Use polkadotjs app🔗

PolkadotJs app is an unhosted web app allowing to connect to any substrate blockchain (not just polkadot, it is wrongly named). In this tutorial, we are going to use the version provided by js.org (https://polkadot.js.org/), but you can use a self-hosted version if you prefer. The "read only" features are available straight ahead, but operation requiring signing documents will need polkadotjs extension.

Connect to a node🔗

The first thing you want to do in PolkadotJs is connect to a node. You can:

• connect to a local node running on the same machine
• connect to a remote node through a ssh tunnel
• connect to a remote node with its public endpoint

Local node🔗

If you have a node running on your local machine and listening to websockets on port 9944, you can visit:

https://polkadot.js.org/apps/?rpc=ws://localhost:9944#/

Notice:

• rpc stands for "Remote Procedure Call", it's the API
• ws not wss (no TLS layer)
• port 9944 (default websocket listening port)
• / root path (no route)

Private remote node through ssh tunnel🔗

If your node is on a remote machine only listening locally, you can still emulate a local node with a ssh tunnel:

# tunnel to remote machine listening on 9944
ssh -NL 9944:localhost:9944 user@host
#         ↑ local port   ↑ remote port

If you configured your node to listen on a different port (example 9945 for validator)

# tunnel to remote machine listening on 9945
ssh -NL 9944:localhost:9945 user@host

This way you will be able to connect to you validator node.

Public remote node through URL🔗

If you want to connect to a public remote node (ex: gdev.axiom-team.fr) listening on port 443 (default for https) on path /ws you can visit:

https://polkadot.js.org/apps/?rpc=wss://gdev.axiom-team.fr/ws#/

The node can be changed in the left bar accessible via the first link in the menu.