Smart Optimistic Rollups

Rollups are a permissionless scaling implementation for the Tezos blockchain. The idea is that anyone can originate and operate one or more rollups, increasing the overall throughput of the Tezos blockchain.

In Taquito, we have implemented some of the operations included in Mumbai protocol update in regards to smart rollups. In this document, we will go through the operations we support. We also won't go too detailed on how rollups work behind the scenes, if you'd like to understand the feature a bit deeper, you can refer to this document.

smart_rollup_originate

The Smart Rollup Originate operation allows a user to originate a smart rollup. Users must pass a kernel, pvmKind, and parameterType.

Examples

const op = await Tezos.contract.smartRollupOriginate({
  pvmKind: 'wasm_2_0_0',
  kernel: '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',
  parametersType: { prim: 'bytes' },

});
await op.confirmation();

please note

• pvmKind at this time the only PVM supported is wasm_2_0_0
• kernel is passed as a hexadecimal string examples can be found at this tezos docs endpoint
• parametersType is a MichelsonV1Expression to define the type.

For more information in regards to Smart Rollup Origination please refer to the this link

smart_rollup_add_messages

The add messages operation allows users to send external messages into a rollup inbox. We will go into a bit more detail down below on what that means.

Usage

The main use case of sending messages, is usually to denote contract calls. These messages usually takes the form of this object:

MESSAGE='[{\
  "destination" : "${CONTRACT}", \
  "parameters" : "\"Hello world\"", \
  "entrypoint" : "default"
  }]'

If you read closely, the message includes a destination, a parameter, and an entrypoint property. All components needed to call an entrypoint of a contract.

These messages can then be claimed back into L1 as a legitimate contract call using the smart_rollup_execute_outbox_message operation which we will go over in another section of this doc.

for more information, refer to this document

Example

const op = await Tezos.contract.smartRollupAddMessages({
    message: [
        '0000000031010000000b48656c6c6f20776f726c6401bdb6f61e4f12c952f807ae7d3341af5367887dac000000000764656661756c74'
    ]
});

await op.confirmation();

• message property receives an array of encoded outbox messages.

smart_rollup_execute_outbox_message

The Smart Rollup Execute Outbox Message operation allows users to execute a transaction from a smart rollup to a smart contract on L1.

Usage

To execute an outbox message you need the Smart Rollup address (sr1 address), a serialized output proof, and a commitment hash. You may obtain the serialized output proof and commitment hash through an RPC call to the Smart Rollup Node at the following URL: <smart-rollup-node-base-url>/global/block/head/helpers/proofs/outbox/${outboxMessageLevel}/messages?index=${outboxMessageIndex} Where:

• outboxMessageLevel is the Tezos level of the outbox message;
• outboxMessageIndex is the index (number) of the the outbox message.

The outbox message can only be executed when the corresponding commitment is cemented.

Example

const op = await Tezos.contract.smartRollupExecuteOutboxMessage({
  rollup: 'sr1JZsZT5u27MUQXeTh1aHqZBo8NvyxRKnyv',
  cementedCommitment: 'src13rFpXGRRwQTPRcvTA8Ka5avJMt6MCrCEodDTCvD65BVVEoShoh',
  outputProof: '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'
});

await op.confirmation();
console.log(op.hash);
// Output: onyjJoL7TeSLy1AjWuLQVRqTWVc7pRhq4VhDyMQXXMTjuv7pEtV

• rollup is a rollup address (sr1 address)
• cementedCommitment is a hash of cemented commitment
• outputProof is a serialized output proof containing the transaction to be executed on L1.