Lichess API - I get HTTPError 400 when trying to stream game state

Question

I am writing an application that interacts with Lichess. However when I use the API to get game state, I must use

for event in client.bots.stream_game_state(game_id):

as provided by the documentation. In fact, this is exactly the code they use in their example. However, I get the following error:

HTTPError: 400 Client Error: Bad Request for url: https://lichess.org/api/bot/game/stream/8Kjolz4k

Here is my code:

# Type "!pip install berserk" in Console to get berserk module
import berserk
import time
import threading

# Initiate a session with my personal API token
token = "***************"
session = berserk.TokenSession(token)
client = berserk.Client(session)

# Stream whats happening and continue when we are challenged
in_game = False
while(not in_game):
    time.sleep(0.5)
    for event in client.bots.stream_incoming_events():
        if event['type'] == 'gameStart':
            game_id = event['game']['id']
            in_game = True
            break
        elif event['type'] == 'challenge':
            game_id = event['challenge']['id']
            client.bots.accept_challenge(game_id)
            in_game = True
print("The game has started!")

# Stream the events of the game and respond accordingly
playing = True
while(playing):
    for event in client.bots.stream_game_state(game_id):
        if event['type'] == 'gameFull':
            if client.account.get()['username'] == event['white']['id']:
                client.bots.post_message(game_id, "I got first, nerd!")
            else:
                client.bots.post_message(game_id, "You got first, nerd!")

Answer 1

I don't know why your code was failing at the time. The 400 response can be catched like this (example for an abort call):

  def abort(self):
    try:
        self.client.bots.abort_game(self.game_id)
        return True
    except requests.exceptions.HTTPError as herr:
        if self.debug:
            print (herr)
        return False

Please find below a slightly modified version that works for me in the context of Play-Chess-With-A-WebCam (where I am a committer). You need a config.yaml file in ~/.pcwawc/config.yaml with your token:

# Play Chess With a Webcam configuration file
# WF 2019-12-21
token: YOUR_TOKEN_HERE

The result of the test is:

gameStart {'type': 'gameStart', 'game': {'id': '20XfiEMn'}}
The game 20XfiEMn has started!
gameFull {'id': '20XfiEMn', 'variant': {'key': 'standard', 'name': 'Standard', 'short': 'Std'}, 'clock': None, 'speed': 'correspondence', 'perf': {'name': 'Correspondence'}, 'rated': False, 'createdAt': datetime.datetime(2019, 12, 23, 19, 54, 20, 470000, tzinfo=datetime.timezone.utc), 'white': {'id': 'seppl2019', 'name': 'seppl2019', 'title': 'BOT', 'rating': 1500, 'provisional': True}, 'black': {'id': 'wolfgangfahl', 'name': 'WolfgangFahl', 'title': None, 'rating': 1662, 'provisional': True}, 'initialFen': 'startpos', 'type': 'gameFull', 'state': {'type': 'gameState', 'moves': 'f2f3 d7d5', 'wtime': 2147483647, 'btime': 2147483647, 'winc': 0, 'binc': 0, 'bdraw': False, 'wdraw': False}}
chatLine {'type': 'chatLine', 'room': 'player', 'username': 'seppl2019', 'text': 'I got first, nerd!'}

test_lichess

'''
Created on 2019-12-21

@author: wf
'''
from pcwawc.lichess import Lichess


def test_stream():
    gameid="20XfiEMn"
    lichess=Lichess(debug=True)
    gameid=lichess.waitForChallenge()
    lichess.streamGame(gameid)

test_stream()

lichess.py

'''
Created on 2019-12-21

@author: wf
'''
# https://github.com/rhgrant10/berserk
# https://berserk.readthedocs.io/en/master/
import berserk
import lichess.api
import os
import yaml
import requests
import time

class Account():
    """" Lichess account wrapper """

    def __init__(self,adict):
        self.adict=adict
        self.id=adict["id"]
        self.username=adict["username"]
        pass

    def __str__(self):
        text="%s - (%s)" % (self.username,self.id)
        return text

class Lichess():
    """ Lichess adapter """

    def __init__(self,debug=False):
        self.debug=debug
        token=self.getToken()
        if token is not None:
            self.session= berserk.TokenSession(token)
            self.client=berserk.Client(self.session)
        else:
            self.client=None

    def getAccount(self):
        account=Account(self.client.account.get())
        return account

    def getToken(self):
        home=os.getenv("HOME")
        #print(home)
        configPath=home+"/.pcwawc/config.yaml"
        if not os.path.isfile(configPath):
            print ("%s is missing please create it" % (configPath))
            return None
        config=yaml.load(open(configPath),Loader=yaml.FullLoader)
        if not "token" in config:
            print ("no token found in %s please add it" % (configPath))
            return None
        return config["token"]

    def pgnImport(self,pgn):
        payload = {
          'pgn': pgn,
          'analyse': 'on'
        }
        res = requests.post('https://lichess.org/import', data=payload)
        print(res.url)
        pass

    def game(self,gameid):
        game=lichess.api.game(gameid)
        return game

    def waitForChallenge(self):
        # Stream whats happening and continue when we are challenged
        in_game = False
        client=self.client
        while(not in_game):
            time.sleep(0.5)
            for event in client.bots.stream_incoming_events():
                eventtype=event['type']
                if self.debug:
                    print (eventtype,event)
                if eventtype == 'gameStart':
                    game_id = event['game']['id']
                    in_game = True
                    break
                elif eventtype == 'challenge':
                    game_id = event['challenge']['id']
                    client.bots.accept_challenge(game_id)
                    in_game = True
        if self.debug:            
            print("The game %s has started!" % (game_id))
        return game_id    

    # Stream the events of the game and respond accordingly
    def streamGame(self,game_id):
        playing = True
        client=self.client
        while(playing):
            for event in client.bots.stream_game_state(game_id):
                eventtype=event['type']
                if self.debug:
                    print (eventtype,event)
                if eventtype == 'gameFull':
                    if client.account.get()['username'] == event['white']['id']:
                        client.bots.post_message(game_id, "I got first, nerd!")
                    else:
                        client.bots.post_message(game_id, "You got first, nerd!")  

excerpt of requirements.txt:

# lichess APIs
# https://github.com/rhgrant10/berserk
berserk
# https://github.com/cyanfish/python-lichess
python-lichess