Creating a Subscription

Subscriptions are created with the RPC call subscribe with the stream (feed) name and subscription options set as parameters. Each stream has a different subscription name and can accept different subscription options. Please refer to the specific stream page for info. For more help subscribing to a stream, follow our step-by-step video walkthrough. 

subscribe returns a subscription ID that will be paired with all related notifications.
WebSocket connection
Before using the subscribe call, you need to open a websocket connection to the Gateway or the Cloud-API. 
Gateway
Cloud-API (Enterprise)
Cloud-API (Non Enterprise)
Notes:
We assume that the Gateway IP is 127.0.0.1 with default ws port 28333 in the example below.
ws://127.0.0.1:28333/ws
​
​
Authentication method: Use authorization header.
wss://<region>.eth.blxrbdn.com     #ETH
wss://<region>.bsc.blxrbdn.com     #BSC
wss://<region>.polygon.blxrbdn.com #Polygon
Authentication method: Use authorization header.
wss://api.blxrbdn.com     #ETH
Examples
Gateway
Cloud-API (Enterprise)
Cloud-API (Non Enterprise)
Subscribing to Gateway Stream in Python (line 6 creates the subscription):
from bxcommon.rpc.provider.ws_provider import WsProvider
ws_uri = "ws://127.0.0.1:28333/ws"
while True:
   try:
       async with WsProvider(ws_uri) as ws:
           subscription_id = await ws.subscribe("newTxs", {"include": ["tx_hash"]})
           while True:
               next_notification = await ws.get_next_subscription_notification_by_id(subscription_id)
               print(next_notification)  # or process it generally
   except Exception as e:
       print(f"Connection broken to feed, {str(e)}, retrying.")
await ws.unsubscribe(subscription_id)
​
Subscribing to Cloud-API Feed in Python (line 8 creates the subscription):
from bxcommon.rpc.provider.ws_provider import WsProvider
async with WsProvider(
    uri="wss://virginia.eth.blxrbdn.com/ws",
    headers={"Authorization": <YOUR-AUTHORIZATION-HEADER>},
    # Add the following line if you work with IP instead of DNS
    # skip_ssl_cert_verify=True
) as ws:
    subscription_id = await ws.subscribe("newTxs", {"include": ["tx_hash"]})
    while True:
        next_notification = await ws.get_next_subscription_notification_by_id(subscription_id)
        print(next_notification)  # or process it generally
    await ws.unsubscribe(subscription_id)
​
Subscribing to Cloud-API Feed in Python (line 8 creates the subscription):
from bxcommon.rpc.provider.ws_provider import WsProvider
async with WsProvider(
    uri="wss://api.blxrbdn.com/ws",
    headers={"Authorization": <YOUR-AUTHORIZATION-HEADER>},
    # Add the following line if you work with IP instead of DNS
    # skip_ssl_cert_verify=True
) as ws:
    subscription_id = await ws.subscribe("newTxs", {"include": ["tx_hash"]})
    while True:
        next_notification = await ws.get_next_subscription_notification_by_id(subscription_id)
        print(next_notification)  # or process it generally
    await ws.unsubscribe(subscription_id)
​
Please check newTxs and pendingTxs for examples in wscat, node.js and Golang.
Working With Streams
Handling the Notification
Last modified 2mo ago