> For the complete documentation index, see [llms.txt](https://docs-v4.venus.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs-v4.venus.io/technical-reference/reference-isolated-pools/interest-rate-models.md).

# Interest Rate Models

Every VToken stores its own `interestRateModel()` address. Markets on the same network or in the same pool can use different model families and parameters, so never select a model from the network name alone.

The v4.4.0 engine source contains three implementations:

| Model                                                                                                                                  | Curve                    | Parameters mutable after deployment? |
| -------------------------------------------------------------------------------------------------------------------------------------- | ------------------------ | ------------------------------------ |
| [`JumpRateModelV2`](/technical-reference/reference-isolated-pools/interest-rate-models/jump-rate-model-v2.md)                          | one kink                 | yes, through AccessControlManager    |
| [`TwoKinksInterestRateModel`](/technical-reference/reference-isolated-pools/interest-rate-models/two-kinks-interest-rate-model.md)     | two kinks, signed slopes | no; constructor immutables           |
| [`WhitePaperInterestRateModel`](/technical-reference/reference-isolated-pools/interest-rate-models/white-paper-interest-rate-model.md) | one linear slope         | no; constructor immutables           |

`BaseJumpRateModelV2` is not a separate contract in the current source. The old page is retained only to route existing links to `JumpRateModelV2`.

## Units and annualization

The shared interface returns a mantissa-scaled rate **per slot**. A slot is either a block or one second, according to the deployed model's `isTimeBased()` value. Read `blocksOrSecondsPerYear()` from that same model before annualizing.

```
nominal annual rate = rate per slot × blocksOrSecondsPerYear
```

Do not assume `2,628,000` blocks/year or `31,536,000` seconds/year globally. In particular, the live BNB Chain and opBNB VToken implementations use different block constants; the [engine version map](/technical-reference/reference-isolated-pools.md) records their current values.

## Selecting the model for a market

1. Start from the market's VToken address in the [deployed markets registry](/deployed-contracts/markets.md).
2. Read `interestRateModel()` from the VToken at the block used by your calculation.
3. Identify the model bytecode or verified source, then read its clock mode and parameters.
4. Preserve the effective block when recording a mutable `JumpRateModelV2` parameter set.

The formulas and current ABI below follow the [`isolated-pools` v4.4.0 source](https://github.com/VenusProtocol/isolated-pools/tree/v4.4.0/contracts).


---

# 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-v4.venus.io/technical-reference/reference-isolated-pools/interest-rate-models.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.