> For the complete documentation index, see [llms.txt](https://docs.cheesecakelabs.com/stellar-plus/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cheesecakelabs.com/stellar-plus/reference/contracts/certificate-of-deposit-client.md).

# Certificate of Deposit Client

The `CertificateOfDepositClient` class extends `ContractEngine` to interact with a specific smart contract implementation for a Certificate of Deposit on the Stellar network. It implements methods for managing deposits, withdrawals, and fetching contract-related data.

{% hint style="info" %}
Refer to the [E2E Certificate of Deposit demo](/stellar-plus/tutorials/e2e-certificate-of-deposit-demo.md) for a detailed use case and code example including this client. A fully integrated version of this contract implementation with UI can also be seen at the [Custodial Asset Sandbox](https://stellar.cheesecakelabs.com/).
{% endhint %}

## **Constructor**

* **Parameters**:
  * `contractId`: Contract ID of the deployed contract.
  * `network`: Network configuration.
  * `rpcHandler`: RPC handler for interactions.
* **Purpose**: Initializes the client with the necessary configurations to interact with the Certificate of Deposit contract.

## **Methods**

### deposit

* **Purpose**: Deposits assets into the contract.
* **Parameters**:
  * `address`: Account address making the deposit.
  * `amount`: Deposit amount.
  * `signers`: Authorizing signers.
  * `header`: Transaction header.
  * `feeBump`: Optional fee bump.

### withdraw

* **Purpose**: Withdraws assets from the contract.
* **Parameters**:
  * `address`: Account address withdrawing assets.
  * `acceptPrematureWithdraw`: Flag for premature withdrawal acceptance.
  * `signers`: Authorizing signers.
  * `header`: Transaction header.
  * `feeBump`: Optional fee bump.

### getEstimatedYield

* **Purpose**: Fetches estimated yield.
* **Parameters**:
  * `address`: Account address.
  * `header`: Transaction header.

### getPosition

* **Purpose**: Retrieves current position.
* **Parameters**:
  * `address`: Account address.
  * `header`: Transaction header.

### getEstimatedPrematureWithdraw

* **Purpose**: Estimates premature withdrawal amount.
* **Parameters**:
  * `address`: Account address.
  * `header`: Transaction header.

### getTimeLeft

* **Purpose**: Determines time left for penalty-free withdrawal.
* **Parameters**:
  * `address`: Account address.
  * `header`: Transaction header.

### initialize

* **Purpose**: Initializes contract state.
* **Parameters**:
  * `admin`, `asset`, `term`, `compoundStep`, `yieldRate`, `minDeposit`, `penaltyRate`, `allowancePeriod`: Contract parameters.
  * `signers`: Authorizing signers.
  * `header`: Transaction header.
  * `feeBump`: Optional fee bump.

{% hint style="info" %}
The initialization parameters affect the CD rules as the following:

* **Admin**\
  Defines which account can manage the CD contract and also receives and provides the funds from/to the users.
* **Asset** \
  The contract id of the Stellar Asset Contract for the wrapped Classic Asset this CD interacts with.
* **Term** (seconds)\
  For how long this CD will accrue interest to a open deposit position.
* **Compound Step** (seconds)\
  How often will the interest be paid/compound. If set to '0', a different yield rate calculation is used and the interest rate will be applied linearly until the end of the term.
* **Yield Rate** (1 unit = 0.01%)\
  How much interest will be paid out. For compounding interest, this means at every compound interval, while the linear rate will reach this rate at the end of the term.
* **Minimum Deposit**\
  Minimum amount accepted for a deposit.
* **Penalty Rate** (1 unit = 0.01%)\
  If a user accepts the early withdraw, before the term is finished, this penalty rate will be applied to the earned interest. \
  \
  E.g.  *A 200 units position (100 deposit + 100 earned yield) withdrawing early with a penalty rate of 50% will receive 150 units(100 deposit + 50 earned yield)* 

$$
Withdrawn Amount=Deposit+(Yield−Penalty Rate×Yield)
$$

* **Allowance Period** (Expiration ledger number)\
  Until which ledger will the allowance for the contract to access the admin funds be valid.
  {% endhint %}

This class provides a structured and convenient way to interact with the Certificate of Deposit contract on the Stellar network, encapsulating complex contract interactions into simpler method calls.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.cheesecakelabs.com/stellar-plus/reference/contracts/certificate-of-deposit-client.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.