Version: 1.0.0

This documentation is for octez.js version 1.0.0 and is no longer being updated. Some information may be outdated. View the latest version .

Estimate Provider

octez.js’s estimate method can be used to estimate fees, gas, and storage associated with an operation.

Note

Our estimation of fee, gasLimit and storageLimit is based on the RPC call response to simulate_operation plus a small buffer. The context and volume at the time of simulate_operation might differ from preapply/operations and injection/operation, potentially causing errors like fees_too_low, storage_exhausted.operation and gas_exhausted.operation.

The Estimate object

The Estimate object has the following properties:

[burnFeeMutez]: The number of Mutez that will be burned for the storage of the operation. Returns a number.

[gasLimit]: The limit on the amount of gas a given operation can consume. Returns a number.

[minimalFeeMutez]: Minimum fees for the operation according to baker defaults. Returns a number.

[storageLimit]: The limit on the amount of storage an operation can use. Returns a number.

[suggestedFeeMutez:]: The suggested fee for the operation includes minimal fees and a small buffer. Returns a number.

[totalCost]: The sum of minimalFeeMutez + burnFeeMutez. Returns a number.

[usingBaseFeeMutez]: Fees according to your specified base fee will ensure that at least minimum fees are used.

Estimate a transfer operation

The following example shows an estimate of the fees associated with transferring 2ꜩ to tz1h3rQ8wBxFd8L9B3d7Jhaawu6Z568XU3xY address. The configuration of the signer is to use a throw-away private key for demonstration purposes.

const amount = 2;
const address = 'tz1h3rQ8wBxFd8L9B3d7Jhaawu6Z568XU3xY';

console.log(`Estimating the transfer of ${amount} ꜩ to ${address} : `);

try {
  const est = await Tezos.estimate.transfer({ to: address, amount: amount });
  console.log(`burnFeeMutez : ${est.burnFeeMutez},
    gasLimit : ${est.gasLimit},
    minimalFeeMutez : ${est.minimalFeeMutez},
    storageLimit : ${est.storageLimit},
    suggestedFeeMutez : ${est.suggestedFeeMutez},
    totalCost : ${est.totalCost},
    usingBaseFeeMutez : ${est.usingBaseFeeMutez}`);
} catch (error) {
  console.table(`Error: ${JSON.stringify(error, null, 2)}`);
}
 
const amount = 2;
const address = 'tz1h3rQ8wBxFd8L9B3d7Jhaawu6Z568XU3xY';

console.log(`Estimating the transfer of ${amount} ꜩ to ${address} : `);

try {
  const est = await Tezos.estimate.transfer({ to: address, amount: amount });
  console.log(`burnFeeMutez : ${est.burnFeeMutez},
    gasLimit : ${est.gasLimit},
    minimalFeeMutez : ${est.minimalFeeMutez},
    storageLimit : ${est.storageLimit},
    suggestedFeeMutez : ${est.suggestedFeeMutez},
    totalCost : ${est.totalCost},
    usingBaseFeeMutez : ${est.usingBaseFeeMutez}`);
} catch (error) {
  console.table(`Error: ${JSON.stringify(error, null, 2)}`);
}

Estimate a smart contract call

This example will demonstrate how to estimate the fees related to calling a smart contract.

We have updated the estimate provider to have a contractCall() method. The contractCall() member method can now be used to estimate contract calls as such:

try {
  const contract = await Tezos.contract.at('KT1R7X47cubgJzgbGERdDarhgKHFGZotsjTU');
  const op = contract.methodsObject.increment(7);

  console.log(`Estimating the smart contract call: `);
  const estimate = await Tezos.estimate.contractCall(op);

  console.log(`burnFeeMutez : ${estimate.burnFeeMutez},
    gasLimit : ${estimate.gasLimit},
    minimalFeeMutez : ${estimate.minimalFeeMutez},
    storageLimit : ${estimate.storageLimit},
    suggestedFeeMutez : ${estimate.suggestedFeeMutez},
    totalCost : ${estimate.totalCost},
    usingBaseFeeMutez : ${estimate.usingBaseFeeMutez}`);
} catch (error) {
  console.table(`Error: ${JSON.stringify(error, null, 2)}`);
}
 
try {
  const contract = await Tezos.wallet.at('KT1R7X47cubgJzgbGERdDarhgKHFGZotsjTU');
  const op = contract.methodsObject.increment(7);

  console.log(`Estimating the smart contract call: `);
  const estimate = await Tezos.estimate.contractCall(op);

  console.log(`burnFeeMutez : ${estimate.burnFeeMutez},
    gasLimit : ${estimate.gasLimit},
    minimalFeeMutez : ${estimate.minimalFeeMutez},
    storageLimit : ${estimate.storageLimit},
    suggestedFeeMutez : ${estimate.suggestedFeeMutez},
    totalCost : ${estimate.totalCost},
    usingBaseFeeMutez : ${estimate.usingBaseFeeMutez}`);
} catch (error) {
  console.table(`Error: ${JSON.stringify(error, null, 2)}`);
}

Estimate a contract origination

In this example, we will use the estimate method of octez.js on a contract origination. The genericMultisigJSONfile variable contains a Michelson Smart Contract.

console.log(`Estimating the contract origination : `);

try {
  const originationOp = await Tezos.estimate.originate({
    code: genericMultisigJSONfile,
    storage: {
      stored_counter: 0,
      threshold: 1,
      keys: ['edpkuLxx9PQD8fZ45eUzrK3BhfDZJHhBuK4Zi49DcEGANwd2rpX82t'],
    },
  });

  console.log(`burnFeeMutez : ${originationOp.burnFeeMutez},
    gasLimit : ${originationOp.gasLimit},
    minimalFeeMutez : ${originationOp.minimalFeeMutez},
    storageLimit : ${originationOp.storageLimit},
    suggestedFeeMutez : ${originationOp.suggestedFeeMutez},
    totalCost : ${originationOp.totalCost},
    usingBaseFeeMutez : ${originationOp.usingBaseFeeMutez}`);
} catch (error) {
  console.log(`Error: ${error}`);
}
 
console.log(`Estimating the contract origination : `);

try {
  const originationOp = await Tezos.estimate.originate({
    code: genericMultisigJSONfile,
    storage: {
      stored_counter: 0,
      threshold: 1,
      keys: ['edpkuLxx9PQD8fZ45eUzrK3BhfDZJHhBuK4Zi49DcEGANwd2rpX82t'],
    },
  });

  console.log(`burnFeeMutez : ${originationOp.burnFeeMutez},
    gasLimit : ${originationOp.gasLimit},
    minimalFeeMutez : ${originationOp.minimalFeeMutez},
    storageLimit : ${originationOp.storageLimit},
    suggestedFeeMutez : ${originationOp.suggestedFeeMutez},
    totalCost : ${originationOp.totalCost},
    usingBaseFeeMutez : ${originationOp.usingBaseFeeMutez}`);
} catch (error) {
  console.log(`Error: ${JSON.stringify(error, null, 2)}`);
}