A python script that queries all of your historic trades and calculates the average price you purchased coins at. This was a quick script based on the examples found here: https://docs.kraken.com/rest/. I am open to feedback!!

kraken-avg-cost.py

#!/usr/local/bin/python3

import base64
import hashlib
import hmac
import json
import os
import requests
import time
import urllib.parse

# SAMPLE OUTPUT
# TICKER       AVG COST     LAST PRICE   GAIN/LOSS
# XETHZUSD     4187.51      3911.61      -6.59%
# KAVAUSD      5.90         5.38         -8.88%
# DOTUSD       40.06        36.15        -9.78%
# XXBTZUSD     56039.83     49928.40     -10.91%
# XDGUSD       0.48         0.43         -9.75%

# Read Kraken API key and secret stored in environment variables
api_url = "https://api.kraken.com"
api_key = os.environ['api_key_KRAKEN']
api_sec = os.environ['api_sec_KRAKEN']

def get_kraken_signature(urlpath, data, secret):
    postdata = urllib.parse.urlencode(data)
    encoded = (str(data['nonce']) + postdata).encode()
    message = urlpath.encode() + hashlib.sha256(encoded).digest()
    mac = hmac.new(base64.b64decode(secret), message, hashlib.sha512)
    sigdigest = base64.b64encode(mac.digest())
    return sigdigest.decode()

# Attaches auth headers and returns results of a POST request
def kraken_request(uri_path, data, api_key, api_sec):
    headers = {}
    headers['API-Key'] = api_key
    # get_kraken_signature() as defined in the 'Authentication' section
    headers['API-Sign'] = get_kraken_signature(uri_path, data, api_sec)
    req = requests.post((api_url + uri_path), headers=headers, data=data)
    return req

def check_errors(resp):
    if resp["error"]:
        print("There were errors with the request:")
        print(resp["error"])
        exit(1)

def get_average_cost():
    resp = kraken_request('/0/private/TradesHistory', {
        "nonce": str(int(1000*time.time())),
        "trades": True
    }, api_key, api_sec).json()
    check_errors(resp)
    trade_history = resp["result"]["trades"]
    average_cost = {}
    total_vol = {}
    total_cost = {}
    for trade_key in trade_history:
        trade = trade_history[trade_key]
        ttype = trade["type"]
        currency_pair = trade["pair"]
        volume = float(trade["vol"])
        cost = float(trade["cost"])
        fee = float(trade["fee"])
        if ttype == "buy":
            total_vol[currency_pair] = total_vol.get(currency_pair, 0.0) + volume
            total_cost[currency_pair] = total_cost.get(currency_pair, 0.0) + (cost + fee)
        elif ttype == "sell":
            total_vol[currency_pair] = total_vol.get(currency_pair, 0.0) - volume
            total_cost[currency_pair] = total_cost.get(currency_pair, 0.0) - (cost - fee)
    for currency_pair in total_vol:
        if total_vol[currency_pair] > 0.0:
            average_cost[currency_pair] = total_cost[currency_pair] / total_vol[currency_pair]
    return average_cost

def get_last_price(currency_pairs):
    last_price = {}
    for currency_pair in currency_pairs:
        resp = requests.get('https://api.kraken.com/0/public/Trades?pair=%s' % currency_pair).json()
        check_errors(resp)
        last_price[currency_pair] = float(resp["result"][currency_pair][-1][0])
    return last_price

def calc_gain_loss_percent(average_cost, last_price):
    gain_loss_percent = {}
    for currency_pair in average_cost:
        gain_loss_percent[currency_pair] = (last_price[currency_pair] - average_cost[currency_pair]) / average_cost[currency_pair] * 100
    return gain_loss_percent

def display_info(average_cost, last_price, gain_loss_percent):
    fcolumns = "{0:<12} {1:<12} {2:<12} {3:<12}"
    ffloat = "{:.2f}"
    fpercent = ffloat+"%"
    print(fcolumns.format("TICKER", "AVG COST", "LAST PRICE", "GAIN/LOSS"))
    for currency_pair in average_cost:
        print(fcolumns.format(
            currency_pair,
            ffloat.format(average_cost[currency_pair]),
            ffloat.format(last_price[currency_pair]),
            fpercent.format(gain_loss_percent[currency_pair])
        ))

average_cost = get_average_cost()
last_price = get_last_price(average_cost.keys())
gain_loss_percent = calc_gain_loss_percent(average_cost, last_price)
display_info(average_cost, last_price, gain_loss_percent)

I use my fiat currency to invest into some coins and thus, the trade tab is empty. Any way to adapt this for the information under the kraken.com/u/history/ledger section? This looks like this: https://pasteboard.co/zXG7FEhc0WXL.png

Hello Dustin,
I am wondering if you can give me a tip how to fix this error:
Error: Invalid base64-encoded string: number of data characters (85) cannot be 1 more than a multiple of 4

It's happening when I try to execute the code.

Thanks Dustin for the good work!

I have added a few extra features (sorry for the sloppy code. Python is not my native language) here: https://gist.github.com/DVN237294/4f40133b79926dd598333580a9f5d82f

• Original script only fetched the previous 50 trades at most. This now loops through all trades in history (that kraken exposes)
• Added some basic api limiting to adhere to krakens limits (seemed like it was actually not necessary in my case. Not sure why)
• Prints the received trades and total trade count
• Changed from floats to decimals to avoid monetary rounding errors
• Added a few more columns to output: TOTAL VOL, TOTAL COST, TOTAL FEES, MIN PRICE and MAX PRICE

@DVN237294 Thanks for the collaboration!

I want to note that I no longer use this script since there are services online that do this for free. I'm using Koinly currently, but there are other options too.