints can be found here.
New WebSocket client to ensure fast, secure and persistent connections.
- Support for all public channels + authenticated events and inputs (a list can be found here).
- Automatic reconnection system in case of network failure (both client and server side).
  - The WebSocket client logs every reconnection failure, success and attempt (as well as other events).
- Connection multiplexing to allow subscribing to a large number of public channels (without affecting performances).
  - The WebSocket server sets a limit of 25 subscriptions per connection, connection multiplexing allows the WebSocket client to bypass this limit.
Full type-hinting and type-checking support with mypy.
- This allow text editors to show helpful hints about the value of a variable:

Installation

To install the latest beta release of bitfinex-api-py:

python3 -m pip install --pre bitfinex-api-py

To install a specific beta version:

python3 -m pip install bitfinex-api-py==3.0.0b1

Basic usage

WebSocket Client documentation

Instantiating the client
- Authentication
- Configuring the logger
Running the client
- Closing the connection
Subscribing to public channels
- Setting a custom sub_id
Listening to events
Advanced Features

Instantiating the client

bfx = Client(wss_host=PUB_WSS_HOST)

Client::wss contains an instance of BfxWebSocketClient (core implementation of the WebSocket client).
The wss_host argument is used to indicate the URL to which the WebSocket client should connect.
The bfxapi package exports 2 constants to quickly set this URL:

Constant	URL	When to use
WSS_HOST	wss://api.bitfinex.com/ws/2	Suitable for all situations, supports authentication.
PUB_WSS_HOST	wss://api-pub.bitfinex.com/ws/2	For public uses only, doesn't support authentication.

PUB_WSS_HOST is recommended over WSS_HOST for applications that don't require authentication.

NOTE: The wss_host parameter is optional, and the default value is WSS_HOST.

Authentication

Configuring the logger

log_filename (Optional[str], default: None):
Relative path of the file where to save the logs the client will emit.
If not given, the client will emit logs on stdout (stderr for errors and warnings).

log_level (str, default: "INFO"):
Available log levels are (in order): ERROR, WARNING, INFO and DEBUG.
The client will only log messages whose level is lower than or equal to log_level.
For example, if log_level=WARNING, the client will only log errors and warnings.

bfx = Client(
    [...],
    log_filename="2023-03-26.log",
    log_level="WARNING"
)

Running the client

The client can be run using BfxWebSocketClient::run:

bfx.wss.run()

If an event loop is already running, users can start the client with BfxWebSocketClient::start:

await bfx.wss.start()

If the client succeeds in connecting to the server, it will emit the open event.
This is the right place for all bootstrap activities, such as subscribing to public channels.
To learn more about events and public channels, see Listening to events and Subscribing to public channels.

@bfx.wss.on("open")
async def on_open():
    await bfx.wss.subscribe(Channel.TICKER, symbol="tBTCUSD")

Closing the connection

Users can close the connection with the WebSocket server using BfxWebSocketClient::close:

await bfx.wss.close()

A custom close code number, along with a verbose reason, can be given as parameters:

await bfx.wss.close(code=1001, reason="Going Away")

After closing the connection, the client will emit the disconnection event:

@bfx.wss.on("disconnection")
def on_disconnection(code: int, reason: str):
    print(f"Closing connection with code: <{code}>. Reason: {reason}.")

Subscribing to public channels

Users can subscribe to public channels using BfxWebSocketClient::subscribe:

await bfx.wss.subscribe("ticker", symbol="tBTCUSD")

On each successful subscription, the client will emit the subscribed event:

@bfx.wss.on("subscribed")
def on_subscribed(subscription: subscriptions.Subscription):
    if subscription["channel"] == "ticker":
        print(f"{subscription['symbol']}: {subscription['subId']}") # tBTCUSD: f2757df2-7e11-4244-9bb7-a53b7343bef8

Setting a custom `sub_id`

The client generates a random sub_id for each subscription.
These values must be unique, as the client uses them to identify subscriptions.
However, it is possible to force this value by passing a custom sub_id to BfxWebSocketClient::subscribe:

await bfx.wss.subscribe("candles", key="trade:1m:tBTCUSD", sub_id="507f1f77bcf86cd799439011")

Listening to events

Whenever the WebSocket client receives data, it will emit a specific event.
Users can either ignore those events or listen for them by registering callback functions.
These callback functions can also be asynchronous; in fact the client fully supports coroutines (asyncio).

To add a listener for a specific event, users can use the decorator BfxWebSocketClient::on:

@bfx.wss.on("candles_update")
def on_candles_update(sub: subscriptions.Candles, candle: Candle):
    print(f"Candle update for key <{sub['key']}>: {candle}")

The same can be done without using decorators:

bfx.wss.on("candles_update", callback=on_candles_update)

You can pass any number of events to register for the same callback function:

bfx.wss.on("t_ticker_update", "f_ticker_update", callback=on_ticker_update)

Advanced features

Connection multiplexing

BfxWebSocketClient::run and BfxWebSocketClient::start accept a connections argument:

bfx.wss.run(connections=3)

connections indicates the number of connections to run concurrently (through connection multiplexing).

Each of these connections can handle up to 25 subscriptions to public channels.
So, using N connections will allow the client to handle at most N * 25 subscriptions.
You should always use the minimum number of connections necessary to handle all the subscriptions that will be made.

For example, if you know that your application will subscribe to 75 public channels, 75 / 25 = 3 connections will be enough to handle all the subscriptions.

The default number of connections is 5; therefore, if the connections argument is not given, the client will be able to handle a maximum of 25 * 5 = 125 subscriptions.

Keep in mind that using a large number of connections could slow down the client performance.

The use of more than 20 connections is not recommended.

Sending custom notifications

Sending custom notifications requires user authentication.

Users can send custom notifications using BfxWebSocketClient::notify:

await bfx.wss.notify({ "foo": 1 })

Any data can be sent along with a custom notification.

Custom notifications are broadcast by the server on all user's open connections.
So, each custom notification will be sent to every online client of the current user.
Whenever a client receives a custom notification, it will emit the notification event:

@bfx.wss.on("notification")
def on_notification(notification: Notification[Any]):
    print(notification.data) # { "foo": 1 }

Handling reconnections in case of network failure

In case of network failure, the client will keep waiting until it is able to restore the connection with the server.

The client will try to reconnect with exponential backoff; the backoff delay starts at three seconds and increases up to one minute.

After a successful reconnection attempt, the client will emit the reconnection event.

This event accepts two arguments:
attemps (int) which is the number of reconnection attempts (including the successful one),
timedelta (datetime.timedelta) which contains the amount of time the client has been down.

Users can use this event for a variety of things, such as sending a notification if the client has been down for too long:

@bfx.wss.on("reconnection")
async def on_reconnection(attempts: int, timedelta: datetime.timedelta):
    if timedelta.total_seconds() >= 60 * 60: # 60s * 60s = 3600s = 1h
        await bfx.wss.notify(f"The client has been down for {timedelta}.")

Building the source code

Testing (with unittest)

Linting the project with pylint

Using mypy to ensure correct type-hinting

How to contribute

License

This project is released under the Apache License 2.0.

The complete license can be found here: https://www.apache.org/licenses/LICENSE-2.0.

README.md

bitfinex-api-py (v3-beta)