Token Approval

Token Approval for EVM and Tezos

Improve user experience by limiting transaction signing with Token Approval. Instead of signing every individual transaction, users can set a 'payment limit' of tokens that can be spent without continually requesting user approval. Until the payment limit is reached, users do not need to sign another transaction.

EVM​ Token Approval

ERC-20

ERC-20

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An ERC-20 token approval is a method of allowing a smart contract or another address to withdraw funds from the address sending the transaction.

Tweed SDK identifies that an ERC-20 token approval transaction is being sent and generates a dedicated UI for the user to approve or reject it. In addition, the user can edit the spending cap. The platform can create a default value for token approval.

Code example:

const provider = new ethers.providers.Web3Provider(tweedProvider)
const signer = provider.getSigner()
const contract = new ethers.Contract(
  'ERC20_CONTRACT_ADDRESS',
  ['function approve(address spender, uint256 amount) public returns (bool)'],
  signer,
)
await contract['approve']('SPENDEE_WALLET_ADDRESS', 'LIMIT_DEFAULT')

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Tezos Token Approvals

FA1.2

FA1.2

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There are two relevant functions in the FA1.2 standard:

1. Approve - Allows a token holder to approve a delegate who can transfer a specified amount of tokens on their behalf.

2. Get_allowance - Lets users query the amount of tokens that a delegate is approved to transfer.

Tweed automatically detects a transaction that requests the FA1.2 contract for approval and shows the user the Approval widget.

FA2

FA2

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The relevant FA2 standard function is:

Update_operators - This operation replaces the approve function in FA1.2. It can grant or revoke permissions to transfer tokens on the owner's behalf.

Tweed automatically detects a transaction that requests the FA1.2 contract for update_operators and shows the user the Approval widget.