BBO RPC provides a realtime best bid/offer stream for all symbols.

Sample Code

import grpc
import common_pb2
import market_data_pb2_grpc

def stream_bbo():
    channel = grpc.secure_channel('mds.pfex.io:443', grpc.ssl_channel_credentials())
    stub = market_data_pb2_grpc.MarketDataServiceStub(channel)

    for bbo in stub.GetBbo(common_pb2.Empty()):
        print(bbo)

if __name__ == '__main__':
    stream_bbo()

Example Response

symbol: "NVDA-USD"
timestamp {
    seconds:1746989556
    nanos:92588003
}
bids {
    price:116.1
    quantity:6.882
}
asks {
    price:116.7
    quantity:6.847
}
sequence: 7262686