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Setting Up a Chain

note

It is possible to run a "committee" composed of a single Wasp node, and this may be fine for testing purposes. However, in normal operation the idea is to have multiple Wasp nodes in order to run the smart contracts in a distributed fashion. If you want to run a committee of several nodes on the same machine, ensure that each Wasp instance runs in separate directory with its own config.json and database. Ports and other settings must be adjusted accordingly.

note

For testing purposes, all Wasp nodes can be connected to the same Goshimmer instance. In normal operation, it is recommended that each Wasp node connects to a different Goshimmer instance.

Requirements

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 its node's public key and NetID by running wasp-cli peering info:

wasp-cli peering info

Example response:

PubKey: 8oQ9xHWvfnShRxB22avvjbMyAumZ7EXKujuthqrzapNM
NetID: 127.0.0.1:4000

PubKey and NetID should be provided to other node operators. They can use this info to trust your node and accept communications with it. That's done by invoking wasp-cli peering trust <PubKey> <NetID>, e.g.:

wasp-cli peering list-trusted
wasp-cli peering trust 8oQ9xHWvfnShRxB22avvjbMyAumZ7EXKujuthqrzapNM 127.0.0.1:4000
wasp-cli peering list-trusted

Example response:

------                                        -----
PubKey NetID
------ -----
8oQ9xHWvfnShRxB22avvjbMyAumZ7EXKujuthqrzapNM 127.0.0.1:4000

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

Starting The Chain

Requesting Test Funds

note

If you are using a seed that already holds fund, you can skip this step.

wasp-cli request-funds

After you have requested the funds, you can deposit funds to a chain by running:

wasp-cli chain deposit IOTA:10000

Deploy the IOTA Smart Contracts Chain

You can deploy your IOTA Smart Contracts chain by running:

wasp-cli chain deploy --committee=0,1,2,3 --quorum=3 --chain=mychain --description="My chain"

The indices in --committee=0,1,2,3 will correspond to wasp.0, wasp.1, etc. in wasp-cli.json.

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

The --quorum flag indicates the minimum amount of nodes required to form a consensus. The recommended formula to obtain this number floor(N*2/3)+1 where N is the number of nodes in your committee.

Testing If It Works

You can check that the chain was properly deployed in the Wasp node dashboard (e.g. 127.0.0.1:7000). Note that the chain was deployed with some core contracts.

Video Tutorial

Deploying a Wasm Contract

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 check the dashboard again, 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 in order 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 request has been processed by the committee, 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

Video Tutorial

Troubleshooting

Common issues can be caused by using an incompatible version of wasp / wasp-cli. It's easy to verify that wasp-cli and wasp nodes are on the same version, by running:

wasp-cli check-versions