> For the complete documentation index, see [llms.txt](https://hinkal-team.gitbook.io/hinkal/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hinkal-team.gitbook.io/hinkal/technical-description/evm-tron-smart-contracts/hinkalinlogic.md).

# HinkalInLogic

**Overview**

`HinkalInLogic` and `HinkalInLogicBase` implement the execution-layer logic that `Hinkal.sol` delegates to. They manage:

* External protocol execution with precise allowance/balance accounting
* Proofless deposit flow (token/NFT collection and UTXO formation)

**Files**

* `contracts/HinkalInLogicBase.sol` — core logic and helpers
* `contracts/HinkalInLogic.sol` — concrete implementation (external actions, proofless deposit)

***

#### External Actions (HinkalInLogic.sol)

```solidity
function handleRunExternalAction(CircomData circomData, int256[] approvalChangesPerToken)
    external returns (UTXO[])
```

* Computes `deltaAmountChanges[i] = calculateDeltaAmount(...)` per token.
* For negative deltas, transfers tokens/NFTs to `externalAddress` pre-call.
* Invokes `IExternalActionV2(externalAddress).runAction(circomData, deltaAmountChanges)` which returns `UTXO[]` created during the action.

This path is used by `Hinkal._internalRunExternalAction` to integrate with DeFi targets in a privacy-preserving, atomic way.

***

#### Proofless Deposit (HinkalInLogic.sol)

```solidity
function handleProoflessDeposit(address[] erc20Addresses, uint256[] amounts, uint256[] tokenIds, StealthAddressStructure[] stealthAddressStructures)
    public payable returns (UTXO[] utxoArray)
```

* Groups identical `(token, tokenId)` pairs with `calcTokenChangesForProoflessDeposit` and accumulates amounts (rejects duplicate NFTs).
* Pulls funds from `msg.sender` via `handleTransfersFromProoflessDeposit` and asserts `balanceAfter - balanceBefore == amount` per token.
* Forms UTXOs one-to-one with user inputs using `handleUtxoCreationEach`, setting `timeStamp` to `block.timestamp`.

Used by `Hinkal.prooflessDeposit` to create on-chain commitments without a ZK proof.

***

#### Safety and Helpers

* `erc20SafetyCheck`: blacklist of ERC20 methods (approve/mint/transferFrom, etc.) disallowed in external calls via metadata selector checks.
* `isERC20`: coarse detection to apply safety checks only when necessary.
* `calculateBalances`/`calculateAllowances`: snapshot helpers.
* `approveMore`: adjusts aggregate ERC20 allowances to match individual approval changes exactly.

***

#### Reverts and Invariants

* Proofless deposit: length checks, duplicate NFT protection, and exact transfer assertions

***

#### Integration Surface with Hinkal.sol

* `Hinkal._internalRunExternalAction` delegates to `handleRunExternalAction`
* `Hinkal.prooflessDeposit` delegates to `handleProoflessDeposit`