> For the complete documentation index, see [llms.txt](https://ai.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ai.ortusbooks.com/main-components/middleware/retry.md).

# RetryMiddleware

Retry failed LLM and tool calls with exponential backoff controls

Class: `bxModules.bxai.models.middleware.core.RetryMiddleware`

Wraps both LLM and tool invocations and retries failures with exponential backoff.

## Features

* Retries around `wrapLLMCall`
* Retries around `wrapToolCall`
* Exponential backoff with maximum delay cap
* Skip retries for configured exception types
* Logs retry attempts and terminal failure

## Constructor

```javascript
middleware = new bxModules.bxai.models.middleware.core.RetryMiddleware(
    maxRetries       : 3,
    initialDelay     : 1000,
    backoffMultiplier: 2,
    maxDelay         : 30000,
    nonRetryableTypes: "InvalidInput,MaxInteractionsExceeded"
)
```

## Configuration

| Option              | Type    | Default                                  | Description                                       |
| ------------------- | ------- | ---------------------------------------- | ------------------------------------------------- |
| `maxRetries`        | numeric | `3`                                      | Retry attempts after initial failure              |
| `initialDelay`      | numeric | `1000`                                   | First backoff delay in milliseconds               |
| `backoffMultiplier` | numeric | `2`                                      | Multiplier for each subsequent delay              |
| `maxDelay`          | numeric | `30000`                                  | Maximum backoff delay in milliseconds             |
| `nonRetryableTypes` | string  | `"InvalidInput,MaxInteractionsExceeded"` | Comma-delimited exception types to bypass retries |

## Hooks Used

* `wrapLLMCall`
* `wrapToolCall`

## Example

```javascript
agent = aiAgent(
    name      : "resilient-agent",
    middleware: [
        new bxModules.bxai.models.middleware.core.RetryMiddleware(
            maxRetries       : 5,
            initialDelay     : 500,
            backoffMultiplier: 1.5,
            maxDelay         : 10000,
            nonRetryableTypes: "InvalidInput,BXAI.SecurityViolation"
        )
    ]
)
```

## Notes

* Retries are applied to exceptions only; successful responses are returned immediately.
* Non-retryable exception types are matched case-insensitively via list lookup.


---

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