Set Up a Chain

note

It is possible to run a "committee" of a single Wasp node, which is okay for testing purposes.

However, in normal operation, multiple Wasp nodesA node is any computer that communicates with other nodes in the network using specific software. Essentially, nodes act as connection points for data transfers. The Tangle employs various node types, including full nodes (Hornet, Bee), permanodes (Chronicle), and smart contract nodes (Wasp). should be used.

Requirements

• wasp-cli configured to interact with your wasp node.

Trust Setup

After starting all the wasp nodes, you should make them trust each other. Node operators should do this manually. It's their responsibility to accept trusted nodes only.

The operator can read their node's public key and PeeringURL by running wasp-cli peering info:

wasp-cli peering info

Example response:

PubKey: 8oQ9xHWvfnShRxB22avvjbMyAumZ7EXKujuthqrzapNM
PeeringURL:  127.0.0.1:4000

You should provide your PubKey and PeeringURL to other node operators. They can use this info to trust and accept communications with your node. That's done by invoking wasp-cli peering trust <Name for the peer> <PubKey> <PeeringURL>, e.g.:

wasp-cli peering trust another-node 8oQ9xHWvfnShRxB22avvjbMyAumZ7EXKujuthqrzapNM 127.0.0.1:4000

You can view the list of your wasp node's trusted peers by calling:

wasp-cli peering list-trusted

All the nodes in a committee must trust each other to run the chain.

Start the Chain

Request Test Funds (only for Testnet)

You can request test funds to safely develop your application by calling:

wasp-cli request-funds

Deploy the IOTA Smart Contracts Chain

You can deploy your IOTA Smart Contracts chain by running:

wasp-cli chain deploy --peers=foo,bar,baz --chain=mychain --block-keep-amount=10000

The names in --peers=foo,bar,baz correspond to the names of the node's trusted peers.

The --chain=mychain flag sets up an alias for the chain. From now on, all chain commands will target this chain.

The --quorum flag indicates the minimum number of nodes required to form a consensusAgreement between nodes on the inclusion of blocks in the Tangle and validation of transactions.. The recommended formula to obtain this number is floor(N*2/3)+1 where N is the number of nodes in your committee.

The --block-keep-amount parameter determines how many blocks are stored in the blocklog core contract.

After deployment, the chain must be activated by the node operators of all peers.

wasp-cli chain add <name> <chainID> # adds the chain to the wasp-cli config, can be skipped on the wasp-cli that initiated the deployment
wasp-cli chain activate --chain=<name>

Test If It Works

You can check that the chain was deployed correctly in the Wasp node dashboard (<URL>/wasp/dashboard when using node-docker-setup). Note that the chain was deployed with some core contracts.

You should also have an EVM-JSONRPC server opened on:

<wasp API URL>/chain/<CHAINID>/evm

Deploying a Wasm Contract

danger

The WASM VM is experimental. However, similar commands can be used to interact with the core contracts

Now you can deploy a Wasm contract to the chain:

wasp-cli chain deploy-contract wasmtime inccounter "inccounter SC" tools/cluster/tests/wasm/inccounter_bg.wasm

The inccounter_bg.wasm file is a precompiled Wasm contract included in the Wasp repo as an example.

If you recheck the dashboard, you should see that the inccounter contract is listed in the chain.

Interacting With a Smart Contract

You can interact with a contract by calling its exposed functions and views.

For instance, the inccounter contract exposes the increment function, which simply increments a counter stored in the state. It also has the getCounter view that returns the current value of the counter.

You can call the getCounter view by running:

wasp-cli chain call-view inccounter getCounter | wasp-cli decode string counter int

Example response:

counter: 0

note

The part after | is necessary because the return value is encoded, and you need to know the schema to decode it. The schema definition is in its early stages and will likely change in the future.

You can now call the increment function by running:

wasp-cli chain post-request inccounter increment

After the committee has processed the request, you should get a new counter value after calling getCounter:

wasp-cli chain call-view inccounter getCounter | wasp-cli decode string counter int

Example response:

counter: 1

Troubleshooting

Common issues can be caused by using an incompatible version of wasp / wasp-cli. You can verify that wasp-cli and wasp nodes are on the same version by running:

wasp-cli check-versions