bcx 0.1.1

Blockchain.com Exchange API

Blockchain Exchange Python API

Table of Contents

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Last Update: 2020-05-11

• Features
• Quick start
  • Prerequisites for trading
• Demos
  • Listen to all public channels
  • Create market and limit orders
• TODO

Features

• Subscribe to all websocket channels available at blockchain.com | exchage:

  • Heartbeat :hearts:
  • Orderbook L2 :blue_book:
  • Orderbook L3 :green_book:
  • Prices :atm:
  • Symbols :symbols:
  • Ticker :chart_with_upwards_trend:
  • Trades :currency_exchange:
  • Trading :bank: :closed_lock_with_key:
  • Balance :moneybag: :closed_lock_with_key:

• Subscription to new channels doesn't require client restart

• Create Market orders

• Create Limit orders

All API is available through a websocket client:

import logging
from blockchain_exchange.client import BlockchainWebsocketClient

logging.basicConfig(level=logging.INFO)

client = BlockchainWebsocketClient()

See our documentation for API reference and gallery of examples for more info.

Quick start

• Get source code

git clone [e-mail]:ilya-bc/blockchain-exchange-api.git
cd blockchain-exchange-api

• Install package. Since there are hundred ways to do that, a standardised way for this project is with Makefile. It will create virtual environment with pipenv and will use python 3.7 as its interpreter

# For general use
make install

# For development
make install-dev

Prerequisites for trading

Actual trading and accessing balance of your account requires authentication with an API key. In order to get one:

1. You should have an account at blockchain.com | exchange

2. Create API key here and store information. Note, you can have setup key with permissions view and view & trade.

3. You should receive an email asking you to activate API key.

4. Setup the following environment variable

export BLOCKCHAIN_API_SECRET="__ENTER_YOUR_API_SECRET_HERE__"

:fire: Tip: If you use pipenv then you can just put it into .env file (ignored by git) at the root of the cloned directory

Demos

Listen to all public channels

• Script
• Script extended

:pencil2: Note: There are time.sleep(2) between calling different methods, in order to be able to see intermediate results.

Create market and limit orders

• Script
• Script extened

:pencil2: Note: Both orders got rejected (expected behaviour) because of invalid quantity and price being to big.

TODO

• Tests
• Something weird is going on with unsubscribing from channels in bulk for the following ones:

[
{"channel": "l2", "symbol": "BTC-USD"},
{"channel": "ticker", "symbol": "BTC-USD"},
{"channel": "trades", "symbol": "BTC-USD"}
]

• Check contradiction with API docs on prices channel

[
{"seqnum":1,"event":"subscribed","channel":"prices","symbol":"BTC-USD","granularity":60},
{"seqnum":2,"event":"subscribed","channel":"prices","symbol":"ETH-USD","granularity":60},
{"seqnum":3,"event":"subscribed","channel":"prices","symbol":"BTC-USD","granularity":300},
{"seqnum":4,"event":"subscribed","channel":"prices","symbol":"ETH-USD","granularity":300}
]

• Docs doesn't say that ticker channel sends update events

[
{"seqnum":0,"event":"subscribed","channel":"ticker","symbol":"BTC-USD"},
{"seqnum":1,"event":"snapshot","channel":"ticker","symbol":"BTC-USD","price_24h":8744.9,"volume_24h":155.77132628,"last_trade_price":8881.0},
{"seqnum":2,"event":"updated","channel":"ticker","symbol":"BTC-USD","price_24h":8754.8,"volume_24h":155.70446581}
]