BEP-20 Compatibility

The BEP20 specification defines a list of API functions (and relevant events) that each token contract is expected to implement (and emit). The failure to meet these requirements means the token contract cannot be considered to be BEP20-compliant. In this section, we examine the list of API functions defined by the BEP20 specification and validate whether there exists any inconsistency or incompatibility in the implementation of the inherent business logic of the audited contract(s)

Expected Functionality

Description according to the BEP20 Standard

Compatible

name

  • is declared as a public view function ✓

Returns the name of the token.

symbol

  • Is declared as a public view function

Returns the symbol of the token.

decimals

  • declared as a public view function

Returns the number of decimals used to get its user representation

totalSupply

  • Is declared as a public view function

Returns the number of tokens in existence.

balanceOf

  • Is declared as a public view function

Returns the number of tokens owned by account.

allowance

  • allowance() Is declared as a public view function

Returns the remaining number of tokens that spender will be allowed to spend on behalf of owner through transferFrom.

transfer

transfer() is declared as a public function

Moves amount tokens from the caller’s account to recipient.

Returns a boolean value indicating whether the operation succeeded.

Emits a Transfer event.

transferFrom

  • Is declared as a public function ✓

  • Returns a boolean value that accurately reflects the token transfer status ✓

  • Reverts if the spender does not have enough token allowances to spend ✓

  • Updates the spender’s token allowances when tokens are transferred successfully ✓

  • Reverts if the from address does not have enough tokens to spend

  • Allows zero amount transfers ✓

  • Emits Transfer() event when tokens are transferred successfully (include 0 amount transfers) ✓

  • Reverts while transferring from zero address ✓

  • Reverts while transferring to zero address ✓

Moves amount tokens from sender to recipient using the allowance mechanism. amount is then deducted from the caller’s allowance.

Returns a boolean value indicating whether the operation succeeded.

Emits a Transfer event.

approve

  • Is declared as a public function ✓

  • Returns a boolean value that accurately reflects the token approval status ✓

  • Emits Approval() event when tokens are approved successfully ✓

  • Reverts while approving to zero address ✓

Sets amount as the allowance of spender over the caller’s tokens.

Returns a boolean value indicating whether the operation succeeded.

Transfer Event

  • Is emitted when tokens are transferred, including zero value transfers

  • Is emitted with the from address set to address(0) when new tokens are generated ✓

Emitted when value tokens are moved from one account (from) to another (to).

Note that value may be zero

Approval Event

  • Is emitted on any successful call to approve ✓

Emitted when the allowance of a spender for an owner is set by a call to approve. value is the new allowance.

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