> ## Documentation Index
> Fetch the complete documentation index at: https://praison.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# register • AI Agent SDK

> register: Register middleware for a specific runtime.

# register

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  <Badge color="purple">Method</Badge>
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> This is a method of the [**MiddlewareRegistry**](../classes/MiddlewareRegistry) class in the [**middleware\_registry**](../modules/middleware_registry) module.

Register middleware for a specific runtime.

## Signature

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
def register(runtime_id: str, middleware: RuntimeToolResultMiddleware) -> None
```

## Parameters

<ParamField query="runtime_id" type="str" required={true}>
  Unique identifier for the runtime (e.g., "claude\_harness")
</ParamField>

<ParamField query="middleware" type="RuntimeToolResultMiddleware" required={true}>
  Middleware instance implementing RuntimeToolResultMiddleware
</ParamField>

## Uses

* `logger.warning`
* `logger.debug`

## Used By

* [`HookRegistry.register_function`](../functions/HookRegistry-register_function)
* [`HookRegistry.register_command`](../functions/HookRegistry-register_command)
* [`register_middleware`](../functions/register_middleware)
* [`register_runtime`](../functions/register_runtime)
* [`tool`](../functions/tool)

## Source

<Card title="View on GitHub" icon="github" href="https://github.com/MervinPraison/PraisonAI/blob/main/src/praisonai-agents/praisonaiagents/runtime/middleware_registry.py#L44">
  `praisonaiagents/runtime/middleware_registry.py` at line 44
</Card>