Step 3 of 5

# WebSocket subscription

Define the subscription handshake, the message templates and the connection tuning that Crank should use before collecting bounded WebSocket events.

Connection
The upstream base URL from step 2 becomes the WebSocket endpoint unless you override it here.
Optional
Socket path
Appended to the upstream URL from step 2. Leave empty if the upstream URL already points to the full WebSocket endpoint.
Subprotocols
One subprotocol per line. Crank offers them during the handshake in the same order.
Subscription messages
Templates are sent after the socket opens. They can reference MCP input through the mapping step.
Optional
Subscribe template
Unsubscribe template
Connection tuning
Used by the runtime adapter for heartbeats and reconnects in bounded session-oriented flows.
Optional
Heartbeat interval (ms)
Reconnect attempts
Reconnect backoff (ms)