@cennznet/signer-cli

A simple CLI interface for offline signing.

Please install the package globally from npm registry as

npm i --global @cennznet/signer-cli

Create a transaction

To create a transaction, you need to use the API to connect to a chain, enabling the creation of a transaction using the chain's metadata. In a terminal, run the submit command with the following form:

npx cennznet-signer-cli submit --account <ss58> --ws <endpoint> <module.method> [param1] [...] [paramX]

For instance, to make a transfer, we run the following command:

npx cennznet-signer-cli submit --account 5HNHXTw65dTNVGRdYkxFUpKcvmUYQMZHcDHmSKpuC8pvVEaN --ws ws://127.0.0.1:9944/ genericAsset.transfer 16000 5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy 9631

On execution, it will prompt us with:

Payload: 0x040300ff4a83f1...a8239139ff3ff7c3f6
Signature>

The Payload is the hex that needs to be signed. Pasting the hex signature (followed by Enter) submits it to the chain.

You can also use this command to submit pre-signed transactions, e.g. generated using the sendOffline command (see below).

The syntax is as follows:

npx cennznet-signer-cli submit --tx <signedTransaction> --ws <endpoint>

Sign a transaction

To sign, you do not need a network connection at all and this command does not use the API to make connections to a chain. In a terminal, run the sign command with the following form:

npx cennznet-signer-cli sign --account <ss58> --seed <suri> --type <ed25519|sr25519> <hex payload>

For instance, to sign the transfer made above, we run:

npx cennznet-signer-cli sign --account 5HNHXTw65dTNVGRdYkxFUpKcvmUYQMZHcDHmSKpuC8pvVEaN --seed "leaf ... rude" --type sr25519 0x040300ff4a83f1...a8239139ff3ff7c3f6

On execution, it will respond with:

Signature: 0xe6facf194a8e...413ce3155c2d1240b

Paste this signature into the submission in the first terminal, and off we go.

By default, submit will create a mortal extrinsic with a lifetime of 50 blocks. Assuming a six-second block time, you will have five minutes to go offline, sign the transaction, paste the signature, and submit the signed transaction.

Send offline

This functionality lets you generate signed transactions for execution at a later time, on a different device or using other tools. It is intended to resemble MyEtherWallet's Send offline feature.

The flow is similar to the submit command. First, run the sendOffline command on a computer with a network connection:

npx cennznet-signer-cli sendOffline --account 5HNHXTw65dTNVGRdYkxFUpKcvmUYQMZHcDHmSKpuC8pvVEaN --ws ws://127.0.0.1:9944/ genericAsset.transfer 16000 5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy 9631

This will give you a payload to sign. Use the sign command as per instructions above.

Once you've pasted the signature into the sendOffline terminal (and hit Enter), it will print the signed transaction that can be stored and submitted later (e.g. using the submit command).

Run npx cennznet-signer-cli --help to learn about optional parameters.