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Connect to a proxy Streamr node

Proxy publishing and subscribing​

In some cases the app using the Streamr SDK might be interested in publishing messages without participating in the stream's message propagation. With this option the nodes can sign all messages they publish by themselves. Alternatively, the app containing the Streamr SDK could open a WS connection to a Streamr node and allow the Streamr node to handle signing with its private key.

Setting subscribe proxies can be useful for cases where Streamr nodes with public IP addresses do not exist in a stream.

Proxy publishing and subscribing are handled on the network overlay level. This means that there is no need to know the IP address of the node that will be used as a proxy. Instead, the node needs to know the ID of the network node it wants to connect to. It is not possible to set publish / subscribe proxies for a stream that is already being "traditionally" subscribed or published to and vice versa.

To open publish proxy connections to multiple nodes on a stream partition:

await publishingClient.setProxies(streamPartition, ['0x11111...', '0x22222...'], ProxyDirection.PUBLISH)

To remove some/all proxies, call the same method with a different set of nodes. If the node list is empty, proxies are no longer used for the given stream partition:

await publishingClient.setProxies(streamPartition, [], ProxyDirection.PUBLISH)

By default the app containing the Streamr SDK will attempt to open proxy connections to all of the nodes set in setProxies. You can limit the number of connections by setting the connectionCount parameter. In this approach, if the app is disconnected from one of the nodes it will attempt to connect to another node by random:

// Opens 2 connections, with an extra candidate to use in case of disconnections
await publishingClient.setProxies(streamPartition, ['0x11111...', '0x22222...', '0x33333...'], ProxyDirection.PUBLISH, 2)
Important:

The node that is used as a proxy must have set the option on the network layer to accept incoming proxy connections and must have joined to the stream that a proxy connection is wanted for.

Example Streamr SDK config​

{
    ...
    "network": {
        ...
        "acceptProxyConnections": true
    }
}

Example Streamr node config​

{
    ...
    "client": {
        ...
        "network": {
            ...
            "acceptProxyConnections": true
        }
    },
    "plugins": {
        ...
        "subscriber": {
            "streams": [
                {
                    "streamId": "STREAM_ID",
                    "streamPartition": 0
                },
                {
                    "streamId": "STREAM_ID2",
                    "streamPartition": 0
                },
            ]
        }
    }
}