> 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/protocol/transactions/deposits-and-withdrawals.md). # Deposits & Withdrawals Depositing and withdrawing are the two core operations in Hinkal. Both follow the same path: an off-chain proof, a single on-chain call to `transact`, and a set of checks and state updates inside the contract. See [Compliance](/hinkal/security-and-compliance/compliance.md) for deposit eligibility. *** #### **Flow** 1. **Generate the proof off-chain**\ The user's client produces a Zero-Knowledge Proof (ZKP) for the operation. 2. **Submit on-chain**\ The proof is sent to the Hinkal contract's `transact` function, together with a calldata hash (see *Frontrunning protection* below). 3. **The contract verifies**\ It checks the proof, verifies the root hashes of both the Hinkal Merkle tree and the Access Token Merkle tree, and confirms the protocol's balances are accurate. 4. **The contract updates state**\ Commitments tied to the provided nullifiers are nullified so they cannot be reused; new commitments are added to Hinkal's Merkle tree. 5. **Funds move** * ***Deposit*** - the user's funds are transferred into the Hinkal contract. * ***Withdrawal*** - the contract pays any relayer fee (if a relayer is involved), then transfers the remaining funds to the recipient. *** #### **Frontrunning protection** A calldata hash is submitted alongside the ZKP. It commits the proof to the exact transaction details - including the relayer - so they cannot be altered in flight.