ValueError: unknown channel A.TSLA (you may need to specify the right data_stream)

Alpaca Products Discussion Alpaca Questions
1

https://paper-api.alpaca.markets

Program was running Friday. This morning I am getting above error.
I changed keys but this did not help. Also changed symbol and ran old copy of code that was working. No luck on either.

Here id the offending code:
def start_trading(self):

    conn = tradeapi.StreamConn(self.key_id, self.secret_key, self.base_url)

    @conn.on(r'A$', [self.symbol])                                                    

    @conn.on(r'trade_updates')

#_______________________________________________

Any Ideas???
Thanks

2

Did you figure out the issue?

3

There was a change in SDK that now defaults to alpaca data stream unless you specify data_stream parameter to the initializer, and alpaca data stream does not support A channel. That is what the error message means but apparently it is still not clear.

4

We are also updating the example code we posted in the past to avoid this confusion.

5

Ah, same issue here, and I posted a question under programming. How do I specify data_stream parameter to the initializer, Hitoshi, would you please give an example? Thanks!

6

Do we have any updates on the example code to resolve the above issue?

7

Any updates on this ?

8

Hi Hitoshi,
My program stopped working yesterday. It gives this error “RuntimeError: This event loop is already running”
I removed all of my code and just left code from examples on the Alpaca site. It still gives the same error message.
Here is the code: It gives error on the con.run( line. Please please please. Tell me what is wrong? Thank you…Thomas

!pip install alpaca-trade-api
import alpaca_trade_api as tradeapi
USE_POLYGON = True
class MartingaleTrader(object):
def init(self):
self.key_id = “PKCD5QCAHON7FRU6VIPQ”
self.secret_key = “yjb83YL4Mzp43o891BkoMr1KgixgxDi60webIaSL”
self.base_url = “https://paper-api.alpaca.markets”
self.data_url = ‘https://data.alpaca.markets’
self.api = tradeapi.REST(self.key_id, self.secret_key, self.base_url)
self.trade_number = 0
self.symbol = ‘TSLA’
def start_trading(self):
conn = tradeapi.StreamConn(self.key_id, self.secret_key, base_url=self.base_url, data_url=self.data_url, data_stream=‘polygon’ if USE_POLYGON else ‘alpacadatav1’)
@conn.on(r’A$’, [self.symbol])
async def handle_agg(conn, channel, data):
self.trade_number = self.traden_number + 1
print(f’trade_number…:{self.trade_number}’)
if USE_POLYGON:
conn.run([f’A.{self.symbol}’, ‘trade_updates’])
else:
conn.run([f’alpacadatav1/T.{self.symbol}’, ‘trade_updates’])
if name == ‘main’:
trader = MartingaleTrader()
trader.start_trading()